v3.14.1

fixes #5102

.github/ISSUE_TEMPLATE.md

@@ -1,25 +0,0 @@
-**Bug report or feature request?**
-
-<!-- Note: sub-optimal but correct code is not a bug -->
-
-**Uglify version (`uglifyjs -V`)**
-
-**JavaScript input**
-
-<!--
-    A complete parsable JS program exhibiting the issue with
-    UglifyJS alone - without third party tools or libraries.
-    Ideally the input should be as small as possible.
-    Post a link to a gist if necessary.
-
-    Issues without a reproducible test case will be closed.
--->
-
-**The `uglifyjs` CLI command executed or `minify()` options used.**
-
-**JavaScript output or error produced.**
-
-<!--
-    Note: `uglify-js` only supports JavaScript.
-    Those wishing to minify ES6+ should transpile first.
--->

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,51 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+<!-- Note: sub-optimal but correct code is not a bug -->
+
+**Uglify version (`uglifyjs -V`)**
+
+**JavaScript input**
+
+<!--
+A complete parsable JS program exhibiting the issue with UglifyJS alone
+- without third party tools or libraries.
+
+Ideally the input should be as small as possible, but may be large if isolating
+the problem proves to be difficult. The most important thing is that the
+standalone program reliably exhibits the bug when minified. Provide a link to a
+gist if necessary.
+
+Solely providing minified output without the original uglify JS input is not
+useful in determining the cause of the problem. Issues without a reproducible
+test case will be closed.
+-->
+
+**The `uglifyjs` CLI command executed or `minify()` options used.**
+
+<!--
+Command-line or API call to UglifyJS without third party tools or libraries.
+
+For users using bundlers or transpilers, you may be able to gather the required
+information through setting the `UGLIFY_BUG_REPORT` environment variable:
+
+    export UGLIFY_BUG_REPORT=1      (bash)
+    set UGLIFY_BUG_REPORT=1         (Command Prompt)
+    $Env:UGLIFY_BUG_REPORT=1        (PowerShell)
+
+before running your usual build process. The resulting "minified" output should
+contain the necessary details for this report.
+-->
+
+**JavaScript output or error produced.**
+
+<!--
+Only minified code that produces different output (or error) from the original
+upon execution would be considered a bug.
+-->

.github/workflows/build.yml

@@ -0,0 +1,58 @@
+name: Build testing
+on:
+  pull_request:
+  push:
+    branches: [ master ]
+jobs:
+  ufuzz:
+    strategy:
+      fail-fast: false
+      matrix:
+        options:
+          - '-mb braces'
+          - '--ie -c'
+          - '-mc'
+          - '-p acorn --toplevel -mco spidermonkey'
+          - '--toplevel -mc passes=3,pure_getters,unsafe'
+        script:
+          - acorn.sh
+          - bootstrap.sh
+          - buble.sh
+          - butternut.sh
+          - mathjs.sh
+          - rollup-es.sh
+          - rollup-ts.sh
+          - sucrase.sh
+          - web-tooling-benchmark.sh
+        include:
+          - node: '14'
+            script: acorn.sh
+          - node: '14'
+            script: bootstrap.sh
+          - node: '14'
+            script: buble.sh
+          - node: '14'
+            script: butternut.sh
+          - node: '14'
+            script: mathjs.sh
+          - node: '8'
+            script: rollup-es.sh
+          - node: '14'
+            script: rollup-ts.sh
+          - node: '14'
+            script: sucrase.sh
+          - node: '14'
+            script: web-tooling-benchmark.sh
+    name: ${{ matrix.script }} ${{ matrix.options }}
+    runs-on: ubuntu-latest
+    env:
+      NODE: ${{ matrix.node }}
+      OPTIONS: ${{ matrix.options }}
+      SCRIPT: ${{ matrix.script }}
+    steps:
+      - uses: actions/checkout@v2
+      - name: Perform uglify, build & test
+        shell: bash
+        run: |
+          . ./test/release/install.sh
+          ./test/release/$SCRIPT $OPTIONS

.github/workflows/ci.yml

@@ -1,16 +1,19 @@
 name: CI
-on: [ push, pull_request ]
+on:
+  pull_request:
+  push:
+    branches: [ master ]
 jobs:
   test:
     strategy:
       matrix:
-        node: [ "0.8", "0.10", "0.12", "4", "6", "8", "10", "12", latest ]
+        node: [ '0.8', '0.10', '0.12', '4', '6', '8', '10', '12', '14', latest ]
         os: [ ubuntu-latest, windows-latest ]
         script: [ compress, mocha, release/benchmark, release/jetstream ]
         exclude:
-          - node: "0.8"
+          - node: '0.8'
             script: release/benchmark
-          - node: "0.8"
+          - node: '0.8'
             script: release/jetstream
     name: ${{ matrix.node }} ${{ matrix.os }} ${{ matrix.script }}
     runs-on: ${{ matrix.os }}
@@ -19,27 +22,12 @@ jobs:
       TYPE: ${{ matrix.script }}
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/cache@v1
+      - uses: actions/cache@v2
         with:
           path: tmp
           key: tmp ${{ matrix.script }}
       - name: Perform tests
         shell: bash
         run: |
-          git clone --branch v1.5.4 --depth 1 https://github.com/jasongin/nvs.git ~/.nvs
-          while ! timeout 60 bash -c '. ~/.nvs/nvs.sh add $NODE && nvs use $NODE'; do
-            cd ~/.nvs
-            while !(git clean -xdf); do echo "'git clean' failed - retrying..."; done
-            cd -
-          done
-          . ~/.nvs/nvs.sh --version
-          nvs use $NODE
-          node --version
-          npm config set audit false
-          npm config set optional false
-          npm config set save false
-          npm config set strict-ssl false
-          npm config set update-notifier false
-          npm --version
-          while !(npm install); do echo "'npm install' failed - retrying..."; done
+          . ./test/release/install.sh
           node test/$TYPE

.github/workflows/ufuzz.yml

@@ -2,34 +2,43 @@ name: Fuzzing
 on:
   pull_request:
   schedule:
-    - cron: "*/8 * * * *"
+    - cron: '*/15 * * * *'
+  workflow_dispatch:
+  workflow_run:
+    branches: [ master ]
+    types: [ completed ]
+    workflows: [ 'Build testing', CI ]
+env:
+  BASE_URL: https://api.github.com/repos/${{ github.repository }}
+  TOKEN: ${{ github.token }}
 jobs:
   ufuzz:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-latest, windows-latest ]
-    name: ${{ matrix.os }}
+        include:
+          - node: latest
+            os: macos-latest
+          - node: '8'
+            os: ubuntu-latest
+          - node: '8'
+            os: ubuntu-latest
+          - node: '8'
+            os: windows-latest
+          - node: '8'
+            os: windows-latest
+    name: ${{ matrix.node }} ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
+    env:
+      NODE: ${{ matrix.node }}
     steps:
       - uses: actions/checkout@v2
       - name: Perform fuzzing
         shell: bash
         run: |
-          git clone --branch v1.5.4 --depth 1 https://github.com/jasongin/nvs.git ~/.nvs
-          while ! timeout 60 bash -c '. ~/.nvs/nvs.sh add 8 && nvs use 8'; do
-            cd ~/.nvs
-            while !(git clean -xdf); do echo "'git clean' failed - retrying..."; done
-            cd -
-          done
-          . ~/.nvs/nvs.sh --version
-          nvs use 8
-          node --version
-          npm config set audit false
-          npm config set optional false
-          npm config set save false
-          npm config set strict-ssl false
-          npm config set update-notifier false
-          npm --version
-          while !(npm install); do echo "'npm install' failed - retrying..."; done
-          node test/ufuzz/job 3600000
+          . ./test/release/install.sh
+          if [[ $GITHUB_EVENT_NAME == "pull_request" ]]; then
+            node test/ufuzz/job 5000
+          else
+            node test/ufuzz/job $BASE_URL $TOKEN $GITHUB_RUN_NUMBER
+          fi

README.md

@@ -4,10 +4,11 @@ UglifyJS 3
 UglifyJS is a JavaScript parser, minifier, compressor and beautifier toolkit.
 
 #### Note:
-- **`uglify-js@3` has a simplified [API](#api-reference) and [CLI](#command-line-usage) that is not backwards compatible with [`uglify-js@2`](https://github.com/mishoo/UglifyJS/tree/v2.x)**.
-- **Documentation for UglifyJS `2.x` releases can be found [here](https://github.com/mishoo/UglifyJS/tree/v2.x)**.
-- `uglify-js` only supports JavaScript (ECMAScript 5).
-- To minify ECMAScript 2015 or above, transpile using tools like [Babel](https://babeljs.io/).
+- `uglify-js` supports JavaScript and most language features in ECMAScript.
+- For more exotic parts of ECMAScript, process your source file with transpilers
+  like [Babel](https://babeljs.io/) before passing onto `uglify-js`.
+- `uglify-js@3` has a simplified [API](#api-reference) and [CLI](#command-line-usage)
+  that is not backwards compatible with [`uglify-js@2`](https://github.com/mishoo/UglifyJS/tree/v2.x).
 
 Install
 -------
@@ -84,13 +85,16 @@ a double dash to prevent input files being used as option arguments:
                                                1 - single
                                                2 - double
                                                3 - original
-                                `wrap_iife`  Wrap IIFEs in parenthesis. Note: you may
+                                `wrap_iife`  Wrap IIFEs in parentheses. Note: you may
                                              want to disable `negate_iife` under
                                              compressor options.
     -O, --output-opts [options] Specify output options (`beautify` disabled by default).
     -o, --output <file>         Output file path (default STDOUT). Specify `ast` or
                                 `spidermonkey` to write UglifyJS or SpiderMonkey AST
                                 as JSON to STDOUT respectively.
+    --annotations               Process and preserve comment annotations.
+                                (`/*@__PURE__*/` or `/*#__PURE__*/`)
+    --no-annotations            Ignore and discard comment annotations.
     --comments [filter]         Preserve copyright comments in the output. By
                                 default this works like Google Closure, keeping
                                 JSDoc-style comments that contain "@license" or
@@ -107,8 +111,8 @@ a double dash to prevent input files being used as option arguments:
     -d, --define <expr>[=value] Global definitions.
     -e, --enclose [arg[:value]] Embed everything in a big function, with configurable
                                 argument(s) & value(s).
-    --ie8                       Support non-standard Internet Explorer 8.
-                                Equivalent to setting `ie8: true` in `minify()`
+    --ie                        Support non-standard Internet Explorer.
+                                Equivalent to setting `ie: true` in `minify()`
                                 for `compress`, `mangle` and `output` options.
                                 By default UglifyJS will not try to be IE-proof.
     --keep-fnames               Do not mangle/drop function names.  Useful for
@@ -133,8 +137,16 @@ a double dash to prevent input files being used as option arguments:
                                        `//# sourceMappingURL`.
     --timings                   Display operations run time on STDERR.
     --toplevel                  Compress and/or mangle variables in top level scope.
+    --v8                        Support non-standard Chrome & Node.js
+                                Equivalent to setting `v8: true` in `minify()`
+                                for `mangle` and `output` options.
+                                By default UglifyJS will not try to be v8-proof.
     --verbose                   Print diagnostic messages.
     --warn                      Print warning messages.
+    --webkit                    Support non-standard Safari/Webkit.
+                                Equivalent to setting `webkit: true` in `minify()`
+                                for `mangle` and `output` options.
+                                By default UglifyJS will not try to be Safari-proof.
     --wrap <name>               Embed everything in a big function, making the
                                 “exports” and “global” variables available. You
                                 need to pass an argument to this option to
@@ -212,17 +224,16 @@ Example:
 To enable the mangler you need to pass `--mangle` (`-m`).  The following
 (comma-separated) options are supported:
 
-- `toplevel` (default `false`) -- mangle names declared in the top level scope.
+- `eval` (default: `false`) — mangle names visible in scopes where `eval` or
+  `with` are used.
 
-- `eval` (default `false`) -- mangle names visible in scopes where `eval` or `with` are used.
+- `reserved` (default: `[]`) — when mangling is enabled but you want to
+  prevent certain names from being mangled, you can declare those names with
+  `--mangle reserved` — pass a comma-separated list of names.  For example:
 
-When mangling is enabled but you want to prevent certain names from being
-mangled, you can declare those names with `--mangle reserved` — pass a
-comma-separated list of names.  For example:
+      uglifyjs ... -m reserved=['$','require','exports']
 
-    uglifyjs ... -m reserved=['$','require','exports']
-
-to prevent the `require`, `exports` and `$` names from being changed.
+  to prevent the `require`, `exports` and `$` names from being changed.
 
 ### CLI mangling property names (`--mangle-props`)
 
@@ -483,43 +494,53 @@ if (result.error) throw result.error;
 
 ## Minify options
 
-- `compress` (default `{}`) — pass `false` to skip compressing entirely.
+- `annotations` — pass `false` to ignore all comment annotations and elide them
+  from output. Useful when, for instance, external tools incorrectly applied
+  `/*@__PURE__*/` or `/*#__PURE__*/`. Pass `true` to both compress and retain
+  comment annotations in output to allow for further processing downstream.
+
+- `compress` (default: `{}`) — pass `false` to skip compressing entirely.
   Pass an object to specify custom [compress options](#compress-options).
 
-- `ie8` (default `false`) -- set to `true` to support IE8.
+- `ie` (default: `false`) — enable workarounds for Internet Explorer bugs.
 
-- `keep_fnames` (default: `false`) -- pass `true` to prevent discarding or mangling
+- `keep_fnames` (default: `false`) — pass `true` to prevent discarding or mangling
   of function names.  Useful for code relying on `Function.prototype.name`.
 
-- `mangle` (default `true`) — pass `false` to skip mangling names, or pass
+- `mangle` (default: `true`) — pass `false` to skip mangling names, or pass
   an object to specify [mangle options](#mangle-options) (see below).
 
-  - `mangle.properties` (default `false`) — a subcategory of the mangle option.
+  - `mangle.properties` (default: `false`) — a subcategory of the mangle option.
     Pass an object to specify custom [mangle property options](#mangle-properties-options).
 
-- `nameCache` (default `null`) -- pass an empty object `{}` or a previously
+- `nameCache` (default: `null`) — pass an empty object `{}` or a previously
   used `nameCache` object if you wish to cache mangled variable and
   property names across multiple invocations of `minify()`. Note: this is
   a read/write property. `minify()` will read the name cache state of this
   object and update it during minification so that it may be
   reused or externally persisted by the user.
 
-- `output` (default `null`) — pass an object if you wish to specify
+- `output` (default: `null`) — pass an object if you wish to specify
   additional [output options](#output-options).  The defaults are optimized
   for best compression.
 
-- `parse` (default `{}`) — pass an object if you wish to specify some
+- `parse` (default: `{}`) — pass an object if you wish to specify some
   additional [parse options](#parse-options).
 
-- `sourceMap` (default `false`) -- pass an object if you wish to specify
+- `sourceMap` (default: `false`) — pass an object if you wish to specify
   [source map options](#source-map-options).
 
-- `toplevel` (default `false`) -- set to `true` if you wish to enable top level
+- `toplevel` (default: `false`) — set to `true` if you wish to enable top level
   variable and function name mangling and to drop unused variables and functions.
 
-- `warnings` (default `false`) — pass `true` to return compressor warnings
+- `v8` (default: `false`) — enable workarounds for Chrome & Node.js bugs.
+
+- `warnings` (default: `false`) — pass `true` to return compressor warnings
   in `result.warnings`. Use the value `"verbose"` for more detailed warnings.
 
+- `webkit` (default: `false`) — enable workarounds for Safari/WebKit bugs.
+  PhantomJS users should set this option to `true`.
+
 ## Minify options structure
 
 ```javascript
@@ -545,7 +566,6 @@ if (result.error) throw result.error;
     },
     nameCache: null, // or specify a name cache object
     toplevel: false,
-    ie8: false,
     warnings: false,
 }
 ```
@@ -602,107 +622,121 @@ to be `false` and all symbol names will be omitted.
 
 ## Parse options
 
-- `bare_returns` (default `false`) -- support top level `return` statements
+- `bare_returns` (default: `false`) — support top level `return` statements
 
-- `html5_comments` (default `true`)
+- `html5_comments` (default: `true`)
 
-- `shebang` (default `true`) -- support `#!command` as the first line
+- `shebang` (default: `true`) — support `#!command` as the first line
 
 ## Compress options
 
-- `arguments` (default: `true`) -- replace `arguments[index]` with function
+- `annotations` (default: `true`) — Pass `false` to disable potentially dropping
+  functions marked as "pure".  A function call is marked as "pure" if a comment
+  annotation `/*@__PURE__*/` or `/*#__PURE__*/` immediately precedes the call. For
+  example: `/*@__PURE__*/foo();`
+
+- `arguments` (default: `true`) — replace `arguments[index]` with function
   parameter name whenever possible.
 
-- `assignments` (default: `true`) -- apply optimizations to assignment expressions.
+- `arrows` (default: `true`) — apply optimizations to arrow functions
 
-- `booleans` (default: `true`) -- various optimizations for boolean context,
+- `assignments` (default: `true`) — apply optimizations to assignment expressions
+
+- `awaits` (default: `true`) — apply optimizations to `await` expressions
+
+- `booleans` (default: `true`) — various optimizations for boolean context,
   for example `!!a ? b : c → a ? b : c`
 
-- `collapse_vars` (default: `true`) -- Collapse single-use non-constant variables,
+- `collapse_vars` (default: `true`) — Collapse single-use non-constant variables,
   side effects permitting.
 
-- `comparisons` (default: `true`) -- apply certain optimizations to binary nodes,
+- `comparisons` (default: `true`) — apply certain optimizations to binary nodes,
   e.g. `!(a <= b) → a > b`, attempts to negate binary nodes, e.g.
   `a = !b && !c && !d && !e → a=!(b||c||d||e)` etc.
 
-- `conditionals` (default: `true`) -- apply optimizations for `if`-s and conditional
+- `conditionals` (default: `true`) — apply optimizations for `if`-s and conditional
   expressions
 
-- `dead_code` (default: `true`) -- remove unreachable code
+- `dead_code` (default: `true`) — remove unreachable code
 
-- `directives` (default: `true`) -- remove redundant or non-standard directives
+- `default_values` (default: `true`) — drop overshadowed default values
 
-- `drop_console` (default: `false`) -- Pass `true` to discard calls to
+- `directives` (default: `true`) — remove redundant or non-standard directives
+
+- `drop_console` (default: `false`) — Pass `true` to discard calls to
   `console.*` functions. If you wish to drop a specific function call
   such as `console.info` and/or retain side effects from function arguments
   after dropping the function call then use `pure_funcs` instead.
 
-- `drop_debugger` (default: `true`) -- remove `debugger;` statements
+- `drop_debugger` (default: `true`) — remove `debugger;` statements
 
-- `evaluate` (default: `true`) -- Evaluate expression for shorter constant
+- `evaluate` (default: `true`) — Evaluate expression for shorter constant
   representation. Pass `"eager"` to always replace function calls whenever
   possible, or a positive integer to specify an upper bound for each individual
   evaluation in number of characters.
 
-- `expression` (default: `false`) -- Pass `true` to preserve completion values
+- `expression` (default: `false`) — Pass `true` to preserve completion values
   from terminal statements without `return`, e.g. in bookmarklets.
 
-- `functions` (default: `true`) -- convert declarations from `var`to `function`
+- `functions` (default: `true`) — convert declarations from `var` to `function`
   whenever possible.
 
-- `global_defs` (default: `{}`) -- see [conditional compilation](#conditional-compilation)
+- `global_defs` (default: `{}`) — see [conditional compilation](#conditional-compilation)
 
-- `hoist_funs` (default: `false`) -- hoist function declarations
+- `hoist_exports` (default: `true`) — hoist `export` statements to facilitate
+  various `compress` and `mangle` optimizations.
 
-- `hoist_props` (default: `true`) -- hoist properties from constant object and
+- `hoist_funs` (default: `false`) — hoist function declarations
+
+- `hoist_props` (default: `true`) — hoist properties from constant object and
   array literals into regular variables subject to a set of constraints. For example:
   `var o={p:1, q:2}; f(o.p, o.q);` is converted to `f(1, 2);`. Note: `hoist_props`
-  works best with `mangle` enabled, the `compress` option `passes` set to `2` or higher,
-  and the `compress` option `toplevel` enabled.
+  works best with `toplevel` and `mangle` enabled, alongside with `compress` option
+  `passes` set to `2` or higher.
 
-- `hoist_vars` (default: `false`) -- hoist `var` declarations (this is `false`
+- `hoist_vars` (default: `false`) — hoist `var` declarations (this is `false`
   by default because it seems to increase the size of the output in general)
 
-- `if_return` (default: `true`) -- optimizations for if/return and if/continue
+- `if_return` (default: `true`) — optimizations for if/return and if/continue
 
-- `inline` (default: `true`) -- inline calls to function with simple/`return` statement:
-  - `false` -- same as `0`
-  - `0` -- disabled inlining
-  - `1` -- inline simple functions
-  - `2` -- inline functions with arguments
-  - `3` -- inline functions with arguments and variables
-  - `true` -- same as `3`
+- `imports` (default: `true`) — drop unreferenced import symbols when used with `unused`
 
-- `join_vars` (default: `true`) -- join consecutive `var` statements
+- `inline` (default: `true`) — inline calls to function with simple/`return` statement:
+  - `false` — same as `0`
+  - `0` — disabled inlining
+  - `1` — inline simple functions
+  - `2` — inline functions with arguments
+  - `3` — inline functions with arguments and variables
+  - `true` — same as `3`
 
-- `keep_fargs` (default: `strict`) -- Discard unused function arguments. Code
-  which relies on `Function.length` will break if this is done indiscriminately,
-  i.e. when passing `true`. Pass `false` to always retain function arguments.
+- `join_vars` (default: `true`) — join consecutive `var` statements
 
-- `keep_fnames` (default: `false`) -- Pass `true` to prevent the
-  compressor from discarding function names.  Useful for code relying on
-  `Function.prototype.name`. See also: the `keep_fnames` [mangle option](#mangle-options).
+- `keep_fargs` (default: `false`) — discard unused function arguments except
+  when unsafe to do so, e.g. code which relies on `Function.prototype.length`.
+  Pass `true` to always retain function arguments.
 
-- `keep_infinity` (default: `false`) -- Pass `true` to prevent `Infinity` from
+- `keep_infinity` (default: `false`) — Pass `true` to prevent `Infinity` from
   being compressed into `1/0`, which may cause performance issues on Chrome.
 
-- `loops` (default: `true`) -- optimizations for `do`, `while` and `for` loops
+- `loops` (default: `true`) — optimizations for `do`, `while` and `for` loops
   when we can statically determine the condition.
 
-- `negate_iife` (default: `true`) -- negate "Immediately-Called Function Expressions"
+- `merge_vars` (default: `true`) — combine and reuse variables.
+
+- `negate_iife` (default: `true`) — negate "Immediately-Called Function Expressions"
   where the return value is discarded, to avoid the parens that the
   code generator would insert.
 
-- `objects` (default: `true`) -- compact duplicate keys in object literals.
+- `objects` (default: `true`) — compact duplicate keys in object literals.
 
-- `passes` (default: `1`) -- The maximum number of times to run compress.
+- `passes` (default: `1`) — The maximum number of times to run compress.
   In some cases more than one pass leads to further compressed code.  Keep in
   mind more passes will take more time.
 
-- `properties` (default: `true`) -- rewrite property access using the dot notation, for
+- `properties` (default: `true`) — rewrite property access using the dot notation, for
   example `foo["bar"] → foo.bar`
 
-- `pure_funcs` (default: `null`) -- You can pass an array of names and
+- `pure_funcs` (default: `null`) — You can pass an array of names and
   UglifyJS will assume that those functions do not produce side
   effects.  DANGER: will not check if the name is redefined in scope.
   An example case here, for instance `var q = Math.floor(a/b)`.  If
@@ -714,22 +748,24 @@ to be `false` and all symbol names will be omitted.
   overhead (compression will be slower). Make sure symbols under `pure_funcs`
   are also under `mangle.reserved` to avoid mangling.
 
-- `pure_getters` (default: `"strict"`) -- If you pass `true` for
+- `pure_getters` (default: `"strict"`) — If you pass `true` for
   this, UglifyJS will assume that object property access
   (e.g. `foo.bar` or `foo["bar"]`) doesn't have any side effects.
   Specify `"strict"` to treat `foo.bar` as side-effect-free only when
   `foo` is certain to not throw, i.e. not `null` or `undefined`.
 
-- `reduce_funcs` (default: `true`) -- Allows single-use functions to be
+- `reduce_funcs` (default: `true`) — Allows single-use functions to be
   inlined as function expressions when permissible allowing further
   optimization.  Enabled by default.  Option depends on `reduce_vars`
   being enabled.  Some code runs faster in the Chrome V8 engine if this
   option is disabled.  Does not negatively impact other major browsers.
 
-- `reduce_vars` (default: `true`) -- Improve optimization on variables assigned with and
+- `reduce_vars` (default: `true`) — Improve optimization on variables assigned with and
   used as constant values.
 
-- `sequences` (default: `true`) -- join consecutive simple statements using the
+- `rests` (default: `true`) — apply optimizations to rest parameters
+
+- `sequences` (default: `true`) — join consecutive simple statements using the
   comma operator.  May be set to a positive integer to specify the maximum number
   of consecutive comma sequences that will be generated. If this option is set to
   `true` then the default `sequences` limit is `200`. Set option to `false` or `0`
@@ -738,64 +774,67 @@ to be `false` and all symbol names will be omitted.
   occasions the default sequences limit leads to very slow compress times in which
   case a value of `20` or less is recommended.
 
-- `side_effects` (default: `true`) -- Pass `false` to disable potentially dropping
-  functions marked as "pure".  A function call is marked as "pure" if a comment
-  annotation `/*@__PURE__*/` or `/*#__PURE__*/` immediately precedes the call. For
-  example: `/*@__PURE__*/foo();`
+- `side_effects` (default: `true`) — drop extraneous code which does not affect
+  outcome of runtime execution.
 
-- `strings` (default: `true`) -- compact string concatenations.
+- `spreads` (default: `true`) — flatten spread expressions.
 
-- `switches` (default: `true`) -- de-duplicate and remove unreachable `switch` branches
+- `strings` (default: `true`) — compact string concatenations.
 
-- `toplevel` (default: `false`) -- drop unreferenced functions (`"funcs"`) and/or
-  variables (`"vars"`) in the top level scope (`false` by default, `true` to drop
-  both unreferenced functions and variables)
+- `switches` (default: `true`) — de-duplicate and remove unreachable `switch` branches
 
-- `top_retain` (default: `null`) -- prevent specific toplevel functions and
+- `templates` (default: `true`) — compact template literals by embedding expressions
+  and/or converting to string literals, e.g. `` `foo ${42}` → "foo 42"``
+
+- `top_retain` (default: `null`) — prevent specific toplevel functions and
   variables from `unused` removal (can be array, comma-separated, RegExp or
   function. Implies `toplevel`)
 
-- `typeofs` (default: `true`) -- Transforms `typeof foo == "undefined"` into
-  `foo === void 0`.  Note: recommend to set this value to `false` for IE10 and
-  earlier versions due to known issues.
+- `toplevel` (default: `false`) — drop unreferenced functions (`"funcs"`) and/or
+  variables (`"vars"`) in the top level scope (`false` by default, `true` to drop
+  both unreferenced functions and variables)
 
-- `unsafe` (default: `false`) -- apply "unsafe" transformations (discussion below)
+- `typeofs` (default: `true`) — compress `typeof` expressions, e.g.
+  `typeof foo == "undefined" → void 0 === foo`
 
-- `unsafe_comps` (default: `false`) -- compress expressions like `a <= b` assuming
+- `unsafe` (default: `false`) — apply "unsafe" transformations (discussion below)
+
+- `unsafe_comps` (default: `false`) — compress expressions like `a <= b` assuming
   none of the operands can be (coerced to) `NaN`.
 
-- `unsafe_Function` (default: `false`) -- compress and mangle `Function(args, code)`
+- `unsafe_Function` (default: `false`) — compress and mangle `Function(args, code)`
   when both `args` and `code` are string literals.
 
-- `unsafe_math` (default: `false`) -- optimize numerical expressions like
+- `unsafe_math` (default: `false`) — optimize numerical expressions like
   `2 * x * 3` into `6 * x`, which may give imprecise floating point results.
 
-- `unsafe_proto` (default: `false`) -- optimize expressions like
+- `unsafe_proto` (default: `false`) — optimize expressions like
   `Array.prototype.slice.call(a)` into `[].slice.call(a)`
 
-- `unsafe_regexp` (default: `false`) -- enable substitutions of variables with
+- `unsafe_regexp` (default: `false`) — enable substitutions of variables with
   `RegExp` values the same way as if they are constants.
 
-- `unsafe_undefined` (default: `false`) -- substitute `void 0` if there is a
+- `unsafe_undefined` (default: `false`) — substitute `void 0` if there is a
   variable named `undefined` in scope (variable name will be mangled, typically
   reduced to a single character)
 
-- `unused` (default: `true`) -- drop unreferenced functions and variables (simple
+- `unused` (default: `true`) — drop unreferenced functions and variables (simple
   direct variable assignments do not count as references unless set to `"keep_assign"`)
 
+- `varify` (default: `true`) — convert block-scoped declaractions into `var`
+  whenever safe to do so
+
+- `yields` (default: `true`) — apply optimizations to `yield` expressions
+
 ## Mangle options
 
-- `eval` (default `false`) -- Pass `true` to mangle names visible in scopes
+- `eval` (default: `false`) — Pass `true` to mangle names visible in scopes
   where `eval` or `with` are used.
 
-- `keep_fnames` (default `false`) -- Pass `true` to not mangle function names.
-  Useful for code relying on `Function.prototype.name`. See also: the `keep_fnames`
-  [compress option](#compress-options).
-
-- `reserved` (default `[]`) -- Pass an array of identifiers that should be
+- `reserved` (default: `[]`) — Pass an array of identifiers that should be
   excluded from mangling. Example: `["foo", "bar"]`.
 
-- `toplevel` (default `false`) -- Pass `true` to mangle names declared in the
+- `toplevel` (default: `false`) — Pass `true` to mangle names declared in the
   top level scope.
 
 Examples:
@@ -822,18 +861,18 @@ UglifyJS.minify(code, { mangle: { toplevel: true } }).code;
 
 ### Mangle properties options
 
-- `builtins` (default: `false`) -- Use `true` to allow the mangling of builtin
+- `builtins` (default: `false`) — Use `true` to allow the mangling of builtin
   DOM properties. Not recommended to override this setting.
 
-- `debug` (default: `false`) -— Mangle names with the original name still present.
+- `debug` (default: `false`) — Mangle names with the original name still present.
   Pass an empty string `""` to enable, or a non-empty string to set the debug suffix.
 
-- `keep_quoted` (default: `false`) -— Only mangle unquoted property names.
+- `keep_quoted` (default: `false`) — Only mangle unquoted property names.
 
-- `regex` (default: `null`) -— Pass a RegExp literal to only mangle property
+- `regex` (default: `null`) — Pass a RegExp literal to only mangle property
   names matching the regular expression.
 
-- `reserved` (default: `[]`) -- Do not mangle property names listed in the
+- `reserved` (default: `[]`) — Do not mangle property names listed in the
   `reserved` array.
 
 ## Output options
@@ -842,76 +881,79 @@ The code generator tries to output shortest code possible by default.  In
 case you want beautified output, pass `--beautify` (`-b`).  Optionally you
 can pass additional arguments that control the code output:
 
-- `ascii_only` (default `false`) -- escape Unicode characters in strings and
+- `annotations` (default: `false`) — pass `true` to retain comment annotations
+  `/*@__PURE__*/` or `/*#__PURE__*/`, otherwise they will be discarded even if
+  `comments` is set.
+
+- `ascii_only` (default: `false`) — escape Unicode characters in strings and
   regexps (affects directives with non-ascii characters becoming invalid)
 
-- `beautify` (default `true`) -- whether to actually beautify the output.
+- `beautify` (default: `true`) — whether to actually beautify the output.
   Passing `-b` will set this to true, but you might need to pass `-b` even
   when you want to generate minified code, in order to specify additional
   arguments, so you can use `-b beautify=false` to override it.
 
-- `braces` (default `false`) -- always insert braces in `if`, `for`,
+- `braces` (default: `false`) — always insert braces in `if`, `for`,
   `do`, `while` or `with` statements, even if their body is a single
   statement.
 
-- `comments` (default `false`) -- pass `true` or `"all"` to preserve all
+- `comments` (default: `false`) — pass `true` or `"all"` to preserve all
   comments, `"some"` to preserve multi-line comments that contain `@cc_on`,
   `@license`, or `@preserve` (case-insensitive), a regular expression string
   (e.g. `/^!/`), or a function which returns `boolean`, e.g.
-  ```js
+  ```javascript
   function(node, comment) {
       return comment.value.indexOf("@type " + node.TYPE) >= 0;
   }
   ```
 
-- `indent_level` (default `4`)
+- `galio` (default: `false`) — enable workarounds for ANT Galio bugs
 
-- `indent_start` (default `0`) -- prefix all lines by that many spaces
+- `indent_level` (default: `4`)
 
-- `inline_script` (default `true`) -- escape HTML comments and the slash in
+- `indent_start` (default: `0`) — prefix all lines by that many spaces
+
+- `inline_script` (default: `true`) — escape HTML comments and the slash in
   occurrences of `</script>` in strings
 
-- `keep_quoted_props` (default `false`) -- when turned on, prevents stripping
+- `keep_quoted_props` (default: `false`) — when turned on, prevents stripping
   quotes from property names in object literals.
 
-- `max_line_len` (default `false`) -- maximum line length (for uglified code)
+- `max_line_len` (default: `false`) — maximum line length (for uglified code)
 
-- `preamble` (default `null`) -- when passed it must be a string and
+- `preamble` (default: `null`) — when passed it must be a string and
   it will be prepended to the output literally.  The source map will
   adjust for this text.  Can be used to insert a comment containing
   licensing information, for example.
 
-- `preserve_line` (default `false`) -- pass `true` to retain line numbering on
+- `preserve_line` (default: `false`) — pass `true` to retain line numbering on
   a best effort basis.
 
-- `quote_keys` (default `false`) -- pass `true` to quote all keys in literal
+- `quote_keys` (default: `false`) — pass `true` to quote all keys in literal
   objects
 
-- `quote_style` (default `0`) -- preferred quote style for strings (affects
+- `quote_style` (default: `0`) — preferred quote style for strings (affects
   quoted property names and directives as well):
-  - `0` -- prefers double quotes, switches to single quotes when there are
+  - `0` — prefers double quotes, switches to single quotes when there are
     more double quotes in the string itself. `0` is best for gzip size.
-  - `1` -- always use single quotes
-  - `2` -- always use double quotes
-  - `3` -- always use the original quotes
+  - `1` — always use single quotes
+  - `2` — always use double quotes
+  - `3` — always use the original quotes
 
-- `semicolons` (default `true`) -- separate statements with semicolons.  If
+- `semicolons` (default: `true`) — separate statements with semicolons.  If
   you pass `false` then whenever possible we will use a newline instead of a
   semicolon, leading to more readable output of uglified code (size before
   gzip could be smaller; size after gzip insignificantly larger).
 
-- `shebang` (default `true`) -- preserve shebang `#!` in preamble (bash scripts)
+- `shebang` (default: `true`) — preserve shebang `#!` in preamble (bash scripts)
 
-- `webkit` (default `false`) -- enable workarounds for WebKit bugs.
-  PhantomJS users should set this option to `true`.
-
-- `width` (default `80`) -- only takes effect when beautification is on, this
+- `width` (default: `80`) — only takes effect when beautification is on, this
   specifies an (orientative) line width that the beautifier will try to
   obey.  It refers to the width of the line text (excluding indentation).
   It doesn't work very well currently, but it does make the code generated
   by UglifyJS more readable.
 
-- `wrap_iife` (default `false`) -- pass `true` to wrap immediately invoked
+- `wrap_iife` (default: `false`) — pass `true` to wrap immediately invoked
   function expressions. See
   [#640](https://github.com/mishoo/UglifyJS/issues/640) for more details.
 
@@ -1112,29 +1154,25 @@ in total it's a bit more than just using UglifyJS's own parser.
 It's not well known, but whitespace removal and symbol mangling accounts
 for 95% of the size reduction in minified code for most JavaScript - not
 elaborate code transforms. One can simply disable `compress` to speed up
-Uglify builds by 3 to 4 times. In this fast `mangle`-only mode Uglify has
-comparable minify speeds and gzip sizes to
-[`butternut`](https://www.npmjs.com/package/butternut):
+Uglify builds by 3 to 5 times.
 
 | d3.js | minify size | gzip size | minify time (seconds) |
 | --- | ---: | ---: | ---: |
-| original | 451,131 | 108,733 | - |
-| uglify-js@3.0.24 mangle=false, compress=false | 316,600 | 85,245 | 0.70 |
-| uglify-js@3.0.24 mangle=true, compress=false | 220,216 | 72,730 | 1.13 |
-| butternut@0.4.6 | 217,568 | 72,738 | 1.41 |
-| uglify-js@3.0.24 mangle=true, compress=true | 212,511 | 71,560 | 3.36 |
-| babili@0.1.4 | 210,713 | 72,140 | 12.64 |
+| original | 511,371 | 119,932 | - |
+| uglify-js@3.13.0 mangle=false, compress=false | 363,988 | 95,695 | 0.56 |
+| uglify-js@3.13.0 mangle=true, compress=false | 253,305 | 81,281 | 0.99 |
+| uglify-js@3.13.0 mangle=true, compress=true | 244,436 | 79,854 | 5.30 |
 
 To enable fast minify mode from the CLI use:
 ```
 uglifyjs file.js -m
 ```
 To enable fast minify mode with the API use:
-```js
+```javascript
 UglifyJS.minify(code, { compress: false, mangle: true });
 ```
 
-#### Source maps and debugging
+### Source maps and debugging
 
 Various `compress` transforms that simplify, rearrange, inline and remove code
 are known to have an adverse effect on debugging with source maps. This is
@@ -1146,6 +1184,10 @@ disable the Uglify `compress` option and just use `mangle`.
 
 To allow for better optimizations, the compiler makes various assumptions:
 
+- The code does not rely on preserving its runtime performance characteristics.
+  Typically uglified code will run faster due to less instructions and easier
+  inlining, but may be slower on rare occasions for a specific platform, e.g.
+  see [`reduce_funcs`](#compress-options).
 - `.toString()` and `.valueOf()` don't have side effects, and for built-in
   objects they have not been overridden.
 - `undefined`, `NaN` and `Infinity` have not been externally redefined.
@@ -1157,3 +1199,156 @@ To allow for better optimizations, the compiler makes various assumptions:
 - Object properties can be added, removed and modified (not prevented with
   `Object.defineProperty()`, `Object.defineProperties()`, `Object.freeze()`,
   `Object.preventExtensions()` or `Object.seal()`).
+- Earlier versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  ({
+      p: 42,
+      get p() {},
+  });
+  // SyntaxError: Object literal may not have data and accessor property with
+  //              the same name
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Iteration order of keys over an object which contains spread syntax in later
+  versions of Chrome and Node.js may be altered.
+- When `toplevel` is enabled, UglifyJS effectively assumes input code is wrapped
+  within `function(){ ... }`, thus forbids aliasing of declared global variables:
+  ```javascript
+  A = "FAIL";
+  var B = "FAIL";
+  // can be `global`, `self`, `window` etc.
+  var top = function() {
+      return this;
+  }();
+  // "PASS"
+  top.A = "PASS";
+  console.log(A);
+  // "FAIL" after compress and/or mangle
+  top.B = "PASS";
+  console.log(B);
+  ```
+- Use of `arguments` alongside destructuring as function parameters, e.g.
+  `function({}, arguments) {}` will result in `SyntaxError` in earlier versions
+  of Chrome and Node.js - UglifyJS may modify the input which in turn may
+  suppress those errors.
+- Earlier versions of Chrome and Node.js will throw `ReferenceError` with the
+  following:
+  ```javascript
+  var a;
+  try {
+      throw 42;
+  } catch ({
+      [a]: b,
+      // ReferenceError: a is not defined
+  }) {
+      let a;
+  }
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  a => {
+      let a;
+  };
+  // SyntaxError: Identifier 'a' has already been declared
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  try {
+      // ...
+  } catch ({ message: a }) {
+      var a;
+  }
+  // SyntaxError: Identifier 'a' has already been declared
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of Chrome and Node.js will throw `ReferenceError` with the
+  following:
+  ```javascript
+  console.log(((a, b = function() {
+      return a;
+      // ReferenceError: a is not defined
+  }()) => b)());
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some arithmetic operations with `BigInt` may throw `TypeError`:
+  ```javascript
+  1n + 1;
+  // TypeError: can't convert BigInt to number
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of JavaScript will throw `SyntaxError` with the
+  following:
+  ```javascript
+  console.log(String.raw`\uFo`);
+  // SyntaxError: Invalid Unicode escape sequence
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of JavaScript will throw `SyntaxError` with the
+  following:
+  ```javascript
+  try {} catch (e) {
+      for (var e of []);
+  }
+  // SyntaxError: Identifier 'e' has already been declared
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of Chrome and Node.js will give incorrect results with the
+  following:
+  ```javascript
+  console.log({
+      ...{
+          set 42(v) {},
+          42: "PASS",
+      },
+  });
+  // Expected: { '42': 'PASS' }
+  // Actual:   { '42': undefined }
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  var await;
+  async function f() {
+      class A {
+          static p = await;
+      }
+  }
+  // SyntaxError: Unexpected reserved word
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  var async;
+  for (async of []);
+  // SyntaxError: The left-hand side of a for-of loop may not be 'async'.
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of Chrome and Node.js will give incorrect results with the
+  following:
+  ```javascript
+  console.log({
+      ...console,
+      get 42() {
+          return "FAIL";
+      },
+      [42]: "PASS",
+  }[42]);
+  // Expected: "PASS"
+  // Actual:   "FAIL"
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Earlier versions of JavaScript will throw `TypeError` with the following:
+  ```javascript
+  (function() {
+      {
+          const a = "foo";
+      }
+      {
+          const a = "bar";
+      }
+  })();
+  // TypeError: const 'a' has already been declared
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.

bin/uglifyjs

@@ -3,14 +3,14 @@
 
 "use strict";
 
-require("../tools/exit");
+require("../tools/tty");
 
 var fs = require("fs");
 var info = require("../package.json");
 var path = require("path");
 var UglifyJS = require("../tools/node");
 
-var skip_keys = [ "cname", "inlined", "parent_scope", "scope", "uses_eval", "uses_with" ];
+var skip_keys = [ "cname", "fixed", "inlined", "parent_scope", "scope", "uses_eval", "uses_with" ];
 var files = {};
 var options = {};
 var short_forms = {
@@ -95,11 +95,13 @@ function process_option(name, no_value) {
                 "  -b, --beautify [options]                 Beautify output/specify output options.",
                 "  -O, --output-opts <options>              Output options (beautify disabled).",
                 "  -o, --output <file>                      Output file (default STDOUT).",
+                "  --annotations                            Process and preserve comment annotations.",
+                "  --no-annotations                         Ignore and discard comment annotations.",
                 "  --comments [filter]                      Preserve copyright comments in the output.",
                 "  --config-file <file>                     Read minify() options from JSON file.",
                 "  -d, --define <expr>[=value]              Global definitions.",
                 "  -e, --enclose [arg[,...][:value[,...]]]  Embed everything in a big function, with configurable argument(s) & value(s).",
-                "  --ie8                                    Support non-standard Internet Explorer 8.",
+                "  --ie                                     Support non-standard Internet Explorer.",
                 "  --keep-fnames                            Do not mangle/drop function names. Useful for code relying on Function.prototype.name.",
                 "  --name-cache <file>                      File to hold mangled name mappings.",
                 "  --rename                                 Force symbol expansion.",
@@ -108,10 +110,15 @@ function process_option(name, no_value) {
                 "  --source-map [options]                   Enable source map/specify source map options.",
                 "  --timings                                Display operations run time on STDERR.",
                 "  --toplevel                               Compress and/or mangle variables in toplevel scope.",
+                "  --v8                                     Support non-standard Chrome & Node.js.",
                 "  --validate                               Perform validation during AST manipulations.",
                 "  --verbose                                Print diagnostic messages.",
                 "  --warn                                   Print warning messages.",
+                "  --webkit                                 Support non-standard Safari/Webkit.",
                 "  --wrap <name>                            Embed everything as a function with “exports” corresponding to “name” globally.",
+                "",
+                "(internal debug use only)",
+                "  --in-situ                                Warning: replaces original source files with minified output.",
                 "  --reduce-test                            Reduce a standalone test case (assumes cloned repository).",
             ].join("\n"));
         }
@@ -138,12 +145,19 @@ function process_option(name, no_value) {
       case "enclose":
         options[name] = read_value();
         break;
+      case "annotations":
+      case "ie":
       case "ie8":
       case "timings":
       case "toplevel":
+      case "v8":
       case "validate":
+      case "webkit":
         options[name] = true;
         break;
+      case "no-annotations":
+        options.annotations = false;
+        break;
       case "keep-fnames":
         options.keep_fnames = true;
         break;
@@ -192,6 +206,7 @@ function process_option(name, no_value) {
       case "no-rename":
         options.rename = false;
         break;
+      case "in-situ":
       case "reduce-test":
       case "self":
         break;
@@ -223,10 +238,11 @@ if (options.mangle && options.mangle.properties) {
         });
     }
 }
-if (output == "ast") options.output = {
-    ast: true,
-    code: false,
-};
+if (/^ast|spidermonkey$/.test(output)) {
+    if (typeof options.output != "object") options.output = {};
+    options.output.ast = true;
+    options.output.code = false;
+}
 if (options.parse && (options.parse.acorn || options.parse.spidermonkey)
     && options.sourceMap && options.sourceMap.content == "inline") {
     fatal("inline source map only works with built-in parser");
@@ -252,18 +268,35 @@ if (specified["self"]) {
     if (!options.wrap) options.wrap = "UglifyJS";
     paths = UglifyJS.FILES;
 }
-if (paths.length) {
+if (specified["in-situ"]) {
+    if (output && output != "spidermonkey" || specified["reduce-test"] || specified["self"]) {
+        fatal("incompatible options specified");
+    }
+    paths.forEach(function(name) {
+        print(name);
+        if (/^ast|spidermonkey$/.test(name)) fatal("invalid file name specified");
+        files = {};
+        files[convert_path(name)] = read_file(name);
+        output = name;
+        run();
+    });
+} else if (paths.length) {
     simple_glob(paths).forEach(function(name) {
         files[convert_path(name)] = read_file(name);
     });
     run();
 } else {
+    var timerId = process.stdin.isTTY && process.argv.length < 3 && setTimeout(function() {
+        print_error("Waiting for input... (use `--help` to print usage information)");
+    }, 1500);
     var chunks = [];
     process.stdin.setEncoding("utf8");
-    process.stdin.on("data", function(chunk) {
+    process.stdin.once("data", function() {
+        clearTimeout(timerId);
+    }).on("data", function(chunk) {
         chunks.push(chunk);
     }).on("end", function() {
-        files = [ chunks.join("") ];
+        files = { STDIN: chunks.join("") };
         run();
     });
     process.stdin.resume();
@@ -276,19 +309,51 @@ function convert_ast(fn) {
 function run() {
     var content = options.sourceMap && options.sourceMap.content;
     if (content && content != "inline") {
-        UglifyJS.AST_Node.info("Using input source map: " + content);
+        UglifyJS.AST_Node.info("Using input source map: {content}", {
+            content : content,
+        });
         options.sourceMap.content = read_file(content, content);
     }
     try {
         if (options.parse) {
             if (options.parse.acorn) {
+                var annotations = Object.create(null);
                 files = convert_ast(function(toplevel, name) {
-                    return require("acorn").parse(files[name], {
+                    var content = files[name];
+                    var list = annotations[name] = [];
+                    var prev = -1;
+                    return require("acorn").parse(content, {
+                        allowHashBang: true,
+                        ecmaVersion: "latest",
                         locations: true,
+                        onComment: function(block, text, start, end) {
+                            var match = /[@#]__PURE__/.exec(text);
+                            if (!match) {
+                                if (start != prev) return;
+                                match = [ list[prev] ];
+                            }
+                            while (/\s/.test(content[end])) end++;
+                            list[end] = match[0];
+                            prev = end;
+                        },
+                        preserveParens: true,
                         program: toplevel,
-                        sourceFile: name
+                        sourceFile: name,
+                        sourceType: "module",
                     });
                 });
+                files.walk(new UglifyJS.TreeWalker(function(node) {
+                    if (!(node instanceof UglifyJS.AST_Call)) return;
+                    var list = annotations[node.start.file];
+                    var pure = list[node.start.pos];
+                    if (!pure) {
+                        var tokens = node.start.parens;
+                        if (tokens) for (var i = 0; !pure && i < tokens.length; i++) {
+                            pure = list[tokens[i].pos];
+                        }
+                    }
+                    if (pure) node.pure = pure;
+                }));
             } else if (options.parse.spidermonkey) {
                 files = convert_ast(function(toplevel, name) {
                     var obj = JSON.parse(files[name]);
@@ -342,17 +407,28 @@ function run() {
         }
         fatal(ex);
     } else if (output == "ast") {
-        if (!options.compress && !options.mangle) result.ast.figure_out_scope({});
+        if (!options.compress && !options.mangle) {
+            var toplevel = result.ast;
+            if (!(toplevel instanceof UglifyJS.AST_Toplevel)) {
+                if (!(toplevel instanceof UglifyJS.AST_Statement)) toplevel = new UglifyJS.AST_SimpleStatement({
+                    body: toplevel,
+                });
+                toplevel = new UglifyJS.AST_Toplevel({
+                    body: [ toplevel ],
+                });
+            }
+            toplevel.figure_out_scope({});
+        }
         print(JSON.stringify(result.ast, function(key, value) {
             if (value) switch (key) {
-              case "thedef":
-                return symdef(value);
               case "enclosed":
                 return value.length ? value.map(symdef) : undefined;
-              case "variables":
               case "functions":
               case "globals":
+              case "variables":
                 return value.size() ? value.map(symdef) : undefined;
+              case "thedef":
+                return symdef(value);
             }
             if (skip_key(key)) return;
             if (value instanceof UglifyJS.AST_Token) return;
@@ -369,16 +445,19 @@ function run() {
             return value;
         }, 2));
     } else if (output == "spidermonkey") {
-        print(JSON.stringify(UglifyJS.minify(result.code, {
-            compress: false,
-            mangle: false,
-            output: {
-                ast: true,
-                code: false
-            },
-        }).ast.to_mozilla_ast(), null, 2));
+        print(JSON.stringify(result.ast.to_mozilla_ast(), null, 2));
     } else if (output) {
-        fs.writeFileSync(output, result.code);
+        var code;
+        if (result.ast) {
+            var opts = {};
+            for (var name in options.output) {
+                if (!/^ast|code$/.test(name)) opts[name] = options.output[name];
+            }
+            code = UglifyJS.AST_Node.from_mozilla_ast(result.ast.to_mozilla_ast()).print_to_string(opts);
+        } else {
+            code = result.code;
+        }
+        fs.writeFileSync(output, code);
         if (result.map) fs.writeFileSync(output + ".map", result.map);
     } else {
         print(result.code);

lib/minify.js

@@ -33,7 +33,9 @@ function read_source_map(name, toplevel) {
             return to_ascii(match[2]);
         }
     }
-    AST_Node.warn("inline source map not found: " + name);
+    AST_Node.warn("inline source map not found: {name}", {
+        name: name,
+    });
 }
 
 function parse_source_map(content) {
@@ -45,14 +47,12 @@ function parse_source_map(content) {
 }
 
 function set_shorthand(name, options, keys) {
-    if (options[name]) {
-        keys.forEach(function(key) {
-            if (options[key]) {
-                if (typeof options[key] != "object") options[key] = {};
-                if (!(name in options[key])) options[key][name] = options[name];
-            }
-        });
-    }
+    keys.forEach(function(key) {
+        if (options[key]) {
+            if (typeof options[key] != "object") options[key] = {};
+            if (!(name in options[key])) options[key][name] = options[name];
+        }
+    });
 }
 
 function init_cache(cache) {
@@ -73,8 +73,10 @@ function to_json(cache) {
 function minify(files, options) {
     try {
         options = defaults(options, {
+            annotations: undefined,
             compress: {},
             enclose: false,
+            ie: false,
             ie8: false,
             keep_fnames: false,
             mangle: {},
@@ -85,30 +87,34 @@ function minify(files, options) {
             sourceMap: false,
             timings: false,
             toplevel: false,
+            v8: false,
             validate: false,
             warnings: false,
+            webkit: false,
             wrap: false,
         }, true);
         if (options.validate) AST_Node.enable_validation();
-        var timings = options.timings && {
-            start: Date.now()
-        };
-        if (options.rename === undefined) {
-            options.rename = options.compress && options.mangle;
-        }
-        set_shorthand("ie8", options, [ "compress", "mangle", "output" ]);
-        set_shorthand("keep_fnames", options, [ "compress", "mangle" ]);
-        set_shorthand("toplevel", options, [ "compress", "mangle" ]);
+        var timings = options.timings && { start: Date.now() };
+        if (options.rename === undefined) options.rename = options.compress && options.mangle;
+        if (options.annotations !== undefined) set_shorthand("annotations", options, [ "compress", "output" ]);
+        if (options.ie8) options.ie = options.ie || options.ie8;
+        if (options.ie) set_shorthand("ie", options, [ "compress", "mangle", "output" ]);
+        if (options.keep_fnames) set_shorthand("keep_fnames", options, [ "compress", "mangle" ]);
+        if (options.toplevel) set_shorthand("toplevel", options, [ "compress", "mangle" ]);
+        if (options.v8) set_shorthand("v8", options, [ "mangle", "output" ]);
+        if (options.webkit) set_shorthand("webkit", options, [ "compress", "mangle", "output" ]);
         var quoted_props;
         if (options.mangle) {
             options.mangle = defaults(options.mangle, {
                 cache: options.nameCache && (options.nameCache.vars || {}),
                 eval: false,
-                ie8: false,
+                ie: false,
                 keep_fnames: false,
                 properties: false,
                 reserved: [],
                 toplevel: false,
+                v8: false,
+                webkit: false,
             }, true);
             if (options.mangle.properties) {
                 if (typeof options.mangle.properties != "object") {
@@ -197,32 +203,32 @@ function minify(files, options) {
             toplevel.mangle_names(options.mangle);
         }
         if (timings) timings.properties = Date.now();
-        if (options.mangle && options.mangle.properties) {
-            toplevel = mangle_properties(toplevel, options.mangle.properties);
-        }
+        if (options.mangle && options.mangle.properties) mangle_properties(toplevel, options.mangle.properties);
         if (timings) timings.output = Date.now();
         var result = {};
-        if (options.output.ast) {
-            result.ast = toplevel;
-        }
-        if (!HOP(options.output, "code") || options.output.code) {
+        var output = defaults(options.output, {
+            ast: false,
+            code: true,
+        });
+        if (output.ast) result.ast = toplevel;
+        if (output.code) {
             if (options.sourceMap) {
-                options.output.source_map = SourceMap(options.sourceMap);
+                output.source_map = SourceMap(options.sourceMap);
                 if (options.sourceMap.includeSources) {
                     if (files instanceof AST_Toplevel) {
                         throw new Error("original source content unavailable");
                     } else for (var name in files) if (HOP(files, name)) {
-                        options.output.source_map.setSourceContent(name, files[name]);
+                        output.source_map.setSourceContent(name, files[name]);
                     }
                 }
             }
-            delete options.output.ast;
-            delete options.output.code;
-            var stream = OutputStream(options.output);
+            delete output.ast;
+            delete output.code;
+            var stream = OutputStream(output);
             toplevel.print(stream);
             result.code = stream.get();
             if (options.sourceMap) {
-                result.map = options.output.source_map.toString();
+                result.map = output.source_map.toString();
                 var url = options.sourceMap.url;
                 if (url) {
                     result.code = result.code.replace(/\n\/\/# sourceMappingURL=\S+\s*$/, "");
@@ -260,6 +266,7 @@ function minify(files, options) {
     } catch (ex) {
         return { error: ex };
     } finally {
+        AST_Node.log_function();
         AST_Node.disable_validation();
     }
 }

lib/propmangle.js

@@ -43,7 +43,8 @@
 
 "use strict";
 
-function find_builtins(reserved) {
+var builtins = function() {
+    var names = [];
     // NaN will be included due to Number.NaN
     [
         "null",
@@ -67,19 +68,23 @@ function find_builtins(reserved) {
     ].forEach(function(ctor) {
         Object.getOwnPropertyNames(ctor).map(add);
         if (ctor.prototype) {
+            Object.getOwnPropertyNames(new ctor()).map(add);
             Object.getOwnPropertyNames(ctor.prototype).map(add);
         }
     });
+    return makePredicate(names);
 
     function add(name) {
-        push_uniq(reserved, name);
+        names.push(name);
     }
-}
+}();
 
 function reserve_quoted_keys(ast, reserved) {
     ast.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_ObjectKeyVal && node.quote) {
-            add(node.key);
+        if (node instanceof AST_ClassProperty) {
+            if (node.start && node.start.quote) add(node.key);
+        } else if (node instanceof AST_ObjectProperty) {
+            if (node.start && node.start.quote) add(node.key);
         } else if (node instanceof AST_Sub) {
             addStrings(node.property, add);
         }
@@ -91,17 +96,14 @@ function reserve_quoted_keys(ast, reserved) {
 }
 
 function addStrings(node, add) {
-    node.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_Sequence) {
-            addStrings(node.tail_node(), add);
-        } else if (node instanceof AST_String) {
-            add(node.value);
-        } else if (node instanceof AST_Conditional) {
-            addStrings(node.consequent, add);
-            addStrings(node.alternative, add);
-        }
-        return true;
-    }));
+    if (node instanceof AST_Conditional) {
+        addStrings(node.consequent, add);
+        addStrings(node.alternative, add);
+    } else if (node instanceof AST_Sequence) {
+        addStrings(node.tail_node(), add);
+    } else if (node instanceof AST_String) {
+        add(node.value);
+    }
 }
 
 function mangle_properties(ast, options) {
@@ -110,21 +112,21 @@ function mangle_properties(ast, options) {
         cache: null,
         debug: false,
         keep_quoted: false,
-        only_cache: false,
         regex: null,
         reserved: null,
     }, true);
 
-    var reserved = options.reserved;
-    if (!Array.isArray(reserved)) reserved = [];
-    if (!options.builtins) find_builtins(reserved);
+    var reserved = Object.create(options.builtins ? null : builtins);
+    if (Array.isArray(options.reserved)) options.reserved.forEach(function(name) {
+        reserved[name] = true;
+    });
 
     var cname = -1;
     var cache;
     if (options.cache) {
         cache = options.cache.props;
-        cache.each(function(mangled_name) {
-            push_uniq(reserved, mangled_name);
+        cache.each(function(name) {
+            reserved[name] = true;
         });
     } else {
         cache = new Dictionary();
@@ -139,72 +141,98 @@ function mangle_properties(ast, options) {
     var debug_suffix;
     if (debug) debug_suffix = options.debug === true ? "" : options.debug;
 
-    var names_to_mangle = [];
-    var unmangleable = [];
+    var names_to_mangle = Object.create(null);
+    var unmangleable = Object.create(reserved);
 
     // step 1: find candidates to mangle
     ast.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_ObjectKeyVal) {
-            add(node.key);
-        } else if (node instanceof AST_ObjectProperty) {
-            // setter or getter, since KeyVal is handled above
-            add(node.key.name);
+        if (node instanceof AST_Binary) {
+            if (node.operator == "in") addStrings(node.left, add);
+        } else if (node.TYPE == "Call") {
+            var exp = node.expression;
+            if (exp instanceof AST_Dot) switch (exp.property) {
+              case "defineProperty":
+              case "getOwnPropertyDescriptor":
+                if (node.args.length < 2) break;
+                exp = exp.expression;
+                if (!(exp instanceof AST_SymbolRef)) break;
+                if (exp.name != "Object") break;
+                if (!exp.definition().undeclared) break;
+                addStrings(node.args[1], add);
+                break;
+              case "hasOwnProperty":
+                if (node.args.length < 1) break;
+                addStrings(node.args[0], add);
+                break;
+            }
+        } else if (node instanceof AST_ClassProperty) {
+            if (typeof node.key == "string") add(node.key);
         } else if (node instanceof AST_Dot) {
             add(node.property);
+        } else if (node instanceof AST_ObjectProperty) {
+            if (typeof node.key == "string") add(node.key);
         } else if (node instanceof AST_Sub) {
             addStrings(node.property, add);
-        } else if (node instanceof AST_Call
-            && node.expression.print_to_string() == "Object.defineProperty") {
-            addStrings(node.args[1], add);
         }
     }));
 
-    // step 2: transform the tree, renaming properties
-    return ast.transform(new TreeTransformer(function(node) {
-        if (node instanceof AST_ObjectKeyVal) {
-            node.key = mangle(node.key);
-        } else if (node instanceof AST_ObjectProperty) {
-            // setter or getter
-            node.key.name = mangle(node.key.name);
+    // step 2: renaming properties
+    ast.walk(new TreeWalker(function(node) {
+        if (node instanceof AST_Binary) {
+            if (node.operator == "in") mangleStrings(node.left);
+        } else if (node.TYPE == "Call") {
+            var exp = node.expression;
+            if (exp instanceof AST_Dot) switch (exp.property) {
+              case "defineProperty":
+              case "getOwnPropertyDescriptor":
+                if (node.args.length < 2) break;
+                exp = exp.expression;
+                if (!(exp instanceof AST_SymbolRef)) break;
+                if (exp.name != "Object") break;
+                if (!exp.definition().undeclared) break;
+                mangleStrings(node.args[1]);
+                break;
+              case "hasOwnProperty":
+                if (node.args.length < 1) break;
+                mangleStrings(node.args[0]);
+                break;
+            }
+        } else if (node instanceof AST_ClassProperty) {
+            if (typeof node.key == "string") node.key = mangle(node.key);
         } else if (node instanceof AST_Dot) {
             node.property = mangle(node.property);
-        } else if (!options.keep_quoted && node instanceof AST_Sub) {
-            node.property = mangleStrings(node.property);
-        } else if (node instanceof AST_Call
-            && node.expression.print_to_string() == "Object.defineProperty") {
-            node.args[1] = mangleStrings(node.args[1]);
+        } else if (node instanceof AST_ObjectProperty) {
+            if (typeof node.key == "string") node.key = mangle(node.key);
+        } else if (node instanceof AST_Sub) {
+            if (!options.keep_quoted) mangleStrings(node.property);
         }
     }));
 
     // only function declarations after this line
 
     function can_mangle(name) {
-        if (unmangleable.indexOf(name) >= 0) return false;
-        if (reserved.indexOf(name) >= 0) return false;
-        if (options.only_cache) return cache.has(name);
+        if (unmangleable[name]) return false;
         if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
         return true;
     }
 
     function should_mangle(name) {
+        if (reserved[name]) return false;
         if (regex && !regex.test(name)) return false;
-        if (reserved.indexOf(name) >= 0) return false;
-        return cache.has(name) || names_to_mangle.indexOf(name) >= 0;
+        return cache.has(name) || names_to_mangle[name];
     }
 
     function add(name) {
-        if (can_mangle(name)) push_uniq(names_to_mangle, name);
-        if (!should_mangle(name)) push_uniq(unmangleable, name);
+        if (can_mangle(name)) names_to_mangle[name] = true;
+        if (!should_mangle(name)) unmangleable[name] = true;
     }
 
     function mangle(name) {
-        if (!should_mangle(name)) {
-            return name;
-        }
+        if (!should_mangle(name)) return name;
         var mangled = cache.get(name);
         if (!mangled) {
             if (debug) {
-                // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo -> o._$foo$NNN_.
+                // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo ---> o._$foo$NNN_.
                 var debug_mangled = "_$" + name + "$" + debug_suffix + "_";
                 if (can_mangle(debug_mangled)) mangled = debug_mangled;
             }
@@ -212,23 +240,20 @@ function mangle_properties(ast, options) {
             if (!mangled) do {
                 mangled = base54(++cname);
             } while (!can_mangle(mangled));
+            if (/^#/.test(name)) mangled = "#" + mangled;
             cache.set(name, mangled);
         }
         return mangled;
     }
 
     function mangleStrings(node) {
-        return node.transform(new TreeTransformer(function(node) {
-            if (node instanceof AST_Sequence) {
-                var last = node.expressions.length - 1;
-                node.expressions[last] = mangleStrings(node.expressions[last]);
-            } else if (node instanceof AST_String) {
-                node.value = mangle(node.value);
-            } else if (node instanceof AST_Conditional) {
-                node.consequent = mangleStrings(node.consequent);
-                node.alternative = mangleStrings(node.alternative);
-            }
-            return node;
-        }));
+        if (node instanceof AST_Sequence) {
+            mangleStrings(node.expressions.tail_node());
+        } else if (node instanceof AST_String) {
+            node.value = mangle(node.value);
+        } else if (node instanceof AST_Conditional) {
+            mangleStrings(node.consequent);
+            mangleStrings(node.alternative);
+        }
     }
 }

lib/scope.js

@@ -45,10 +45,10 @@
 
 function SymbolDef(id, scope, orig, init) {
     this.eliminated = 0;
+    this.exported = false;
     this.global = false;
     this.id = id;
     this.init = init;
-    this.lambda = orig instanceof AST_SymbolLambda;
     this.mangled_name = null;
     this.name = orig.name;
     this.orig = [ orig ];
@@ -59,24 +59,20 @@ function SymbolDef(id, scope, orig, init) {
 }
 
 SymbolDef.prototype = {
-    unmangleable: function(options) {
-        return this.global && !options.toplevel
-            || this.undeclared
-            || !options.eval && this.scope.pinned()
-            || options.keep_fnames
-                && (this.orig[0] instanceof AST_SymbolLambda
-                    || this.orig[0] instanceof AST_SymbolDefun);
+    forEach: function(fn) {
+        this.orig.forEach(fn);
+        this.references.forEach(fn);
     },
     mangle: function(options) {
         var cache = options.cache && options.cache.props;
         if (this.global && cache && cache.has(this.name)) {
             this.mangled_name = cache.get(this.name);
         } else if (!this.mangled_name && !this.unmangleable(options)) {
-            var def;
-            if (def = this.redefined()) {
+            var def = this.redefined();
+            if (def) {
                 this.mangled_name = def.mangled_name || def.name;
             } else {
-                this.mangled_name = next_mangled_name(this.scope, options, this);
+                this.mangled_name = next_mangled_name(this, options);
             }
             if (this.global && cache) {
                 cache.set(this.name, this.mangled_name);
@@ -84,42 +80,114 @@ SymbolDef.prototype = {
         }
     },
     redefined: function() {
-        return this.defun && this.defun.variables.get(this.name);
-    }
+        var self = this;
+        var scope = self.defun;
+        if (!scope) return;
+        var name = self.name;
+        var def = scope.variables.get(name)
+            || scope instanceof AST_Toplevel && scope.globals.get(name)
+            || self.orig[0] instanceof AST_SymbolConst && find_if(function(def) {
+                return def.name == name;
+            }, scope.enclosed);
+        if (def && def !== self) return def.redefined() || def;
+    },
+    unmangleable: function(options) {
+        return this.global && !options.toplevel
+            || this.exported
+            || this.undeclared
+            || !options.eval && this.scope.pinned()
+            || options.keep_fnames
+                && (this.orig[0] instanceof AST_SymbolClass
+                    || this.orig[0] instanceof AST_SymbolDefClass
+                    || this.orig[0] instanceof AST_SymbolDefun
+                    || this.orig[0] instanceof AST_SymbolLambda);
+    },
 };
 
+var unary_side_effects = makePredicate("delete ++ --");
+
+function is_lhs(node, parent) {
+    if (parent instanceof AST_Assign) return parent.left === node && node;
+    if (parent instanceof AST_DefaultValue) return parent.name === node && node;
+    if (parent instanceof AST_Destructured) return node;
+    if (parent instanceof AST_DestructuredKeyVal) return node;
+    if (parent instanceof AST_ForEnumeration) return parent.init === node && node;
+    if (parent instanceof AST_Unary) return unary_side_effects[parent.operator] && parent.expression;
+}
+
 AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     options = defaults(options, {
         cache: null,
-        ie8: false,
+        ie: false,
     });
 
     // pass 1: setup scope chaining and handle definitions
     var self = this;
-    var scope = self.parent_scope = null;
     var defun = null;
+    var exported = false;
+    var next_def_id = 0;
+    var scope = self.parent_scope = null;
     var tw = new TreeWalker(function(node, descend) {
-        if (node instanceof AST_Catch) {
-            var save_scope = scope;
-            scope = new AST_Scope(node);
-            scope.init_scope_vars(save_scope);
-            descend();
-            scope = save_scope;
+        if (node instanceof AST_DefClass) {
+            var save_exported = exported;
+            exported = tw.parent() instanceof AST_ExportDeclaration;
+            node.name.walk(tw);
+            exported = save_exported;
+            walk_scope(function() {
+                if (node.extends) node.extends.walk(tw);
+                node.properties.forEach(function(prop) {
+                    prop.walk(tw);
+                });
+            });
             return true;
         }
-        if (node instanceof AST_Scope) {
-            node.init_scope_vars(scope);
-            var save_scope = scope;
-            var save_defun = defun;
-            defun = scope = node;
+        if (node instanceof AST_Definitions) {
+            var save_exported = exported;
+            exported = tw.parent() instanceof AST_ExportDeclaration;
             descend();
-            scope = save_scope;
-            defun = save_defun;
+            exported = save_exported;
+            return true;
+        }
+        if (node instanceof AST_LambdaDefinition) {
+            var save_exported = exported;
+            exported = tw.parent() instanceof AST_ExportDeclaration;
+            node.name.walk(tw);
+            exported = save_exported;
+            walk_scope(function() {
+                node.argnames.forEach(function(argname) {
+                    argname.walk(tw);
+                });
+                if (node.rest) node.rest.walk(tw);
+                walk_body(node, tw);
+            });
+            return true;
+        }
+        if (node instanceof AST_SwitchBranch) {
+            node.init_vars(scope);
+            descend();
+            return true;
+        }
+        if (node instanceof AST_Try) {
+            walk_scope(function() {
+                walk_body(node, tw);
+            });
+            if (node.bcatch) node.bcatch.walk(tw);
+            if (node.bfinally) node.bfinally.walk(tw);
             return true;
         }
         if (node instanceof AST_With) {
-            for (var s = scope; s; s = s.parent_scope) s.uses_with = true;
-            return;
+            var s = scope;
+            do {
+                s = s.resolve();
+                if (s.uses_with) break;
+                s.uses_with = true;
+            } while (s = s.parent_scope);
+            walk_scope(descend);
+            return true;
+        }
+        if (node instanceof AST_BlockScope) {
+            walk_scope(descend);
+            return true;
         }
         if (node instanceof AST_Symbol) {
             node.scope = scope;
@@ -128,73 +196,162 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             node.thedef = node;
             node.references = [];
         }
-        if (node instanceof AST_SymbolDefun) {
-            // This should be defined in the parent scope, as we encounter the
-            // AST_Defun node before getting to its AST_Symbol.
-            (node.scope = defun.parent_scope.resolve()).def_function(node, defun);
+        if (node instanceof AST_SymbolCatch) {
+            scope.def_variable(node).defun = defun;
+        } else if (node instanceof AST_SymbolConst) {
+            var def = scope.def_variable(node);
+            def.defun = defun;
+            if (exported) def.exported = true;
+        } else if (node instanceof AST_SymbolDefun) {
+            var def = defun.def_function(node, tw.parent());
+            if (exported) def.exported = true;
+            entangle(defun, scope);
+        } else if (node instanceof AST_SymbolFunarg) {
+            defun.def_variable(node);
+            entangle(defun, scope);
         } else if (node instanceof AST_SymbolLambda) {
             var def = defun.def_function(node, node.name == "arguments" ? undefined : defun);
-            if (options.ie8) def.defun = defun.parent_scope.resolve();
+            if (options.ie) def.defun = defun.parent_scope.resolve();
+        } else if (node instanceof AST_SymbolLet) {
+            var def = scope.def_variable(node);
+            if (exported) def.exported = true;
         } else if (node instanceof AST_SymbolVar) {
-            defun.def_variable(node, node.TYPE == "SymbolVar" ? null : undefined);
-            if (defun !== scope) {
-                node.mark_enclosed(options);
-                var def = scope.find_variable(node);
-                if (node.thedef !== def) {
-                    node.thedef = def;
-                }
-                node.reference(options);
-            }
-        } else if (node instanceof AST_SymbolCatch) {
-            scope.def_variable(node).defun = defun;
+            var def = defun.def_variable(node, node instanceof AST_SymbolImport ? undefined : null);
+            if (exported) def.exported = true;
+            entangle(defun, scope);
+        }
+
+        function walk_scope(descend) {
+            node.init_vars(scope);
+            var save_defun = defun;
+            var save_scope = scope;
+            if (node instanceof AST_Scope) defun = node;
+            scope = node;
+            descend();
+            scope = save_scope;
+            defun = save_defun;
+        }
+
+        function entangle(defun, scope) {
+            if (defun === scope) return;
+            node.mark_enclosed(options);
+            var def = scope.find_variable(node.name);
+            if (node.thedef === def) return;
+            node.thedef = def;
+            def.orig.push(node);
+            node.mark_enclosed(options);
         }
     });
-    self.next_def_id = 0;
+    self.make_def = function(orig, init) {
+        return new SymbolDef(++next_def_id, this, orig, init);
+    };
     self.walk(tw);
 
     // pass 2: find back references and eval
     self.globals = new Dictionary();
+    var in_arg = [];
     var tw = new TreeWalker(function(node) {
+        if (node instanceof AST_Catch) {
+            if (!(node.argname instanceof AST_Destructured)) return;
+            in_arg.push(node);
+            node.argname.walk(tw);
+            in_arg.pop();
+            walk_body(node, tw);
+            return true;
+        }
+        if (node instanceof AST_Lambda) {
+            in_arg.push(node);
+            node.argnames.forEach(function(argname) {
+                argname.walk(tw);
+            });
+            if (node.rest) node.rest.walk(tw);
+            in_arg.pop();
+            walk_lambda(node, tw);
+            return true;
+        }
         if (node instanceof AST_LoopControl) {
             if (node.label) node.label.thedef.references.push(node);
             return true;
         }
+        if (node instanceof AST_SymbolDeclaration) {
+            var def = node.definition();
+            def.preinit = def.references.length;
+            if (node instanceof AST_SymbolCatch) {
+                // ensure mangling works if `catch` reuses a scope variable
+                var redef = def.redefined();
+                if (redef) for (var s = node.scope; s; s = s.parent_scope) {
+                    push_uniq(s.enclosed, redef);
+                    if (s === redef.scope) break;
+                }
+            } else if (node instanceof AST_SymbolConst) {
+                // ensure compression works if `const` reuses a scope variable
+                var redef = def.redefined();
+                if (redef) redef.const_redefs = true;
+            }
+            if (node.name != "arguments") return true;
+            var parent = node instanceof AST_SymbolVar && tw.parent();
+            if (parent instanceof AST_VarDef && !parent.value) return true;
+            var sym = node.scope.resolve().find_variable("arguments");
+            if (sym && is_arguments(sym)) sym.scope.uses_arguments = 3;
+            return true;
+        }
         if (node instanceof AST_SymbolRef) {
             var name = node.name;
             var sym = node.scope.find_variable(name);
+            for (var i = in_arg.length; i > 0 && sym;) {
+                i = in_arg.lastIndexOf(sym.scope, i - 1);
+                if (i < 0) break;
+                var decl = sym.orig[0];
+                if (decl instanceof AST_SymbolCatch
+                    || decl instanceof AST_SymbolFunarg
+                    || decl instanceof AST_SymbolLambda) {
+                    node.in_arg = true;
+                    break;
+                }
+                sym = sym.scope.parent_scope.find_variable(name);
+            }
             if (!sym) {
                 sym = self.def_global(node);
-            } else if (sym.scope instanceof AST_Lambda && name == "arguments") {
-                sym.scope.uses_arguments = true;
+            } else if (name == "arguments" && is_arguments(sym)) {
+                var parent = tw.parent();
+                if (is_lhs(node, parent)) {
+                    sym.scope.uses_arguments = 3;
+                } else if (sym.scope.uses_arguments < 2
+                    && !(parent instanceof AST_PropAccess && parent.expression === node)) {
+                    sym.scope.uses_arguments = 2;
+                } else if (!sym.scope.uses_arguments) {
+                    sym.scope.uses_arguments = true;
+                }
             }
             if (name == "eval") {
                 var parent = tw.parent();
                 if (parent.TYPE == "Call" && parent.expression === node) {
-                    for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) {
+                    var s = node.scope;
+                    do {
+                        s = s.resolve();
+                        if (s.uses_eval) break;
                         s.uses_eval = true;
-                    }
+                    } while (s = s.parent_scope);
                 } else if (sym.undeclared) {
                     self.uses_eval = true;
                 }
             }
+            if (sym.init instanceof AST_LambdaDefinition && sym.scope !== sym.init.name.scope) {
+                var scope = node.scope;
+                do {
+                    if (scope === sym.init.name.scope) break;
+                } while (scope = scope.parent_scope);
+                if (!scope) sym.init = undefined;
+            }
             node.thedef = sym;
             node.reference(options);
             return true;
         }
-        // ensure mangling works if catch reuses a scope variable
-        if (node instanceof AST_SymbolCatch) {
-            var def = node.definition().redefined();
-            if (def) for (var s = node.scope; s; s = s.parent_scope) {
-                push_uniq(s.enclosed, def);
-                if (s === def.scope) break;
-            }
-            return true;
-        }
     });
     self.walk(tw);
 
     // pass 3: fix up any scoping issue with IE8
-    if (options.ie8) self.walk(new TreeWalker(function(node) {
+    if (options.ie) self.walk(new TreeWalker(function(node) {
         if (node instanceof AST_SymbolCatch) {
             var scope = node.thedef.defun;
             if (scope.name instanceof AST_SymbolLambda && scope.name.name == node.name) {
@@ -205,8 +362,9 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
         }
         if (node instanceof AST_SymbolLambda) {
             var def = node.thedef;
-            redefine(node, node.scope.parent_scope.resolve());
-            if (typeof node.thedef.init !== "undefined") {
+            if (!redefine(node, node.scope.parent_scope.resolve())) {
+                delete def.defun;
+            } else if (typeof node.thedef.init !== "undefined") {
                 node.thedef.init = false;
             } else if (def.init) {
                 node.thedef.init = def.init;
@@ -215,13 +373,22 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
         }
     }));
 
+    function is_arguments(sym) {
+        return sym.orig[0] instanceof AST_SymbolFunarg
+            && !(sym.orig[1] instanceof AST_SymbolFunarg || sym.orig[2] instanceof AST_SymbolFunarg)
+            && !is_arrow(sym.scope);
+    }
+
     function redefine(node, scope) {
         var name = node.name;
         var old_def = node.thedef;
+        if (!all(old_def.orig, function(sym) {
+            return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
+        })) return false;
         var new_def = scope.find_variable(name);
         if (new_def) {
-            var redef;
-            while (redef = new_def.redefined()) new_def = redef;
+            var redef = new_def.redefined();
+            if (redef) new_def = redef;
         } else {
             new_def = self.globals.get(name);
         }
@@ -230,22 +397,18 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
         } else {
             new_def = scope.def_variable(node);
         }
+        if (new_def.undeclared) self.variables.set(name, new_def);
+        if (name == "arguments" && is_arguments(old_def) && node instanceof AST_SymbolLambda) return true;
         old_def.defun = new_def.scope;
-        old_def.orig.concat(old_def.references).forEach(function(node) {
+        old_def.forEach(function(node) {
+            node.redef = old_def;
             node.thedef = new_def;
             node.reference(options);
         });
-        if (old_def.lambda) new_def.lambda = true;
-        if (new_def.undeclared) self.variables.set(name, new_def);
+        return true;
     }
 });
 
-AST_Scope.DEFMETHOD("make_def", function(orig, init) {
-    var top = this;
-    while (top.parent_scope) top = top.parent_scope;
-    return new SymbolDef(++top.next_def_id, this, orig, init);
-});
-
 AST_Toplevel.DEFMETHOD("def_global", function(node) {
     var globals = this.globals, name = node.name;
     if (globals.has(name)) {
@@ -259,31 +422,51 @@ AST_Toplevel.DEFMETHOD("def_global", function(node) {
     }
 });
 
-AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope) {
-    this.variables = new Dictionary();  // map name to AST_SymbolVar (variables defined in this scope; includes functions)
-    this.functions = new Dictionary();  // map name to AST_SymbolDefun (functions defined in this scope)
-    this.uses_with = false;             // will be set to true if this or some nested scope uses the `with` statement
-    this.uses_eval = false;             // will be set to true if this or nested scope uses the global `eval`
-    this.parent_scope = parent_scope;   // the parent scope
-    this.enclosed = [];                 // a list of variables from this or outer scope(s) that are referenced from this or inner scopes
-    this.cname = -1;                    // the current index for mangling functions/variables
-});
+function init_block_vars(scope, parent) {
+    scope.enclosed = [];                            // variables from this or outer scope(s) that are referenced from this or inner scopes
+    scope.parent_scope = parent;                    // the parent scope (null if this is the top level)
+    scope.functions = new Dictionary();             // map name to AST_SymbolDefun (functions defined in this scope)
+    scope.variables = new Dictionary();             // map name to AST_SymbolVar (variables defined in this scope; includes functions)
+    if (parent) scope.make_def = parent.make_def;   // top-level tracking of SymbolDef instances
+}
 
-AST_Lambda.DEFMETHOD("init_scope_vars", function() {
-    AST_Scope.prototype.init_scope_vars.apply(this, arguments);
+function init_scope_vars(scope, parent) {
+    init_block_vars(scope, parent);
+    scope.uses_eval = false;                        // will be set to true if this or nested scope uses the global `eval`
+    scope.uses_with = false;                        // will be set to true if this or some nested scope uses the `with` statement
+}
+
+AST_BlockScope.DEFMETHOD("init_vars", function(parent_scope) {
+    init_block_vars(this, parent_scope);
+});
+AST_Scope.DEFMETHOD("init_vars", function(parent_scope) {
+    init_scope_vars(this, parent_scope);
+});
+AST_Arrow.DEFMETHOD("init_vars", function(parent_scope) {
+    init_scope_vars(this, parent_scope);
+    return this;
+});
+AST_AsyncArrow.DEFMETHOD("init_vars", function(parent_scope) {
+    init_scope_vars(this, parent_scope);
+});
+AST_Lambda.DEFMETHOD("init_vars", function(parent_scope) {
+    init_scope_vars(this, parent_scope);
     this.uses_arguments = false;
     this.def_variable(new AST_SymbolFunarg({
         name: "arguments",
         start: this.start,
-        end: this.end
+        end: this.end,
     }));
+    return this;
 });
 
 AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
     var def = this.definition();
     for (var s = this.scope; s; s = s.parent_scope) {
         push_uniq(s.enclosed, def);
-        if (options.keep_fnames) {
+        if (!options) {
+            delete s._var_names;
+        } else if (options.keep_fnames) {
             s.functions.each(function(d) {
                 push_uniq(def.scope.enclosed, d);
             });
@@ -297,24 +480,23 @@ AST_Symbol.DEFMETHOD("reference", function(options) {
     this.mark_enclosed(options);
 });
 
-AST_Scope.DEFMETHOD("find_variable", function(name) {
-    if (name instanceof AST_Symbol) name = name.name;
+AST_BlockScope.DEFMETHOD("find_variable", function(name) {
     return this.variables.get(name)
-        || (this.parent_scope && this.parent_scope.find_variable(name));
+        || this.parent_scope && this.parent_scope.find_variable(name);
 });
 
-AST_Scope.DEFMETHOD("def_function", function(symbol, init) {
+AST_BlockScope.DEFMETHOD("def_function", function(symbol, init) {
     var def = this.def_variable(symbol, init);
-    if (!def.init || def.init instanceof AST_Defun) def.init = init;
+    if (!def.init || def.init instanceof AST_LambdaDefinition) def.init = init;
     this.functions.set(symbol.name, def);
     return def;
 });
 
-AST_Scope.DEFMETHOD("def_variable", function(symbol, init) {
+AST_BlockScope.DEFMETHOD("def_variable", function(symbol, init) {
     var def = this.variables.get(symbol.name);
     if (def) {
         def.orig.push(symbol);
-        if (def.init instanceof AST_Function) def.init = init;
+        if (def.init instanceof AST_LambdaExpression) def.init = init;
     } else {
         def = this.make_def(symbol, init);
         this.variables.set(symbol.name, def);
@@ -323,17 +505,12 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol, init) {
     return symbol.thedef = def;
 });
 
-AST_Lambda.DEFMETHOD("resolve", return_this);
-AST_Scope.DEFMETHOD("resolve", function() {
-    return this.parent_scope.resolve();
-});
-AST_Toplevel.DEFMETHOD("resolve", return_this);
-
 function names_in_use(scope, options) {
     var names = scope.names_in_use;
     if (!names) {
-        scope.names_in_use = names = Object.create(scope.mangled_names || null);
+        scope.cname = -1;
         scope.cname_holes = [];
+        scope.names_in_use = names = Object.create(null);
         var cache = options.cache && options.cache.props;
         scope.enclosed.forEach(function(def) {
             if (def.unmangleable(options)) names[def.name] = true;
@@ -345,12 +522,13 @@ function names_in_use(scope, options) {
     return names;
 }
 
-function next_mangled_name(scope, options, def) {
+function next_mangled_name(def, options) {
+    var scope = def.scope;
     var in_use = names_in_use(scope, options);
     var holes = scope.cname_holes;
     var names = Object.create(null);
     var scopes = [ scope ];
-    def.references.forEach(function(sym) {
+    def.forEach(function(sym) {
         var scope = sym.scope;
         do {
             if (scopes.indexOf(scope) < 0) {
@@ -366,7 +544,7 @@ function next_mangled_name(scope, options, def) {
         name = base54(holes[i]);
         if (names[name]) continue;
         holes.splice(i, 1);
-        scope.names_in_use[name] = true;
+        in_use[name] = true;
         return name;
     }
     while (true) {
@@ -375,7 +553,7 @@ function next_mangled_name(scope, options, def) {
         if (!names[name]) break;
         holes.push(scope.cname);
     }
-    scope.names_in_use[name] = true;
+    in_use[name] = true;
     return name;
 }
 
@@ -387,25 +565,19 @@ AST_Symbol.DEFMETHOD("unmangleable", function(options) {
 // labels are always mangleable
 AST_Label.DEFMETHOD("unmangleable", return_false);
 
-AST_Symbol.DEFMETHOD("unreferenced", function() {
-    return !this.definition().references.length && !this.scope.pinned();
-});
-
 AST_Symbol.DEFMETHOD("definition", function() {
     return this.thedef;
 });
 
-AST_Symbol.DEFMETHOD("global", function() {
-    return this.definition().global;
-});
-
 function _default_mangler_options(options) {
     options = defaults(options, {
         eval        : false,
-        ie8         : false,
+        ie          : false,
         keep_fnames : false,
         reserved    : [],
         toplevel    : false,
+        v8          : false,
+        webkit      : false,
     });
     if (!Array.isArray(options.reserved)) options.reserved = [];
     // Never mangle arguments
@@ -424,7 +596,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
     var lname = -1;
 
     if (options.cache && options.cache.props) {
-        var mangled_names = this.mangled_names = Object.create(null);
+        var mangled_names = names_in_use(this, options);
         options.cache.props.each(function(mangled_name) {
             mangled_names[mangled_name] = true;
         });
@@ -436,10 +608,29 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             // lname is incremented when we get to the AST_Label
             var save_nesting = lname;
             descend();
-            lname = save_nesting;
+            if (!options.v8 || !in_label(tw)) lname = save_nesting;
             return true;
         }
-        if (node instanceof AST_Scope) {
+        if (node instanceof AST_BlockScope) {
+            if (options.webkit && node instanceof AST_IterationStatement && node.init instanceof AST_Let) {
+                node.init.definitions.forEach(function(defn) {
+                    defn.name.match_symbol(function(sym) {
+                        if (!(sym instanceof AST_SymbolLet)) return;
+                        var def = sym.definition();
+                        var scope = sym.scope.parent_scope;
+                        var redef = scope.def_variable(sym);
+                        sym.thedef = def;
+                        scope.to_mangle.push(redef);
+                        def.redefined = function() {
+                            return redef;
+                        };
+                    });
+                }, true);
+            }
+            node.to_mangle = [];
+            node.variables.each(function(def) {
+                if (!defer_redef(def)) node.to_mangle.push(def);
+            });
             descend();
             if (options.cache && node instanceof AST_Toplevel) {
                 node.globals.each(mangle);
@@ -449,9 +640,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
                 sym.scope = node;
                 sym.reference(options);
             }
-            node.variables.each(function(def) {
-                if (!defer_redef(def)) mangle(def);
-            });
+            node.to_mangle.forEach(mangle);
             return true;
         }
         if (node instanceof AST_Label) {
@@ -462,13 +651,6 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             node.mangled_name = name;
             return true;
         }
-        if (!options.ie8 && node instanceof AST_Catch) {
-            var def = node.argname.definition();
-            var redef = defer_redef(def, node.argname);
-            descend();
-            if (!redef) mangle(def);
-            return true;
-        }
     });
     this.walk(tw);
     redefined.forEach(mangle);
@@ -478,12 +660,20 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
         def.mangle(options);
     }
 
-    function defer_redef(def, node) {
+    function defer_redef(def) {
+        var sym = def.orig[0];
         var redef = def.redefined();
-        if (!redef) return false;
+        if (!redef) {
+            if (!(sym instanceof AST_SymbolConst)) return false;
+            var scope = def.scope.resolve();
+            if (def.scope === scope) return false;
+            if (def.scope.parent_scope.find_variable(sym.name)) return false;
+            redef = scope.def_variable(sym);
+            scope.to_mangle.push(redef);
+        }
         redefined.push(def);
         def.references.forEach(reference);
-        if (node) reference(node);
+        if (sym instanceof AST_SymbolCatch || sym instanceof AST_SymbolConst) reference(sym);
         return true;
 
         function reference(sym) {
@@ -492,16 +682,23 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             sym.thedef = def;
         }
     }
+
+    function in_label(tw) {
+        var level = 0, parent;
+        while (parent = tw.parent(level++)) {
+            if (parent instanceof AST_Block) return parent instanceof AST_Toplevel && !options.toplevel;
+            if (parent instanceof AST_LabeledStatement) return true;
+        }
+    }
 });
 
 AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
     var cache = options.cache && options.cache.props;
-    var avoid = Object.create(null);
+    var avoid = Object.create(RESERVED_WORDS);
     options.reserved.forEach(to_avoid);
     this.globals.each(add_def);
     this.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_Scope) node.variables.each(add_def);
-        if (node instanceof AST_SymbolCatch) add_def(node.definition());
+        if (node instanceof AST_BlockScope) node.variables.each(add_def);
     }));
     return avoid;
 
@@ -525,15 +722,14 @@ AST_Toplevel.DEFMETHOD("expand_names", function(options) {
     var cname = 0;
     this.globals.each(rename);
     this.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_Scope) node.variables.each(rename);
-        if (node instanceof AST_SymbolCatch) rename(node.definition());
+        if (node instanceof AST_BlockScope) node.variables.each(rename);
     }));
 
     function next_name() {
         var name;
         do {
             name = base54(cname++);
-        } while (avoid[name] || RESERVED_WORDS[name]);
+        } while (avoid[name]);
         return name;
     }
 
@@ -544,7 +740,7 @@ AST_Toplevel.DEFMETHOD("expand_names", function(options) {
         var redef = def.redefined();
         var name = redef ? redef.rename || redef.name : next_name();
         def.rename = name;
-        def.orig.concat(def.references).forEach(function(sym) {
+        def.forEach(function(sym) {
             if (sym.definition() === def) sym.name = name;
         });
     }
@@ -558,22 +754,24 @@ AST_Sequence.DEFMETHOD("tail_node", function() {
 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options) {
     options = _default_mangler_options(options);
     base54.reset();
+    var fn = AST_Symbol.prototype.add_source_map;
     try {
-        AST_Node.prototype.print = function(stream, force_parens) {
-            this._print(stream, force_parens);
-            if (this instanceof AST_Symbol && !this.unmangleable(options)) {
-                base54.consider(this.name, -1);
-            } else if (options.properties) {
-                if (this instanceof AST_Dot) {
-                    base54.consider(this.property, -1);
-                } else if (this instanceof AST_Sub) {
-                    skip_string(this.property);
-                }
-            }
+        AST_Symbol.prototype.add_source_map = function() {
+            if (!this.unmangleable(options)) base54.consider(this.name, -1);
         };
+        if (options.properties) {
+            AST_Dot.prototype.add_source_map = function() {
+                base54.consider(this.property, -1);
+            };
+            AST_Sub.prototype.add_source_map = function() {
+                skip_string(this.property);
+            };
+        }
         base54.consider(this.print_to_string(), 1);
     } finally {
-        AST_Node.prototype.print = AST_Node.prototype._print;
+        AST_Symbol.prototype.add_source_map = fn;
+        delete AST_Dot.prototype.add_source_map;
+        delete AST_Sub.prototype.add_source_map;
     }
     base54.sort();
 
@@ -604,6 +802,7 @@ var base54 = (function() {
     var leading = init("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_");
     var chars, frequency;
     function reset() {
+        chars = null;
         frequency = Object.create(freq);
     }
     base54.consider = function(str, delta) {
@@ -615,19 +814,15 @@ var base54 = (function() {
         return frequency[b] - frequency[a];
     }
     base54.sort = function() {
-        chars = leading.sort(compare).concat(digits.sort(compare));
+        chars = leading.sort(compare).concat(digits).sort(compare);
     };
     base54.reset = reset;
     reset();
     function base54(num) {
-        var ret = "", base = 54;
-        num++;
-        do {
-            num--;
-            ret += chars[num % base];
-            num = Math.floor(num / base);
-            base = 64;
-        } while (num > 0);
+        var ret = leading[num % 54];
+        for (num = Math.floor(num / 54); --num >= 0; num >>= 6) {
+            ret += chars[num & 0x3F];
+        }
         return ret;
     }
     return base54;

lib/sourcemap.js

@@ -144,7 +144,9 @@ function SourceMap(options) {
             add(source, gen_line, gen_col, orig_line, orig_col, name);
         } : add,
         setSourceContent: sources_content ? function(source, content) {
-            sources_content[source] = content;
+            if (!(source in sources_content)) {
+                sources_content[source] = content;
+            }
         } : noop,
         toString: function() {
             return JSON.stringify({

lib/transform.js

@@ -82,7 +82,7 @@ TreeTransformer.prototype = new TreeWalker;
         if (self.step) self.step = self.step.transform(tw);
         self.body = self.body.transform(tw);
     });
-    DEF(AST_ForIn, function(self, tw) {
+    DEF(AST_ForEnumeration, function(self, tw) {
         self.init = self.init.transform(tw);
         self.object = self.object.transform(tw);
         self.body = self.body.transform(tw);
@@ -116,7 +116,7 @@ TreeTransformer.prototype = new TreeWalker;
         if (self.bfinally) self.bfinally = self.bfinally.transform(tw);
     });
     DEF(AST_Catch, function(self, tw) {
-        self.argname = self.argname.transform(tw);
+        if (self.argname) self.argname = self.argname.transform(tw);
         self.body = do_list(self.body, tw);
     });
     DEF(AST_Definitions, function(self, tw) {
@@ -126,11 +126,36 @@ TreeTransformer.prototype = new TreeWalker;
         self.name = self.name.transform(tw);
         if (self.value) self.value = self.value.transform(tw);
     });
+    DEF(AST_DefaultValue, function(self, tw) {
+        self.name = self.name.transform(tw);
+        self.value = self.value.transform(tw);
+    });
     DEF(AST_Lambda, function(self, tw) {
         if (self.name) self.name = self.name.transform(tw);
         self.argnames = do_list(self.argnames, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
         self.body = do_list(self.body, tw);
     });
+    function transform_arrow(self, tw) {
+        self.argnames = do_list(self.argnames, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
+        if (self.value) {
+            self.value = self.value.transform(tw);
+        } else {
+            self.body = do_list(self.body, tw);
+        }
+    }
+    DEF(AST_Arrow, transform_arrow);
+    DEF(AST_AsyncArrow, transform_arrow);
+    DEF(AST_Class, function(self, tw) {
+        if (self.name) self.name = self.name.transform(tw);
+        if (self.extends) self.extends = self.extends.transform(tw);
+        self.properties = do_list(self.properties, tw);
+    });
+    DEF(AST_ClassProperty, function(self, tw) {
+        if (self.key instanceof AST_Node) self.key = self.key.transform(tw);
+        if (self.value) self.value = self.value.transform(tw);
+    });
     DEF(AST_Call, function(self, tw) {
         self.expression = self.expression.transform(tw);
         self.args = do_list(self.args, tw);
@@ -138,6 +163,12 @@ TreeTransformer.prototype = new TreeWalker;
     DEF(AST_Sequence, function(self, tw) {
         self.expressions = do_list(self.expressions, tw);
     });
+    DEF(AST_Await, function(self, tw) {
+        self.expression = self.expression.transform(tw);
+    });
+    DEF(AST_Yield, function(self, tw) {
+        if (self.expression) self.expression = self.expression.transform(tw);
+    });
     DEF(AST_Dot, function(self, tw) {
         self.expression = self.expression.transform(tw);
     });
@@ -145,6 +176,9 @@ TreeTransformer.prototype = new TreeWalker;
         self.expression = self.expression.transform(tw);
         self.property = self.property.transform(tw);
     });
+    DEF(AST_Spread, function(self, tw) {
+        self.expression = self.expression.transform(tw);
+    });
     DEF(AST_Unary, function(self, tw) {
         self.expression = self.expression.transform(tw);
     });
@@ -160,12 +194,43 @@ TreeTransformer.prototype = new TreeWalker;
     DEF(AST_Array, function(self, tw) {
         self.elements = do_list(self.elements, tw);
     });
+    DEF(AST_DestructuredArray, function(self, tw) {
+        self.elements = do_list(self.elements, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
+    });
+    DEF(AST_DestructuredKeyVal, function(self, tw) {
+        if (self.key instanceof AST_Node) self.key = self.key.transform(tw);
+        self.value = self.value.transform(tw);
+    });
+    DEF(AST_DestructuredObject, function(self, tw) {
+        self.properties = do_list(self.properties, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
+    });
     DEF(AST_Object, function(self, tw) {
         self.properties = do_list(self.properties, tw);
     });
     DEF(AST_ObjectProperty, function(self, tw) {
+        if (self.key instanceof AST_Node) self.key = self.key.transform(tw);
         self.value = self.value.transform(tw);
     });
+    DEF(AST_ExportDeclaration, function(self, tw) {
+        self.body = self.body.transform(tw);
+    });
+    DEF(AST_ExportDefault, function(self, tw) {
+        self.body = self.body.transform(tw);
+    });
+    DEF(AST_ExportReferences, function(self, tw) {
+        self.properties = do_list(self.properties, tw);
+    });
+    DEF(AST_Import, function(self, tw) {
+        if (self.all) self.all = self.all.transform(tw);
+        if (self.default) self.default = self.default.transform(tw);
+        if (self.properties) self.properties = do_list(self.properties, tw);
+    });
+    DEF(AST_Template, function(self, tw) {
+        if (self.tag) self.tag = self.tag.transform(tw);
+        self.expressions = do_list(self.expressions, tw);
+    });
 })(function(node, descend) {
     node.DEFMETHOD("transform", function(tw, in_list) {
         var x, y;

lib/utils.js

@@ -112,51 +112,29 @@ function return_this() { return this; }
 function return_null() { return null; }
 
 var List = (function() {
-    function List(a, f, backwards) {
-        var ret = [], top = [], i;
-        function doit() {
+    function List(a, f) {
+        var ret = [];
+        for (var i = 0; i < a.length; i++) {
             var val = f(a[i], i);
-            var is_last = val instanceof Last;
-            if (is_last) val = val.v;
-            if (val instanceof AtTop) {
-                val = val.v;
-                if (val instanceof Splice) {
-                    top.push.apply(top, backwards ? val.v.slice().reverse() : val.v);
-                } else {
-                    top.push(val);
-                }
-            } else if (val !== skip) {
-                if (val instanceof Splice) {
-                    ret.push.apply(ret, backwards ? val.v.slice().reverse() : val.v);
-                } else {
-                    ret.push(val);
-                }
-            }
-            return is_last;
-        }
-        if (Array.isArray(a)) {
-            if (backwards) {
-                for (i = a.length; --i >= 0;) if (doit()) break;
-                ret.reverse();
-                top.reverse();
+            if (val === skip) continue;
+            if (val instanceof Splice) {
+                ret.push.apply(ret, val.v);
             } else {
-                for (i = 0; i < a.length; ++i) if (doit()) break;
+                ret.push(val);
             }
-        } else {
-            for (i in a) if (HOP(a, i)) if (doit()) break;
         }
-        return top.concat(ret);
+        return ret;
     }
     List.is_op = function(val) {
-        return val === skip || val instanceof AtTop || val instanceof Last || val instanceof Splice;
+        return val === skip || val instanceof Splice;
+    };
+    List.splice = function(val) {
+        return new Splice(val);
     };
-    List.at_top = function(val) { return new AtTop(val); };
-    List.splice = function(val) { return new Splice(val); };
-    List.last = function(val) { return new Last(val); };
     var skip = List.skip = {};
-    function AtTop(val) { this.v = val; }
-    function Splice(val) { this.v = val; }
-    function Last(val) { this.v = val; }
+    function Splice(val) {
+        this.v = val;
+    }
     return List;
 })();
 
@@ -165,8 +143,9 @@ function push_uniq(array, el) {
 }
 
 function string_template(text, props) {
-    return text.replace(/\{(.+?)\}/g, function(str, p) {
-        return props && props[p];
+    return text.replace(/\{([^}]+)\}/g, function(str, p) {
+        var value = props[p];
+        return value instanceof AST_Node ? value.print_to_string() : value;
     });
 }
 
@@ -259,21 +238,27 @@ function HOP(obj, prop) {
 // return true if the node at the top of the stack (that means the
 // innermost node in the current output) is lexically the first in
 // a statement.
-function first_in_statement(stack) {
+function first_in_statement(stack, arrow, export_default) {
     var node = stack.parent(-1);
     for (var i = 0, p; p = stack.parent(i++); node = p) {
-        if (p.TYPE == "Call") {
-            if (p.expression === node) continue;
+        if (is_arrow(p)) {
+            return arrow && p.value === node;
         } else if (p instanceof AST_Binary) {
             if (p.left === node) continue;
+        } else if (p.TYPE == "Call") {
+            if (p.expression === node) continue;
         } else if (p instanceof AST_Conditional) {
             if (p.condition === node) continue;
+        } else if (p instanceof AST_ExportDefault) {
+            return export_default;
         } else if (p instanceof AST_PropAccess) {
             if (p.expression === node) continue;
         } else if (p instanceof AST_Sequence) {
             if (p.expressions[0] === node) continue;
-        } else if (p instanceof AST_Statement) {
-            return p.body === node;
+        } else if (p instanceof AST_SimpleStatement) {
+            return true;
+        } else if (p instanceof AST_Template) {
+            if (p.tag === node) continue;
         } else if (p instanceof AST_UnaryPostfix) {
             if (p.expression === node) continue;
         }

package.json

@@ -3,7 +3,7 @@
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.10.1",
+  "version": "3.14.1",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -23,7 +23,7 @@
     "LICENSE"
   ],
   "devDependencies": {
-    "acorn": "~7.1.0",
+    "acorn": "~8.2.1",
     "semver": "~6.3.0"
   },
   "scripts": {

test/benchmark.js

@@ -16,7 +16,7 @@ var urls = [
     "https://code.angularjs.org/1.7.8/angular.js",
     "https://unpkg.com/mathjs@6.2.3/dist/math.js",
     "https://unpkg.com/react@15.3.2/dist/react.js",
-    "https://cdnjs.cloudflare.com/ajax/libs/d3/5.12.0/d3.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/d3/6.7.0/d3.js",
     "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.js",
     "https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js",
     "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.12.2/ember.prod.js",

test/compress.js

@@ -1,6 +1,6 @@
 "use strict";
 
-require("../tools/exit");
+require("../tools/tty");
 
 var assert = require("assert");
 var child_process = require("child_process");
@@ -10,33 +10,38 @@ var sandbox = require("./sandbox");
 var semver = require("semver");
 var U = require("./node");
 
-var file = process.argv[2];
+var batch = 50;
 var dir = path.resolve(path.dirname(module.filename), "compress");
-if (file) {
+if (process.argv.length > 3) {
+    var file = process.argv[2];
+    var start = process.argv[3] | 0;
     var minify_options = require("./ufuzz/options.json").map(JSON.stringify);
-    log("--- {file}", { file: file });
     var tests = parse_test(path.resolve(dir, file));
-    process.exit(Object.keys(tests).filter(function(name) {
+    process.exit(Object.keys(tests).slice(start, start + batch).filter(function(name) {
         return !test_case(tests[name]);
     }).length);
 } else {
-    var files = fs.readdirSync(dir).filter(function(name) {
+    var files = process.argv.length == 3 ? [ process.argv[2] ] : fs.readdirSync(dir).filter(function(name) {
         return /\.js$/i.test(name);
     });
     var failures = 0;
     var failed_files = Object.create(null);
-    (function next() {
-        var file = files.shift();
-        if (file) {
-            child_process.spawn(process.argv[0], [ process.argv[1], file ], {
+    (function next(file, start, length) {
+        if (start < length) {
+            child_process.spawn(process.argv[0], [ process.argv[1], file, start, batch ], {
                 stdio: [ "ignore", 1, 2 ]
             }).on("exit", function(code) {
                 if (code) {
                     failures += code;
-                    failed_files[file] = code;
+                    failed_files[file] = true;
                 }
-                next();
+                next(file, start + batch, length);
             });
+        } else if (file = files.shift()) {
+            log("--- {file}", { file: file });
+            start = 0;
+            length = Object.keys(parse_test(path.resolve(dir, file))).length;
+            next(file, start, length);
         } else if (failures) {
             console.error();
             console.error("!!! Failed " + failures + " test case(s).");
@@ -63,7 +68,6 @@ function make_code(ast, options) {
 
 function parse_test(file) {
     var script = fs.readFileSync(file, "utf8");
-    // TODO try/catch can be removed after fixing https://github.com/mishoo/UglifyJS/issues/348
     try {
         var ast = U.parse(script, {
             filename: file
@@ -210,7 +214,7 @@ function reminify(orig_options, input_code, input_formatted, stdout) {
         } else {
             var toplevel = sandbox.has_toplevel(options);
             var expected = stdout[toplevel ? 1 : 0];
-            var actual = run_code(result.code, toplevel);
+            var actual = sandbox.run_code(result.code, toplevel);
             if (typeof expected != "string" && typeof actual != "string" && expected.name == actual.name) {
                 actual = expected;
             }
@@ -245,11 +249,6 @@ function reminify(orig_options, input_code, input_formatted, stdout) {
     return true;
 }
 
-function run_code(code, toplevel) {
-    var result = sandbox.run_code(code, toplevel);
-    return typeof result == "string" ? result.replace(/\u001b\[\d+m/g, "") : result;
-}
-
 function test_case(test) {
     log("    Running test [{name}]", { name: test.name });
     U.AST_Node.enable_validation();
@@ -263,6 +262,7 @@ function test_case(test) {
     var input = to_toplevel(test.input, test.mangle);
     var input_code = make_code(input);
     var input_formatted = make_code(test.input, {
+        annotations: true,
         beautify: true,
         comments: "all",
         keep_quoted_props: true,
@@ -312,11 +312,10 @@ function test_case(test) {
     if (test.mangle) {
         output.compute_char_frequency(test.mangle);
         output.mangle_names(test.mangle);
-        if (test.mangle.properties) {
-            output = U.mangle_properties(output, test.mangle.properties);
-        }
+        if (test.mangle.properties) U.mangle_properties(output, test.mangle.properties);
     }
     var output_code = make_code(output, output_options);
+    U.AST_Node.log_function();
     if (expect != output_code) {
         log([
             "!!! failed",
@@ -382,13 +381,13 @@ function test_case(test) {
         }
     }
     if (test.expect_stdout && (!test.node_version || semver.satisfies(process.version, test.node_version))) {
-        var stdout = [ run_code(input_code), run_code(input_code, true) ];
+        var stdout = [ sandbox.run_code(input_code), sandbox.run_code(input_code, true) ];
         var toplevel = sandbox.has_toplevel({
             compress: test.options,
             mangle: test.mangle
         });
         var actual = stdout[toplevel ? 1 : 0];
-        if (test.expect_stdout === true) {
+        if (test.expect_stdout === true || test.expect_stdout instanceof Error && test.expect_stdout.name === actual.name) {
             test.expect_stdout = actual;
         }
         if (!sandbox.same_stdout(test.expect_stdout, actual)) {
@@ -411,7 +410,7 @@ function test_case(test) {
             });
             return false;
         }
-        actual = run_code(output_code, toplevel);
+        actual = sandbox.run_code(output_code, toplevel);
         if (!sandbox.same_stdout(test.expect_stdout, actual)) {
             log([
                 "!!! failed",

test/compress/annotations.js

@@ -0,0 +1,474 @@
+issue_2629_1: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ a();
+        /*@__PURE__*/ (b());
+        (/*@__PURE__*/ c)();
+        (/*@__PURE__*/ d());
+    }
+    expect_exact: "c();"
+}
+
+issue_2629_2: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ a(1)(2)(3);
+        /*@__PURE__*/ (b(1))(2)(3);
+        /*@__PURE__*/ (c(1)(2))(3);
+        /*@__PURE__*/ (d(1)(2)(3));
+        (/*@__PURE__*/ e)(1)(2)(3);
+        (/*@__PURE__*/ f(1))(2)(3);
+        (/*@__PURE__*/ g(1)(2))(3);
+        (/*@__PURE__*/ h(1)(2)(3));
+    }
+    expect_exact: [
+        "e(1)(2)(3);",
+        "f(1)(2)(3);",
+        "g(1)(2)(3);",
+    ]
+}
+
+issue_2629_3: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ a.x(1).y(2).z(3);
+        /*@__PURE__*/ (b.x)(1).y(2).z(3);
+        /*@__PURE__*/ (c.x(1)).y(2).z(3);
+        /*@__PURE__*/ (d.x(1).y)(2).z(3);
+        /*@__PURE__*/ (e.x(1).y(2)).z(3);
+        /*@__PURE__*/ (f.x(1).y(2).z)(3);
+        /*@__PURE__*/ (g.x(1).y(2).z(3));
+        (/*@__PURE__*/ h).x(1).y(2).z(3);
+        (/*@__PURE__*/ i.x)(1).y(2).z(3);
+        (/*@__PURE__*/ j.x(1)).y(2).z(3);
+        (/*@__PURE__*/ k.x(1).y)(2).z(3);
+        (/*@__PURE__*/ l.x(1).y(2)).z(3);
+        (/*@__PURE__*/ m.x(1).y(2).z)(3);
+        (/*@__PURE__*/ n.x(1).y(2).z(3));
+    }
+    expect_exact: [
+        "h.x(1).y(2).z(3);",
+        "i.x(1).y(2).z(3);",
+        "j.x(1).y(2).z(3);",
+        "k.x(1).y(2).z(3);",
+        "l.x(1).y(2).z(3);",
+        "m.x(1).y(2).z(3);",
+    ]
+}
+
+issue_2629_4: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    input: {
+        (/*@__PURE__*/ x(), y());
+        (w(), /*@__PURE__*/ x(), y());
+    }
+    expect: {
+        y();
+        w(), y();
+    }
+}
+
+issue_2629_5: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    input: {
+        [ /*@__PURE__*/ x() ];
+        [ /*@__PURE__*/ x(), y() ];
+        [ w(), /*@__PURE__*/ x(), y() ];
+    }
+    expect: {
+        y();
+        w(), y();
+    }
+}
+
+issue_2638: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/(g() || h())(x(), y());
+        (/*@__PURE__*/ (a() || b()))(c(), d());
+    }
+    expect_exact: [
+        "x(),y();",
+        "(a()||b())(c(),d());",
+    ]
+}
+
+issue_2705_1: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ new a();
+        /*@__PURE__*/ (new b());
+        new (/*@__PURE__*/ c)();
+        (/*@__PURE__*/ new d());
+    }
+    expect_exact: [
+        "new c;",
+    ]
+}
+
+issue_2705_2: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ new a(1)(2)(3);
+        /*@__PURE__*/ new (b(1))(2)(3);
+        /*@__PURE__*/ new (c(1)(2))(3);
+        /*@__PURE__*/ new (d(1)(2)(3));
+        new (/*@__PURE__*/ e)(1)(2)(3);
+        (/*@__PURE__*/ new f(1))(2)(3);
+        (/*@__PURE__*/ new g(1)(2))(3);
+        (/*@__PURE__*/ new h(1)(2)(3));
+    }
+    expect_exact: [
+        "new e(1)(2)(3);",
+        "new f(1)(2)(3);",
+        "new g(1)(2)(3);",
+    ]
+}
+
+issue_2705_3: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ new a.x(1).y(2).z(3);
+        /*@__PURE__*/ new (b.x)(1).y(2).z(3);
+        /*@__PURE__*/ new (c.x(1)).y(2).z(3);
+        /*@__PURE__*/ new (d.x(1).y)(2).z(3);
+        /*@__PURE__*/ new (e.x(1).y(2)).z(3);
+        /*@__PURE__*/ new (f.x(1).y(2).z)(3);
+        /*@__PURE__*/ new (g.x(1).y(2).z(3));
+        new (/*@__PURE__*/ h).x(1).y(2).z(3);
+        /* */ new (/*@__PURE__*/ i.x)(1).y(2).z(3);
+        (/*@__PURE__*/ new j.x(1)).y(2).z(3);
+        (/*@__PURE__*/ new k.x(1).y)(2).z(3);
+        (/*@__PURE__*/ new l.x(1).y(2)).z(3);
+        (/*@__PURE__*/ new m.x(1).y(2).z)(3);
+        (/*@__PURE__*/ new n.x(1).y(2).z(3));
+    }
+    expect_exact: [
+        "new h.x(1).y(2).z(3);",
+        "/* */new i.x(1).y(2).z(3);",
+        "new j.x(1).y(2).z(3);",
+        "new k.x(1).y(2).z(3);",
+        "new l.x(1).y(2).z(3);",
+        "new m.x(1).y(2).z(3);",
+    ]
+}
+
+issue_2705_4: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    input: {
+        (/*@__PURE__*/ new x(), y());
+        (w(), /*@__PURE__*/ new x(), y());
+    }
+    expect: {
+        y();
+        w(), y();
+    }
+}
+
+issue_2705_5: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    input: {
+        [ /*@__PURE__*/ new x() ];
+        [ /*@__PURE__*/ new x(), y() ];
+        [ w(), /*@__PURE__*/ new x(), y() ];
+    }
+    expect: {
+        y();
+        w(), y();
+    }
+}
+
+issue_2705_6: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/new (g() || h())(x(), y());
+        /* */ new (/*@__PURE__*/ (a() || b()))(c(), d());
+    }
+    expect_exact: [
+        "x(),y();",
+        "/* */new(a()||b())(c(),d());",
+    ]
+}
+
+issue_3858: {
+    options = {
+        annotations: true,
+        collapse_vars: true,
+        inline: true,
+        keep_fargs: false,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var f = function(a) {
+            return /*@__PURE__*/ function(b) {
+                console.log(b);
+            }(a);
+        };
+        f("PASS");
+    }
+    expect: {
+        var f = function(a) {
+            return function() {
+                console.log(a);
+            }();
+        };
+        f("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+inline_pure_call_1: {
+    options = {
+        annotations: true,
+        collapse_vars: true,
+        inline: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var f = function(a) {
+            return /*@__PURE__*/ function(b) {
+                console.log(b);
+            }(a);
+        };
+        f("PASS");
+    }
+    expect: {}
+}
+
+inline_pure_call_2: {
+    options = {
+        annotations: true,
+        collapse_vars: true,
+        inline: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var f = function(a) {
+            return /*@__PURE__*/ function(b) {
+                console.log(b);
+            }(a);
+        };
+        var a = f("PASS");
+    }
+    expect: {}
+}
+
+inline_pure_call_3: {
+    options = {
+        annotations: true,
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        keep_fargs: false,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var f = function(a) {
+            return /*@__PURE__*/ function(b) {
+                console.log(b);
+            }(a);
+        };
+        var a = f("PASS");
+        console.log(a);
+    }
+    expect: {
+        var a = function() {
+            console.log("PASS");
+        }();
+        console.log(a);
+    }
+    expect_stdout: [
+        "PASS",
+        "undefined",
+    ]
+}
+
+inline_pure_call_4: {
+    options = {
+        annotations: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = /*@__PURE__*/ function() {
+            return console.log("PASS"), 42;
+        }();
+        console.log(a);
+    }
+    expect: {
+        var a = function() {
+            return console.log("PASS"), 42;
+        }();
+        console.log(a);
+    }
+    expect_stdout: [
+        "PASS",
+        "42",
+    ]
+}
+
+compress_and_output_annotations_enabled: {
+    options = {
+        annotations: true,
+        side_effects: true,
+    }
+    beautify = {
+        annotations: true,
+        beautify: true,
+        comments: false,
+    }
+    input: {
+        var top = /*@__PURE__*/ foo();
+        /*@__PURE__*/ a(1)(2)(3);
+        /*@__PURE__*/ (b(1))(2)(3);
+        /*@__PURE__*/ (c(1)(2))(3);
+        /*@__PURE__*/ (d(1)(2)(3));
+        (/*@__PURE__*/ e)(1)(2)(3);
+        (/*@__PURE__*/ f(1))(2)(3);
+        (/*@__PURE__*/ g(1)(2))(3);
+        (/*@__PURE__*/ h(1)(2)(3));
+        /*@__PURE__*/ l(1).p(2);
+        (/*@__PURE__*/ m(1)).p(2);
+        (/*@__PURE__*/ n(1).p)(2);
+        (/*@__PURE__*/ o(1).p(2));
+    }
+    expect_exact: [
+        "var top = /*@__PURE__*/foo();",
+        "",
+        "e(1)(2)(3);",
+        "",
+        "f(1)(2)(3);",
+        "",
+        "g(1)(2)(3);",
+        "",
+        "m(1).p(2);",
+        "",
+        "n(1).p(2);",
+    ]
+}
+
+compress_annotations_disabled_output_annotations_enabled: {
+    options = {
+        annotations: false,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    beautify = {
+        annotations: true,
+        comments: true,
+    }
+    input: {
+        /*@__PURE__*/ a(1+2);
+        /*#__PURE__*/ (b(2+3));
+        (/*@__PURE__*/ c)(side_effect);
+        (/*#__PURE__*/ d(effect()));
+    }
+    expect_exact: [
+        "/*@__PURE__*/a(3),",
+        "/*#__PURE__*/b(5),",
+        "c(side_effect),",
+        "/*#__PURE__*/d(effect());",
+    ]
+}
+
+compress_and_output_annotations_disabled: {
+    options = {
+        annotations: false,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    beautify = {
+        annotations: false,
+        comments: true,
+    }
+    input: {
+        /*@__PURE__*/ a(1+2);
+        /*@__PURE__*/ (b(2+3));
+        (/*@__PURE__*/ c)(side_effect);
+        (/*@__PURE__*/ d(effect()));
+    }
+    expect_exact: [
+        "a(3),",
+        "b(5),",
+        "c(side_effect),",
+        "d(effect());",
+    ]
+}

test/compress/arguments.js

@@ -78,12 +78,13 @@ replace_index_strict: {
     ]
 }
 
-replace_index_keep_fargs: {
+replace_index_drop_fargs_1: {
     options = {
         arguments: true,
         evaluate: true,
         keep_fargs: false,
         properties: true,
+        reduce_vars: true,
     }
     input: {
         var arguments = [];
@@ -101,6 +102,13 @@ replace_index_keep_fargs: {
             var arguments;
             console.log(arguments[1], arguments["1"], arguments["foo"]);
         })("bar", 42);
+        (function() {
+            var arguments = {
+                1: "foo",
+                foo: "bar",
+            };
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
     }
     expect: {
         var arguments = [];
@@ -112,10 +120,17 @@ replace_index_keep_fargs: {
             console.log(b, b, arguments.foo);
         })("bar", 42);
         (function(arguments) {
-            console.log(arguments[1], arguments[1], arguments.foo);
+            console.log("bar"[1], "bar"[1], "bar".foo);
+        })("bar", 42);
+        (function(argument_0, argument_1) {
+            var arguments;
+            console.log(argument_1, argument_1, arguments.foo);
         })("bar", 42);
         (function() {
-            var arguments;
+            var arguments = {
+                1: "foo",
+                foo: "bar",
+            };
             console.log(arguments[1], arguments[1], arguments.foo);
         })("bar", 42);
     }
@@ -125,10 +140,11 @@ replace_index_keep_fargs: {
         "42 42 undefined",
         "a a undefined",
         "42 42 undefined",
+        "foo foo bar",
     ]
 }
 
-replace_index_keep_fargs_strict: {
+replace_index_drop_fargs_2: {
     options = {
         arguments: true,
         evaluate: true,
@@ -238,6 +254,25 @@ duplicate_argname: {
     expect_stdout: "bar 42 foo 42 bar"
 }
 
+fraction: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            return arguments[0.3];
+        }("FAIL") || "PASS");
+    }
+    expect: {
+        console.log(function() {
+            return arguments[0.3];
+        }("FAIL") || "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
 issue_3273: {
     options = {
         arguments: true,
@@ -412,7 +447,7 @@ issue_3273_global_strict_reduce_vars: {
     ]
 }
 
-issue_3273_keep_fargs_false: {
+issue_3273_drop_fargs_1: {
     options = {
         arguments: true,
         keep_fargs: false,
@@ -435,10 +470,10 @@ issue_3273_keep_fargs_false: {
     expect_stdout: "1"
 }
 
-issue_3273_keep_fargs_strict: {
+issue_3273_drop_fargs_2: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
     }
     input: {
@@ -633,7 +668,8 @@ issue_3282_2_passes: {
 issue_3420_1: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         console.log(function() {
@@ -655,7 +691,8 @@ issue_3420_1: {
 issue_3420_2: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         var foo = function() {
@@ -675,7 +712,8 @@ issue_3420_2: {
 issue_3420_3: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         "use strict";
@@ -697,7 +735,8 @@ issue_3420_3: {
 issue_3420_4: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         !function() {
@@ -722,7 +761,8 @@ issue_3420_4: {
 issue_3420_5: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         "use strict";
@@ -749,7 +789,8 @@ issue_3420_5: {
 issue_3420_6: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         console.log(function() {
@@ -767,7 +808,8 @@ issue_3420_6: {
 issue_3420_7: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         "use strict";
@@ -783,3 +825,230 @@ issue_3420_7: {
     }
     expect_stdout: "true"
 }
+
+issue_4200: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+    }
+    input: {
+        var o = {
+            get p() {
+                return arguments[0];
+            },
+        };
+        console.log(o.p);
+    }
+    expect: {
+        var o = {
+            get p() {
+                return arguments[0];
+            },
+        };
+        console.log(o.p);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4291_1: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            arguments[0] = "PASS";
+            return arguments;
+        }()[0]);
+    }
+    expect: {
+        console.log(function() {
+            arguments[0] = "PASS";
+            return arguments;
+        }()[0]);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4291_2: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        var a = function() {
+            if (arguments[0])
+                arguments[1] = "PASS";
+            return arguments;
+        }(42);
+        console.log(a[1], a[0], a.length);
+    }
+    expect: {
+        var a = function() {
+            if (arguments[0])
+                arguments[1] = "PASS";
+            return arguments;
+        }(42);
+        console.log(a[1], a[0], a.length);
+    }
+    expect_stdout: "PASS 42 1"
+}
+
+issue_4397: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(typeof function() {
+            arguments += 0;
+            return arguments[0];
+        }());
+    }
+    expect: {
+        console.log(typeof function() {
+            arguments += 0;
+            return arguments[0];
+        }());
+    }
+    expect_stdout: "string"
+}
+
+issue_4410_1: {
+    options = {
+        arguments: true,
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            console.log(arguments[0] === (a = 0) ? "FAIL" : "PASS");
+        })(1);
+    }
+    expect: {
+        (function(a) {
+            console.log(a === (a = 0) ? "FAIL" : "PASS");
+        })(1);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4410_2: {
+    options = {
+        arguments: true,
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function f(a) {
+            console.log(arguments[0] === (a = 0) ? "FAIL" : "PASS");
+        })(1);
+    }
+    expect: {
+        (function f(a) {
+            console.log(arguments[0] === (a = 0) ? "FAIL" : "PASS");
+        })(1);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4410_3: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        var a = 1;
+        (function f(b) {
+            a-- && f();
+            for (var c = 2; c--;)
+                switch (arguments[0]) {
+                  case b = 42:
+                  case 42:
+                    console.log("PASS");
+                }
+        })(null);
+    }
+    expect: {
+        var a = 1;
+        (function f(b) {
+            a-- && f();
+            for (var c = 2; c--;)
+                switch (arguments[0]) {
+                  case b = 42:
+                  case 42:
+                    console.log("PASS");
+                }
+        })(null);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4432: {
+    options = {
+        arguments: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            for (a in { FAIL: 42 });
+            return arguments[0];
+        }() || "PASS");
+    }
+    expect: {
+        console.log(function(a) {
+            for (a in { FAIL: 42 });
+            return arguments[0];
+        }() || "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4696: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+    }
+    input: {
+        console.log(function() {
+            for (arguments in [ 42 ]);
+            for (var a in arguments[0])
+                return "PASS";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            for (arguments in [ 42 ]);
+            for (var a in arguments[0])
+                return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4809: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        A = 0;
+        (function() {
+            arguments[A] = "PASS";
+            console.log(arguments[0]);
+        })();
+    }
+    expect: {
+        A = 0;
+        (function() {
+            arguments[A] = "PASS";
+            console.log(arguments[0]);
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/arrays.js

@@ -13,9 +13,10 @@ holes_and_undefined: {
     }
 }
 
-constant_join: {
+constant_join_1: {
     options = {
         evaluate: true,
+        side_effects: true,
         strings: true,
         unsafe: true,
     }
@@ -57,7 +58,7 @@ constant_join: {
         var c5 = [ boo() + bar() + "foo", 1, 2, 3, "bar", bar() + "foo" ].join();
         var c6 = [ "1,2,,,foo,bar", baz() ].join();
         var d = "foo-3bar-baz";
-        var e = [].join(foo + bar);
+        var e = (foo, bar, "");
         var f = "";
         var g = "";
     }
@@ -354,3 +355,72 @@ constructor_good: {
     expect_stdout: true
     expect_warnings: []
 }
+
+unsafe_evaluate_modified_binary: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        (function(a) {
+            (console && a).push(1);
+            if (a.length)
+                console.log("PASS");
+        })([]);
+    }
+    expect: {
+        (function(a) {
+            (console && a).push(1);
+            if (a.length)
+                console.log("PASS");
+        })([]);
+    }
+    expect_stdout: "PASS"
+}
+
+unsafe_evaluate_modified_conditional: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        (function(a) {
+            (console ? a : []).push(1);
+            if (a.length)
+                console.log("PASS");
+        })([]);
+    }
+    expect: {
+        (function(a) {
+            (console ? a : []).push(1);
+            if (a.length)
+                console.log("PASS");
+        })([]);
+    }
+    expect_stdout: "PASS"
+}
+
+unsafe_evaluate_modified_sequence: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        (function(a) {
+            (0, a).push(1);
+            if (a.length)
+                console.log("PASS");
+        })([]);
+    }
+    expect: {
+        (function(a) {
+            (0, a).push(1);
+            if (a.length)
+                console.log("PASS");
+        })([]);
+    }
+    expect_stdout: "PASS"
+}

test/compress/arrows.js

@@ -0,0 +1,886 @@
+no_funarg: {
+    input: {
+        (() => console.log(42))();
+    }
+    expect_exact: "(()=>console.log(42))();"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+single_funarg: {
+    input: {
+        (a => console.log(a))(42);
+    }
+    expect_exact: "(a=>console.log(a))(42);"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+multiple_funargs: {
+    input: {
+        ((a, b) => console.log(a, b))("foo", "bar");
+    }
+    expect_exact: '((a,b)=>console.log(a,b))("foo","bar");'
+    expect_stdout: "foo bar"
+    node_version: ">=4"
+}
+
+destructured_funarg: {
+    input: {
+        (([ a, b, c ]) => console.log(a, b, c))("foo");
+    }
+    expect_exact: '(([a,b,c])=>console.log(a,b,c))("foo");'
+    expect_stdout: "f o o"
+    node_version: ">=6"
+}
+
+await_parentheses: {
+    input: {
+        async function f() {
+            await (a => a);
+        }
+    }
+    expect_exact: "async function f(){await(a=>a)}"
+}
+
+for_parentheses_init: {
+    input: {
+        for (a => (a in a); console.log(42););
+    }
+    expect_exact: "for((a=>a in a);console.log(42););"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+for_parentheses_condition: {
+    input: {
+        for (console.log(42); a => (a in a);)
+            break;
+    }
+    expect_exact: "for(console.log(42);a=>a in a;)break;"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+for_parentheses_step: {
+    input: {
+        for (; console.log(42); a => (a in a));
+    }
+    expect_exact: "for(;console.log(42);a=>a in a);"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+for_assign_parentheses_init: {
+    input: {
+        for (f = a => (a in a); console.log(42););
+    }
+    expect_exact: "for((f=a=>a in a);console.log(42););"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+for_assign_parentheses_condition: {
+    input: {
+        for (console.log(42); f = a => (a in a);)
+            break;
+    }
+    expect_exact: "for(console.log(42);f=a=>a in a;)break;"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+for_assign_parentheses_step: {
+    input: {
+        for (; console.log(42); f = a => (a in a));
+    }
+    expect_exact: "for(;console.log(42);f=a=>a in a);"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+for_declaration_parentheses_init: {
+    input: {
+        for (var f = a => (a in a); console.log(42););
+    }
+    expect_exact: "for(var f=(a=>a in a);console.log(42););"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+for_statement_parentheses_init: {
+    input: {
+        for (a => {
+            a in a;
+        }; console.log(42););
+    }
+    expect_exact: "for(a=>{a in a};console.log(42););"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+body_call: {
+    input: {
+        (() => {
+            console.log("foo");
+            console.log("bar");
+        })();
+    }
+    expect_exact: '(()=>{console.log("foo");console.log("bar")})();'
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    node_version: ">=4"
+}
+
+body_conditional: {
+    input: {
+        console.log((a => {}) ? "PASS" : "FAIL");
+    }
+    expect_exact: 'console.log((a=>{})?"PASS":"FAIL");'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+destructured_object_value: {
+    input: {
+        console.log((a => ({} = a))(42));
+    }
+    expect_exact: "console.log((a=>({}=a))(42));"
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+function_value: {
+    input: {
+        console.log((a => function() {
+            return a;
+        })(42)());
+    }
+    expect_exact: "console.log((a=>function(){return a})(42)());"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+in_value: {
+    input: {
+        console.log((a => a in {
+            foo: 42,
+        })("foo"));
+    }
+    expect_exact: 'console.log((a=>a in{foo:42})("foo"));'
+    expect_stdout: "true"
+    node_version: ">=4"
+}
+
+object_value: {
+    input: {
+        console.log((() => ({
+            4: 2,
+        }))()[4]);
+    }
+    expect_exact: "console.log((()=>({4:2}))()[4]);"
+    expect_stdout: "2"
+    node_version: ">=4"
+}
+
+object_first_in_value: {
+    input: {
+        console.log((a => ({
+            p: a,
+        }.p ? "FAIL" : "PASS"))());
+    }
+    expect_exact: 'console.log((a=>({p:a}).p?"FAIL":"PASS")());'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+sequence_value: {
+    input: {
+        console.log((a => (console.log("foo"), a))("bar"));
+    }
+    expect_exact: 'console.log((a=>(console.log("foo"),a))("bar"));'
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    node_version: ">=4"
+}
+
+side_effects_value: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        console.log((a => function() {
+            return a;
+        })(42)());
+    }
+    expect: {
+        console.log((a => function() {
+            return a;
+        })(42)());
+    }
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+arrow_property: {
+    input: {
+        console.log((a => 42).prototype);
+    }
+    expect_exact: "console.log((a=>42).prototype);"
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+assign_arrow: {
+    input: {
+        var f = a => a;
+        console.log(f(42));
+    }
+    expect_exact: "var f=a=>a;console.log(f(42));"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+binary_arrow: {
+    input: {
+        console.log(4 || (() => 2));
+    }
+    expect_exact: "console.log(4||(()=>2));"
+    expect_stdout: "4"
+    node_version: ">=4"
+}
+
+unary_arrow: {
+    input: {
+        console.log(+(() => 42));
+    }
+    expect_exact: "console.log(+(()=>42));"
+    expect_stdout: "NaN"
+    node_version: ">=4"
+}
+
+trailing_comma: {
+    input: {
+        ((a,) => console.log(a))(42);
+    }
+    expect_exact: "(a=>console.log(a))(42);"
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+drop_arguments: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            return () => arguments[0];
+        }("PASS")("FAIL"));
+    }
+    expect: {
+        console.log(function(argument_0) {
+            return () => argument_0;
+        }("PASS")("FAIL"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+funarg_arguments: {
+    options = {
+        inline: true,
+    }
+    input: {
+        console.log((arguments => arguments)(42));
+    }
+    expect: {
+        console.log(42);
+    }
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+inline_arguments: {
+    options = {
+        inline: true,
+    }
+    input: {
+        console.log(function() {
+            return () => arguments[0];
+        }("PASS")("FAIL"));
+    }
+    expect: {
+        console.log(function() {
+            return () => arguments[0];
+        }("PASS")("FAIL"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+var_arguments: {
+    options = {
+        inline: true,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            return () => {
+                var arguments = [ "PASS" ];
+                return arguments;
+            };
+        }("FAIL 1")("FAIL 2")[0]);
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+negate: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        if (!console ? 0 : () => 1)
+            console.log("PASS");
+    }
+    expect: {
+        (console ? () => 1 : 0) && console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+inline_this: {
+    options = {
+        inline: true,
+    }
+    input: {
+        var o = {
+            p: function() {
+                return function() {
+                    return () => this.q;
+                }();
+            },
+            q: "FAIL",
+        };
+        q = "PASS";
+        console.log(o.p()());
+    }
+    expect: {
+        var o = {
+            p: function() {
+                return function() {
+                    return () => this.q;
+                }();
+            },
+            q: "FAIL",
+        };
+        q = "PASS";
+        console.log(o.p()());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+trim_body: {
+    options = {
+        arrows: true,
+        if_return: true,
+        side_effects: true,
+    }
+    input: {
+        var f = a => {
+            return a;
+        };
+        var g = b => void b;
+        console.log(f("PASS"), g("FAIL"));
+    }
+    expect: {
+        var f = a => a;
+        var g = b => {};
+        console.log(f("PASS"), g("FAIL"));
+    }
+    expect_stdout: "PASS undefined"
+    node_version: ">=4"
+}
+
+collapse_value: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        keep_fargs: false,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = 42;
+        console.log((b => Math.floor(b))(a));
+    }
+    expect: {
+        var a = 42;
+        console.log((() => Math.floor(a))());
+    }
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+collapse_property_lambda: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+    }
+    input: {
+        console.log(function f() {
+            f.g = () => 42;
+            return f.g();
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            return (f.g = () => 42)();
+        }());
+    }
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+drop_return: {
+    options = {
+        arrows: true,
+        side_effects: true,
+    }
+    input: {
+        (a => {
+            while (!console);
+            return console.log(a);
+        })(42);
+    }
+    expect: {
+        (a => {
+            while (!console);
+            console.log(a);
+        })(42);
+    }
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+drop_value: {
+    options = {
+        arrows: true,
+        side_effects: true,
+    }
+    input: {
+        ((a, b) => a + b)(console.log(42));
+    }
+    expect: {
+        ((a, b) => {})(console.log(42));
+    }
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+reduce_iife_1: {
+    options = {
+        evaluate: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (a => console.log(a + a))(21);
+    }
+    expect: {
+        (() => console.log(42))();
+    }
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+reduce_iife_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 21;
+        (() => console.log(a + a))();
+    }
+    expect: {
+        (() => console.log(42))();
+    }
+    expect_stdout: "42"
+    node_version: ">=4"
+}
+
+reduce_iife_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "foo";
+        (() => {
+            console.log(a);
+            console.log(a);
+        })();
+        a = "bar";
+    }
+    expect: {
+        (() => {
+            console.log("foo");
+            console.log("foo");
+        })();
+    }
+    expect_stdout: [
+        "foo",
+        "foo",
+    ]
+    node_version: ">=4"
+}
+
+reduce_lambda_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var f = () => {
+            console.log(a, b);
+        };
+        var a = "foo", b = 42;
+        f();
+        b = "bar";
+        f();
+    }
+    expect: {
+        var f = () => {
+            console.log("foo", b);
+        };
+        var b = 42;
+        f();
+        b = "bar";
+        f();
+    }
+    expect_stdout: [
+        "foo 42",
+        "foo bar",
+    ]
+    node_version: ">=4"
+}
+
+reduce_lambda_2: {
+    options = {
+        evaluate: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function(f, a, b) {
+            f = () => {
+                console.log(a, b);
+            };
+            a = "foo", b = 42;
+            f();
+            b = "bar";
+            f();
+        })();
+    }
+    expect: {
+        (function(f, a, b) {
+            f = () => {
+                console.log("foo", b);
+            };
+            b = 42;
+            f();
+            b = "bar";
+            f();
+        })();
+    }
+    expect_stdout: [
+        "foo 42",
+        "foo bar",
+    ]
+    node_version: ">=4"
+}
+
+single_use_recursive: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return (() => f)();
+        }
+        console.log(typeof f());
+    }
+    expect: {
+        console.log(typeof function f() {
+            return (() => f)();
+        }());
+    }
+    expect_stdout: "function"
+    node_version: ">=4"
+}
+
+issue_4388: {
+    options = {
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        (arguments => console.log(arguments && arguments))();
+    }
+    expect: {
+        (arguments => console.log(arguments && arguments))();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_4390: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        function log() {
+            console.log.apply(console, arguments);
+        }
+        var a = 42, b = "FAIL";
+        b = "PASS";
+        (c => log(b, c))(a);
+        log(b);
+    }
+    expect: {
+        function log() {
+            console.log.apply(console, arguments);
+        }
+        var a = 42, b = "FAIL";
+        b = "PASS";
+        (c => log(b, c))(a);
+        log(b);
+    }
+    expect_stdout: [
+        "PASS 42",
+        "PASS",
+    ]
+    node_version: ">=4"
+}
+
+issue_4401: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        (function() {
+            var a = (b => b(a))(console.log || a);
+            var c = console.log;
+            c && c(typeof b);
+        })();
+    }
+    expect: {
+        (function() {
+            var a = (b => b(a))(console.log || a);
+            var c = console.log;
+            c && c(typeof b);
+        })();
+    }
+    expect_stdout: [
+        "undefined",
+        "undefined",
+    ]
+    node_version: ">=4"
+}
+
+issue_4448: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        var A;
+        try {
+            (arguments => {
+                arguments[0];
+            })(A);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        var A;
+        try {
+            (arguments => {
+                arguments[0];
+            })(A);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4476: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        (function(a, b) {
+            (a => {
+                console.log(arguments[0], a);
+            })(b);
+        })("foo", "bar");
+    }
+    expect: {
+        (function(a, b) {
+            (a => {
+                console.log(arguments[0], a);
+            })(b);
+        })("foo", "bar");
+    }
+    expect_stdout: "foo bar"
+    node_version: ">=4"
+}
+
+issue_4666: {
+    input: {
+        console.log((a => /[0-9]/.test(a))(42));
+    }
+    expect_exact: "console.log((a=>/[0-9]/.test(a))(42));"
+    expect_stdout: "true"
+    node_version: ">=4"
+}
+
+issue_4685_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        new function(f) {
+            if (f() !== this)
+                console.log("PASS");
+        }(() => this);
+    }
+    expect: {
+        new function(f) {
+            if (f() !== this)
+                console.log("PASS");
+        }(() => this);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4685_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        new function(f) {
+            if (f() !== this)
+                console.log("PASS");
+        }(() => {
+            if (console)
+                return this;
+        });
+    }
+    expect: {
+        new function(f) {
+            if (f() !== this)
+                console.log("PASS");
+        }(() => {
+            if (console)
+                return this;
+        });
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4687_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        new function() {
+            console.log(function(f) {
+                return f() === this;
+            }(() => this) || "PASS");
+        }
+    }
+    expect: {
+        new function() {
+            console.log(function(f) {
+                return f() === this;
+            }(() => this) || "PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4687_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        new function() {
+            console.log(function(f) {
+                return f() === this;
+            }(() => {
+                if (console)
+                    return this;
+            }) || "PASS");
+        }
+    }
+    expect: {
+        new function() {
+            console.log(function(f) {
+                return f() === this;
+            }(() => {
+                if (console)
+                    return this;
+            }) || "PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4772: {
+    input: {
+        var f = a => (a)
+        /**/ console.log(f("PASS"));
+    }
+    expect_exact: 'var f=a=>a;console.log(f("PASS"));'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}

test/compress/ascii.js

@@ -1,35 +0,0 @@
-ascii_only_true: {
-    options = {}
-    beautify = {
-        ascii_only : true,
-        ie8        : false,
-        beautify   : false,
-    }
-    input: {
-        function f() {
-            return "\x000\x001\x007\x008\x00" +
-                   "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
-                   "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
-                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
-        }
-    }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\x008\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\f\\r\\x0e\\x0f"+"\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f"+\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\'}'
-}
-
-ascii_only_false: {
-    options = {}
-    beautify = {
-        ascii_only : false,
-        ie8        : false,
-        beautify   : false,
-    }
-    input: {
-        function f() {
-            return "\x000\x001\x007\x008\x00" +
-                   "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
-                   "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
-                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
-        }
-    }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\x008\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\f\\r\x0e\x0f"+"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"+\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
-}

test/compress/asm.js

@@ -76,9 +76,8 @@ asm_mixed: {
                 start = start | 0;
                 end = end | 0;
                 var sum = 0.0, p = 0, q = 0;
-                for (p = start << 3, q = end << 3; (p | 0) < (q | 0); p = p + 8 | 0) {
+                for (p = start << 3, q = end << 3; (p | 0) < (q | 0); p = p + 8 | 0)
                     sum = sum + +log(values[p >> 3]);
-                }
                 return +sum;
             }
             function geometricMean(start, end) {
@@ -91,11 +90,12 @@ asm_mixed: {
         function no_asm_GeometricMean(stdlib, foreign, buffer) {
             function logSum(start, end) {
                 start |= 0, end |= 0;
-                for (var sum = 0, p = 0, q = 0, p = start << 3, q = end << 3; (0 | p) < (0 | q); p = p + 8 | 0) sum += +log(values[p >> 3]);
+                for (var sum = 0, p = 0, q = 0, p = start << 3, q = end << 3; (0 | p) < (0 | q); p = p + 8 | 0)
+                    sum += +log(values[p >> 3]);
                 return +sum;
             }
             function geometricMean(start, end) {
-                return start |= 0, end |= 0, +exp(logSum(start, end) / (end - start | 0));
+                return start |= 0, end |= 0, +exp(+logSum(start, end) / (end - start | 0));
             }
             var exp = stdlib.Math.exp, log = stdlib.Math.log, values = new stdlib.Float64Array(buffer);
             return { geometricMean: geometricMean };

test/compress/assignments.js

@@ -461,3 +461,288 @@ issue_3949_2: {
     }
     expect_stdout: "100"
 }
+
+issue_4521: {
+    options = {
+        assignments: true,
+        dead_code: true,
+    }
+    input: {
+        var a = (a = 42 | a) ? console.log(a) : 0;
+    }
+    expect: {
+        var a = (a |= 42) ? console.log(a) : 0;
+    }
+    expect_stdout: "42"
+}
+
+logical_assignments: {
+    input: {
+        var a = 42, b = null, c;
+        a &&= "foo";
+        b ||= "bar";
+        c ??= "baz";
+        console.log(a, b, c);
+    }
+    expect_exact: 'var a=42,b=null,c;a&&="foo";b||="bar";c??="baz";console.log(a,b,c);'
+    expect_stdout: "foo bar baz"
+    node_version: ">=15"
+}
+
+logical_collapse_vars: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "FAIL", b = false;
+        a = "PASS";
+        b ??= a;
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL", b = false;
+        a = "PASS";
+        b ??= a;
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+logical_reduce_vars: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS", b = 42;
+        b ??= a = "FAIL";
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS", b = 42;
+        b ??= a = "FAIL";
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+logical_side_effects: {
+    options = {
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS", b = 42;
+        b ??= a = "FAIL";
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS", b = 42;
+        b ??= a = "FAIL";
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4815_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        42..p &&= a = "FAIL";
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        42..p &&= a = "FAIL";
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4815_2: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        var a = "PASS";
+        42..p &&= a = "FAIL";
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        42..p &&= a = "FAIL";
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4819: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        console.log(void 0 === ([].p &&= 42));
+    }
+    expect: {
+        console.log(void 0 === ([].p &&= 42));
+    }
+    expect_stdout: "true"
+    node_version: ">=15"
+}
+
+issue_4827_1: {
+    options = {
+        collapse_vars: true,
+        toplevel: true,
+    }
+    input: {
+        A = "FAIL";
+        var a = A, b = "PASS", c;
+        c &&= b = a, console.log(b);
+    }
+    expect: {
+        A = "FAIL";
+        var a = A, b = "PASS", c;
+        c &&= b = a, console.log(b);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4827_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0, b = "PASS";
+        function f(c) {
+            a++,
+            c &&= b = a;
+        }
+        f();
+        console.log(b);
+    }
+    expect: {
+        var a = 0, b = "PASS";
+        a++,
+        c &&= b = a;
+        var c;
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4827_3: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 0, b, c;
+        a++;
+        c &&= b = a;
+        console.log(b);
+    }
+    expect: {
+        var a = 0, b, c;
+        a++;
+        c &&= b = a;
+        console.log(b);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=15"
+}
+
+issue_4876: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        try {
+            var a = null;
+            var b = a &&= 42;
+            b.p;
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            var a = null;
+            var b = a &&= 42;
+            b.p;
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4924_1: {
+    options = {
+        collapse_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, b;
+        console.log("PASS");
+        a = function() {};
+        b = function() {}(b ||= a);
+    }
+    expect: {
+        var b;
+        console.log("PASS");
+        b = void (b ||= function() {});
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4924_2: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        passes: 2,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, b;
+        console.log("PASS");
+        a = function() {};
+        b = function() {}(b ||= a);
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}

test/compress/bigint.js

@@ -0,0 +1,92 @@
+arithmetic: {
+    input: {
+        console.log(((1n + 0x2n) * (0o3n - -4n)) >> (5n - 6n));
+    }
+    expect_exact: "console.log((1n+0x2n)*(0o3n- -4n)>>5n-6n);"
+    expect_stdout: "42n"
+    node_version: ">=10"
+}
+
+minus_dot: {
+    input: {
+        console.log(typeof -42n.toString(), typeof (-42n).toString());
+    }
+    expect_exact: "console.log(typeof-42n.toString(),typeof(-42n).toString());"
+    expect_stdout: "number string"
+    node_version: ">=10"
+}
+
+evaluate: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log((0xDEAD_BEEFn).toString(16));
+    }
+    expect: {
+        console.log(0xdeadbeefn.toString(16));
+    }
+    expect_stdout: "deadbeef"
+    node_version: ">=10"
+}
+
+Number: {
+    options = {
+        unsafe: true,
+    }
+    input: {
+        console.log(Number(-0xfeed_dead_beef_badn));
+    }
+    expect: {
+        console.log(+("" + -0xfeed_dead_beef_badn));
+    }
+    expect_stdout: "-1148098955808013200"
+    node_version: ">=10"
+}
+
+issue_4590: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        A = 1;
+        0n || console.log("PASS");
+    }
+    expect: {
+        A = 1;
+        0n || console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}
+
+issue_4801: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        try {
+            (function(a) {
+                A = 42;
+                a || A;
+            })(!(0 == 42 >> 0o644n));
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            (function(a) {
+                0 != (A = 42) >> 0o644n || A;
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}

test/compress/booleans.js

@@ -29,6 +29,404 @@ iife_boolean_context: {
     ]
 }
 
+de_morgan_1a: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        function f(a) {
+            return a || a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect: {
+        function f(a) {
+            return a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect_stdout: "null 42"
+}
+
+de_morgan_1b: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        function f(a) {
+            return a && a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect: {
+        function f(a) {
+            return a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect_stdout: "null 42"
+}
+
+de_morgan_1c: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        console.log(delete (NaN && NaN));
+    }
+    expect: {
+        console.log(delete (0, NaN));
+    }
+    expect_stdout: "true"
+}
+
+de_morgan_2a: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b) {
+            return a || (a || b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a || b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "undefined {}",
+        "42 42",
+    ]
+}
+
+de_morgan_2b: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a || (a && b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "42 42",
+    ]
+}
+
+de_morgan_2c: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a && (a || b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "42 42",
+    ]
+}
+
+de_morgan_2d: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            return a && (a && b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a && b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "undefined {}",
+    ]
+}
+
+de_morgan_3a: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a || b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || b || c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "undefined {} true true",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3b: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a || b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || b && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "false false undefined {}",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3c: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a && b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "undefined {} undefined {}",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3d: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a && b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3e: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a || b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3f: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a || b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "undefined {} undefined {}",
+    ]
+}
+
+de_morgan_3g: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a && b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && (b || c);
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "undefined {} true true",
+    ]
+}
+
+de_morgan_3h: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a && b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && b && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "false false undefined {}",
+    ]
+}
+
+conditional_chain: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a ? a : b ? b : 42;
+        }
+        console.log(f("PASS", "FAIL"));
+    }
+    expect: {
+        function f(a, b) {
+            return a || b || 42;
+        }
+        console.log(f("PASS", "FAIL"));
+    }
+    expect_stdout: "PASS"
+}
+
+negated_if: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(function(a) {
+            if (!a)
+                return a ? "FAIL" : "PASS";
+        }(!console));
+    }
+    expect: {
+        console.log(function(a) {
+            if (!a)
+                return "PASS";
+        }(!console));
+    }
+    expect_stdout: "PASS"
+}
+
 issue_3465_1: {
     options = {
         booleans: true,
@@ -153,3 +551,149 @@ issue_3690: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4374: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        if_return: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            console.log(f());
+            function f(a) {
+                if (null) return 0;
+                if (a) return 1;
+                return 0;
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            console.log(function(a) {
+                return !null && a ? 1 : 0;
+            }());
+        })();
+    }
+    expect_stdout: "0"
+}
+
+issue_5028_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var a = 1;
+        console.log(function() {
+            return a-- ? a-- ? "FAIL 1" : "PASS" : "FAIL 2";
+        }());
+    }
+    expect: {
+        var a = 1;
+        console.log(function() {
+            return a-- ? a-- ? "FAIL 1" : "PASS" : "FAIL 2";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5028_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        dead_code: true,
+        if_return: true,
+    }
+    input: {
+        var a = 1;
+        (function() {
+            if (a--)
+                if (a--)
+                    a = "FAIL";
+                else
+                    return;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        (function() {
+            a-- && a-- && (a = "FAIL");
+        })();
+        console.log(a);
+    }
+    expect_stdout: "-1"
+}
+
+issue_5028_3: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        if_return: true,
+    }
+    input: {
+        var a = 1;
+        (function() {
+            if (a--)
+                if (a--)
+                    a = "FAIL";
+                else
+                    return;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        (function() {
+            a-- && a-- && (a = "FAIL");
+        })();
+        console.log(a);
+    }
+    expect_stdout: "-1"
+}
+
+issue_5041_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var a = 42;
+        if (a)
+            if ([ a = null ])
+                if (a)
+                    console.log("FAIL");
+                else
+                    console.log("PASS");
+    }
+    expect: {
+        var a = 42;
+        a && [ a = null ] && (a ? console.log("FAIL") : console.log("PASS"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5041_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var a;
+        if (!a)
+            if (a = 42)
+                if (a)
+                    console.log("PASS");
+                else
+                    console.log("FAIL");
+    }
+    expect: {
+        var a;
+        a || (a = 42) && (a ? console.log("PASS") : console.log("FAIL"));
+    }
+    expect_stdout: "PASS"
+}

test/compress/comparisons.js

@@ -123,6 +123,29 @@ self_comparison_3: {
     ]
 }
 
+self_comparison_4: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {};
+        console.log(o == o, o != o);
+        console.log(o === o, o !== o);
+    }
+    expect: {
+        console.log(!0, !1);
+        console.log(!0, !1);
+    }
+    expect_stdout: [
+        "true false",
+        "true false",
+    ]
+}
+
 issue_2857_1: {
     options = {
         comparisons: true,

test/compress/concat-strings.js

@@ -238,6 +238,41 @@ concat_8: {
     expect_stdout: true
 }
 
+concat_9: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        reduce_vars: true,
+        strings: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "foo";
+        console.log(
+            12 + (34 + a),
+            null + (34 + a),
+            12 + (null + a),
+            false + (34 + a),
+            12 + (false + a),
+            "bar" + (34 + a),
+            12 + ("bar" + a)
+        );
+    }
+    expect: {
+        var a = "foo";
+        console.log(
+            "1234" + a,
+            "null34" + a,
+            "12null" + a,
+            !1 + (34 + a),
+            12 + (!1 + a),
+            "bar34" + a,
+            "12bar" + a
+        );
+    }
+    expect_stdout: true
+}
+
 issue_3689: {
     options = {
         strings: true,

test/compress/conditionals.js

@@ -55,14 +55,15 @@ ifs_3_should_warn: {
     }
     input: {
         var x, y;
-        if (x && !(x + "1") && y) { // 1
+        // 1
+        if (x && !(x + "1") && y) {
             var qq;
             foo();
         } else {
             bar();
         }
-
-        if (x || !!(x + "1") || y) { // 2
+        // 2
+        if (x || !!(x + "1") || y) {
             foo();
         } else {
             var jj;
@@ -71,9 +72,25 @@ ifs_3_should_warn: {
     }
     expect: {
         var x, y;
-        var qq; bar();          // 1
-        var jj; foo();          // 2
+        // 1
+        var qq; bar();
+        // 2
+        foo(); var jj;
     }
+    expect_warnings: [
+        "WARN: + in boolean context always true [test/compress/conditionals.js:3,18]",
+        "WARN: Boolean && always false [test/compress/conditionals.js:3,12]",
+        "WARN: Condition left of && always false [test/compress/conditionals.js:3,12]",
+        "WARN: Condition always false [test/compress/conditionals.js:3,12]",
+        "WARN: Dropping unreachable code [test/compress/conditionals.js:3,34]",
+        "WARN: + in boolean context always true [test/compress/conditionals.js:10,19]",
+        "WARN: Boolean || always true [test/compress/conditionals.js:10,12]",
+        "WARN: Condition left of || always true [test/compress/conditionals.js:10,12]",
+        "WARN: Condition always true [test/compress/conditionals.js:10,12]",
+        "WARN: Dropping unreachable code [test/compress/conditionals.js:12,15]",
+        "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:3,12]",
+        "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:10,12]",
+    ]
 }
 
 ifs_4: {
@@ -783,6 +800,55 @@ cond_12: {
     }
 }
 
+cond_13: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        x ? y(a) : z(a);
+        x ? y.f(a) : z.f(a);
+        x ? y.f(a) : z.g(a);
+        x ? y.f()(a) : z.g()(a);
+        x ? y.f.u(a) : z.g.u(a);
+        x ? y.f().u(a) : z.g().u(a);
+    }
+    expect: {
+        (x ? y : z)(a);
+        (x ? y : z).f(a);
+        x ? y.f(a) : z.g(a);
+        (x ? y.f() : z.g())(a);
+        (x ? y.f : z.g).u(a);
+        (x ? y.f() : z.g()).u(a);
+    }
+}
+
+cond_14: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a) {
+            if (a)
+                if (a)
+                    console.log("PASS");
+                else
+                    console.log("FAIL");
+        }
+        f(null);
+        f(42);
+    }
+    expect: {
+        function f(a) {
+            a && console.log("PASS");
+        }
+        f(null);
+        f(42);
+    }
+    expect_stdout: "PASS"
+}
+
 ternary_boolean_consequent: {
     options = {
         booleans: true,
@@ -1137,7 +1203,7 @@ issue_1645_2: {
     expect_stdout: true
 }
 
-condition_symbol_matches_consequent: {
+condition_matches_consequent: {
     options = {
         conditionals: true,
     }
@@ -1166,6 +1232,35 @@ condition_symbol_matches_consequent: {
     expect_stdout: "3 7 true 4"
 }
 
+condition_matches_alternative: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function foo(x, y) {
+            return x.p ? y[0] : x.p;
+        }
+        function bar() {
+            return g ? h : g;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo({ p: 3 }, [ null ]), foo({ p: 0 }, [ 7 ]), foo({ p: true } , [ false ]), bar());
+    }
+    expect: {
+        function foo(x, y) {
+            return x.p && y[0];
+        }
+        function bar() {
+            return g && h;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo({ p: 3 }, [ null ]), foo({ p: 0 }, [ 7 ]), foo({ p: true } , [ false ]), bar());
+    }
+    expect_stdout: "null 0 false 5"
+}
+
 delete_conditional_1: {
     options = {
         booleans: true,
@@ -1793,3 +1888,39 @@ issue_3808_2: {
     }
     expect_stdout: " PASS"
 }
+
+object_super: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        Object.setPrototypeOf({
+            f(a) {
+                a ? this.g("FAIL") : super.g("FAIL");
+            },
+            g(b) {
+                console.log(b);
+            },
+        }, {
+            g() {
+                console.log("PASS");
+            },
+        }).f();
+    }
+    expect: {
+        Object.setPrototypeOf({
+            f(a) {
+                a ? this.g("FAIL") : super.g("FAIL");
+            },
+            g(b) {
+                console.log(b);
+            },
+        }, {
+            g() {
+                console.log("PASS");
+            },
+        }).f();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}

test/compress/dead-code.js

@@ -53,13 +53,17 @@ dead_code_2_should_warn: {
             g();
             x = 10;
             throw new Error("foo");
-            var x;
-            function g(){};
+            {
+                var x;
+                function g(){};
+            }
         }
         f();
     }
     expect_stdout: true
-    node_version: "<=4"
+    expect_warnings: [
+        "WARN: Dropping unreachable code [test/compress/dead-code.js:8,12]",
+    ]
 }
 
 dead_code_constant_boolean_should_warn_more: {
@@ -85,15 +89,27 @@ dead_code_constant_boolean_should_warn_more: {
         bar();
     }
     expect: {
-        var foo;
-        function bar() {}
+        {
+            var foo;
+            function bar() {}
+        }
         // nothing for the while
         // as for the for, it should keep:
-        var moo;
         var x = 10, y;
+        var moo;
         bar();
     }
     expect_stdout: true
+    expect_warnings: [
+        "WARN: + in boolean context always true [test/compress/dead-code.js:1,33]",
+        "WARN: Boolean || always true [test/compress/dead-code.js:1,16]",
+        "WARN: Dropping unreachable code [test/compress/dead-code.js:1,45]",
+        "WARN: Boolean expression always true [test/compress/dead-code.js:6,47]",
+        "WARN: Boolean && always false [test/compress/dead-code.js:6,28]",
+        "WARN: Dropping unreachable code [test/compress/dead-code.js:6,63]",
+        "WARN: Dropping side-effect-free statement [test/compress/dead-code.js:1,15]",
+        "WARN: Dropping side-effect-free statement [test/compress/dead-code.js:6,28]",
+    ]
     node_version: "<=4"
 }
 
@@ -712,7 +728,7 @@ issue_2749: {
     expect: {
         var a = 2, c = "PASS";
         while (a--)
-            b = void 0, b ? c = "FAIL" : b = 1;
+            b = void 0, b ? c = "FAIL" : 1;
         var b;
         console.log(c);
     }
@@ -923,6 +939,185 @@ catch_return_assign: {
     expect_stdout: "PASS"
 }
 
+catch_return_assign_may_throw: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        function f() {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                return e = console.log("PASS");
+            }
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                return console.log("PASS");
+            }
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+finally_return_assign: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        console.log(function(a) {
+            try {
+                throw "FAIL";
+            } finally {
+                return a = "PASS";
+            }
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            try {
+                throw "FAIL";
+            } finally {
+                return "PASS";
+            }
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+last_assign_statement: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        function f(a) {
+            a = a("PASS");
+        }
+        f(console.log);
+    }
+    expect: {
+        function f(a) {
+            a("PASS");
+        }
+        f(console.log);
+    }
+    expect_stdout: "PASS"
+}
+
+last_assign_if_else: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        function f(a) {
+            if (a)
+                a = console.log("foo");
+            else {
+                console.log("bar");
+                a = console.log("baz");
+            }
+        }
+        f(42);
+        f(null);
+    }
+    expect: {
+        function f(a) {
+            if (a)
+                console.log("foo");
+            else {
+                console.log("bar");
+                console.log("baz");
+            }
+        }
+        f(42);
+        f(null);
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
+last_assign_catch: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        function f() {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                e = console.log("PASS");
+            }
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                console.log("PASS");
+            }
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+last_assign_finally: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        function f(a) {
+            try {
+                throw a.log;
+            } catch (e) {
+                a = e;
+            } finally {
+                a = a("PASS");
+            }
+        }
+        f(console);
+    }
+    expect: {
+        function f(a) {
+            try {
+                throw a.log;
+            } catch (e) {
+                a = e;
+            } finally {
+                a("PASS");
+            }
+        }
+        f(console);
+    }
+    expect_stdout: "PASS"
+}
+
+consecutive_assignments: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        while (a = void 0, a = "PASS", console.log(a));
+        var a;
+    }
+    expect: {
+        while (void 0, a = "PASS", console.log(a));
+        var a;
+    }
+    expect_stdout: "PASS"
+}
+
 issue_3578: {
     options = {
         dead_code: true,
@@ -1341,3 +1536,100 @@ issue_3967: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4051: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        try {
+            delete (A = A);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            delete (A = A);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4366: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        function f() {
+            return "PASS";
+            ({
+                p: 42,
+                get p() {},
+            });
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            return "PASS";
+        }
+        console.log(f());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4570: {
+    options = {
+        dead_code: true,
+        inline: true,
+    }
+    input: {
+        var a = function(b) {
+            return a += b;
+        }() ? 0 : a;
+        console.log(a);
+    }
+    expect: {
+        var a = (a += void 0) ? 0 : a;
+        console.log(a);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_5030: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        (function(a, b) {
+            a = function f() {
+                if (a)
+                    if (b--)
+                        setImmediate(f);
+                    else
+                        console.log("FAIL");
+                else
+                    console.log("PASS");
+            }();
+        })(42, 1);
+    }
+    expect: {
+        (function(a, b) {
+            a = function f() {
+                if (a)
+                    if (b--)
+                        setImmediate(f);
+                    else
+                        console.log("FAIL");
+                else
+                    console.log("PASS");
+            }();
+        })(42, 1);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=0.12"
+}

test/compress/drop-unused.js

@@ -4,15 +4,16 @@ unused_funarg_1: {
         unused: true,
     }
     input: {
-        function f(a, b, c, d, e) {
+        console.log(function f(a, b, c, d, e) {
             return a + b;
-        }
+        }(14, 28));
     }
     expect: {
-        function f(a, b) {
+        console.log(function(a, b) {
             return a + b;
-        }
+        }(14, 28));
     }
+    expect_stdout: "42"
 }
 
 unused_funarg_2: {
@@ -21,15 +22,16 @@ unused_funarg_2: {
         unused: true,
     }
     input: {
-        function f(a, b, c, d, e) {
+        console.log(function f(a, b, c, d, e) {
             return a + c;
-        }
+        }(14, 21, 28));
     }
     expect: {
-        function f(a, b, c) {
+        console.log(function(a, c) {
             return a + c;
-        }
+        }(14, 28));
     }
+    expect_stdout: "42"
 }
 
 unused_nested_function: {
@@ -357,37 +359,6 @@ drop_toplevel_vars: {
     }
 }
 
-drop_toplevel_vars_fargs: {
-    options = {
-        keep_fargs: false,
-        toplevel: "vars",
-        unused: true,
-    }
-    input: {
-        var a, b = 1, c = g;
-        function f(d) {
-            return function() {
-                c = 2;
-            };
-        }
-        a = 2;
-        function g() {}
-        function h() {}
-        console.log(b = 3);
-    }
-    expect: {
-        function f() {
-            return function() {
-                2;
-            };
-        }
-        2;
-        function g() {}
-        function h() {}
-        console.log(3);
-    }
-}
-
 drop_toplevel_all: {
     options = {
         toplevel: true,
@@ -625,13 +596,14 @@ drop_fargs: {
         unused: true,
     }
     input: {
-        function f(a) {
+        console.log(function f(a) {
             var b = a;
-        }
+        }());
     }
     expect: {
-        function f() {}
+        console.log(function() {}());
     }
+    expect_stdout: "undefined"
 }
 
 drop_fnames: {
@@ -823,9 +795,9 @@ issue_1656: {
         beautify: true,
     }
     input: {
-        for(var a=0;;);
+        for (var a=0;;);
     }
-    expect_exact: "for (;;) ;"
+    expect_exact: "for (;;);"
 }
 
 issue_1709: {
@@ -1138,7 +1110,7 @@ issue_1838: {
     }
     expect_exact: [
         "function f() {",
-        "    for (a; c; ) ;",
+        "    for (a; c; );",
         "}",
     ]
 }
@@ -1730,7 +1702,7 @@ chained_3: {
     expect: {
         console.log(function(a, b) {
             var c = b;
-            b++;
+            +b;
             return c;
         }(0, 2));
     }
@@ -1997,7 +1969,7 @@ issue_3146_4: {
     expect_stdout: "PASS"
 }
 
-issue_3192: {
+issue_3192_1: {
     options = {
         unused: true,
     }
@@ -2025,6 +1997,26 @@ issue_3192: {
     ]
 }
 
+issue_3192_2: {
+    options = {
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        (function(a) {
+            console.log(a = "foo", arguments[0]);
+        })("bar");
+    }
+    expect: {
+        "use strict";
+        (function() {
+            console.log("foo", arguments[0]);
+        })("bar");
+    }
+    expect_stdout: "foo bar"
+}
+
 issue_3233: {
     options = {
         pure_getters: "strict",
@@ -2146,6 +2138,7 @@ issue_3497: {
 issue_3515_1: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         reduce_vars: true,
         unused: true,
     }
@@ -2161,8 +2154,7 @@ issue_3515_1: {
     expect: {
         var c = 0;
         (function() {
-            this[c++] = 0;
-            for (var key20 in !0);
+            for (var key20 in !(this[c++] = 0));
         })();
         console.log(c);
     }
@@ -2198,6 +2190,7 @@ issue_3515_2: {
 issue_3515_3: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         unused: true,
     }
     input: {
@@ -2265,6 +2258,7 @@ function_assign: {
 issue_3598: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         reduce_vars: true,
         unused: true,
     }
@@ -2351,7 +2345,7 @@ function_argument_reference: {
 
 function_parameter_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         reduce_vars: true,
         unused: true,
     }
@@ -2377,6 +2371,7 @@ function_parameter_ie8: {
 issue_3664: {
     options = {
         pure_getters: "strict",
+        side_effects: true,
         unused: true,
     }
     input: {
@@ -2387,7 +2382,7 @@ issue_3664: {
     }
     expect: {
         console.log(function() {
-            var b = ([ b && console.log("FAIL") ].p = 0, 0);
+            var a, b = (a = (a = [ b && console.log("FAIL") ]).p = 0, 0);
             return "PASS";
         }());
     }
@@ -2397,6 +2392,7 @@ issue_3664: {
 issue_3673: {
     options = {
         pure_getters: "strict",
+        sequences: true,
         side_effects: true,
         toplevel: true,
         unused: true,
@@ -2407,8 +2403,6 @@ issue_3673: {
         console.log("PASS");
     }
     expect: {
-        var a;
-        (a = [ a ]).p = 42;
         console.log("PASS");
     }
     expect_stdout: "PASS"
@@ -2416,7 +2410,7 @@ issue_3673: {
 
 issue_3746: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -2678,8 +2672,7 @@ issue_3956: {
         })();
     }
     expect: {
-        var c, d;
-        c += 0,
+        var d;
         console.log(NaN),
         d = 1 ^ console.log(1),
         console.log(d);
@@ -2694,7 +2687,7 @@ issue_3956: {
 issue_3962_1: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -2712,13 +2705,13 @@ issue_3962_1: {
     }
     expect: {
         var a = 0;
-        a = (function(c) {
+        (function(c) {
             do {
                 console;
                 0..toString();
             } while (0);
             if (c) console.log("PASS");
-        }((a--, 1)), 0);
+        })(1);
         void 0;
     }
     expect_stdout: "PASS"
@@ -2726,7 +2719,7 @@ issue_3962_1: {
 
 issue_3962_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         side_effects: true,
         toplevel: true,
@@ -2745,13 +2738,13 @@ issue_3962_2: {
     }
     expect: {
         var a = 0;
-        a = (function(c) {
+        (function(c) {
             do {
                 console;
                 0..toString();
             } while (0);
             if (c) console.log("PASS");
-        }((a--, 1)), 0);
+        })(1);
     }
     expect_stdout: "PASS"
 }
@@ -2808,7 +2801,9 @@ issue_4017: {
         var a = 0;
         console.log(function() {
             c &= 0;
-            var c = (a++, A = a, 0);
+            var c;
+            a++,
+            A = a;
         }());
     }
     expect_stdout: "undefined"
@@ -2834,11 +2829,11 @@ issue_4025: {
         console.log(a, b, d);
     }
     expect: {
-        var d, c = 0;
+        var c = 0;
         try {
             console.log(c);
         } finally {
-            d = c + 1;
+            var d = c + 1;
             c = 0;
         }
         console.log(1, 1, d);
@@ -2848,3 +2843,652 @@ issue_4025: {
         "1 1 1",
     ]
 }
+
+forin_var_1: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var k;
+        for (k in [ 1, 2 ])
+            console.log(k);
+        for (k in { PASS: 3 })
+            console.log(k);
+        console.log(k);
+    }
+    expect: {
+        for (var k in [ 1, 2 ])
+            console.log(k);
+        for (k in { PASS: 3 })
+            console.log(k);
+        console.log(k);
+    }
+    expect_stdout: [
+        "0",
+        "1",
+        "PASS",
+        "PASS",
+    ]
+}
+
+forin_var_2: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            switch (0) {
+              case function() {
+                    for (a in 0);
+                }:
+                var b = 0;
+            }
+            for (var c = 0; a;);
+            var a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            switch (0) {
+              case function() {
+                    for (a in 0);
+                }:
+            }
+            for (; a;);
+            var a;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4133: {
+    options = {
+        evaluate: true,
+        merge_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        var b = [ a-- ], c = b && b[c];
+        console.log(a);
+    }
+    expect: {
+        var b = 1;
+        console.log(0);
+    }
+    expect_stdout: "0"
+}
+
+issue_4144: {
+    options = {
+        keep_fargs: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a, b) {
+            var b = console, c = ++b;
+        })(console.log("PASS"), 0);
+    }
+    expect: {
+        (function(b) {
+            b = console,
+            ++b;
+        })(console.log("PASS"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4146: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            function g() {}
+            var a = g;
+            var c = b;
+            c.p;
+            console.log(typeof a);
+        }
+        f("FAIL", 42);
+    }
+    expect: {
+        (function(a, b) {
+            a = function () {};
+            var c = b;
+            c.p;
+            console.log(typeof a);
+        })(0, 42);
+    }
+    expect_stdout: "function"
+}
+
+var_catch_redefined: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw "PASS";
+        } catch (a) {
+            function f() {
+                return a;
+            }
+            console.log(a);
+        }
+        f();
+    }
+    expect: {
+        var a = "FAIL";
+        try {
+            throw "PASS";
+        } catch (a) {
+            function f() {
+                return a;
+            }
+            console.log(a);
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+single_use_catch_redefined: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect_stdout: true
+}
+
+issue_4184: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = function() {}, b = [ a, 1 && b, a = {} ];
+            try {
+                throw 42;
+            } catch (a) {
+                {
+                    console.log(a);
+                }
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            var b = [ function() {}, 1 && b, {} ];
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(a);
+            }
+        })();
+    }
+    expect_stdout: "42"
+}
+
+issue_4235: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        (function() {
+            {
+                const f = 0;
+            }
+            (function f() {
+                var f = console.log(f);
+            })();
+        })();
+    }
+    expect: {
+        void function() {
+            var f;
+            console.log(f);
+        }();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4404: {
+    options = {
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            arguments[0] = "PASS";
+            console.log(a);
+        }
+        f("FAIL");
+    }
+    expect: {
+        function f(a) {
+            arguments[0] = "PASS";
+            console.log(a);
+        }
+        f("FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4413: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function f(arguments) {
+            var arguments = function() {};
+            return arguments.length;
+        }());
+    }
+    expect: {
+        console.log(function(arguments) {
+            return function() {}.length;
+        }());
+    }
+    expect_stdout: "0"
+}
+
+issue_4464_1: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var a = function() {};
+            return [ arguments, a ];
+        }
+        console.log(typeof f()[1]);
+    }
+    expect: {
+        function f(a) {
+            a = function() {};
+            return [ arguments, a ];
+        }
+        console.log(typeof f()[1]);
+    }
+    expect_stdout: "function"
+}
+
+issue_4464_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var a = function() {};
+            return [ arguments, a ];
+        }
+        console.log(typeof f(42)[0][0]);
+    }
+    expect: {
+        function f(a) {
+            a = function() {};
+            return [ arguments, a ];
+        }
+        console.log(typeof f(42)[0][0]);
+    }
+    expect_stdout: "function"
+}
+
+issue_4464_3: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function a(a) {
+            var a = function() {};
+            return [ arguments[0], a ];
+        })(42).forEach(function(b) {
+            console.log(typeof b);
+        });
+    }
+    expect: {
+        (function(a) {
+            a = function() {};
+            return [ arguments[0], a ];
+        })(42).forEach(function(b) {
+            console.log(typeof b);
+        });
+    }
+    expect_stdout: [
+        "function",
+        "function",
+    ]
+}
+
+issue_4558_1: {
+    options = {
+        evaluate: true,
+        pure_getters: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        var b = 1, b = c >>>= a;
+        var c = 0;
+        b && 0[a++],
+        console.log(a);
+    }
+    expect: {
+        var a = 0;
+        var b = c >>>= a;
+        var c;
+        b && a++,
+        console.log(a);
+    }
+    expect_stdout: "0"
+}
+
+issue_4558_2: {
+    options = {
+        evaluate: true,
+        ie: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = 1;
+            var b = (a = NaN) || (console.log("PASS"), 2);
+            return a;
+        })();
+    }
+    expect: {
+        (function() {
+            var a;
+            (a = NaN) || console.log("PASS");
+            return a;
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4662: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        function f(b, c) {
+            console.log(b, c);
+        }
+        f(++a, a = a, a);
+    }
+    expect: {
+        var a = 0;
+        (function(b, c) {
+            console.log(b, c);
+        })(++a, a = 1);
+    }
+    expect_stdout: "1 1"
+}
+
+issue_4806_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        O = {
+            f: function() {
+                console.log(this === O ? "FAIL" : "PASS");
+            },
+        };
+        var a;
+        (a = 42, O.f)();
+        a;
+    }
+    expect: {
+        O = {
+            f: function() {
+                console.log(this === O ? "FAIL" : "PASS");
+            },
+        };
+        (0, O.f)();
+        42;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4806_2: {
+    options = {
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        O = {
+            f: function() {
+                console.log(this === O ? "FAIL" : "PASS");
+            },
+        };
+        var a;
+        (a = 42, O.f)();
+        a;
+    }
+    expect: {
+        O = {
+            f: function() {
+                console.log(this === O ? "FAIL" : "PASS");
+            },
+        },
+        (0, O.f)();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4806_3: {
+    options = {
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        O = {
+            f: function() {
+                console.log(this === O ? "FAIL" : "PASS");
+            },
+        };
+        var a;
+        (a = 42, O.f)();
+        a;
+    }
+    expect: {
+        O = {
+            f: function() {
+                console.log(this === O ? "FAIL" : "PASS");
+            },
+        };
+        (0, O.f)();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4834: {
+    options = {
+        inline: true,
+        keep_fargs: false,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            new function(a, b) {
+                b;
+                b.p;
+            }(42);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            void b.p;
+        } catch (e) {
+            console.log("PASS");
+        }
+        var b;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4912_1: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = A = function() {};
+        A;
+        a.prototype = {
+            f: function() {
+                console.log("PASS");
+            },
+        };
+        new A().f();
+    }
+    expect: {
+        var a = A = function() {};
+        A;
+        a.prototype = {
+            f: function() {
+                console.log("PASS");
+            },
+        };
+        new A().f();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4912_2: {
+    options = {
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var g, f = function() {};
+            f.p = {};
+            (g = f.p.q = function() {}).r = "PASS";
+            return f;
+        }().p.q.r);
+    }
+    expect: {
+        console.log(function() {
+            var g, f = function() {};
+            f.p = {};
+            (f.p.q = function() {}).r = "PASS";
+            return f;
+        }().p.q.r);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4912_3: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(f, g) {
+            f = function() {};
+            f.p = {};
+            g = f.p.q = function() {};
+            g.r = "PASS";
+            return f;
+        }().p.q.r);
+    }
+    expect: {
+        console.log(function(f, g) {
+            f = function() {};
+            f.p = {};
+            g = f.p.q = function() {};
+            g.r = "PASS";
+            return f;
+        }().p.q.r);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5079: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        do {
+            (a = 123456).p = a;
+            a.q = null;
+        } while (console.log("PASS"));
+    }
+    expect: {
+        do {
+            0, 0, null;
+        } while (console.log("PASS"));
+    }
+    expect_stdout: "PASS"
+}

test/compress/evaluate.js

@@ -399,18 +399,18 @@ unsafe_object_accessor: {
         function f() {
             var a = {
                 get b() {},
-                set b() {}
+                set b(v) {},
             };
-            return {a:a};
+            return { a: a };
         }
     }
     expect: {
         function f() {
             var a = {
                 get b() {},
-                set b() {}
+                set b(v) {},
             };
-            return {a:a};
+            return { a: a };
         }
     }
 }
@@ -684,25 +684,47 @@ prototype_function: {
         side_effects: true,
     }
     input: {
-        var a = ({valueOf: 0}) < 1;
-        var b = ({toString: 0}) < 1;
-        var c = ({valueOf: 0}) + "";
-        var d = ({toString: 0}) + "";
-        var e = (({valueOf: 0}) + "")[2];
-        var f = (({toString: 0}) + "")[2];
-        var g = ({valueOf: 0}).valueOf();
-        var h = ({toString: 0}).toString();
+        function v() {
+            return this.valueOf === v ? "PASS" : "FAIL";
+        }
+        console.log(({ valueOf: v }) < 1);
+        console.log(({ valueOf: v }) + "");
+        console.log((( {valueOf: v }) + "")[2]);
+        console.log(({ valueOf: v }).valueOf());
+        function t() {
+            return this.toString === t ? "PASS" : "FAIL";
+        }
+        console.log(({ toString: t }) < 1);
+        console.log(({ toString: t }) + "");
+        console.log((( {toString: t }) + "")[2]);
+        console.log(({ toString: t }).toString());
     }
     expect: {
-        var a = ({valueOf: 0}) < 1;
-        var b = ({toString: 0}) < 1;
-        var c = ({valueOf: 0}) + "";
-        var d = ({toString: 0}) + "";
-        var e = (({valueOf: 0}) + "")[2];
-        var f = (({toString: 0}) + "")[2];
-        var g = 0();
-        var h = 0();
+        function v() {
+            return this.valueOf === v ? "PASS" : "FAIL";
+        }
+        console.log(({ valueOf: v }) < 1);
+        console.log(({ valueOf: v }) + "");
+        console.log((( {valueOf: v }) + "")[2]);
+        console.log(({ valueOf: v }).valueOf());
+        function t() {
+            return this.toString === t ? "PASS" : "FAIL";
+        }
+        console.log(({ toString: t }) < 1);
+        console.log(({ toString: t }) + "");
+        console.log((( {toString: t }) + "")[2]);
+        console.log(({ toString: t }).toString());
     }
+    expect_stdout: [
+        "false",
+        "PASS",
+        "S",
+        "PASS",
+        "false",
+        "PASS",
+        "S",
+        "PASS",
+    ]
 }
 
 call_args: {
@@ -846,6 +868,8 @@ unsafe_charAt_noop: {
         unsafe: true,
     }
     input: {
+        s = "foo";
+        x = 42;
         console.log(
             s.charAt(0),
             "string".charAt(x),
@@ -853,12 +877,15 @@ unsafe_charAt_noop: {
         );
     }
     expect: {
+        s = "foo";
+        x = 42;
         console.log(
-            s[0],
-            "string"[0 | x],
-            (typeof x)[0]
+            s[0] || "",
+            "string"[0 | x] || "",
+            (typeof x)[0] || ""
         );
     }
+    expect_stdout: "f  n"
 }
 
 issue_1649: {
@@ -2800,7 +2827,7 @@ operator_in: {
         console.log("PASS" in { });
         console.log("FAIL" in { });
         console.log("toString" in { });
-        console.log(true);
+        console.log("toString" in { toString: 3 });
     }
     expect_stdout: [
         "true",
@@ -2833,3 +2860,365 @@ issue_3997: {
     }
     expect_stdout: "string"
 }
+
+issue_4035: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        var a = 0;
+        (function() {
+            var b = --a;
+            console.log(delete (0 + b));
+            console.log(delete (1 * b));
+            console.log(delete (b + 0));
+            console.log(delete (b - 0));
+            console.log(delete (b / 1));
+        })();
+    }
+    expect: {
+        var a = 0;
+        (function() {
+            var b = --a;
+            console.log((0 + b, true));
+            console.log((1 * b, true));
+            console.log((0 + b, true));
+            console.log((b - 0, true));
+            console.log((b / 1, true));
+        })();
+    }
+    expect_stdout: [
+        "true",
+        "true",
+        "true",
+        "true",
+        "true",
+    ]
+}
+
+issue_4067: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        (function(a) {
+            (function(b) {
+                b[0] += 0;
+                console.log(+a);
+            })(a);
+        })([]);
+    }
+    expect: {
+        (function(a) {
+            (function(b) {
+                b[0] += 0;
+                console.log(+a);
+            })(a);
+        })([]);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_4077: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log((a = []) - (a[0]++, 1) || "PASS");
+    }
+    expect: {
+        console.log((a = []) - (a[0]++, 1) || "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4119_1: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var a, b;
+        b = a = [];
+        a[0] += 0;
+        if (+b + 1) {
+            console.log("FAIL");
+        } else {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        var a, b;
+        b = a = [];
+        a[0] += 0;
+        +b + 1 ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4119_2: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        var a;
+        (function(b) {
+            a[0] += 0;
+            console.log(+b + 1 ? "FAIL" : "PASS");
+        })(a = []);
+    }
+    expect: {
+        var a;
+        (function(b) {
+            a[0] += 0;
+            console.log(+b + 1 ? "FAIL" : "PASS");
+        })(a = []);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4119_3: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var a, b;
+        b = a = {
+            p: 42,
+        };
+        delete a.p;
+        console.log(b.p ? "FAIL" : "PASS");
+    }
+    expect: {
+        var a, b;
+        b = a = {
+            p: 42,
+        };
+        delete a.p;
+        console.log(b.p ? "FAIL" : "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4119_4: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a, b;
+        b = a = {
+            p: 42,
+        };
+        delete a.p;
+        console.log(!b ? "FAIL" : "PASS");
+    }
+    expect: {
+        var a, b;
+        b = a = {
+            p: 42,
+        };
+        delete a.p;
+        console.log((b, 0, "PASS"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4214: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            return function() {
+                try {
+                    return a;
+                } finally {
+                    var b = 0;
+                }
+            }(a++ && this());
+        }
+        var c = f();
+        console.log(c);
+    }
+    expect: {
+        var c = function(a) {
+            return function() {
+                try {
+                    return a;
+                } finally {}
+            }(a++ && this());
+        }();
+        console.log(c);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_4271: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        ({
+            p: null,
+            q: (console.log("foo"), 42),
+            p: function() {}
+        })[console.log("bar"), "p"] && console.log("PASS");
+    }
+    expect: {
+        ({
+            p: null,
+            q: (console.log("foo"), 42),
+            p: function() {}
+        })[console.log("bar"), "p"],
+        console.log("PASS");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "PASS",
+    ]
+}
+
+issue_4393: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function f(a) {
+            a = "PASS";
+            console.log(arguments[0]);
+        })("FAIL");
+    }
+    expect: {
+        (function f(a) {
+            a = "PASS";
+            console.log(arguments[0]);
+        })("FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4422: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function f(a) {
+            a = "FAIL 1";
+            arguments[0] = "PASS";
+            return a;
+        }("FAIL 2"));
+    }
+    expect: {
+        console.log(function(a) {
+            a = "FAIL 1";
+            arguments[0] = "PASS";
+            return a;
+        }("FAIL 2"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4480: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = function f(b) {
+            b = "FAIL";
+            arguments[0] = "PASS";
+            var arguments = 0;
+            console.log(b);
+        }(a);
+    }
+    expect: {
+        var a = function(b) {
+            b = "FAIL";
+            arguments[0] = "PASS";
+            var arguments = 0;
+            console.log(b);
+        }(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4552: {
+    options = {
+        evaluate: true,
+        keep_fnames: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function f(b) {
+            return function() {
+                b++;
+                try {
+                    return b;
+                } catch (e) {}
+            }();
+        }();
+        console.log(a);
+    }
+    expect: {
+        var a = function f(b) {
+            return function() {
+                b++;
+                try {
+                    return b;
+                } catch (e) {}
+            }();
+        }();
+        console.log(a);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_4886: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log("length" in {
+            __proto__: function() {},
+            length: void 0,
+        });
+    }
+    expect: {
+        console.log("length" in {
+            __proto__: function() {},
+            length: void 0,
+        });
+    }
+    expect_stdout: "true"
+}

test/compress/exponentiation.js

@@ -0,0 +1,147 @@
+precedence_1: {
+    input: {
+        console.log(-4 ** 3 ** 2);
+    }
+    expect_exact: "console.log((-4)**3**2);"
+    expect_stdout: "-262144"
+    node_version: ">=8"
+}
+
+precedence_2: {
+    input: {
+        console.log(-4 ** (3 ** 2));
+    }
+    expect_exact: "console.log((-4)**3**2);"
+    expect_stdout: "-262144"
+    node_version: ">=8"
+}
+
+precedence_3: {
+    input: {
+        console.log(-(4 ** 3) ** 2);
+    }
+    expect_exact: "console.log((-(4**3))**2);"
+    expect_stdout: "4096"
+    node_version: ">=8"
+}
+
+precedence_4: {
+    input: {
+        console.log((-4 ** 3) ** 2);
+    }
+    expect_exact: "console.log(((-4)**3)**2);"
+    expect_stdout: "4096"
+    node_version: ">=8"
+}
+
+await: {
+    input: {
+        (async a => a * await a ** ++a % a)(2).then(console.log);
+    }
+    expect_exact: "(async a=>a*(await a)**++a%a)(2).then(console.log);"
+    expect_stdout: "1"
+    node_version: ">=8"
+}
+
+assignment_1: {
+    input: {
+        var a = 2;
+        a **= 5;
+        console.log(a);
+    }
+    expect_exact: "var a=2;a**=5;console.log(a);"
+    expect_stdout: "32"
+    node_version: ">=8"
+}
+
+assignment_2: {
+    input: {
+        var a = 8n;
+        a **= a;
+        console.log(a);
+    }
+    expect_exact: "var a=8n;a**=a;console.log(a);"
+    expect_stdout: "16777216n"
+    node_version: ">=10"
+}
+
+evaluate: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log(1 + 2 ** 3 - 4);
+    }
+    expect: {
+        console.log(5);
+    }
+    expect_stdout: "5"
+    node_version: ">=8"
+}
+
+issue_4664: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            new function(a) {
+                console.log(typeof f, a, typeof this);
+            }((A = 0, (NaN ^ 1) * 2 ** 30), 0);
+        }
+        f();
+    }
+    expect: {
+        (function f() {
+            new function(a) {
+                console.log(typeof f, 1073741824, typeof this);
+            }(A = 0);
+        })();
+    }
+    expect_stdout: "function 1073741824 object"
+    node_version: ">=8"
+}
+
+issue_4715: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        A = 1;
+        console.log((-0) ** A + 0);
+        console.log((-0) ** A - 0);
+        console.log((-0) ** A * 1);
+        console.log((-0) ** A / 1);
+        console.log(Math.pow(-0, A) + 0);
+        console.log(Math.pow(-0, A) - 0);
+        console.log(Math.pow(-0, A) * 1);
+        console.log(Math.pow(-0, A) / 1);
+    }
+    expect: {
+        A = 1;
+        console.log((-0) ** A + 0);
+        console.log((-0) ** A);
+        console.log((-0) ** A * 1);
+        console.log((-0) ** A);
+        console.log(Math.pow(-0, A) + 0);
+        console.log(+Math.pow(-0, A));
+        console.log(+Math.pow(-0, A));
+        console.log(+Math.pow(-0, A));
+    }
+    expect_stdout: [
+        "0",
+        "-0",
+        "-0",
+        "-0",
+        "0",
+        "-0",
+        "-0",
+        "-0",
+    ]
+    node_version: ">=8"
+}

test/compress/exports.js

@@ -0,0 +1,498 @@
+refs: {
+    input: {
+        export {};
+        export { a, b as B, c as case, d as default };
+    }
+    expect_exact: "export{};export{a,b as B,c as case,d as default};"
+}
+
+var_defs: {
+    input: {
+        export const a = 1;
+        export let b = 2, c = 3;
+        export var { d, e: [] } = f;
+    }
+    expect_exact: "export const a=1;export let b=2,c=3;export var{d,e:[]}=f;"
+}
+
+defuns: {
+    input: {
+        export class A {}
+        export function e() {}
+        export function* f(a) {}
+        export async function g(b, c) {}
+        export async function* h({}, ...[]) {}
+    }
+    expect_exact: "export class A{}export function e(){}export function*f(a){}export async function g(b,c){}export async function*h({},...[]){}"
+}
+
+defaults: {
+    input: {
+        export default 42;
+        export default async;
+        export default (x, y) => x * x;
+        export default class {};
+        export default function*(a, b) {};
+        export default async function f({ c }, ...[ d ]) {};
+    }
+    expect_exact: "export default 42;export default async;export default(x,y)=>x*x;export default class{}export default function*(a,b){}export default async function f({c},...[d]){}"
+}
+
+defaults_parentheses_1: {
+    input: {
+        export default function() {
+            console.log("FAIL");
+        }(console.log("PASS"));
+    }
+    expect_exact: 'export default function(){console.log("FAIL")}console.log("PASS");'
+}
+
+defaults_parentheses_2: {
+    input: {
+        export default (async function() {
+            console.log("PASS");
+        })();
+    }
+    expect_exact: 'export default(async function(){console.log("PASS")})();'
+}
+
+defaults_parentheses_3: {
+    input: {
+        export default (42, "PASS");
+    }
+    expect_exact: 'export default(42,"PASS");'
+}
+
+defaults_parentheses_4: {
+    input: {
+        export default (function f() {});
+    }
+    expect_exact: "export default(function f(){});"
+}
+
+defaults_parentheses_5: {
+    input: {
+        export default (function(a) {
+            console.log(a[0]);
+        }`PASS`);
+    }
+    expect_exact: "export default(function(a){console.log(a[0])})`PASS`;"
+}
+
+defaults_parentheses_6: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        export default !function() {
+            while (!console);
+        }() ? "PASS" : "FAIL";
+    }
+    expect_exact: 'export default(function(){while(!console);})()?"FAIL":"PASS";'
+}
+
+defaults_regexp: {
+    input: {
+        export default /foo/;
+    }
+    expect_exact: "export default/foo/;"
+}
+
+foreign: {
+    input: {
+        export * from "foo";
+        export {} from "bar";
+        export * as a from "baz";
+        export { default } from "moo";
+        export { b, c as case, default as delete, d } from "moz";
+    }
+    expect_exact: 'export*from"foo";export{}from"bar";export*as a from"baz";export{default}from"moo";export{b,c as case,default as delete,d}from"moz";'
+}
+
+same_quotes: {
+    beautify = {
+        beautify: true,
+        quote_style: 3,
+    }
+    input: {
+        export * from 'foo';
+        export {} from "bar";
+    }
+    expect_exact: [
+        "export * from 'foo';",
+        "",
+        'export {} from "bar";',
+    ]
+}
+
+drop_unused: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default 42;
+        export default (x, y) => x * x;
+        export default class A extends B { get p() { h() } }
+        export default function*(a, b) {}
+        export default async function f({ c }, ...[ d ]) {}
+        export var e;
+        export function g(x, [ y ], ...z) {}
+        function h() {}
+    }
+    expect: {
+        export default 42;
+        export default (x, y) => x * x;
+        export default class extends B { get p() { h() } }
+        export default function*(a, b) {}
+        export default async function({}) {}
+        export var e;
+        export function g(x, []) {}
+        function h() {}
+    }
+}
+
+mangle: {
+    rename = false
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        const a = 42;
+        export let b, { foo: c } = a;
+        export function f(d, { [b]: e }) {
+            d(e, f);
+        }
+        export default a;
+        export default async function g(x, ...{ [c]: y }) {
+            (await x)(g, y);
+        }
+    }
+    expect: {
+        const t = 42;
+        export let b, { foo: c } = t;
+        export function f(t, { [b]: o }) {
+            t(o, f);
+        }
+        export default t;
+        export default async function e(t, ...{ [c]: o}) {
+            (await t)(e, o);
+        }
+    }
+}
+
+mangle_rename: {
+    rename = true
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        const a = 42;
+        export let b, { foo: c } = a;
+        export function f(d, { [b]: e }) {
+            d(e, f);
+        }
+        export default a;
+        export default async function g(x, ...{ [c]: y }) {
+            (await x)(g, y);
+        }
+    }
+    expect: {
+        const t = 42;
+        export let b, { foo: c } = t;
+        export function f(t, { [b]: o }) {
+            t(o, f);
+        }
+        export default t;
+        export default async function e(t, ...{ [c]: o}) {
+            (await t)(e, o);
+        }
+    }
+}
+
+hoist_exports_1: {
+    options = {
+        hoist_exports: true,
+    }
+    input: {
+        export { a };
+        export var b;
+        export function f() {}
+    }
+    expect: {
+        var b;
+        function f() {}
+        export { a, b, f };
+    }
+}
+
+hoist_exports_2: {
+    options = {
+        evaluate: true,
+        hoist_exports: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        const a = 42;
+        export let bbb, { foo: ccc } = a;
+        export function fff(d, { [bbb]: e }) {
+            d(e, fff);
+        }
+        export default a;
+        export default async function g(x, ...{ [ccc]: y }) {
+            (await x)(g, y);
+        }
+    }
+    expect: {
+        let e, a = 42["foo"];
+        function f(t, { [e]: o }) {
+            t(o, f);
+        }
+        export default 42;
+        export default async function n(t, ...{ [a]: o }) {
+            (await t)(n, o);
+        };
+        export { e as bbb, a as ccc, f as fff };
+    }
+}
+
+hoist_vars: {
+    options = {
+        hoist_vars: true,
+    }
+    input: {
+        var a;
+        export var b = 42;
+    }
+    expect: {
+        var a;
+        export var b = 42;
+    }
+}
+
+keep_return_values: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        export default function() {
+            return [];
+        }
+        export default function f() {
+            return null;
+        }
+    }
+    expect: {
+        export default function() {
+            return [];
+        }
+        export default function f() {
+            return null;
+        }
+    }
+}
+
+in_use: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f() {}
+        f.prototype.p = 42;
+    }
+    expect: {
+        export function f() {}
+        f.prototype.p = 42;
+    }
+}
+
+in_use_default: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f() {}
+        f.prototype.p = 42;
+    }
+    expect: {
+        export default function f() {}
+        f.prototype.p = 42;
+    }
+}
+
+single_use: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f() {
+            console.log("PASS");
+        }
+        f();
+    }
+    expect: {
+        export function f() {
+            console.log("PASS");
+        }
+        f();
+    }
+}
+
+single_use_default: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f() {
+            console.log("PASS");
+        }
+        f();
+    }
+    expect: {
+        export default function f() {
+            console.log("PASS");
+        }
+        f();
+    }
+}
+
+single_use_class: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export class A {}
+        A.prototype.p = "PASS";
+    }
+    expect: {
+        export class A {}
+        A.prototype.p = "PASS";
+    }
+}
+
+single_use_class_default: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class A {}
+        A.prototype.p = "PASS";
+    }
+    expect: {
+        export default class A {}
+        A.prototype.p = "PASS";
+    }
+}
+
+hoist_funs: {
+    options = {
+        hoist_funs: true,
+    }
+    input: {
+        export function f() {}
+        export default async function* g() {}
+    }
+    expect_exact: "export function f(){}export default async function*g(){}"
+}
+
+issue_4742_join_vars_1: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        var a = 42;
+        export var a;
+    }
+    expect: {
+        var a = 42;
+        export var a;
+    }
+}
+
+issue_4742_join_vars_2: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        export var a = "foo";
+        var b;
+        b = "bar";
+    }
+    expect: {
+        export var a = "foo";
+        var b, b = "bar";
+    }
+}
+
+issue_4742_unused_1: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = 42;
+        export var a;
+    }
+    expect: {
+        var a = 42;
+        export var a;
+    }
+}
+
+issue_4742_unused_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export var a = "foo";
+        var a = "bar";
+    }
+    expect: {
+        export var a = "foo";
+        a = "bar";
+    }
+}
+
+issue_4761: {
+    input: {
+        export default "function" == 42;
+    }
+    expect_exact: 'export default"function"==42;'
+}
+
+issue_4766: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = "foo";
+        export var a = "bar";
+    }
+    expect: {
+        var a = "foo";
+        export var a = "bar";
+    }
+}

test/compress/hoist_props.js

@@ -297,6 +297,33 @@ name_collision_3: {
     expect_stdout: "true 4 6"
 }
 
+name_collision_4: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 0,
+                q: "PASS",
+            };
+            return function(o_p) {
+                if (!o.p) return o_p;
+            }(o.q);
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o_p$0 = 0, o_q = "PASS";
+            return function(o_p) {
+                if (!o_p$0) return o_p;
+            }(o_q);
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
 contains_this_1: {
     options = {
         evaluate: true,
@@ -750,6 +777,32 @@ issue_3046: {
 }
 
 issue_3071_1: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        join_vars: true,
+        passes: 3,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var obj = {};
+            obj.one = 1;
+            obj.two = 2;
+            console.log(obj.one, obj.two);
+        })();
+    }
+    expect: {
+        console.log(1, 2);
+    }
+    expect_stdout: "1 2"
+}
+
+issue_3071_1_toplevel: {
     options = {
         evaluate: true,
         hoist_props: true,
@@ -1041,3 +1094,50 @@ issue_4023: {
     }
     expect_stdout: "true"
 }
+
+object_super: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            f(a) {
+                return a ? console.log("PASS") : super.log("PASS");
+            },
+        };
+        o.f(42);
+    }
+    expect: {
+        var o = {
+            f(a) {
+                return a ? console.log("PASS") : super.log("PASS");
+            },
+        };
+        o.f(42);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4985: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = { p: 42 };
+        console.log(function() {
+            a;
+        }());
+    }
+    expect: {
+        var a_p = 42;
+        console.log(function() {
+            ({});
+        }());
+    }
+    expect_stdout: "undefined"
+}

test/compress/hoist_vars.js

@@ -89,6 +89,31 @@ sequences_funs: {
     }
 }
 
+catch_var: {
+    options = {
+        dead_code: true,
+        hoist_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            a;
+        } catch (a) {
+            var a = 0;
+            a;
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
 issue_2295: {
     options = {
         collapse_vars: true,
@@ -109,3 +134,264 @@ issue_2295: {
         }
     }
 }
+
+issue_4487: {
+    options = {
+        functions: true,
+        hoist_vars: true,
+        keep_fnames: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function f() {
+            var f = console.log(typeof f);
+        };
+        var b = a();
+    }
+    expect: {
+        function a() {
+            var f;
+            console.log(typeof f);
+        }
+        a();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4489: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        A = 0;
+        var o = !0 || null;
+        for (var k in o);
+        console.log(k);
+    }
+    expect: {
+        !(A = 0);
+        for (var k in true);
+        console.log(k);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4517: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        join_vars: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var a = 2;
+            A = a;
+            var b = typeof !1;
+            return A + b;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var a = 2;
+            A = a;
+            return A + typeof !1;
+        }());
+    }
+    expect_stdout: "2boolean"
+}
+
+issue_4736: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        function f() {
+            (function g() {
+                var b = (a = 0, 1 << 30);
+                var c = (a = 0, console.log(b));
+                var d = c;
+            })(f);
+        }
+        f();
+    }
+    expect: {
+        (function() {
+            (function() {
+                0,
+                console.log(1073741824);
+            })();
+        })();
+    }
+    expect_stdout: "1073741824"
+}
+
+issue_4839: {
+    options = {
+        evaluate: true,
+        hoist_vars: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = function(a, b) {
+            return b && b;
+        }("foo");
+        for (var k in o)
+            throw "FAIL";
+        console.log("PASS");
+    }
+    expect: {
+        var k, o = void 0;
+        for (k in o)
+            throw "FAIL";
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4859: {
+    options = {
+        evaluate: true,
+        hoist_vars: true,
+        keep_infinity: true,
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var b = (a = 2, 1 / 0), c = 3;
+            var d = a + b;
+            console.log(d);
+            return f;
+        }
+        f();
+    }
+    expect: {
+        (function f(a) {
+            var d = 1 / 0, d = Infinity;
+            console.log(d);
+            return f;
+        })();
+    }
+    expect_stdout: "Infinity"
+}
+
+issue_4893_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            var a = null;
+            var b = null;
+            var c = null;
+            b.p += a = 42;
+            f;
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try{
+            (function f() {
+                null.p += 42;
+                f;
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4893_2: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            var a = null;
+            var b = null;
+            var c = null;
+            b.p += a = 42;
+            f;
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try{
+            (function() {
+                var b;
+                b = null;
+                b.p += 42;
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4898: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        loops: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        do {
+            var b = [ console.log("PASS") ];
+            var c = b;
+        } while (c.p = 0);
+    }
+    expect: {
+        var b;
+        b = [ console.log("PASS") ];
+        b.p = 0;
+    }
+    expect_stdout: "PASS"
+}

test/compress/if_return.js

@@ -594,3 +594,157 @@ iife_if_return_simple: {
     }
     expect_stdout: "PASS"
 }
+
+nested_if_break: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        for (var i = 0; i < 3; i++)
+            L1: if ("number" == typeof i) {
+                if (0 === i) break L1;
+                console.log(i);
+            }
+    }
+    expect: {
+        for (var i = 0; i < 3; i++)
+            L1: if ("number" == typeof i)
+                if (0 !== i) console.log(i);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+nested_if_continue: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        join_vars: true,
+        loops: true,
+    }
+    input: {
+        function f(n) {
+            var i = 0;
+            do {
+                if ("number" == typeof n) {
+                    if (0 === n) {
+                        console.log("even", i);
+                        continue;
+                    }
+                    if (1 === n) {
+                        console.log("odd", i);
+                        continue;
+                    }
+                    i++;
+                }
+            } while (0 <= (n -= 2));
+        }
+        f(37);
+        f(42);
+    }
+    expect: {
+        function f(n) {
+            for (var i = 0;
+                "number" == typeof n
+                    && (0 !== n
+                        ? 1 !== n
+                            ? i++
+                            : console.log("odd", i)
+                        : console.log("even", i)),
+                0 <= (n -= 2););
+        }
+        f(37);
+        f(42);
+    }
+    expect_stdout: [
+        "odd 18",
+        "even 21",
+    ]
+}
+
+nested_if_return: {
+    options = {
+        conditionals: true,
+        if_return: true,
+    }
+    input: {
+        function f() {
+            if (A) {
+                if (B)
+                    return B;
+                if (C)
+                    return D;
+                if (E)
+                    return F;
+                if (G)
+                    return H;
+                if (I) {
+                    if (J)
+                        return K;
+                    return;
+                }
+                if (L) {
+                    if (M)
+                        return;
+                    return N;
+                }
+            }
+        }
+    }
+    expect: {
+        function f() {
+            if (A)
+                return B || (C ? D : E ? F : G ? H : I ? J ? K : void 0 : L && !M ? N : void 0);
+        }
+    }
+}
+
+issue_866_1: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: false,
+    };
+    input: {
+        function f(a) {
+            if (a)
+                return "";
+            console.log(a);
+        }
+    }
+    expect: {
+        function f(a) {
+            if (a)
+                return "";
+            console.log(a);
+        }
+    }
+}
+
+issue_866_2: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+    }
+    input: {
+        (function() {
+            if (a)
+                if (b)
+                    c;
+                else
+                    return d;
+        })();
+    }
+    expect: {
+        (function() {
+            if (a) {
+                if (!b)
+                    return d;
+                c;
+            }
+        })();
+    }
+}

test/compress/imports.js

@@ -0,0 +1,213 @@
+nought: {
+    input: {
+        import "foo";
+    }
+    expect_exact: 'import"foo";'
+}
+
+default_only: {
+    input: {
+        import foo from "bar";
+    }
+    expect_exact: 'import foo from"bar";'
+}
+
+all_only: {
+    input: {
+        import * as foo from "bar";
+    }
+    expect_exact: 'import*as foo from"bar";'
+}
+
+keys_only: {
+    input: {
+        import { as as foo, bar, delete as baz } from "moo";
+    }
+    expect_exact: 'import{as as foo,bar,delete as baz}from"moo";'
+}
+
+default_all: {
+    input: {
+        import foo, * as bar from "baz";
+    }
+    expect_exact: 'import foo,*as bar from"baz";'
+}
+
+default_keys: {
+    input: {
+        import foo, { bar } from "baz";
+    }
+    expect_exact: 'import foo,{bar}from"baz";'
+}
+
+dynamic: {
+    input: {
+        (async a => await import(a))("foo").then(bar);
+    }
+    expect_exact: '(async a=>await import(a))("foo").then(bar);'
+}
+
+dynamic_nought: {
+    input: {
+        import(foo);
+    }
+    expect_exact: "import(foo);"
+}
+
+import_meta_1: {
+    input: {
+        console.log(import.meta, import.meta.url);
+    }
+    expect_exact: "console.log(import.meta,import.meta.url);"
+}
+
+import_meta_2: {
+    input: {
+        import.meta.url.split("/").forEach(function(part, index) {
+            console.log(index, part);
+        });
+    }
+    expect_exact: 'import.meta.url.split("/").forEach(function(part,index){console.log(index,part)});'
+}
+
+same_quotes: {
+    beautify = {
+        beautify: true,
+        quote_style: 3,
+    }
+    input: {
+        import 'foo';
+        import "bar";
+    }
+    expect_exact: [
+        "import 'foo';",
+        "",
+        'import "bar";',
+    ]
+}
+
+drop_unused: {
+    options = {
+        imports: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        import a, * as b from "foo";
+        import { c } from "bar";
+        import { d, _ as e } from "baz";
+        console.log(d);
+    }
+    expect: {
+        import "foo";
+        import "bar";
+        import { d as d } from "baz";
+        console.log(d);
+    }
+}
+
+mangle: {
+    rename = false
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        import foo, { bar } from "baz";
+        consoe.log(moo);
+        import * as moo from "moz";
+    }
+    expect: {
+        import o, { bar as m } from "baz";
+        consoe.log(r);
+        import * as r from "moz";
+    }
+}
+
+rename_mangle: {
+    rename = true
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        import foo, { bar } from "baz";
+        consoe.log(moo);
+        import * as moo from "moz";
+    }
+    expect: {
+        import o, { bar as m } from "baz";
+        consoe.log(r);
+        import * as r from "moz";
+    }
+}
+
+keep_ref: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        import foo from "bar";
+        foo();
+    }
+    expect: {
+        import foo from "bar";
+        foo();
+    }
+}
+
+forbid_merge: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        import A from "foo";
+        export default class extends A {}
+        var f = () => () => {};
+        f();
+        f();
+    }
+    expect: {
+        import A from "foo";
+        export default class extends A {}
+        var f = () => () => {};
+        f();
+        f();
+    }
+}
+
+issue_4708_1: {
+    options = {
+        imports: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        import a from "foo";
+    }
+    expect: {
+        var a;
+        import a from "foo";
+    }
+}
+
+issue_4708_2: {
+    options = {
+        imports: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        console.log(a);
+        import a from "foo";
+    }
+    expect: {
+        var a;
+        console.log(a);
+        import a from "foo";
+    }
+}

test/compress/issue-1034.js

@@ -39,7 +39,7 @@ non_hoisted_function_after_return: {
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:4,16]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:10,12]",
-        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:11,21]"
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:11,21]",
     ]
 }
 
@@ -84,19 +84,16 @@ non_hoisted_function_after_return_2a: {
         }
     }
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:4,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:4,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:7,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:4,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:7,16]",
         "WARN: Dropping unused variable a [test/compress/issue-1034.js:4,20]",
         "WARN: Dropping unused function nope [test/compress/issue-1034.js:11,21]",
-        "INFO: pass 0: last_count: Infinity, count: 36",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:9,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:9,12]",
+        "INFO: pass 0: last_count: Infinity, count: 35",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:9,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
         "INFO: Dropping unused variable b [test/compress/issue-1034.js:7,20]",
         "INFO: Dropping unused variable c [test/compress/issue-1034.js:9,16]",
-        "INFO: pass 1: last_count: 36, count: 18",
+        "INFO: pass 1: last_count: 35, count: 18",
     ]
 }
 
@@ -138,10 +135,7 @@ non_hoisted_function_after_return_2b: {
         }
     }
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:6,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:6,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:8,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:8,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
     ]
 }
@@ -242,19 +236,16 @@ non_hoisted_function_after_return_2a_strict: {
     }
     expect_stdout: "5 6"
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:5,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:5,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:8,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:8,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:5,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,16]",
         "WARN: Dropping unused variable a [test/compress/issue-1034.js:5,20]",
         "WARN: Dropping unused function nope [test/compress/issue-1034.js:12,21]",
-        "INFO: pass 0: last_count: Infinity, count: 47",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:10,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:10,12]",
+        "INFO: pass 0: last_count: Infinity, count: 46",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:10,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:13,12]",
         "INFO: Dropping unused variable b [test/compress/issue-1034.js:8,20]",
         "INFO: Dropping unused variable c [test/compress/issue-1034.js:10,16]",
-        "INFO: pass 1: last_count: 47, count: 29",
+        "INFO: pass 1: last_count: 46, count: 29",
     ]
 }
 
@@ -301,10 +292,7 @@ non_hoisted_function_after_return_2b_strict: {
     }
     expect_stdout: "5 6"
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:7,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:9,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:9,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:9,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:13,12]",
     ]
 }

test/compress/issue-1052.js

@@ -16,7 +16,7 @@ multiple_functions: {
         ( function() {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
-            if ( window );
+            if ( !window );
             function f() {}
             function g() {}
         } )();
@@ -38,7 +38,7 @@ single_function: {
     }
     expect: {
         ( function() {
-            if ( window );
+            if ( !window );
             function f() {}
         } )();
     }
@@ -67,7 +67,7 @@ deeply_nested: {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
             if ( window )
-                if (document);
+                if ( !document );
             function f() {}
             function g() {}
             function h() {}

test/compress/issue-1105.js

@@ -151,15 +151,18 @@ Infinity_not_in_with_scope: {
         unused: true,
     }
     input: {
-        var o = { Infinity: 'oInfinity' };
+        var o = { Infinity: "FAIL" };
         var vInfinity = "Infinity";
         vInfinity = Infinity;
+        console.log(vInfinity);
     }
     expect: {
-        var o = { Infinity: 'oInfinity' }
-        var vInfinity = "Infinity"
-        vInfinity = 1/0
+        var o = { Infinity: "FAIL" };
+        var vInfinity = "Infinity";
+        vInfinity = 1/0;
+        console.log(vInfinity);
     }
+    expect_stdout: "Infinity"
 }
 
 Infinity_in_with_scope: {
@@ -167,15 +170,18 @@ Infinity_in_with_scope: {
         unused: true,
     }
     input: {
-        var o = { Infinity: 'oInfinity' };
+        var o = { Infinity: "PASS" };
         var vInfinity = "Infinity";
         with (o) { vInfinity = Infinity; }
+        console.log(vInfinity);
     }
     expect: {
-        var o = { Infinity: 'oInfinity' }
-        var vInfinity = "Infinity"
-        with (o) vInfinity = Infinity
+        var o = { Infinity: "PASS" };
+        var vInfinity = "Infinity";
+        with (o) vInfinity = Infinity;
+        console.log(vInfinity);
     }
+    expect_stdout: "PASS"
 }
 
 assorted_Infinity_NaN_undefined_in_with_scope: {

test/compress/issue-12.js

@@ -2,61 +2,77 @@ keep_name_of_getter: {
     options = {
         unused: true,
     }
-    input: { a = { get foo () {} } }
-    expect: { a = { get foo () {} } }
+    input: {
+        a = {
+            get foo() {},
+        };
+    }
+    expect: {
+        a = {
+            get foo() {},
+        };
+    }
 }
 
 keep_name_of_setter: {
     options = {
         unused: true,
     }
-    input: { a = { set foo () {} } }
-    expect: { a = { set foo () {} } }
+    input: {
+        a = {
+            set foo(v) {},
+        };
+    }
+    expect: {
+        a = {
+            set foo(v) {},
+        };
+    }
 }
 
 setter_with_operator_keys: {
     input: {
-        var tokenCodes  = {
-            get instanceof(){
+        var tokenCodes = {
+            get instanceof() {
                 return test0;
             },
-            set instanceof(value){
+            set instanceof(value) {
                 test0 = value;
             },
-            set typeof(value){
+            set typeof(value) {
                 test1 = value;
             },
-            get typeof(){
+            get typeof() {
                 return test1;
             },
-            set else(value){
+            set else(value) {
                 test2 = value;
             },
-            get else(){
+            get else() {
                 return test2;
-            }
+            },
         };
     }
     expect: {
-        var tokenCodes  = {
-            get instanceof(){
+        var tokenCodes = {
+            get instanceof() {
                 return test0;
             },
-            set instanceof(value){
+            set instanceof(value) {
                 test0 = value;
             },
-            set typeof(value){
+            set typeof(value) {
                 test1 = value;
             },
-            get typeof(){
+            get typeof() {
                 return test1;
             },
-            set else(value){
+            set else(value) {
                 test2 = value;
             },
-            get else(){
+            get else() {
                 return test2;
-            }
+            },
         };
     }
-}
+}

test/compress/issue-1202.js

@@ -4,7 +4,7 @@ mangle_keep_fnames_false: {
         keep_fnames: true,
     }
     mangle = {
-        keep_fnames : false,
+        keep_fnames: false,
     }
     input: {
         "use strict";
@@ -30,7 +30,7 @@ mangle_keep_fnames_true: {
         keep_fnames: true,
     }
     mangle = {
-        keep_fnames : true,
+        keep_fnames: true,
     }
     input: {
         "use strict";

test/compress/issue-1261.js

@@ -1,5 +1,6 @@
 pure_function_calls: {
     options = {
+        annotations: true,
         booleans: true,
         comparisons: true,
         conditionals: true,
@@ -60,6 +61,7 @@ pure_function_calls: {
 
 pure_function_calls_toplevel: {
     options = {
+        annotations: true,
         booleans: true,
         comparisons: true,
         conditionals: true,
@@ -126,6 +128,7 @@ pure_function_calls_toplevel: {
 
 should_warn: {
     options = {
+        annotations: true,
         booleans: true,
         conditionals: true,
         evaluate: true,

test/compress/issue-1446.js

@@ -24,7 +24,7 @@ typeof_eq_undefined: {
 typeof_eq_undefined_ie8: {
     options = {
         comparisons: true,
-        ie8: true,
+        ie: true,
         typeofs: true,
     }
     input: {

test/compress/issue-1588.js

@@ -1,9 +1,9 @@
 screw_ie8: {
     options = {
-        ie8: false,
+        ie: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
     }
     input: {
         try { throw "foo"; } catch (x) { console.log(x); }
@@ -16,10 +16,10 @@ screw_ie8: {
 
 support_ie8: {
     options = {
-        ie8: true,
+        ie: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
     }
     input: {
         try { throw "foo"; } catch (x) { console.log(x); }

test/compress/issue-1704.js

@@ -1,10 +1,10 @@
 mangle_catch: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -22,11 +22,11 @@ mangle_catch: {
 
 mangle_catch_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -44,11 +44,11 @@ mangle_catch_ie8: {
 
 mangle_catch_var: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -66,11 +66,11 @@ mangle_catch_var: {
 
 mangle_catch_var_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -88,11 +88,11 @@ mangle_catch_var_ie8: {
 
 mangle_catch_toplevel: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -110,11 +110,11 @@ mangle_catch_toplevel: {
 
 mangle_catch_ie8_toplevel: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -132,11 +132,11 @@ mangle_catch_ie8_toplevel: {
 
 mangle_catch_var_toplevel: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -154,11 +154,11 @@ mangle_catch_var_toplevel: {
 
 mangle_catch_var_ie8_toplevel: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -176,11 +176,11 @@ mangle_catch_var_ie8_toplevel: {
 
 mangle_catch_redef_1: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -198,11 +198,11 @@ mangle_catch_redef_1: {
 
 mangle_catch_redef_1_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -220,11 +220,11 @@ mangle_catch_redef_1_ie8: {
 
 mangle_catch_redef_1_toplevel: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -242,11 +242,11 @@ mangle_catch_redef_1_toplevel: {
 
 mangle_catch_redef_1_ie8_toplevel: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -264,11 +264,11 @@ mangle_catch_redef_1_ie8_toplevel: {
 
 mangle_catch_redef_2: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -285,11 +285,11 @@ mangle_catch_redef_2: {
 
 mangle_catch_redef_2_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -306,11 +306,11 @@ mangle_catch_redef_2_ie8: {
 
 mangle_catch_redef_2_toplevel: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -327,11 +327,11 @@ mangle_catch_redef_2_toplevel: {
 
 mangle_catch_redef_2_ie8_toplevel: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -348,7 +348,7 @@ mangle_catch_redef_2_ie8_toplevel: {
 
 mangle_catch_redef_3: {
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -371,7 +371,7 @@ mangle_catch_redef_3: {
 
 mangle_catch_redef_3_toplevel: {
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -394,7 +394,7 @@ mangle_catch_redef_3_toplevel: {
 
 mangle_catch_redef_3_ie8: {
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -417,7 +417,7 @@ mangle_catch_redef_3_ie8: {
 
 mangle_catch_redef_3_ie8_toplevel: {
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {

test/compress/issue-1733.js

@@ -1,6 +1,6 @@
 function_iife_catch: {
     mangle = {
-        ie8: false,
+        ie: false,
     }
     input: {
         function f(n) {
@@ -21,7 +21,7 @@ function_iife_catch: {
 
 function_iife_catch_ie8: {
     mangle = {
-        ie8: true,
+        ie: true,
     }
     input: {
         function f(n) {
@@ -42,7 +42,7 @@ function_iife_catch_ie8: {
 
 function_catch_catch: {
     mangle = {
-        ie8: false,
+        ie: false,
     }
     input: {
         var o = 0;
@@ -70,7 +70,7 @@ function_catch_catch: {
 
 function_catch_catch_ie8: {
     mangle = {
-        ie8: true,
+        ie: true,
     }
     input: {
         var o = 0;

test/compress/issue-269.js

@@ -17,7 +17,7 @@ issue_269_1: {
     expect: {
         var x = {};
         console.log(
-            x + "", +x, !!x,
+            "" + x, +("" + x), !!x,
             "", 0, false
         );
     }

test/compress/issue-281.js

@@ -426,6 +426,7 @@ wrap_iife_in_return_call: {
 
 pure_annotation_1: {
     options = {
+        annotations: true,
         inline: true,
         side_effects: true,
     }
@@ -439,6 +440,7 @@ pure_annotation_1: {
 
 pure_annotation_2: {
     options = {
+        annotations: true,
         collapse_vars: true,
         inline: true,
         side_effects: true,
@@ -463,15 +465,19 @@ drop_fargs: {
         var a = 1;
         !function(a_1) {
             a++;
-        }(a++ + (a && a.var));
+        }(a++ + (a && console.log(a)));
         console.log(a);
     }
     expect: {
         var a = 1;
-        ++a && a.var, a++;
+        ++a && console.log(a),
+        a++;
         console.log(a);
     }
-    expect_stdout: "3"
+    expect_stdout: [
+        "2",
+        "3",
+    ]
 }
 
 keep_fargs: {
@@ -486,13 +492,17 @@ keep_fargs: {
         var a = 1;
         !function(a_1) {
             a++;
-        }(a++ + (a && a.var));
+        }(a++ + (a && console.log(a)));
         console.log(a);
     }
     expect: {
         var a = 1;
-        ++a && a.var, a++;
+        ++a && console.log(a),
+        a++;
         console.log(a);
     }
-    expect_stdout: "3"
+    expect_stdout: [
+        "2",
+        "3",
+    ]
 }

test/compress/issue-976.js

@@ -63,42 +63,81 @@ eval_unused: {
         unused: true,
     }
     input: {
-        function f1(a, eval, c, d, e) {
-            return a('c') + eval;
-        }
-        function f2(a, b, c, d, e) {
-            return a + eval('c');
-        }
-        function f3(a, eval, c, d, e) {
-            return a + eval('c');
+        function o(k) {
+            return { c: 14 }[k];
         }
+        console.log(function f1(a, eval, c, d, e) {
+            return a("c") + eval;
+        }(o, 28, true));
+        console.log(function f2(a, b, c, d, e) {
+            return a + eval("c");
+        }(14, true, 28));
+        console.log(function f3(a, eval, c, d, e) {
+            return a + eval("c");
+        }(28, o, true));
     }
     expect: {
-        function f1(a, eval) {
-            return a('c') + eval;
-        }
-        function f2(a, b, c, d, e) {
-            return a + eval('c');
-        }
-        function f3(a, eval, c, d, e) {
-            return a + eval('c');
+        function o(k) {
+            return { c: 14 }[k];
         }
+        console.log(function(a, eval) {
+            return a("c") + eval;
+        }(o, 28));
+        console.log(function f2(a, b, c, d, e) {
+            return a + eval("c");
+        }(14, true, 28));
+        console.log(function f3(a, eval, c, d, e) {
+            return a + eval("c");
+        }(28, o, true));
     }
+    expect_stdout: [
+        "42",
+        "42",
+        "42",
+    ]
 }
 
 eval_mangle: {
-    mangle = {
-    };
-    input: {
-        function f1(a, eval, c, d, e) {
-            return a('c') + eval;
-        }
-        function f2(a, b, c, d, e) {
-            return a + eval('c');
-        }
-        function f3(a, eval, c, d, e) {
-            return a + eval('c');
-        }
+    mangle = {}
+    beautify = {
+        beautify: true,
     }
-    expect_exact: 'function f1(n,c,e,a,f){return n("c")+c}function f2(a,b,c,d,e){return a+eval("c")}function f3(a,eval,c,d,e){return a+eval("c")}'
+    input: {
+        function o(k) {
+            return { cc: 14 }[k + "c"];
+        }
+        console.log(function f1(a, eval, c, d, e) {
+            return a("c") + eval;
+        }(o, 28, true));
+        console.log(function f2(a, b, c, d, e) {
+            return a + eval("c");
+        }(14, true, 28));
+        console.log(function f3(a, eval, c, d, e) {
+            return a + eval("c");
+        }(28, o, true));
+    }
+    expect_exact: [
+        "function o(o) {",
+        "    return {",
+        "        cc: 14",
+        '    }[o + "c"];',
+        "}",
+        "",
+        "console.log(function o(c, e, n, r, t) {",
+        '    return c("c") + e;',
+        "}(o, 28, true));",
+        "",
+        "console.log(function f2(a, b, c, d, e) {",
+        '    return a + eval("c");',
+        "}(14, true, 28));",
+        "",
+        "console.log(function f3(a, eval, c, d, e) {",
+        '    return a + eval("c");',
+        "}(28, o, true));",
+    ]
+    expect_stdout: [
+        "42",
+        "42",
+        "42",
+    ]
 }

test/compress/join_vars.js

@@ -277,8 +277,8 @@ join_object_assignments_forin: {
     }
     expect: {
         console.log(function() {
-            var o = { a: "PASS" };
-            for (var a in o)
+            var o = { a: "PASS" }, a;
+            for (a in o)
                 return o[a];
         }());
     }
@@ -790,7 +790,7 @@ issue_3795: {
         dead_code: true,
         evaluate: true,
         join_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         loops: true,
         passes: 2,
         reduce_vars: true,
@@ -1015,7 +1015,7 @@ issue_3856: {
         console.log(function() {
             (function() {
                 var a, b;
-                if (a) return !!a;
+                if (a) return a, 1;
                 for (a = 0; !console;);
                 return 0;
             })();
@@ -1024,7 +1024,7 @@ issue_3856: {
     expect_stdout: "undefined"
 }
 
-issue_3916: {
+issue_3916_1: {
     options = {
         join_vars: true,
     }
@@ -1044,8 +1044,8 @@ issue_3916: {
         var o = {
             p: "PASS",
             __proto__: 42,
-            q: "FAIL",
         };
+        o.q = "FAIL";
         o.__proto__ = {
             p: "FAIL",
             q: "PASS",
@@ -1055,3 +1055,131 @@ issue_3916: {
     }
     expect_stdout: "object PASS true PASS"
 }
+
+issue_3916_2: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        var log = console.log, o = {};
+        o.p = "FAIL 1";
+        o.__proto__ = {
+            get p() {
+                return "FAIL 2";
+            },
+            set p(u) {
+                log("FAIL 3");
+            },
+            set q(v) {
+                log("PASS 1");
+            },
+            get q() {
+                return "PASS 3";
+            },
+        };
+        o.p = "PASS 2";
+        o.q = "FAIL 4";
+        log(o.p);
+        log(o.q);
+    }
+    expect: {
+        var log = console.log, o = {
+            p: "FAIL 1",
+            __proto__: {
+                get p() {
+                    return "FAIL 2";
+                },
+                set p(u) {
+                    log("FAIL 3");
+                },
+                set q(v) {
+                    log("PASS 1");
+                },
+                get q() {
+                    return "PASS 3";
+                },
+            },
+        };
+        o.p = "PASS 2";
+        o.q = "FAIL 4";
+        log(o.p);
+        log(o.q);
+    }
+    expect_stdout: [
+        "PASS 1",
+        "PASS 2",
+        "PASS 3",
+    ]
+}
+
+assign_var: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        b = "foo";
+        var a = [ , "bar" ];
+        console.log(b);
+        for (var b in a)
+            console.log(b, a[b]);
+    }
+    expect: {
+        var b = "foo", a = [ , "bar" ], b;
+        console.log(b);
+        for (b in a)
+            console.log(b, a[b]);
+    }
+    expect_stdout: [
+        "foo",
+        "1 bar",
+    ]
+}
+
+assign_for_var: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        i = "foo",
+        a = new Array(i, "bar");
+        for (var i = 2; --i >= 0;) {
+            console.log(a[i]);
+            for (var a in i);
+        }
+    }
+    expect: {
+        for (var i = "foo", a = new Array(i, "bar"), i = 2; --i >= 0;) {
+            console.log(a[i]);
+            for (var a in i);
+        }
+    }
+    expect_stdout: [
+        "bar",
+        "foo",
+    ]
+}
+
+assign_sequence_var: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        var a = 0, b = 1;
+        console.log(a),
+        a++,
+        b = 2;
+        var c = 3;
+        console.log(a, b, c);
+    }
+    expect: {
+        var a = 0, b = 1;
+        console.log(a),
+        a++;
+        var b = 2, c = 3;
+        console.log(a, b, c);
+    }
+    expect_stdout: [
+        "0",
+        "1 2 3",
+    ]
+}

test/compress/keep_fargs.js

@@ -18,43 +18,6 @@ keep_fargs_false: {
         function j(e) {}
         console.log(h(), i().length, j.length);
     }
-    expect: {
-        console.log(function f() {
-            return f.length;
-        }(), function g() {
-            return g;
-        }().length);
-        function h() {
-            return h.length;
-        }
-        function i() {
-            return i;
-        }
-        function j() {}
-        console.log(h(), i().length, j.length);
-    }
-}
-
-keep_fargs_strict: {
-    options = {
-        keep_fargs: "strict",
-        unused: true,
-    }
-    input: {
-        console.log(function f(a) {
-            return f.length;
-        }(), function g(b) {
-            return g;
-        }().length);
-        function h(c) {
-            return h.length;
-        }
-        function i(d) {
-            return i;
-        }
-        function j(e) {}
-        console.log(h(), i().length, j.length);
-    }
     expect: {
         console.log(function f(a) {
             return f.length;
@@ -117,61 +80,11 @@ keep_fargs_true: {
     ]
 }
 
-replace_index: {
-    options = {
-        arguments: true,
-        evaluate: true,
-        keep_fargs: "strict",
-        properties: true,
-    }
-    input: {
-        var arguments = [];
-        console.log(arguments[0]);
-        (function() {
-            console.log(arguments[1], arguments["1"], arguments["foo"]);
-        })("bar", 42);
-        (function(a, b) {
-            console.log(arguments[1], arguments["1"], arguments["foo"]);
-        })("bar", 42);
-        (function(arguments) {
-            console.log(arguments[1], arguments["1"], arguments["foo"]);
-        })("bar", 42);
-        (function() {
-            var arguments;
-            console.log(arguments[1], arguments["1"], arguments["foo"]);
-        })("bar", 42);
-    }
-    expect: {
-        var arguments = [];
-        console.log(arguments[0]);
-        (function(argument_0, argument_1) {
-            console.log(argument_1, argument_1, arguments.foo);
-        })("bar", 42);
-        (function(a, b) {
-            console.log(b, b, arguments.foo);
-        })("bar", 42);
-        (function(arguments) {
-            console.log(arguments[1], arguments[1], arguments.foo);
-        })("bar", 42);
-        (function() {
-            var arguments;
-            console.log(arguments[1], arguments[1], arguments.foo);
-        })("bar", 42);
-    }
-    expect_stdout: [
-        "undefined",
-        "42 42 undefined",
-        "42 42 undefined",
-        "a a undefined",
-        "42 42 undefined",
-    ]
-}
-
 replace_index_strict: {
     options = {
         arguments: true,
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         properties: true,
         reduce_vars: true,
     }
@@ -202,8 +115,9 @@ replace_index_strict: {
 issue_1858: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: true,
+        reduce_vars: true,
         unused: true,
     }
     input: {
@@ -224,7 +138,7 @@ issue_1858: {
 issue_2187_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -245,7 +159,7 @@ issue_2187_2: {
 issue_2203_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -280,7 +194,7 @@ issue_2203_2: {
 issue_2298: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -306,7 +220,6 @@ issue_2298: {
     expect: {
         !function() {
             (function() {
-                0;
                 try {
                     !function() {
                         (void 0)[1] = "foo";
@@ -324,7 +237,7 @@ issue_2298: {
 issue_2319_1: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -347,7 +260,7 @@ issue_2319_1: {
 issue_2319_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -372,7 +285,7 @@ issue_2319_2: {
 issue_2319_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -397,7 +310,7 @@ issue_2319_3: {
 issue_2425_1: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -420,7 +333,7 @@ issue_2425_1: {
 issue_2425_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -443,7 +356,7 @@ issue_2425_2: {
 issue_2425_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -466,7 +379,7 @@ issue_2425_3: {
 issue_2436_13: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -500,7 +413,7 @@ issue_2436_13: {
 issue_2506: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -539,7 +452,7 @@ issue_2506: {
 
 issue_2226_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -586,7 +499,7 @@ issue_2226_1: {
 issue_2226_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         sequences: true,
         side_effects: true,
         unused: true,
@@ -608,7 +521,7 @@ issue_2226_2: {
 issue_2226_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -628,7 +541,7 @@ issue_2226_3: {
 
 issue_3192: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -658,7 +571,7 @@ issue_3192: {
 if_increment: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -680,7 +593,7 @@ if_increment: {
 try_increment: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -704,7 +617,7 @@ try_increment: {
 issue_2630_3: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -741,7 +654,7 @@ issue_2630_3: {
 issue_3364: {
     options = {
         functions: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -806,7 +719,7 @@ issue_3364: {
 
 defun_label: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -838,7 +751,7 @@ defun_label: {
 
 iife_func_side_effects: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -890,7 +803,7 @@ iife_func_side_effects: {
 issue_1595_1: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -910,7 +823,7 @@ issue_1595_1: {
 issue_1595_2: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -930,7 +843,7 @@ issue_1595_2: {
 issue_1595_3: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -951,7 +864,7 @@ issue_1595_3: {
 issue_1595_4: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -973,7 +886,7 @@ issue_1595_4: {
 
 duplicate_lambda_defun_name_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
     }
     input: {
@@ -993,7 +906,7 @@ duplicate_lambda_defun_name_1: {
 
 duplicate_lambda_defun_name_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -1014,7 +927,7 @@ duplicate_lambda_defun_name_2: {
 
 function_name_mangle: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         keep_fnames: true,
         reduce_vars: true,
         unused: true,
@@ -1032,13 +945,13 @@ function_name_mangle: {
 
 function_name_mangle_ie8: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         keep_fnames: true,
         reduce_vars: true,
         unused: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -1053,7 +966,7 @@ function_name_mangle_ie8: {
 
 issue_3420_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1076,7 +989,7 @@ issue_3420_1: {
 issue_3420_2: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1097,7 +1010,7 @@ issue_3420_2: {
 issue_3420_3: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1119,7 +1032,7 @@ issue_3420_3: {
 
 issue_3423_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1139,7 +1052,7 @@ issue_3423_1: {
 
 issue_3423_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1166,7 +1079,7 @@ collapse_vars_repeated: {
         hoist_funs: true,
         if_return: true,
         join_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         loops: true,
         properties: true,
         reduce_funcs: true,
@@ -1213,7 +1126,7 @@ collapse_vars_repeated: {
 chained_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1237,7 +1150,7 @@ replace_all_var_scope: {
     rename = true
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     mangle = {}
@@ -1245,8 +1158,8 @@ replace_all_var_scope: {
         var a = 100, b = 10;
         (function(r, a) {
             switch (~a) {
-            case (b += a):
-            case a++:
+              case (b += a):
+              case a++:
             }
         })(--b, a);
         console.log(a, b);
@@ -1255,8 +1168,8 @@ replace_all_var_scope: {
         var a = 100, b = 10;
         (function(c) {
             switch (~a) {
-            case (b += a):
-            case c++:
+              case (b += a):
+              case c++:
             }
         })((--b, a));
         console.log(a, b);
@@ -1266,7 +1179,7 @@ replace_all_var_scope: {
 
 issue_1583: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -1303,7 +1216,7 @@ issues_3267_1: {
         dead_code: true,
         evaluate: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         side_effects: true,
@@ -1332,7 +1245,7 @@ issues_3267_1: {
 
 trailing_argument_side_effects: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1356,7 +1269,7 @@ trailing_argument_side_effects: {
 
 recursive_iife_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1375,7 +1288,7 @@ recursive_iife_1: {
 
 recursive_iife_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1453,3 +1366,37 @@ issue_3619: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4353_1: {
+    options = {
+        keep_fargs: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function f(a) {}.length);
+    }
+    expect: {
+        console.log(function(a) {}.length);
+    }
+    expect_stdout: "1"
+}
+
+issue_4353_2: {
+    options = {
+        keep_fargs: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function f(a) {
+            while (console.log("PASS"));
+        })();
+    }
+    expect: {
+        (function() {
+            while (console.log("PASS"));
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/labels.js

@@ -207,3 +207,123 @@ labels_10: {
         }
     }
 }
+
+issue_4466_1: {
+    mangle = {
+        v8: false,
+    }
+    input: {
+        A: if (console.log("PASS"))
+            B:;
+        else
+            C:;
+    }
+    expect: {
+        e: if (console.log("PASS"))
+            l:;
+        else
+            l:;
+    }
+    expect_stdout: "PASS"
+    node_version: ">=12"
+}
+
+issue_4466_1_v8: {
+    mangle = {
+        v8: true,
+    }
+    input: {
+        A: if (console.log("PASS"))
+            B:;
+        else
+            C:;
+    }
+    expect: {
+        e: if (console.log("PASS"))
+            l:;
+        else
+            o:;
+    }
+    expect_stdout: "PASS"
+    node_version: ">=12"
+}
+
+issue_4466_2: {
+    mangle = {
+        toplevel: false,
+        v8: false,
+    }
+    input: {
+        if (console.log("PASS"))
+            A:;
+        else
+            B:;
+    }
+    expect: {
+        if (console.log("PASS"))
+            e:;
+        else
+            e:;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4466_2_v8: {
+    mangle = {
+        toplevel: false,
+        v8: true,
+    }
+    input: {
+        if (console.log("PASS"))
+            A:;
+        else
+            B:;
+    }
+    expect: {
+        if (console.log("PASS"))
+            e:;
+        else
+            l:;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4466_2_toplevel: {
+    mangle = {
+        toplevel: true,
+        v8: false,
+    }
+    input: {
+        if (console.log("PASS"))
+            A:;
+        else
+            B:;
+    }
+    expect: {
+        if (console.log("PASS"))
+            e:;
+        else
+            e:;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4466_2_toplevel_v8: {
+    mangle = {
+        toplevel: true,
+        v8: true,
+    }
+    input: {
+        if (console.log("PASS"))
+            A:;
+        else
+            B:;
+    }
+    expect: {
+        if (console.log("PASS"))
+            e:;
+        else
+            e:;
+    }
+    expect_stdout: "PASS"
+}

test/compress/loops.js

@@ -193,15 +193,15 @@ evaluate: {
         } while (false);
     }
     expect: {
-        for(;;)
+        for (;;)
             a();
-        for(;;)
+        for (;;)
             c();
         d();
     }
 }
 
-issue_1532: {
+issue_1532_1: {
     options = {
         evaluate: true,
         loops: true,
@@ -210,24 +210,62 @@ issue_1532: {
         function f(x, y) {
             do {
                 if (x) break;
-                foo();
+                console.log(y);
             } while (false);
         }
+        f(null, "PASS");
+        f(42, "FAIL");
+    }
+    expect: {
+        function f(x, y) {
+            for (; !x && (console.log(y), false););
+        }
+        f(null, "PASS");
+        f(42, "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_1532_2: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        function f(x, y) {
+            do {
+                if (x) {
+                    console.log(x);
+                    break;
+                }
+                console.log(y);
+            } while (false);
+        }
+        f(null, "PASS");
+        f(42, "FAIL");
     }
     expect: {
         function f(x, y) {
             do {
-                if (x) break;
-                foo();
-            } while (false);
+                if (x) {
+                    console.log(x);
+                    break;
+                }
+            } while (console.log(y), false);
         }
+        f(null, "PASS");
+        f(42, "FAIL");
     }
+    expect_stdout: [
+        "PASS",
+        "42",
+    ]
 }
 
 issue_186: {
     beautify = {
         beautify: false,
-        ie8: false,
+        ie: false,
     }
     input: {
         var x = 3;
@@ -246,7 +284,7 @@ issue_186: {
 issue_186_ie8: {
     beautify = {
         beautify: false,
-        ie8: true,
+        ie: true,
     }
     input: {
         var x = 3;
@@ -265,7 +303,7 @@ issue_186_ie8: {
 issue_186_beautify: {
     beautify = {
         beautify: true,
-        ie8: false,
+        ie: false,
     }
     input: {
         var x = 3;
@@ -292,7 +330,7 @@ issue_186_beautify: {
 issue_186_beautify_ie8: {
     beautify = {
         beautify: true,
-        ie8: true,
+        ie: true,
     }
     input: {
         var x = 3;
@@ -322,7 +360,7 @@ issue_186_braces: {
     beautify = {
         beautify: false,
         braces: true,
-        ie8: false,
+        ie: false,
     }
     input: {
         var x = 3;
@@ -342,7 +380,7 @@ issue_186_braces_ie8: {
     beautify = {
         beautify: false,
         braces: true,
-        ie8: true,
+        ie: true,
     }
     input: {
         var x = 3;
@@ -362,7 +400,7 @@ issue_186_beautify_braces: {
     beautify = {
         beautify: true,
         braces: true,
-        ie8: false,
+        ie: false,
     }
     input: {
         var x = 3;
@@ -394,7 +432,7 @@ issue_186_beautify_braces_ie8: {
     beautify = {
         beautify: true,
         braces: true,
-        ie8: true,
+        ie: true,
     }
     input: {
         var x = 3;
@@ -463,14 +501,14 @@ do_switch: {
     }
 }
 
-in_parenthesis_1: {
+in_parentheses_1: {
     input: {
         for (("foo" in {});0;);
     }
     expect_exact: 'for(("foo"in{});0;);'
 }
 
-in_parenthesis_2: {
+in_parentheses_2: {
     input: {
         for ((function(){ "foo" in {}; });0;);
     }
@@ -509,8 +547,8 @@ dead_code_condition: {
         console.log(a);
     }
     expect: {
-        var c;
         var a = 0, b = 5;
+        var c;
         a += 1, 0,
         console.log(a);
     }
@@ -756,10 +794,78 @@ empty_for_in_side_effects: {
     expect_warnings: [
         "WARN: Dropping unused variable b [test/compress/loops.js:4,16]",
         "INFO: Dropping unused loop variable a [test/compress/loops.js:1,17]",
-        "WARN: Side effects in object of for-in loop [test/compress/loops.js:1,17]",
+        "WARN: Side effects in object of for-in loop [test/compress/loops.js:2,17]",
     ]
 }
 
+empty_for_in_prop_init: {
+    options = {
+        loops: true,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        console.log(function f() {
+            var a = "bar";
+            for ((a, f)[a] in console.log("foo"));
+            return a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var a = "bar";
+            console.log("foo");
+            return a;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    expect_warnings: [
+        "INFO: Dropping unused loop variable f [test/compress/loops.js:3,21]",
+        "WARN: Side effects in object of for-in loop [test/compress/loops.js:3,30]",
+    ]
+}
+
+for_of: {
+    input: {
+        var a = [ "PASS", 42 ];
+        a.p = "FAIL";
+        for (a of (null, a))
+            console.log(a);
+    }
+    expect_exact: 'var a=["PASS",42];a.p="FAIL";for(a of(null,a))console.log(a);'
+    expect_stdout: true
+    node_version: ">=0.12"
+}
+
+for_async_of: {
+    input: {
+        var async = [ "PASS", 42 ];
+        async.p = "FAIL";
+        for (async of (null, async))
+            console.log(async);
+    }
+    expect_exact: 'var async=["PASS",42];async.p="FAIL";for(async of(null,async))console.log(async);'
+    expect_stdout: true
+    node_version: ">=0.12 <16"
+}
+
+for_of_regexp: {
+    input: {
+        for (var a of /foo/);
+    }
+    expect_exact: "for(var a of/foo/);"
+}
+
+for_await_of_regexp: {
+    input: {
+        for await (var a of /foo/);
+    }
+    expect_exact: "for await(var a of/foo/);"
+}
+
 issue_3631_1: {
     options = {
         dead_code: true,
@@ -933,3 +1039,312 @@ issue_3634_2: {
     }
     expect_stdout: "1"
 }
+
+issue_4075: {
+    options = {
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL";
+        (function() {
+            for (a in { PASS: 0 });
+        })()
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        (function() {
+            for (a in { PASS: 0 });
+        })()
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4082: {
+    options = {
+        keep_fargs: false,
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        (function(a) {
+            for (a in "foo")
+                var b;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        (function(a) {
+            for (a in "foo");
+        })();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4084: {
+    options = {
+        keep_fargs: false,
+        loops: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            function f(a) {
+                var b = a++;
+                for (a in "foo");
+            }
+            f();
+            return typeof a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            (function() {
+                0;
+            })();
+            return typeof a;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4091_1: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            for (var e in 42);
+        }
+        console.log(e && e);
+    }
+    expect: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4091_2: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            for (e in 42);
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4182_1: {
+    options = {
+        loops: true,
+    }
+    input: {
+        (function() {
+            do {
+                try {
+                    return;
+                } finally {
+                    continue;
+                }
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect: {
+        (function() {
+            do {
+                try {
+                    return;
+                } finally {
+                    continue;
+                }
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4182_2: {
+    options = {
+        loops: true,
+    }
+    input: {
+        (function() {
+            L: do {
+                do {
+                    try {
+                        return;
+                    } finally {
+                        continue L;
+                    }
+                    console.log("FAIL");
+                } while (0);
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect: {
+        (function() {
+            L: do {
+                do {
+                    try {
+                        return;
+                    } finally {
+                        continue L;
+                    }
+                } while (console.log("FAIL"), 0);
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+do_continue: {
+    options = {
+        loops: true,
+    }
+    input: {
+        try {
+            do {
+                continue;
+            } while ([ A ]);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            do {
+                continue;
+            } while ([ A ]);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4240: {
+    options = {
+        loops: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            function f() {
+                var o = { PASS: 42 };
+                for (a in o);
+            }
+            (function() {
+                if (f());
+            })();
+            console.log(a);
+        })();
+    }
+    expect: {
+        (function(a) {
+            (function() {
+                if (function() {
+                    for (a in { PASS: 42 });
+                }());
+            })();
+            console.log(a);
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4355: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        loops: true,
+        passes: 2,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        while (function() {
+            var a;
+            for (a in console.log("PASS"))
+                var b = 0;
+        }())
+            var c;
+    }
+    expect: {
+        (function() {
+            console.log("PASS");
+        })();
+        var c;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4564: {
+    options = {
+        loops: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw null;
+        } catch (a) {
+            var a;
+            (function() {
+                for (a in "foo");
+            })();
+            console.log(a);
+        }
+    }
+    expect: {
+        try {
+            throw null;
+        } catch (a) {
+            var a;
+            (function() {
+                for (a in "foo");
+            })();
+            console.log(a);
+        }
+    }
+    expect_stdout: "2"
+}

test/compress/new.js

@@ -85,7 +85,7 @@ new_with_unary_prefix: {
     expect_exact: 'var bar=(+new Date).toString(32);';
 }
 
-dot_parenthesis_1: {
+dot_parentheses_1: {
     input: {
         console.log(new (Math.random().constructor) instanceof Number);
     }
@@ -93,7 +93,7 @@ dot_parenthesis_1: {
     expect_stdout: "true"
 }
 
-dot_parenthesis_2: {
+dot_parentheses_2: {
     input: {
         console.log(typeof new function(){Math.random()}.constructor);
     }

test/compress/nullish.js

@@ -0,0 +1,282 @@
+parentheses: {
+    input: {
+        (console.log("foo") || console.log("bar") ?? console.log("baz")) && console.log("moo");
+    }
+    expect_exact:'((console.log("foo")||console.log("bar"))??console.log("baz"))&&console.log("moo");'
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=14"
+}
+
+evaluate: {
+    options = {
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        void console.log("foo" ?? "bar") ?? console.log("baz");
+    }
+    expect: {
+        console.log("foo"),
+        console.log("baz");
+    }
+    expect_stdout: [
+        "foo",
+        "baz",
+    ]
+    node_version: ">=14"
+}
+
+conditional_assignment_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        console.log(function(a, b) {
+            b ?? (a = "FAIL");
+            return a;
+        }("PASS", !console));
+    }
+    expect: {
+        console.log(function(a, b) {
+            b ?? (a = "FAIL");
+            return a;
+        }("PASS", !console));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+conditional_assignment_2: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a, b = false;
+        a = "PASS",
+        b ?? (a = "FAIL"),
+        console.log(a);
+    }
+    expect: {
+        var a, b = false;
+        a = "PASS",
+        b ?? (a = "FAIL"),
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+conditional_assignment_3: {
+    options = {
+        conditionals: true,
+        join_vars: true,
+    }
+    input: {
+        var a, b = false;
+        a = "PASS",
+        b ?? (a = "FAIL"),
+        console.log(a);
+    }
+    expect: {
+        var a, b = false, a = "PASS";
+        b ?? (a = "FAIL"),
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+conditional_assignment_4: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        console.log(function(a) {
+            !console ?? (a = "FAIL");
+            return a;
+        }("PASS"));
+    }
+    expect: {
+        console.log(function(a) {
+            !console ?? (a = "FAIL");
+            return a;
+        }("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+de_morgan_1: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        function f(a) {
+            return a ?? a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect: {
+        function f(a) {
+            return a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect_stdout: "null 42"
+    node_version: ">=14"
+}
+
+de_morgan_2a: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a || (a ?? b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a || (a ?? b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "undefined {}",
+        "42 42",
+    ]
+    node_version: ">=14"
+}
+
+de_morgan_2b: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a && (a ?? b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "42 42",
+    ]
+    node_version: ">=14"
+}
+
+de_morgan_2c: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            return a ?? (a || b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a ?? b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "undefined {}",
+        "42 42",
+    ]
+    node_version: ">=14"
+}
+
+de_morgan_2d: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a ?? (a && b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "42 42",
+    ]
+    node_version: ">=14"
+}
+
+de_morgan_2e: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b) {
+            return a ?? (a ?? b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a ?? b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "undefined {}",
+        "42 42",
+    ]
+    node_version: ">=14"
+}
+
+issue_4679: {
+    options = {
+        comparisons: true,
+        ie: true,
+    }
+    input: {
+        var a;
+        if (void 0 === (undefined ?? a))
+            console.log("PASS");
+    }
+    expect: {
+        var a;
+        if (void 0 === (undefined ?? a))
+            console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}

test/compress/numbers.js

@@ -1,49 +1,141 @@
-hex_numbers_in_parentheses_for_prototype_functions: {
+literal_infinity: {
+    input: {
+        console.log(2e308, -1e2345);
+    }
+    expect_exact: "console.log(1/0,-(1/0));"
+}
+
+parentheses_for_prototype_functions: {
     beautify = {
         beautify: true,
     }
     input: {
-        function f() {
-            (-2);
-            (-2).toFixed(0);
+        (function() {
+            console.log((-2));
+            console.log((-2).toFixed(0));
 
-            (2);
-            (2).toFixed(0);
+            console.log((2));
+            console.log((2).toFixed(0));
 
-            (0.2);
-            (0.2).toFixed(0);
+            console.log((0.2));
+            console.log((0.2).toFixed(0));
 
-            (2.34e20);
-            (2.34e20).toFixed(0);
+            console.log((2.34e20));
+            console.log((2.34e20).toFixed(0));
 
-            (0.00000002);
-            (0.00000002).toFixed(0);
+            console.log((0.00000002));
+            console.log((0.00000002).toFixed(0));
 
-            (1000000000000000128);
-            (1000000000000000128).toFixed(0);
+            console.log((1000000000000000128));
+            console.log((1000000000000000128).toFixed(0));
 
-            (-1000000000000000128);
-            (-1000000000000000128).toFixed(0);
-        }
+            console.log((-1000000000000000128));
+            console.log((-1000000000000000128).toFixed(0));
+        })();
     }
     expect_exact: [
-        "function f() {",
-        "    -2;",
-        "    (-2).toFixed(0);",
-        "    2;",
-        "    2..toFixed(0);",
-        "    .2;",
-        "    .2.toFixed(0);",
-        "    234e18;",
-        "    234e18.toFixed(0);",
-        "    2e-8;",
-        "    2e-8.toFixed(0);",
-        "    0xde0b6b3a7640080;",
-        "    (0xde0b6b3a7640080).toFixed(0);",
-        "    -0xde0b6b3a7640080;",
-        "    (-0xde0b6b3a7640080).toFixed(0);",
-        "}",
+        "(function() {",
+        "    console.log(-2);",
+        "    console.log((-2).toFixed(0));",
+        "    console.log(2);",
+        "    console.log(2..toFixed(0));",
+        "    console.log(.2);",
+        "    console.log(.2.toFixed(0));",
+        "    console.log(234e18);",
+        "    console.log(234e18.toFixed(0));",
+        "    console.log(2e-8);",
+        "    console.log(2e-8.toFixed(0));",
+        "    console.log(0xde0b6b3a7640080);",
+        "    console.log(0xde0b6b3a7640080.toFixed(0));",
+        "    console.log(-0xde0b6b3a7640080);",
+        "    console.log((-0xde0b6b3a7640080).toFixed(0));",
+        "})();",
     ]
+    expect_stdout: true
+}
+
+parentheses_for_prototype_functions_galio: {
+    beautify = {
+        beautify: true,
+        galio: true,
+    }
+    input: {
+        (function() {
+            console.log((-2));
+            console.log((-2).toFixed(0));
+
+            console.log((2));
+            console.log((2).toFixed(0));
+
+            console.log((0.2));
+            console.log((0.2).toFixed(0));
+
+            console.log((2.34e20));
+            console.log((2.34e20).toFixed(0));
+
+            console.log((0.00000002));
+            console.log((0.00000002).toFixed(0));
+
+            console.log((1000000000000000128));
+            console.log((1000000000000000128).toFixed(0));
+
+            console.log((-1000000000000000128));
+            console.log((-1000000000000000128).toFixed(0));
+        })();
+    }
+    expect_exact: [
+        "(function() {",
+        "    console.log(-2);",
+        "    console.log((-2).toFixed(0));",
+        "    console.log(2);",
+        "    console.log(2..toFixed(0));",
+        "    console.log(.2);",
+        "    console.log(.2.toFixed(0));",
+        "    console.log(234e18);",
+        "    console.log(234e18.toFixed(0));",
+        "    console.log(2e-8);",
+        "    console.log(2e-8.toFixed(0));",
+        "    console.log(0xde0b6b3a7640080);",
+        "    console.log((0xde0b6b3a7640080).toFixed(0));",
+        "    console.log(-0xde0b6b3a7640080);",
+        "    console.log((-0xde0b6b3a7640080).toFixed(0));",
+        "})();",
+    ]
+    expect_stdout: true
+}
+
+octal: {
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        (function() {
+            console.log(052);
+            console.log(-052);
+
+            console.log(018);
+            console.log(-018);
+
+            console.log(052.toFixed(0));
+            console.log(-052.toFixed(0));
+
+            console.log(018..toFixed(0));
+            console.log(-018..toFixed(0));
+        })();
+    }
+    expect_exact: [
+        "(function() {",
+        "    console.log(42);",
+        "    console.log(-42);",
+        "    console.log(18);",
+        "    console.log(-18);",
+        "    console.log(42..toFixed(0));",
+        "    console.log(-42..toFixed(0));",
+        "    console.log(18..toFixed(0));",
+        "    console.log(-18..toFixed(0));",
+        "})();",
+    ]
+    expect_stdout: true
 }
 
 comparisons: {
@@ -91,7 +183,7 @@ evaluate_1: {
     expect: {
         console.log(
             x + 1 + 2,
-            2 * x,
+            2 * +x,
             +x + 1 + 2,
             1 + x + 2 + 3,
             3 | x,
@@ -130,7 +222,7 @@ evaluate_1_unsafe_math: {
     expect: {
         console.log(
             x + 1 + 2,
-            2 * x,
+            2 * +x,
             +x + 3,
             1 + x + 2 + 3,
             3 | x,
@@ -148,45 +240,52 @@ evaluate_1_unsafe_math: {
 evaluate_2: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: false,
     }
     input: {
-        var x = "42", y = null;
-        [
-            x + 1 + 2,
-            x * 1 * 2,
-            +x + 1 + 2,
-            1 + x + 2 + 3,
-            1 | x | 2 | 3,
-            1 + x-- + 2 + 3,
-            1 + (x*y + 2) + 3,
-            1 + (2 + x + 3),
-            1 + (2 + ~x + 3),
-            -y + (2 + ~x + 3),
-            1 & (2 & x & 3),
-            1 + (2 + (x |= 0) + 3),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var x = "" + num, y = null;
+            [
+                x + 1 + 2,
+                x * 1 * 2,
+                +x + 1 + 2,
+                1 + x + 2 + 3,
+                1 | x | 2 | 3,
+                1 + x-- + 2 + 3,
+                1 + (x*y + 2) + 3,
+                1 + (2 + x + 3),
+                1 + (2 + ~x + 3),
+                -y + (2 + ~x + 3),
+                1 & (2 & x & 3),
+                1 + (2 + (x |= 0) + 3),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect: {
-        var x = "42", y = null;
-        [
-            x + 1 + 2,
-            2 * x,
-            +x + 1 + 2,
-            1 + x + 2 + 3,
-            3 | x,
-            1 + x-- + 2 + 3,
-            x*y + 2 + 1 + 3,
-            1 + (2 + x + 3),
-            2 + ~x + 3 + 1,
-            2 + ~x + 3 - y,
-            0 & x,
-            2 + (x |= 0) + 3 + 1,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var x = "" + num, y = null;
+            [
+                x + "12",
+                2 * x,
+                +x + 1 + 2,
+                1 + x + "23",
+                3 | x,
+                1 + x-- + 2 + 3,
+                x*y + 2 + 1 + 3,
+                2 + x + 3 + 1,
+                2 + ~x + 3 + 1,
+                2 + ~x + 3,
+                0 & x,
+                2 + (x |= 0) + 3 + 1,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect_stdout: [
         "string 4212",
@@ -207,45 +306,52 @@ evaluate_2: {
 evaluate_2_unsafe_math: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: true,
     }
     input: {
-        var x = "42", y = null;
-        [
-            x + 1 + 2,
-            x * 1 * 2,
-            +x + 1 + 2,
-            1 + x + 2 + 3,
-            1 | x | 2 | 3,
-            1 + x-- + 2 + 3,
-            1 + (x*y + 2) + 3,
-            1 + (2 + x + 3),
-            1 + (2 + ~x + 3),
-            -y + (2 + ~x + 3),
-            1 & (2 & x & 3),
-            1 + (2 + (x |= 0) + 3),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var x = "" + num, y = null;
+            [
+                x + 1 + 2,
+                x * 1 * 2,
+                +x + 1 + 2,
+                1 + x + 2 + 3,
+                1 | x | 2 | 3,
+                1 + x-- + 2 + 3,
+                1 + (x*y + 2) + 3,
+                1 + (2 + x + 3),
+                1 + (2 + ~x + 3),
+                -y + (2 + ~x + 3),
+                1 & (2 & x & 3),
+                1 + (2 + (x |= 0) + 3),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect: {
-        var x = "42", y = null;
-        [
-            x + 1 + 2,
-            2 * x,
-            +x + 3,
-            1 + x + 2 + 3,
-            3 | x,
-            6 + x--,
-            x*y + 6,
-            1 + (2 + x + 3),
-            6 + ~x,
-            5 + ~x - y,
-            0 & x,
-            6 + (x |= 0),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var x = "" + num, y = null;
+            [
+                x + "12",
+                2 * x,
+                +x + 3,
+                1 + x + "23",
+                3 | x,
+                6 + x--,
+                x*y + 6,
+                6 + x,
+                6 + ~x,
+                5 + ~x,
+                0 & x,
+                6 + (x |= 0),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect_stdout: [
         "string 4212",
@@ -273,7 +379,7 @@ evaluate_3: {
         console.log(1 + Number(x) + 2);
     }
     expect: {
-        console.log(+x + 3);
+        console.log(+("" + x) + 3);
     }
 }
 
@@ -310,45 +416,52 @@ evaluate_4: {
 evaluate_5: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: false,
     }
     input: {
-        var a = "1";
-        [
-            +a + 2 + 3,
-            +a + 2 - 3,
-            +a - 2 + 3,
-            +a - 2 - 3,
-            2 + +a + 3,
-            2 + +a - 3,
-            2 - +a + 3,
-            2 - +a - 3,
-            2 + 3 + +a,
-            2 + 3 - +a,
-            2 - 3 + +a,
-            2 - 3 - +a,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var a = "" + num;
+            [
+                +a + 2 + 3,
+                +a + 2 - 3,
+                +a - 2 + 3,
+                +a - 2 - 3,
+                2 + +a + 3,
+                2 + +a - 3,
+                2 - +a + 3,
+                2 - +a - 3,
+                2 + 3 + +a,
+                2 + 3 - +a,
+                2 - 3 + +a,
+                2 - 3 - +a,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(1);
     }
     expect: {
-        var a = "1";
-        [
-            +a + 2 + 3,
-            +a + 2 - 3,
-            a - 2 + 3,
-            a - 2 - 3,
-            +a + 2 + 3,
-            +a + 2 - 3,
-            2 - a + 3,
-            2 - a - 3,
-            +a + 5,
-            5 - a,
-            +a - 1,
-            -1 - a,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var a = "" + num;
+            [
+                +a + 2 + 3,
+                +a + 2 - 3,
+                a - 2 + 3,
+                a - 2 - 3,
+                +a + 2 + 3,
+                +a + 2 - 3,
+                2 - a + 3,
+                2 - a - 3,
+                +a + 5,
+                5 - a,
+                +a - 1,
+                -1 - a,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(1);
     }
     expect_stdout: [
         "number 6",
@@ -369,45 +482,52 @@ evaluate_5: {
 evaluate_5_unsafe_math: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: true,
     }
     input: {
-        var a = "1";
-        [
-            +a + 2 + 3,
-            +a + 2 - 3,
-            +a - 2 + 3,
-            +a - 2 - 3,
-            2 + +a + 3,
-            2 + +a - 3,
-            2 - +a + 3,
-            2 - +a - 3,
-            2 + 3 + +a,
-            2 + 3 - +a,
-            2 - 3 + +a,
-            2 - 3 - +a,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var a = "" + num;
+            [
+                +a + 2 + 3,
+                +a + 2 - 3,
+                +a - 2 + 3,
+                +a - 2 - 3,
+                2 + +a + 3,
+                2 + +a - 3,
+                2 - +a + 3,
+                2 - +a - 3,
+                2 + 3 + +a,
+                2 + 3 - +a,
+                2 - 3 + +a,
+                2 - 3 - +a,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(1);
     }
     expect: {
-        var a = "1";
-        [
-            +a + 5,
-            +a + -1,
-            a - -1,
-            a - 5,
-            +a + 5,
-            +a + -1,
-            5 - a,
-            -1 - a,
-            +a + 5,
-            5 - a,
-            +a - 1,
-            -1 - a,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var a = "" + num;
+            [
+                +a + 5,
+                +a + -1,
+                a - -1,
+                a - 5,
+                +a + 5,
+                +a + -1,
+                5 - a,
+                -1 - a,
+                +a + 5,
+                5 - a,
+                +a - 1,
+                -1 - a,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(1);
     }
     expect_stdout: [
         "number 6",
@@ -546,37 +666,44 @@ evaluate_6_unsafe_math: {
 evaluate_7: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: false,
     }
     input: {
-        var x = "42", y;
-        [
-            +x + 2 + (3 + !y),
-            +x + 2 + (3 - !y),
-            +x + 2 - (3 + !y),
-            +x + 2 - (3 - !y),
-            +x - 2 + (3 + !y),
-            +x - 2 + (3 - !y),
-            +x - 2 - (3 + !y),
-            +x - 2 - (3 - !y),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num, y) {
+            var x = "" + num;
+            [
+                +x + 2 + (3 + !y),
+                +x + 2 + (3 - !y),
+                +x + 2 - (3 + !y),
+                +x + 2 - (3 - !y),
+                +x - 2 + (3 + !y),
+                +x - 2 + (3 - !y),
+                +x - 2 - (3 + !y),
+                +x - 2 - (3 - !y),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect: {
-        var x = "42", y;
-        [
-            +x + 2 + (3 + !y),
-            +x + 2 + (3 - !y),
-            +x + 2 - (3 + !y),
-            +x + 2 - (3 - !y),
-            x - 2 + (3 + !y),
-            x - 2 + (3 - !y),
-            x - 2 - (3 + !y),
-            x - 2 - (3 - !y),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num, y) {
+            var x = "" + num;
+            [
+                +x + 2 + (3 + !y),
+                +x + 2 + (3 - !y),
+                +x + 2 - (3 + !y),
+                +x + 2 - (3 - !y),
+                x - 2 + (3 + !y),
+                x - 2 + (3 - !y),
+                x - 2 - (3 + !y),
+                x - 2 - (3 - !y),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect_stdout: [
         "number 48",
@@ -593,37 +720,44 @@ evaluate_7: {
 evaluate_7_unsafe_math: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: true,
     }
     input: {
-        var x = "42", y;
-        [
-            +x + 2 + (3 + !y),
-            +x + 2 + (3 - !y),
-            +x + 2 - (3 + !y),
-            +x + 2 - (3 - !y),
-            +x - 2 + (3 + !y),
-            +x - 2 + (3 - !y),
-            +x - 2 - (3 + !y),
-            +x - 2 - (3 - !y),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num, y) {
+            var x = "" + num;
+            [
+                +x + 2 + (3 + !y),
+                +x + 2 + (3 - !y),
+                +x + 2 - (3 + !y),
+                +x + 2 - (3 - !y),
+                +x - 2 + (3 + !y),
+                +x - 2 + (3 - !y),
+                +x - 2 - (3 + !y),
+                +x - 2 - (3 - !y),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect: {
-        var x = "42", y;
-        [
-            +x + 5 + !y,
-            +x + 5 - !y,
-            +x + -1 - !y,
-            +x + -1 + !y,
-            x - -1 + !y,
-            x - -1 - !y,
-            x - 5 - !y,
-            x - 5 + !y,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num, y) {
+            var x = "" + num;
+            [
+                +x + 5 + !y,
+                +x + 5 - !y,
+                +x + -1 - !y,
+                +x + -1 + !y,
+                x - -1 + !y,
+                x - -1 - !y,
+                x - 5 - !y,
+                x - 5 + !y,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect_stdout: [
         "number 48",
@@ -637,6 +771,22 @@ evaluate_7_unsafe_math: {
     ]
 }
 
+evaluate_8_unsafe_math: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        var a = [ "42" ];
+        console.log(a * (1 / 7));
+    }
+    expect: {
+        var a = [ "42" ];
+        console.log(+a / 7);
+    }
+    expect_stdout: "6"
+}
+
 NaN_redefined: {
     options = {
         evaluate: true,
@@ -668,7 +818,7 @@ issue_1710: {
     expect_stdout: true
 }
 
-unary_binary_parenthesis: {
+unary_binary_parentheses: {
     options = {
         evaluate: true,
     }
@@ -1251,3 +1401,101 @@ issue_3695: {
     }
     expect_stdout: "NaN"
 }
+
+issue_4137: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log(+(A = []) * (A[0] = 1));
+    }
+    expect: {
+        console.log(+(A = []) * (A[0] = 1));
+    }
+    expect_stdout: "0"
+}
+
+issue_4142: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log("" + +(0 === console));
+    }
+    expect: {
+        console.log("" + +(0 === console));
+    }
+    expect_stdout: "0"
+}
+
+issue_4542_1: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a / (1 / (a[0] = 2));
+        }([ 3 ]));
+    }
+    expect: {
+        console.log(function(a) {
+            return a / (1 / (a[0] = 2));
+        }([ 3 ]));
+    }
+    expect_stdout: "4"
+}
+
+issue_4542_2: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a / (1 / --a[0]);
+        }([ 3 ]));
+    }
+    expect: {
+        console.log(function(a) {
+            return a / (1 / --a[0]);
+        }([ 3 ]));
+    }
+    expect_stdout: "4"
+}
+
+issue_4542_3: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a / (0 / (a[0] = 0, 1));
+        }([ 1 ]));
+    }
+    expect: {
+        console.log(function(a) {
+            return a / (0 / (a[0] = 0, 1));
+        }([ 1 ]));
+    }
+    expect_stdout: "NaN"
+}
+
+issue_4542_4: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a / (1 / (a.length = 1));
+        }([ 2, 3 ]));
+    }
+    expect: {
+        console.log(function(a) {
+            return a / (1 / (a.length = 1));
+        }([ 2, 3 ]));
+    }
+    expect_stdout: "2"
+}

test/compress/objects.js

@@ -45,8 +45,8 @@ duplicate_key_strict: {
         "use strict";
         var o = {
             a: 1,
-            b: 2,
             a: 3,
+            b: 2,
         };
         for (var k in o)
             console.log(k, o[k]);
@@ -221,3 +221,303 @@ numeric_literal: {
         "8 7 8",
     ]
 }
+
+evaluate_computed_key: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            ["foo" + "bar"]: "PASS",
+        }.foobar);
+    }
+    expect: {
+        console.log({
+            foobar: "PASS",
+        }.foobar);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+keep_computed_key: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        ({
+            [console.log("PASS")]: 42,
+        });
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+shorthand_keywords: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var async = 1, get = 2, set = 3, o = {
+            async,
+            get,
+            set,
+        };
+        console.log(o.async, o.get, o.set);
+    }
+    expect: {
+        console.log(1, 2, 3);
+    }
+    expect_stdout: "1 2 3"
+    node_version: ">=6"
+}
+
+object_super: {
+    input: {
+        var o = {
+            f() {
+                return super.p;
+            },
+            p: "FAIL",
+        };
+        Object.setPrototypeOf(o, { p: "PASS" });
+        console.log(o.f());
+    }
+    expect_exact: 'var o={f(){return super.p},p:"FAIL"};Object.setPrototypeOf(o,{p:"PASS"});console.log(o.f());'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+object_super_async: {
+    input: {
+        var o = {
+            async f() {
+                return super.p;
+            },
+            p: "FAIL",
+        };
+        Object.setPrototypeOf(o, { p: "PASS" });
+        o.f().then(console.log);
+    }
+    expect_exact: 'var o={async f(){return super.p},p:"FAIL"};Object.setPrototypeOf(o,{p:"PASS"});o.f().then(console.log);'
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+object_super_generator: {
+    input: {
+        var o = {
+            *f() {
+                yield super.p;
+            },
+            p: "FAIL",
+        };
+        Object.setPrototypeOf(o, { p: "PASS" });
+        console.log(o.f().next().value);
+    }
+    expect_exact: 'var o={*f(){yield super.p},p:"FAIL"};Object.setPrototypeOf(o,{p:"PASS"});console.log(o.f().next().value);'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+object_super_async_generator: {
+    input: {
+        var o = {
+            async *f() {
+                return super.p;
+            },
+            p: "FAIL",
+        };
+        Object.setPrototypeOf(o, { p: "PASS" });
+        o.f().next().then(function(v) {
+            console.log(v.value, v.done);
+        });
+    }
+    expect_exact: 'var o={async*f(){return super.p},p:"FAIL"};Object.setPrototypeOf(o,{p:"PASS"});o.f().next().then(function(v){console.log(v.value,v.done)});'
+    expect_stdout: "PASS true"
+    node_version: ">=10"
+}
+
+issue_4269_1: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            get 0() {
+                return "FAIL";
+            },
+            [0]: "PASS",
+        }[0]);
+    }
+    expect: {
+        console.log({
+            get 0() {
+                return "FAIL";
+            },
+            [0]: "PASS",
+        }[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4269_2: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            get [0]() {
+                return "FAIL";
+            },
+            0: "PASS",
+        }[0]);
+    }
+    expect: {
+        console.log({
+            get [0]() {
+                return "FAIL";
+            },
+            0: "PASS",
+        }[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4269_3: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            ["foo"]: "bar",
+            get 42() {
+                return "FAIL";
+            },
+            42: "PASS",
+        }[42]);
+    }
+    expect: {
+        console.log({
+            foo: "bar",
+            get [42]() {
+                return "FAIL";
+            },
+            42: "PASS",
+        }[42]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4269_4: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            get 42() {
+                return "FAIL";
+            },
+            ["foo"]: "bar",
+            42: "PASS",
+        }[42]);
+    }
+    expect: {
+        console.log({
+            get 42() {
+                return "FAIL";
+            },
+            foo: "bar",
+            [42]: "PASS",
+        }[42]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4269_5: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            get 42() {
+                return "FAIL";
+            },
+            [console]: "bar",
+            42: "PASS",
+        }[42]);
+    }
+    expect: {
+        console.log({
+            get 42() {
+                return "FAIL";
+            },
+            [console]: "bar",
+            42: "PASS",
+        }[42]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4380: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            get 0() {
+                return "FAIL 1";
+            },
+            0: "FAIL 2",
+            [0]: "PASS",
+        }[0]);
+    }
+    expect: {
+        console.log({
+            get 0() {
+                return "FAIL 1";
+            },
+            [0]: ("FAIL 2", "PASS"),
+        }[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4415: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            ["00"]: "FAIL",
+        }[0] || "PASS");
+    }
+    expect: {
+        console.log({
+            "00": "FAIL",
+        }[0] || "PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}

test/compress/optional-chains.js

@@ -0,0 +1,355 @@
+call: {
+    input: {
+        console.log?.(undefined?.(console.log("FAIL")));
+    }
+    expect_exact: 'console.log?.((void 0)?.(console.log("FAIL")));'
+    expect_stdout: "undefined"
+    node_version: ">=14"
+}
+
+dot: {
+    input: {
+        console?.log((void 0)?.p);
+    }
+    expect_exact: "console?.log((void 0)?.p);"
+    expect_stdout: "undefined"
+    node_version: ">=14"
+}
+
+dot_in: {
+    input: {
+        var o = { in: 42 };
+        console.log(o.in, o?.in);
+    }
+    expect_exact: "var o={in:42};console.log(o.in,o?.in);"
+    expect_stdout: "42 42"
+    node_version: ">=14"
+}
+
+sub: {
+    input: {
+        console?.["log"](null?.[console.log("FAIL")]);
+    }
+    expect_exact: 'console?.["log"](null?.[console.log("FAIL")]);'
+    expect_stdout: "undefined"
+    node_version: ">=14"
+}
+
+ternary_decimal: {
+    input: {
+        null ? .42 : console.log("PASS");
+    }
+    expect_exact: 'null?.42:console.log("PASS");'
+    expect_stdout: "PASS"
+}
+
+assign_parentheses_call: {
+    input: {
+        var o = {};
+        ((() => o)?.()).p = "PASS";
+        console.log(o.p);
+    }
+    expect_exact: 'var o={};((()=>o)?.()).p="PASS";console.log(o.p);'
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+assign_parentheses_dot: {
+    input: {
+        (console?.log).name.p = console.log("PASS");
+    }
+    expect_exact: '(console?.log.name).p=console.log("PASS");'
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+assign_no_parentheses: {
+    input: {
+        console[console.log?.("PASS")] = 42;
+    }
+    expect_exact: 'console[console.log?.("PASS")]=42;'
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+unary_parentheses: {
+    input: {
+        var o = { p: 41 };
+        (function() {
+            return o;
+        }?.()).p++;
+        console.log(o.p);
+    }
+    expect_exact: "var o={p:41};(function(){return o}?.()).p++;console.log(o.p);"
+    expect_stdout: "42"
+    node_version: ">=14"
+}
+
+collapse_vars_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a;
+        A = 42;
+        a?.[42];
+        console.log(typeof A);
+    }
+    expect: {
+        var a;
+        A = 42;
+        a?.[42];
+        console.log(typeof A);
+    }
+    expect_stdout: "number"
+    node_version: ">=14"
+}
+
+collapse_vars_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a;
+        A = 42;
+        a?.(42);
+        console.log(typeof A);
+    }
+    expect: {
+        var a;
+        A = 42;
+        a?.(42);
+        console.log(typeof A);
+    }
+    expect_stdout: "number"
+    node_version: ">=14"
+}
+
+properties: {
+    options = {
+        evaluate: true,
+        properties: true,
+    }
+    input: {
+        var a;
+        console.log(a?.["FAIL"]);
+    }
+    expect: {
+        var a;
+        console.log(a?.FAIL);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=14"
+}
+
+reduce_vars_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        null?.[a = 0];
+        console.log(a ? "PASS" : "FAIL");
+    }
+    expect: {
+        var a = 1;
+        null?.[a = 0];
+        console.log(a ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+reduce_vars_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        null?.(a = 0);
+        console.log(a ? "PASS" : "FAIL");
+    }
+    expect: {
+        var a = 1;
+        null?.(a = 0);
+        console.log(a ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+side_effects: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        var a;
+        a?.[a = "FAIL"];
+        console.log(a);
+    }
+    expect: {
+        var a;
+        a?.[a = "FAIL"];
+        console.log(a);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=14"
+}
+
+trim_1: {
+    options = {
+        evaluate: true,
+        optional_chains: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        (function(a, b) {
+            console?.log?.(a?.p, b?.[console.log("FAIL")]);
+        })?.({ p: "PASS" });
+    }
+    expect: {
+        (function(a, b) {
+            console?.log?.(a.p, void 0);
+        })({ p: "PASS" });
+    }
+    expect_stdout: "PASS undefined"
+    node_version: ">=14"
+}
+
+trim_2: {
+    options = {
+        evaluate: true,
+        optional_chains: true,
+        side_effects: true,
+    }
+    input: {
+        (void console.log("PASS"))?.[console.log("FAIL")];
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+issue_4906: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        do {
+            var a = a?.[42];
+        } while (console.log("PASS"));
+    }
+    expect: {
+        do {} while (console.log("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+issue_4928: {
+    options = {
+        ie: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = a?.[function f() {
+            f(a);
+        }];
+        console.log(typeof f);
+    }
+    expect: {
+        var a = a?.[function f() {
+            f(a);
+        }];
+        console.log(typeof f);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=14"
+}
+
+issue_4947_1: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        console.log(console.foo ? 42..p : console.bar?.p);
+    }
+    expect: {
+        console.log(console.foo ? 42..p : console.bar?.p);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=14"
+}
+
+issue_4947_2: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var log = console.log, fail;
+        log("PASS") ? log(42) : fail?.(42);
+    }
+    expect: {
+        var log = console.log, fail;
+        log("PASS") ? log(42) : fail?.(42);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+issue_5039: {
+    options = {
+        ie: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = a?.[function f() {
+            f;
+            a;
+        }];
+        console.log("PASS");
+    }
+    expect: {
+        (function f() {});
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}
+
+issue_5091: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a) {
+            var b = a.p;
+            var c;
+            b?.[c = "FAIL 2"];
+            return b || c;
+        }
+        console.log(f("FAIL 1") || "PASS");
+    }
+    expect: {
+        function f(b) {
+            var b = b.p;
+            var c;
+            b?.[c = "FAIL 2"];
+            return b || c;
+        }
+        console.log(f("FAIL 1") || "PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=14"
+}

test/compress/properties.js

@@ -17,7 +17,7 @@ dot_properties: {
         properties: true,
     }
     beautify = {
-        ie8: true,
+        ie: true,
     }
     input: {
         a["foo"] = "bar";
@@ -43,7 +43,7 @@ dot_properties_es5: {
         properties: true,
     }
     beautify = {
-        ie8: false,
+        ie: false,
     }
     input: {
         a["foo"] = "bar";
@@ -130,7 +130,7 @@ evaluate_string_length: {
     }
 }
 
-mangle_properties: {
+mangle_properties_1: {
     mangle = {
         properties: {
             keep_quoted: false,
@@ -152,6 +152,53 @@ mangle_properties: {
     }
 }
 
+mangle_properties_2: {
+    mangle = {
+        properties: {
+            reserved: [
+                "value",
+            ]
+        },
+    }
+    input: {
+        var o = {
+            prop1: 1,
+        };
+        Object.defineProperty(o, "prop2", {
+            value: 2,
+        });
+        Object.defineProperties(o, {
+            prop3: {
+                value: 3,
+            },
+        });
+        console.log("prop1", o.prop1, "prop1" in o);
+        console.log("prop2", o.prop2, o.hasOwnProperty("prop2"));
+        console.log("prop3", o.prop3, Object.getOwnPropertyDescriptor(o, "prop3").value);
+    }
+    expect: {
+        var o = {
+            o: 1,
+        };
+        Object.defineProperty(o, "p", {
+            value: 2,
+        });
+        Object.defineProperties(o, {
+            r: {
+                value: 3,
+            },
+        });
+        console.log("prop1", o.o, "o" in o);
+        console.log("prop2", o.p, o.hasOwnProperty("p"));
+        console.log("prop3", o.r, Object.getOwnPropertyDescriptor(o, "r").value);
+    }
+    expect_stdout: [
+        "prop1 1 true",
+        "prop2 2 true",
+        "prop3 3 3",
+    ]
+}
+
 mangle_unquoted_properties: {
     options = {
         evaluate: true,
@@ -1076,11 +1123,7 @@ new_this: {
             }
         }.f(42);
     }
-    expect: {
-        new function(a) {
-            this.a = a;
-        }(42);
-    }
+    expect: {}
 }
 
 issue_2513: {
@@ -1335,3 +1378,135 @@ issue_3389: {
     }
     expect_stdout: "PASS"
 }
+
+object_super: {
+    options = {
+        properties: true,
+    }
+    input: {
+        ({
+            f(a) {
+                return a ? console.log("PASS") : super.log("PASS");
+            },
+        }).f(console);
+    }
+    expect: {
+        ({
+            f(a) {
+                return a ? console.log("PASS") : super.log("PASS");
+            },
+        }).f(console);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4831_1: {
+    options = {
+        properties: true,
+    }
+    input: {
+        console.log({
+            f() {
+                return arguments;
+            },
+        }.f("PASS")[0]);
+    }
+    expect: {
+        console.log([
+            function() {
+                return arguments;
+            },
+        ][0]("PASS")[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4831_2: {
+    options = {
+        properties: true,
+    }
+    input: {
+        var f = {
+            f() {
+                return arguments;
+            },
+        }.f;
+        console.log(f("PASS")[0]);
+    }
+    expect: {
+        var f = {
+            f() {
+                return arguments;
+            },
+        }.f;
+        console.log(f("PASS")[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4888: {
+    options = {
+        properties: true,
+    }
+    input: {
+        console.log(typeof {
+            __proto__: 42,
+        }.__proto__);
+    }
+    expect: {
+        console.log(typeof {
+            __proto__: 42,
+        }.__proto__);
+    }
+    expect_stdout: "object"
+}
+
+issue_5093: {
+    beautify = {
+        keep_quoted_props: true,
+    }
+    input: {
+        console.log({
+            a: true,
+            '42': "PASS",
+            "null": [],
+        }[6 * 7]);
+    }
+    expect_exact: 'console.log({a:true,"42":"PASS","null":[]}[6*7]);'
+    expect_stdout: "PASS"
+}
+
+issue_5093_quote_keys: {
+    beautify = {
+        keep_quoted_props: true,
+        quote_keys: true,
+    }
+    input: {
+        console.log({
+            a: true,
+            '42': "PASS",
+            "null": [],
+        }[6 * 7]);
+    }
+    expect_exact: 'console.log({"a":true,"42":"PASS","null":[]}[6*7]);'
+    expect_stdout: "PASS"
+}
+
+issue_5093_quote_style: {
+    beautify = {
+        keep_quoted_props: true,
+        quote_style: 3,
+    }
+    input: {
+        console.log({
+            a: true,
+            '42': "PASS",
+            "null": [],
+        }[6 * 7]);
+    }
+    expect_exact: 'console.log({a:true,\'42\':"PASS","null":[]}[6*7]);'
+    expect_stdout: "PASS"
+}

test/compress/pure_funcs.js

@@ -133,7 +133,7 @@ conditional: {
 relational: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         foo() in new foo();
@@ -158,7 +158,7 @@ relational: {
 arithmetic: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         foo() + foo();
@@ -183,7 +183,7 @@ arithmetic: {
 boolean_and: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         foo() && foo();
@@ -208,7 +208,7 @@ boolean_and: {
 boolean_or: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         foo() || foo();
@@ -233,7 +233,7 @@ boolean_or: {
 assign: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         var a;
@@ -256,7 +256,7 @@ assign: {
 unary: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         typeof foo();
@@ -294,248 +294,6 @@ unary: {
     }
 }
 
-issue_2629_1: {
-    options = {
-        side_effects: true,
-    }
-    beautify = {
-        comments: "all",
-    }
-    input: {
-        /*@__PURE__*/ a();
-        /*@__PURE__*/ (b());
-        (/*@__PURE__*/ c)();
-        (/*@__PURE__*/ d());
-    }
-    expect_exact: [
-        "/* */c();",
-    ]
-}
-
-issue_2629_2: {
-    options = {
-        side_effects: true,
-    }
-    beautify = {
-        comments: "all",
-    }
-    input: {
-        /*@__PURE__*/ a(1)(2)(3);
-        /*@__PURE__*/ (b(1))(2)(3);
-        /*@__PURE__*/ (c(1)(2))(3);
-        /*@__PURE__*/ (d(1)(2)(3));
-        (/*@__PURE__*/ e)(1)(2)(3);
-        (/*@__PURE__*/ f(1))(2)(3);
-        (/*@__PURE__*/ g(1)(2))(3);
-        (/*@__PURE__*/ h(1)(2)(3));
-    }
-    expect_exact: [
-        "/* */e(1)(2)(3);",
-        "/* */f(1)(2)(3);",
-        "/* */g(1)(2)(3);",
-    ]
-}
-
-issue_2629_3: {
-    options = {
-        side_effects: true,
-    }
-    beautify = {
-        comments: "all",
-    }
-    input: {
-        /*@__PURE__*/ a.x(1).y(2).z(3);
-        /*@__PURE__*/ (b.x)(1).y(2).z(3);
-        /*@__PURE__*/ (c.x(1)).y(2).z(3);
-        /*@__PURE__*/ (d.x(1).y)(2).z(3);
-        /*@__PURE__*/ (e.x(1).y(2)).z(3);
-        /*@__PURE__*/ (f.x(1).y(2).z)(3);
-        /*@__PURE__*/ (g.x(1).y(2).z(3));
-        (/*@__PURE__*/ h).x(1).y(2).z(3);
-        (/*@__PURE__*/ i.x)(1).y(2).z(3);
-        (/*@__PURE__*/ j.x(1)).y(2).z(3);
-        (/*@__PURE__*/ k.x(1).y)(2).z(3);
-        (/*@__PURE__*/ l.x(1).y(2)).z(3);
-        (/*@__PURE__*/ m.x(1).y(2).z)(3);
-        (/*@__PURE__*/ n.x(1).y(2).z(3));
-    }
-    expect_exact: [
-        "/* */h.x(1).y(2).z(3);",
-        "/* */i.x(1).y(2).z(3);",
-        "/* */j.x(1).y(2).z(3);",
-        "/* */k.x(1).y(2).z(3);",
-        "/* */l.x(1).y(2).z(3);",
-        "/* */m.x(1).y(2).z(3);",
-    ]
-}
-
-issue_2629_4: {
-    options = {
-        side_effects: true,
-    }
-    input: {
-        (/*@__PURE__*/ x(), y());
-        (w(), /*@__PURE__*/ x(), y());
-    }
-    expect: {
-        y();
-        w(), y();
-    }
-}
-
-issue_2629_5: {
-    options = {
-        side_effects: true,
-    }
-    input: {
-        [ /*@__PURE__*/ x() ];
-        [ /*@__PURE__*/ x(), y() ];
-        [ w(), /*@__PURE__*/ x(), y() ];
-    }
-    expect: {
-        y();
-        w(), y();
-    }
-}
-
-issue_2638: {
-    options = {
-        side_effects: true,
-    }
-    beautify = {
-        comments: "all",
-    }
-    input: {
-        /*@__PURE__*/(g() || h())(x(), y());
-        (/*@__PURE__*/ (a() || b()))(c(), d());
-    }
-    expect_exact: [
-        "/* */x(),y();",
-        "/* */(a()||b())(c(),d());",
-    ]
-}
-
-issue_2705_1: {
-    options = {
-        side_effects: true,
-    }
-    beautify = {
-        comments: "all",
-    }
-    input: {
-        /*@__PURE__*/ new a();
-        /*@__PURE__*/ (new b());
-        new (/*@__PURE__*/ c)();
-        (/*@__PURE__*/ new d());
-    }
-    expect_exact: [
-        "new/* */c;",
-    ]
-}
-
-issue_2705_2: {
-    options = {
-        side_effects: true,
-    }
-    beautify = {
-        comments: "all",
-    }
-    input: {
-        /*@__PURE__*/ new a(1)(2)(3);
-        /*@__PURE__*/ new (b(1))(2)(3);
-        /*@__PURE__*/ new (c(1)(2))(3);
-        /*@__PURE__*/ new (d(1)(2)(3));
-        new (/*@__PURE__*/ e)(1)(2)(3);
-        (/*@__PURE__*/ new f(1))(2)(3);
-        (/*@__PURE__*/ new g(1)(2))(3);
-        (/*@__PURE__*/ new h(1)(2)(3));
-    }
-    expect_exact: [
-        "new/* */e(1)(2)(3);",
-        "/* */new f(1)(2)(3);",
-        "/* */new g(1)(2)(3);",
-    ]
-}
-
-issue_2705_3: {
-    options = {
-        side_effects: true,
-    }
-    beautify = {
-        comments: "all",
-    }
-    input: {
-        /*@__PURE__*/ new a.x(1).y(2).z(3);
-        /*@__PURE__*/ new (b.x)(1).y(2).z(3);
-        /*@__PURE__*/ new (c.x(1)).y(2).z(3);
-        /*@__PURE__*/ new (d.x(1).y)(2).z(3);
-        /*@__PURE__*/ new (e.x(1).y(2)).z(3);
-        /*@__PURE__*/ new (f.x(1).y(2).z)(3);
-        /*@__PURE__*/ new (g.x(1).y(2).z(3));
-        new (/*@__PURE__*/ h).x(1).y(2).z(3);
-        /* */ new (/*@__PURE__*/ i.x)(1).y(2).z(3);
-        (/*@__PURE__*/ new j.x(1)).y(2).z(3);
-        (/*@__PURE__*/ new k.x(1).y)(2).z(3);
-        (/*@__PURE__*/ new l.x(1).y(2)).z(3);
-        (/*@__PURE__*/ new m.x(1).y(2).z)(3);
-        (/*@__PURE__*/ new n.x(1).y(2).z(3));
-    }
-    expect_exact: [
-        "new/* */h.x(1).y(2).z(3);",
-        "/* */new/* */i.x(1).y(2).z(3);",
-        "/* */new j.x(1).y(2).z(3);",
-        "/* */new k.x(1).y(2).z(3);",
-        "/* */new l.x(1).y(2).z(3);",
-        "/* */new m.x(1).y(2).z(3);",
-    ]
-}
-
-issue_2705_4: {
-    options = {
-        side_effects: true,
-    }
-    input: {
-        (/*@__PURE__*/ new x(), y());
-        (w(), /*@__PURE__*/ new x(), y());
-    }
-    expect: {
-        y();
-        w(), y();
-    }
-}
-
-issue_2705_5: {
-    options = {
-        side_effects: true,
-    }
-    input: {
-        [ /*@__PURE__*/ new x() ];
-        [ /*@__PURE__*/ new x(), y() ];
-        [ w(), /*@__PURE__*/ new x(), y() ];
-    }
-    expect: {
-        y();
-        w(), y();
-    }
-}
-
-issue_2705_6: {
-    options = {
-        side_effects: true,
-    }
-    beautify = {
-        comments: "all",
-    }
-    input: {
-        /*@__PURE__*/new (g() || h())(x(), y());
-        /* */ new (/*@__PURE__*/ (a() || b()))(c(), d());
-    }
-    expect_exact: [
-        "/* */x(),y();",
-        "/* */new(/* */a()||b())(c(),d());",
-    ]
-}
-
 issue_3065_1: {
     options = {
         inline: true,
@@ -680,130 +438,3 @@ issue_3325_2: {
     }
     expect_stdout: "PASS"
 }
-
-issue_3858: {
-    options = {
-        collapse_vars: true,
-        inline: true,
-        keep_fargs: "strict",
-        unused: true,
-    }
-    input: {
-        var f = function(a) {
-            return /*@__PURE__*/ function(b) {
-                console.log(b);
-            }(a);
-        };
-        f("PASS");
-    }
-    expect: {
-        var f = function(a) {
-            return function() {
-                console.log(a);
-            }();
-        };
-        f("PASS");
-    }
-    expect_stdout: "PASS"
-}
-
-inline_pure_call_1: {
-    options = {
-        collapse_vars: true,
-        inline: true,
-        keep_fargs: "strict",
-        reduce_vars: true,
-        sequences: true,
-        side_effects: true,
-        toplevel: true,
-        unused: true,
-    }
-    input: {
-        var f = function(a) {
-            return /*@__PURE__*/ function(b) {
-                console.log(b);
-            }(a);
-        };
-        f("PASS");
-    }
-    expect: {}
-}
-
-inline_pure_call_2: {
-    options = {
-        collapse_vars: true,
-        inline: true,
-        keep_fargs: "strict",
-        reduce_vars: true,
-        sequences: true,
-        side_effects: true,
-        toplevel: true,
-        unused: true,
-    }
-    input: {
-        var f = function(a) {
-            return /*@__PURE__*/ function(b) {
-                console.log(b);
-            }(a);
-        };
-        var a = f("PASS");
-    }
-    expect: {}
-}
-
-inline_pure_call_3: {
-    options = {
-        collapse_vars: true,
-        evaluate: true,
-        inline: true,
-        keep_fargs: "strict",
-        passes: 2,
-        reduce_vars: true,
-        toplevel: true,
-        unused: true,
-    }
-    input: {
-        var f = function(a) {
-            return /*@__PURE__*/ function(b) {
-                console.log(b);
-            }(a);
-        };
-        var a = f("PASS");
-        console.log(a);
-    }
-    expect: {
-        var a = function() {
-            console.log("PASS");
-        }();
-        console.log(a);
-    }
-    expect_stdout: [
-        "PASS",
-        "undefined",
-    ]
-}
-
-inline_pure_call_4: {
-    options = {
-        evaluate: true,
-        reduce_vars: true,
-        toplevel: true,
-        unused: true,
-    }
-    input: {
-        var a = /*@__PURE__*/ function() {
-            return console.log("PASS"), 42;
-        }();
-        console.log(a);
-    }
-    expect: {
-        var a = function() {
-            return console.log("PASS"), 42;
-        }();
-        console.log(a);
-    }
-    expect_stdout: [
-        "PASS",
-        "42",
-    ]
-}

test/compress/pure_getters.js

@@ -248,6 +248,35 @@ issue_2110_2: {
     expect_stdout: "function"
 }
 
+issue_2110_3: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+    }
+    input: {
+        function g() {
+            return this;
+        }
+        console.log(typeof function() {
+            function f() {}
+            f.g = g;
+            return f.g();
+        }());
+    }
+    expect: {
+        function g() {
+            return this;
+        }
+        console.log(typeof function() {
+            function f() {}
+            f.g = g;
+            return f.g();
+        }());
+    }
+    expect_stdout: "function"
+}
+
 set_immutable_1: {
     options = {
         collapse_vars: true,
@@ -848,9 +877,8 @@ collapse_vars_1_true: {
     }
     expect: {
         function f(a, b) {
-            for (;;) {
+            for (;;)
                 if (a.g() || b.p) break;
-            }
         }
     }
 }
@@ -980,6 +1008,7 @@ collapse_vars_2_strict: {
 collapse_rhs_true: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         pure_getters: true,
     }
     input: {
@@ -1016,6 +1045,7 @@ collapse_rhs_true: {
 collapse_rhs_false: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         pure_getters: false,
     }
     input: {
@@ -1052,6 +1082,7 @@ collapse_rhs_false: {
 collapse_rhs_strict: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         pure_getters: "strict",
     }
     input: {
@@ -1088,6 +1119,7 @@ collapse_rhs_strict: {
 collapse_rhs_setter: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         pure_getters: "strict",
     }
     input: {
@@ -1188,13 +1220,111 @@ drop_arguments: {
     expect_stdout: "PASS"
 }
 
+lvalues_def: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var a = 0, b = 1;
+        var a = b++, b = +function() {}();
+        a && a[a++];
+        console.log(a, b);
+    }
+    expect: {
+        var a = 0, b = 1;
+        a = b++, b = +void 0;
+        a && a++;
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+side_effects_assign: {
+    options = {
+        evaluate: true,
+        pure_getters: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = typeof void (a && a.in == 1, 0);
+        console.log(a);
+    }
+    expect: {
+        var a = "undefined";
+        console.log(a);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_2062: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 1;
+        if ([ a || a++ + a--, a++ + a--, a && a.var ]);
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        a || (a++, a--), a++, a--;
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+issue_2878: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+        sequences: true,
+    }
+    input: {
+        var c = 0;
+        (function(a, b) {
+            function f2() {
+                if (a) c++;
+            }
+            b = f2();
+            a = 1;
+            b && b.b;
+            f2();
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        (function(a, b) {
+            function f2() {
+                if (a) c++;
+            }
+            b = f2(),
+            a = 1,
+            f2();
+        })(),
+        console.log(c);
+    }
+    expect_stdout: "1"
+}
+
 issue_3427: {
     options = {
         assignments: true,
-        collapse_vars: true,
+        evaluate: true,
         inline: true,
-        passes: 2,
         pure_getters: "strict",
+        reduce_vars: true,
         sequences: true,
         side_effects: true,
         toplevel: true,
@@ -1209,3 +1339,329 @@ issue_3427: {
     expect: {}
     expect_stdout: true
 }
+
+issue_3490_1: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        inline: true,
+        pure_getters: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var b = 42, c = "FAIL";
+        if ({
+            3: function() {
+                var a;
+                return (a && a.p) < this;
+            }(),
+        }) c = "PASS";
+        if (b) while ("" == typeof d);
+        console.log(c, b);
+    }
+    expect: {
+        var b = 42, c = "FAIL";
+        if (function() {
+            var a;
+        }(), c = "PASS", b) while ("" == typeof d);
+        console.log(c, b);
+    }
+    expect_stdout: "PASS 42"
+}
+
+issue_4135: {
+    options = {
+        evaluate: true,
+        inline: true,
+        merge_vars: true,
+        pure_getters: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0, b = 0;
+        --b;
+        a++;
+        if (!a)
+            var c = function() {
+                var d = 0;
+                function f() {
+                    d && d.p;
+                }
+                f();
+                this;
+            }(a++);
+        console.log(a, b, c);
+    }
+    expect: {
+        var a = 0;
+        0;
+        a++;
+        if (!a)
+            var c = void a++;
+        console.log(a, -1, c);
+    }
+    expect_stdout: "1 -1 undefined"
+}
+
+issue_4440: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        try {
+            (function() {
+                arguments = null;
+                console.log(arguments.p = "FAIL");
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            (function() {
+                arguments = null;
+                console.log(arguments.p = "FAIL");
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4730_1: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        var a;
+        console.log("PASS") + (a && a[a.p]);
+    }
+    expect: {
+        var a;
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4730_2: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        var a;
+        !console.log("PASS") || a && a[a.p];
+    }
+    expect: {
+        var a;
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4751: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        var o = {
+            get p() {
+                console.log("PASS");
+            },
+        };
+        o && o.p;
+    }
+    expect: {
+        var o = {
+            get p() {
+                console.log("PASS");
+            },
+        };
+    }
+}
+
+super_toString: {
+    options = {
+        pure_getters: true,
+        unsafe: true,
+    }
+    input: {
+        console.log({
+            f() {
+                return super.toString();
+            },
+        }.f());
+    }
+    expect: {
+        console.log({
+            f() {
+                return super.toString();
+            },
+        }.f());
+    }
+    expect_stdout: "[object Object]"
+    node_version: ">=4"
+}
+
+this_toString: {
+    options = {
+        pure_getters: true,
+        unsafe: true,
+    }
+    input: {
+        console.log({
+            f() {
+                return this.toString();
+            },
+        }.f());
+    }
+    expect: {
+        console.log({
+            f() {
+                return "" + this;
+            },
+        }.f());
+    }
+    expect_stdout: "[object Object]"
+    node_version: ">=4"
+}
+
+issue_4803: {
+    options = {
+        hoist_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            get f() {
+                console.log("PASS");
+            },
+        } || 42;
+        for (var k in o)
+            o[k];
+    }
+    expect: {
+        var k, o = {
+            get f() {
+                console.log("PASS");
+            },
+        } || 42;
+        for (k in o)
+            o[k];
+    }
+    expect_stdout: "PASS"
+}
+
+nested_property_assignments_1: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var f;
+        ((f = function() {
+            console.log("FAIL");
+        }).p = f).q = console.log("PASS");
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+nested_property_assignments_2: {
+    options = {
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        var o = {};
+        (function() {
+            var a;
+            (o.p = a = {}).q = "PASS";
+        })();
+        console.log(o.p.q);
+    }
+    expect: {
+        var o = {};
+        (function() {
+            (o.p = {}).q = "PASS";
+        })();
+        console.log(o.p.q);
+    }
+    expect_stdout: "PASS"
+}
+
+nested_property_assignments_3: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var o = { p: {} };
+        (function(a) {
+            console && a;
+            if (console) {
+                a = a.p;
+                a.q = a;
+            }
+        })(o);
+        console.log(o.p.q === o.p ? "PASS" : "FAIL");
+    }
+    expect: {
+        var o = { p: {} };
+        (function(a) {
+            console;
+            if (console)
+                (a = a.p).q = a;
+        })(o);
+        console.log(o.p.q === o.p ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4939: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        ({
+            __proto__: {
+                get p() {
+                    console.log("PASS");
+                },
+            },
+        }).p;
+    }
+    expect: {
+        ({
+            __proto__: {
+                get p() {
+                    console.log("PASS");
+                },
+            },
+        }).p;
+    }
+    expect_stdout: "PASS"
+}

test/compress/reduce_vars.js

@@ -120,7 +120,7 @@ modified: {
     expect: {
         function f0() {
             var b = 2;
-            b++;
+            +b;
             console.log(2);
             console.log(4);
         }
@@ -1292,6 +1292,7 @@ toplevel_on_loops_3: {
         loops: true,
         reduce_funcs: true,
         reduce_vars: true,
+        side_effects: true,
         toplevel: true,
         unused: true,
     }
@@ -1624,7 +1625,7 @@ defun_label: {
     expect_stdout: true
 }
 
-double_reference: {
+double_reference_1: {
     options = {
         reduce_funcs: true,
         reduce_vars: true,
@@ -1638,6 +1639,32 @@ double_reference: {
             g();
         }
     }
+    expect: {
+        function f() {
+            var g = function g() {
+                g();
+            };
+            g();
+        }
+    }
+}
+
+double_reference_2: {
+    options = {
+        functions: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var g = function g() {
+                g();
+            };
+            g();
+        }
+    }
     expect: {
         function f() {
             (function g() {
@@ -1647,6 +1674,60 @@ double_reference: {
     }
 }
 
+double_reference_3: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var x = function f() {
+            return f;
+        };
+        function g() {
+            return x();
+        }
+        console.log(g() === g());
+    }
+    expect: {
+        var x = function f() {
+            return f;
+        };
+        function g() {
+            return x();
+        }
+        console.log(g() === g());
+    }
+    expect_stdout: "true"
+}
+
+double_reference_4: {
+    options = {
+        comparisons: true,
+        functions: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var x = function f() {
+            return f;
+        };
+        function g() {
+            return x();
+        }
+        console.log(g() === g());
+    }
+    expect: {
+        console.log(true);
+    }
+    expect_stdout: "true"
+}
+
 iife_arguments_1: {
     options = {
         reduce_funcs: true,
@@ -1686,8 +1767,35 @@ iife_arguments_2: {
     }
     expect: {
         (function() {
-            console.log(function f() {
+            var x = function f() {
                 return f;
+            };
+            console.log(x() === arguments[0]);
+        })();
+    }
+    expect_stdout: true
+}
+
+iife_arguments_3: {
+    options = {
+        functions: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var x = function f() {
+                return f;
+            };
+            console.log(x() === arguments[0]);
+        })();
+    }
+    expect: {
+        (function() {
+            console.log(function x() {
+                return x;
             }() === arguments[0]);
         })();
     }
@@ -1892,7 +2000,7 @@ issue_1606: {
             var a, b;
             function g(){};
             b = 2;
-            x(b);
+            x(2);
         }
     }
 }
@@ -1965,72 +2073,7 @@ issue_1670_2: {
 
 issue_1670_3: {
     options = {
-        comparisons: true,
         conditionals: true,
-        dead_code: true,
-        evaluate: true,
-        reduce_funcs: true,
-        reduce_vars: true,
-        side_effects: true,
-        switches: true,
-        typeofs: true,
-        unused: true,
-    }
-    input: {
-        (function f() {
-            switch (1) {
-              case 0:
-                var a = true;
-                break;
-              case 1:
-                if (typeof a === "undefined") console.log("PASS");
-                else console.log("FAIL");
-            }
-        })();
-    }
-    expect: {
-        (function() {
-            var a;
-            void 0 === a ? console.log("PASS") : console.log("FAIL");
-        })();
-    }
-    expect_stdout: "PASS"
-}
-
-issue_1670_4: {
-    options = {
-        conditionals: true,
-        dead_code: true,
-        evaluate: true,
-        passes: 2,
-        reduce_funcs: true,
-        reduce_vars: true,
-        side_effects: true,
-        switches: true,
-        unused: true,
-    }
-    input: {
-        (function f() {
-            switch (1) {
-              case 0:
-                var a = true;
-                break;
-              case 1:
-                if (typeof a === "undefined") console.log("PASS");
-                else console.log("FAIL");
-            }
-        })();
-    }
-    expect: {
-        (function() {
-            console.log("PASS");
-        })();
-    }
-    expect_stdout: "PASS"
-}
-
-issue_1670_5: {
-    options = {
         dead_code: true,
         evaluate: true,
         keep_fargs: false,
@@ -2060,13 +2103,15 @@ issue_1670_5: {
     expect_stdout: "1"
 }
 
-issue_1670_6: {
+issue_1670_4: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
+        sequences: true,
         side_effects: true,
         switches: true,
         unused: true,
@@ -2084,10 +2129,9 @@ issue_1670_6: {
         })(1);
     }
     expect: {
-        (function(a) {
-            a = 1;
-            console.log(a);
-        })(1);
+        (function() {
+            console.log(1);
+        })();
     }
     expect_stdout: "1"
 }
@@ -2264,7 +2308,7 @@ redefine_farg_1: {
         function f(a) {
             return typeof a;
         }
-        function g() {
+        function g(a) {
             return "number";
         }
         function h(a, b) {
@@ -2306,7 +2350,7 @@ redefine_farg_2: {
         console.log(typeof [], "number",function(a, b) {
             a = b;
             return typeof a;
-        }([]));
+        }());
     }
     expect_stdout: "object number undefined"
 }
@@ -2351,6 +2395,7 @@ delay_def: {
         evaluate: true,
         reduce_funcs: true,
         reduce_vars: true,
+        side_effects: true,
         unused: true,
     }
     input: {
@@ -3048,7 +3093,7 @@ accessor_1: {
                 a = 2;
                 return a;
             },
-            b: 1
+            b: 1,
         }.b, a);
     }
     expect: {
@@ -3058,7 +3103,7 @@ accessor_1: {
                 a = 2;
                 return a;
             },
-            b: 1
+            b: 1,
         }.b, a);
     }
     expect_stdout: "1 1"
@@ -3078,7 +3123,7 @@ accessor_2: {
         var B = {
             get c() {
                 console.log(A);
-            }
+            },
         };
         B.c;
     }
@@ -3086,7 +3131,7 @@ accessor_2: {
         ({
             get c() {
                 console.log(1);
-            }
+            },
         }).c;
     }
     expect_stdout: "1"
@@ -3132,7 +3177,7 @@ obj_var_1: {
         var obj = {
             bar: function() {
                 return C + C;
-            }
+            },
         };
         console.log(obj.bar());
     }
@@ -3140,7 +3185,7 @@ obj_var_1: {
         console.log({
             bar: function() {
                 return 2;
-            }
+            },
         }.bar());
     }
     expect_stdout: "2"
@@ -3164,7 +3209,7 @@ obj_var_2: {
         var obj = {
             bar: function() {
                 return C + C;
-            }
+            },
         };
         console.log(obj.bar());
     }
@@ -4378,6 +4423,7 @@ perf_2: {
 
 perf_3: {
     options = {
+        passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
         toplevel: true,
@@ -4386,10 +4432,10 @@ perf_3: {
     input: {
         var foo = function(x, y, z) {
             return x < y ? x * y + z : x * z - y;
-        }
+        };
         var indirect_foo = function(x, y, z) {
             return foo(x, y, z);
-        }
+        };
         var sum = 0;
         for (var i = 0; i < 100; ++i)
             sum += indirect_foo(i, i + 1, 3 * i);
@@ -4418,10 +4464,10 @@ perf_4: {
     input: {
         var foo = function(x, y, z) {
             return x < y ? x * y + z : x * z - y;
-        }
+        };
         var indirect_foo = function(x, y, z) {
             return foo(x, y, z);
-        }
+        };
         var sum = 0;
         for (var i = 0; i < 100; ++i)
             sum += indirect_foo(i, i + 1, 3 * i);
@@ -4430,10 +4476,10 @@ perf_4: {
     expect: {
         var foo = function(x, y, z) {
             return x < y ? x * y + z : x * z - y;
-        }
+        };
         var indirect_foo = function(x, y, z) {
             return foo(x, y, z);
-        }
+        };
         var sum = 0;
         for (var i = 0; i < 100; ++i)
             sum += indirect_foo(i, i + 1, 3 * i);
@@ -4522,9 +4568,9 @@ perf_7: {
         var indirect_foo = function(x, y, z) {
             var foo = function(x, y, z) {
                 return x < y ? x * y + z : x * z - y;
-            }
+            };
             return foo(x, y, z);
-        }
+        };
         var sum = 0;
         for (var i = 0; i < 100; ++i)
             sum += indirect_foo(i, i + 1, 3 * i);
@@ -4554,9 +4600,9 @@ perf_8: {
         var indirect_foo = function(x, y, z) {
             var foo = function(x, y, z) {
                 return x < y ? x * y + z : x * z - y;
-            }
+            };
             return foo(x, y, z);
-        }
+        };
         var sum = 0;
         for (var i = 0; i < 100; ++i)
             sum += indirect_foo(i, i + 1, 3 * i);
@@ -4567,7 +4613,7 @@ perf_8: {
             return function(x, y, z) {
                 return x < y ? x * y + z : x * z - y;
             }(x, y, z);
-        }
+        };
         var sum = 0;
         for (var i = 0; i < 100; ++i)
             sum += indirect_foo(i, i + 1, 3 * i);
@@ -5265,11 +5311,11 @@ defun_catch_4: {
         try {
             throw 42;
         } catch (a) {
+            function a() {}
             console.log(a);
         }
     }
-    expect_stdout: "42"
-    node_version: "<=4"
+    expect_stdout: true
 }
 
 defun_catch_5: {
@@ -5291,10 +5337,10 @@ defun_catch_5: {
             throw 42;
         } catch (a) {
             console.log(a);
+            function a() {}
         }
     }
-    expect_stdout: "42"
-    node_version: "<=4"
+    expect_stdout: true
 }
 
 defun_catch_6: {
@@ -5481,7 +5527,7 @@ lvalues_def_1: {
     }
     expect: {
         var b = 1;
-        var a = b++, b = NaN;
+        var a = +b, b = NaN;
         console.log(a, b);
     }
     expect_stdout: "1 NaN"
@@ -6819,7 +6865,7 @@ issue_3622: {
     options = {
         evaluate: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         toplevel: true,
@@ -7087,7 +7133,7 @@ issue_3894: {
 issue_3922: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: "strict",
         reduce_vars: true,
         side_effects: true,
@@ -7402,7 +7448,327 @@ issue_4030: {
     }
     expect: {
         A = "PASS";
-        console.log("PASS");
+        console.log(A);
+    }
+    expect_stdout: "PASS"
+}
+
+global_assign: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        A = "FAIL";
+        this.A = "PASS";
+        console.log(A);
+    }
+    expect: {
+        A = "FAIL";
+        this.A = "PASS";
+        console.log(A);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4188_1: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            try {
+                while (A)
+                    var a = function() {}, b = a;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                while (A)
+                    var a = function() {}, b = a;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+        })();
+    }
+    expect_stdout: "object undefined"
+}
+
+issue_4188_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+            while (!console)
+                var a = function() {}, b = a;
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+            while (!console)
+                var a = function() {}, b = a;
+        })();
+    }
+    expect_stdout: "number undefined"
+}
+
+issue_4568: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        loops: true,
+        passes: 2,
+        reduce_vars: true,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            a && console.log("FAIL");
+            if (1)
+                do {
+                    if (!console.log("PASS")) break;
+                } while (1);
+        })(!(0 !== delete NaN));
+    }
+    expect: {
+        (function(a) {
+            for (a && console.log("FAIL"), 1; console.log("PASS"); ) 1;
+        })(!(0 !== delete NaN));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4937: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            while (console.log("PASS"));
+        }
+        do {
+            function g() {
+                f();
+            }
+        } while (!g);
+        f();
+    }
+    expect: {
+        function f() {
+            while (console.log("PASS"));
+        }
+        do {
+            function g() {
+                f();
+            }
+        } while (!g);
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4943_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a, b = 1;
+        (function f() {
+            a = "foo";
+            b-- && f();
+            console.log(a);
+            a = "bar";
+        })();
+    }
+    expect: {
+        var a, b = 1;
+        (function f() {
+            a = "foo";
+            b-- && f();
+            console.log(a);
+            a = "bar";
+        })();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+}
+
+issue_4943_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, b = 1;
+        (function f() {
+            a = "foo";
+            b-- && f();
+            console.log(a);
+            a = "bar";
+        })();
+    }
+    expect: {
+        var a, b = 1;
+        (function f() {
+            a = "foo";
+            b-- && f();
+            console.log(a);
+            a = "bar";
+        })();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+}
+
+issue_4949: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function f(a) {
+            a = 0;
+            console.log(a++, arguments[0]);
+        })(0);
+    }
+    expect: {
+        (function(a) {
+            a = 0;
+            console.log(a++, arguments[0]);
+        })(0);
+    }
+    expect_stdout: "0 1"
+}
+
+issue_5048: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var a = function() {
+                return a + 42;
+            };
+        }());
+    }
+    expect: {
+        console.log(function() {}());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5050: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        function f() {
+            console.log(a);
+        }
+        this;
+        var a = 1;
+        f(console.log(2), f(), a = 3);
+    }
+    expect: {
+        function f() {
+            console.log(a);
+        }
+        this;
+        var a = 1;
+        f(console.log(2), f(), a = 3);
+    }
+    expect_stdout: [
+        "2",
+        "1",
+        "3",
+    ]
+}
+
+issue_5055_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        function f() {
+            console.log(a || "FAIL");
+        }
+        f(0 && (a = 0)(f(this)));
+    }
+    expect: {
+        var a = "PASS";
+        function f() {
+            console.log(a || "FAIL");
+        }
+        f(0);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5055_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        function f() {
+            console.log(a || "FAIL");
+        }
+        f(0 && (a = 0)(f(this)));
+    }
+    expect: {
+        var a = "PASS";
+        function f() {
+            console.log(a || "FAIL");
+        }
+        f(0 && (a = 0)(f()));
     }
     expect_stdout: "PASS"
 }

test/compress/rename.js

@@ -1,11 +1,11 @@
 mangle_catch: {
     rename = true
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -24,11 +24,11 @@ mangle_catch: {
 mangle_catch_ie8: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -47,11 +47,11 @@ mangle_catch_ie8: {
 mangle_catch_var: {
     rename = true
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -70,11 +70,11 @@ mangle_catch_var: {
 mangle_catch_var_ie8: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -93,11 +93,11 @@ mangle_catch_var_ie8: {
 mangle_catch_toplevel: {
     rename = true
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -116,11 +116,11 @@ mangle_catch_toplevel: {
 mangle_catch_ie8_toplevel: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -139,11 +139,11 @@ mangle_catch_ie8_toplevel: {
 mangle_catch_var_toplevel: {
     rename = true
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -162,11 +162,11 @@ mangle_catch_var_toplevel: {
 mangle_catch_var_ie8_toplevel: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -185,11 +185,11 @@ mangle_catch_var_ie8_toplevel: {
 mangle_catch_redef_1: {
     rename = true
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -208,11 +208,11 @@ mangle_catch_redef_1: {
 mangle_catch_redef_1_ie8: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -231,11 +231,11 @@ mangle_catch_redef_1_ie8: {
 mangle_catch_redef_1_toplevel: {
     rename = true
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -254,11 +254,11 @@ mangle_catch_redef_1_toplevel: {
 mangle_catch_redef_1_ie8_toplevel: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -277,11 +277,11 @@ mangle_catch_redef_1_ie8_toplevel: {
 mangle_catch_redef_2: {
     rename = true
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -299,11 +299,11 @@ mangle_catch_redef_2: {
 mangle_catch_redef_2_ie8: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -321,11 +321,11 @@ mangle_catch_redef_2_ie8: {
 mangle_catch_redef_2_toplevel: {
     rename = true
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -343,11 +343,11 @@ mangle_catch_redef_2_toplevel: {
 mangle_catch_redef_2_ie8_toplevel: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -365,7 +365,7 @@ mangle_catch_redef_2_ie8_toplevel: {
 issue_2120_1: {
     rename = true
     mangle = {
-        ie8: false,
+        ie: false,
     }
     input: {
         "aaaaaaaa";
@@ -401,7 +401,7 @@ issue_2120_1: {
 issue_2120_2: {
     rename = true
     mangle = {
-        ie8: true,
+        ie: true,
     }
     input: {
         "aaaaaaaa";
@@ -436,7 +436,7 @@ issue_2120_2: {
 function_iife_catch: {
     rename = true
     mangle = {
-        ie8: false,
+        ie: false,
     }
     input: {
         function f(n) {
@@ -458,7 +458,7 @@ function_iife_catch: {
 function_iife_catch_ie8: {
     rename = true
     mangle = {
-        ie8: true,
+        ie: true,
     }
     input: {
         function f(n) {
@@ -480,7 +480,7 @@ function_iife_catch_ie8: {
 function_catch_catch: {
     rename = true
     mangle = {
-        ie8: false,
+        ie: false,
     }
     input: {
         var o = 0;
@@ -509,7 +509,7 @@ function_catch_catch: {
 function_catch_catch_ie8: {
     rename = true
     mangle = {
-        ie8: true,
+        ie: true,
     }
     input: {
         var o = 0;
@@ -538,12 +538,12 @@ function_catch_catch_ie8: {
 function_do_catch_ie8: {
     rename = true
     options = {
-        ie8: true,
+        ie: true,
         side_effects: true,
         unused: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -615,7 +615,7 @@ function_do_catch_ie8: {
 issue_3480: {
     rename = true,
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -647,7 +647,7 @@ issue_3480: {
 issue_3480_ie8: {
     rename = true,
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -679,7 +679,7 @@ issue_3480_ie8: {
 issue_3480_toplevel: {
     rename = true,
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -711,7 +711,7 @@ issue_3480_toplevel: {
 issue_3480_ie8_toplevel: {
     rename = true,
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {

test/compress/sandbox.js

@@ -13,6 +13,23 @@ console_log: {
     ]
 }
 
+console_log_console: {
+    input: {
+        var log = console.log;
+        log(console);
+        log(typeof console.log);
+    }
+    expect: {
+        var log = console.log;
+        log(console);
+        log(typeof console.log);
+    }
+    expect_stdout: [
+        "{ log: 'function(){}' }",
+        "function",
+    ]
+}
+
 typeof_arguments: {
     options = {
         evaluate: true,
@@ -80,3 +97,107 @@ log_global: {
     }
     expect_stdout: "[object global]"
 }
+
+log_nested: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var o = { p: 42 };
+        for (var i = 0; i < 10; i++)
+            o = {
+                p: o,
+                q: function foo() {},
+            };
+        console.log(o);
+    }
+    expect: {
+        var o = { p: 42 };
+        for (var i = 0; i < 10; i++)
+            o = {
+                p: o,
+                q: function() {},
+            };
+        console.log(o);
+    }
+    expect_stdout: true
+}
+
+timers: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var count = 0, interval = 1000, duration = 3210;
+        var timer = setInterval(function() {
+            console.log(++count);
+        }, interval);
+        setTimeout(function() {
+            clearInterval(timer);
+        }, duration);
+    }
+    expect: {
+        var count = 0;
+        var timer = setInterval(function() {
+            console.log(++count);
+        }, 1000);
+        setTimeout(function() {
+            clearInterval(timer);
+        }, 3210);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+        "3",
+    ]
+    node_version: ">=0.12"
+}
+
+issue_4054: {
+    input: {
+        console.log({
+            set p(v) {
+                throw "FAIL";
+            },
+        });
+    }
+    expect: {
+        console.log({
+            set p(v) {
+                throw "FAIL";
+            },
+        });
+    }
+    expect_stdout: "{ p: [Setter] }"
+}
+
+issue_4811_1: {
+    input: {
+        for (var PASS in this);
+        console.log(PASS, this, {} < this);
+    }
+    expect: {
+        for (var PASS in this);
+        console.log(PASS, this, {} < this);
+    }
+    expect_stdout: "PASS [object global] true"
+}
+
+issue_4811_2: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        (async function() {});
+        for (var PASS in this);
+        console.log(PASS, this, {} < this);
+    }
+    expect: {
+        for (var PASS in this);
+        console.log(PASS, this, {} < this);
+    }
+    expect_stdout: "PASS [object global] true"
+    node_version: ">=8"
+}

test/compress/sequences.js

@@ -564,6 +564,34 @@ delete_seq_3: {
 }
 
 delete_seq_4: {
+    options = {
+        booleans: true,
+        evaluate: false,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {}
+        console.log(delete (f(), undefined));
+        console.log(delete (f(), void 0));
+        console.log(delete (f(), Infinity));
+        console.log(delete (f(), 1 / 0));
+        console.log(delete (f(), NaN));
+        console.log(delete (f(), 0 / 0));
+    }
+    expect: {
+        function f() {}
+        console.log(delete void f()),
+        console.log(delete void f()),
+        console.log((f(), delete (1 / 0))),
+        console.log((f(), delete (1 / 0))),
+        console.log(delete (f(), NaN)),
+        console.log((f(), delete(0 / 0)));
+    }
+    expect_stdout: true
+}
+
+delete_seq_4_evaluate: {
     options = {
         booleans: true,
         evaluate: true,
@@ -592,6 +620,35 @@ delete_seq_4: {
 }
 
 delete_seq_5: {
+    options = {
+        booleans: true,
+        evaluate: false,
+        keep_infinity: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {}
+        console.log(delete (f(), undefined));
+        console.log(delete (f(), void 0));
+        console.log(delete (f(), Infinity));
+        console.log(delete (f(), 1 / 0));
+        console.log(delete (f(), NaN));
+        console.log(delete (f(), 0 / 0));
+    }
+    expect: {
+        function f() {}
+        console.log(delete void f()),
+        console.log(delete void f()),
+        console.log(delete (f(), Infinity)),
+        console.log((f(), delete (1 / 0))),
+        console.log(delete (f(), NaN)),
+        console.log((f(), delete (0 / 0)));
+    }
+    expect_stdout: true
+}
+
+delete_seq_5_evaluate: {
     options = {
         booleans: true,
         evaluate: true,
@@ -663,12 +720,21 @@ side_effects_cascade_1: {
             if (a < 0) a = 0;
             b.a = a;
         }
+        var m = {}, n = {};
+        f(13, m);
+        f("foo", n);
+        console.log(m.a, n.a);
     }
     expect: {
         function f(a, b) {
-            (a -= 42) < 0 && (a = 0), b.a = a;
+            b.a = a = (a -= 42) < 0 ? 0 : a;
         }
+        var m = {}, n = {};
+        f(13, m),
+        f("foo", n),
+        console.log(m.a, n.a);
     }
+    expect_stdout: "0 NaN"
 }
 
 side_effects_cascade_2: {
@@ -877,7 +943,7 @@ for_init_var: {
     expect_stdout: "PASS"
 }
 
-forin: {
+forin_1: {
     options = {
         sequences: true,
     }
@@ -895,6 +961,49 @@ forin: {
     expect_stdout: "PASS"
 }
 
+forin_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            p: 1,
+            q: 2,
+        };
+        var k = "k";
+        for ((console.log("exp"), o)[function() {
+            console.log("prop");
+            return k;
+        }()] in function() {
+            console.log("obj");
+            return o;
+        }())
+            console.log(o.k, o[o.k]);
+    }
+    expect: {
+        var o = {
+            p: 1,
+            q: 2,
+        };
+        for ((console.log("exp"), o)[console.log("prop"), "k"] in console.log("obj"), o)
+            console.log(o.k, o[o.k]);
+    }
+    expect_stdout: [
+        "obj",
+        "exp",
+        "prop",
+        "p 1",
+        "exp",
+        "prop",
+        "q 2",
+    ]
+}
+
 call: {
     options = {
         sequences: true,
@@ -1112,3 +1221,25 @@ issue_3703: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4079: {
+    options = {
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        try {
+            typeof (0, A);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            A;
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}

test/compress/side_effects.js

@@ -198,6 +198,36 @@ global_fns: {
     ]
 }
 
+global_constructors: {
+    options = {
+        side_effects: true,
+        unsafe: true,
+    }
+    input: {
+        Map;
+        new Map(console.log("foo"));
+        Set;
+        new Set(console.log("bar"));
+        WeakMap;
+        new WeakMap(console.log("baz"));
+        WeakSet;
+        new WeakSet(console.log("moo"));
+    }
+    expect: {
+        console.log("foo");
+        console.log("bar");
+        console.log("baz");
+        console.log("moo");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+        "moo",
+    ]
+    node_version: ">=0.12"
+}
+
 unsafe_builtin_1: {
     options = {
         side_effects: true,
@@ -245,6 +275,31 @@ unsafe_builtin_2: {
     expect_stdout: "object PASS PASS"
 }
 
+unsafe_builtin_3: {
+    options = {
+        conditionals: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var o = {};
+        if (42 < Math.random())
+            o.p = "FAIL";
+        else
+            o.p = "PASS";
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect: {
+        var o = {};
+        o.p = 42 < Math.random() ? "FAIL" : "PASS";
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect_stdout: "p PASS"
+}
+
 unsafe_string_replace: {
     options = {
         side_effects: true,
@@ -323,8 +378,6 @@ issue_3983_1: {
     }
     expect: {
         var a = "PASS";
-        g();
-        function g() {}
         console.log(a);
     }
     expect_stdout: "PASS"
@@ -391,3 +444,204 @@ issue_4008: {
         "PASS",
     ]
 }
+
+trim_new: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        new function(a) {
+            console.log(a);
+        }("PASS");
+    }
+    expect: {
+        (function(a) {
+            console.log(a);
+        })("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4325: {
+    options = {
+        keep_fargs: false,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function f() {
+            (function(b, c) {
+                try {
+                    c.p = 0;
+                } catch (e) {
+                    console.log("PASS");
+                    return b;
+                }
+                c;
+            })(f++);
+        })();
+    }
+    expect: {
+        (function() {
+            (function(c) {
+                try {
+                    c.p = 0;
+                } catch (e) {
+                    console.log("PASS");
+                    return;
+                }
+            })(void 0);
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4366_1: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        ({
+            p: 42,
+            get p() {},
+            q: console.log("PASS"),
+        });
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4366_2: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        ({
+            set p(v) {},
+            q: console.log("PASS"),
+            p: 42,
+        });
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4668: {
+    options = {
+        conditionals: true,
+        keep_fargs: false,
+        keep_fnames: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var b, c;
+            function g() {
+                return a = 0 + a, !d || (a = 0);
+            }
+            c = g();
+        }
+        console.log(f());
+        var d = 0;
+    }
+    expect: {
+        console.log(function f() {
+            (function g() {
+                0;
+            })();
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+drop_side_effect_free_call: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        function f(a) {
+            return "PA" + a;
+        }
+        f(42);
+        console.log(f("SS"));
+    }
+    expect: {
+        function f(a) {
+            return "PA" + a;
+        }
+        console.log(f("SS"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4730_1: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        var a;
+        console.log("PASS") + (a && a[a.p]);
+    }
+    expect: {
+        var a;
+        console.log("PASS"),
+        a && a[a.p];
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4730_2: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        var a;
+        !console.log("PASS") || a && a[a.p];
+    }
+    expect: {
+        var a;
+        !console.log("PASS") || a && a[a.p];
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4751: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        var o = {
+            get p() {
+                console.log("PASS");
+            },
+        };
+        o && o.p;
+    }
+    expect: {
+        var o = {
+            get p() {
+                console.log("PASS");
+            },
+        };
+        o && o.p;
+    }
+    expect_stdout: "PASS"
+}

test/compress/switches.js

@@ -1,5 +1,6 @@
 constant_switch_1: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -19,6 +20,7 @@ constant_switch_1: {
 
 constant_switch_2: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -39,6 +41,7 @@ constant_switch_2: {
 
 constant_switch_3: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -60,6 +63,7 @@ constant_switch_3: {
 
 constant_switch_4: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -86,6 +90,7 @@ constant_switch_4: {
 
 constant_switch_5: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -108,7 +113,7 @@ constant_switch_5: {
         // the break inside the if ruins our job
         // we can still get rid of irrelevant cases.
         switch (1) {
-          case 1:
+          default:
             x();
             if (foo) break;
             y();
@@ -120,6 +125,7 @@ constant_switch_5: {
 
 constant_switch_6: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -154,6 +160,7 @@ constant_switch_6: {
 
 constant_switch_7: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -197,6 +204,7 @@ constant_switch_7: {
 
 constant_switch_8: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -226,6 +234,7 @@ constant_switch_8: {
 
 constant_switch_9: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -291,6 +300,37 @@ drop_default_2: {
     }
 }
 
+drop_default_3: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        function f() {
+            console.log("PASS");
+            return 42;
+        }
+        switch (42) {
+          case f():
+            break;
+          case void console.log("FAIL"):
+          default:
+        }
+    }
+    expect: {
+        function f() {
+            console.log("PASS");
+            return 42;
+        }
+        switch (42) {
+          case f():
+          case void console.log("FAIL"):
+        }
+    }
+    expect_stdout: "PASS"
+}
+
 keep_default: {
     options = {
         dead_code: true,
@@ -315,6 +355,7 @@ keep_default: {
 
 issue_1663: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -413,7 +454,6 @@ drop_case_3: {
         switch ({}.p) {
           default:
           case void 0:
-            break;
           case c = "FAIL":
         }
         console.log(c);
@@ -444,7 +484,168 @@ drop_case_4: {
     expect_stdout: "PASS"
 }
 
-keep_case: {
+drop_case_5: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        switch (42) {
+          case void console.log("PASS 1"):
+            console.log("FAIL 1");
+          case 42:
+          case console.log("FAIL 2"):
+            console.log("PASS 2");
+        }
+    }
+    expect: {
+        switch (42) {
+          default:
+            void console.log("PASS 1");
+            console.log("PASS 2");
+        }
+    }
+    expect_stdout: [
+        "PASS 1",
+        "PASS 2",
+    ]
+}
+
+drop_case_6: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        switch (console.log("PASS 1"), 2) {
+          case 0:
+            console.log("FAIL 1");
+          case (console.log("PASS 2"), 1):
+            console.log("FAIL 2");
+        }
+    }
+    expect: {
+        switch (console.log("PASS 1"), 2) {
+          case (console.log("PASS 2"), 1):
+        }
+    }
+    expect_stdout: [
+        "PASS 1",
+        "PASS 2",
+    ]
+}
+
+drop_case_7: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        switch (2) {
+          case 0:
+            console.log("FAIL 1");
+          case (console.log("PASS 1"), 1):
+            console.log("FAIL 2");
+          case 2:
+            console.log("PASS 2");
+        }
+    }
+    expect: {
+        switch (2) {
+          default:
+            console.log("PASS 1"), 1;
+            console.log("PASS 2");
+        }
+    }
+    expect_stdout: [
+        "PASS 1",
+        "PASS 2",
+    ]
+}
+
+drop_case_8: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        function log(msg) {
+            console.log(msg);
+            return msg;
+        }
+        switch (log("foo")) {
+          case "bar":
+            log("moo");
+            break;
+          case log("baz"):
+            log("moo");
+            break;
+          default:
+            log("moo");
+        }
+    }
+    expect: {
+        function log(msg) {
+            console.log(msg);
+            return msg;
+        }
+        switch (log("foo")) {
+          case "bar":
+          case log("baz"):
+          default:
+            log("moo");
+        }
+    }
+    expect_stdout: [
+        "foo",
+        "baz",
+        "moo",
+    ]
+}
+
+drop_case_9: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        function log(msg) {
+            console.log(msg);
+            return msg;
+        }
+        switch (log("foo")) {
+          case log("bar"):
+            log("moo");
+            break;
+          case "baz":
+            log("moo");
+            break;
+          default:
+            log("moo");
+        }
+    }
+    expect: {
+        function log(msg) {
+            console.log(msg);
+            return msg;
+        }
+        switch (log("foo")) {
+          default:
+            log("bar");
+            log("moo");
+        }
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "moo",
+    ]
+}
+
+keep_case_1: {
     options = {
         dead_code: true,
         switches: true,
@@ -464,6 +665,76 @@ keep_case: {
     }
 }
 
+keep_case_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        switch ("foo") {
+          case console.log("bar"):
+          case console.log("baz"), "moo":
+        }
+    }
+    expect: {
+        switch ("foo") {
+          case console.log("bar"):
+          case console.log("baz"), "moo":
+        }
+    }
+    expect_stdout: [
+        "bar",
+        "baz",
+    ]
+}
+
+keep_case_3: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a;
+        switch (void console.log("PASS")) {
+          case a:
+          case console.log("FAIL"), 42:
+        }
+    }
+    expect: {
+        var a;
+        switch (void console.log("PASS")) {
+          case a:
+          case console.log("FAIL"), 42:
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+keep_case_4: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a;
+        switch (void console.log("PASS")) {
+          case a:
+          case void console.log("FAIL"):
+        }
+    }
+    expect: {
+        var a;
+        switch (void console.log("PASS")) {
+          case a:
+          case void console.log("FAIL"):
+        }
+    }
+    expect_stdout: "PASS"
+}
+
 issue_376: {
     options = {
         dead_code: true,
@@ -551,6 +822,7 @@ issue_441_2: {
 
 issue_1674: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         side_effects: true,
@@ -650,7 +922,7 @@ issue_1680_1: {
           case f(0):
           case f(1):
             f(2);
-          case 2:
+          default:
             f(5);
         }
     }
@@ -876,6 +1148,7 @@ beautify: {
 
 issue_1758: {
     options = {
+        conditionals: true,
         dead_code: true,
         switches: true,
     }
@@ -898,20 +1171,20 @@ issue_1758: {
 
 issue_2535: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         switches: true,
     }
     input: {
         switch(w(), 42) {
-            case 13: x();
-            case 42: y();
-            default: z();
+          case 13: x();
+          case 42: y();
+          default: z();
         }
     }
     expect: {
         w(), 42;
-        42;
         y();
         z();
     }
@@ -919,6 +1192,7 @@ issue_2535: {
 
 issue_1750: {
     options = {
+        conditionals: true,
         dead_code: true,
         evaluate: true,
         switches: true,
@@ -936,7 +1210,6 @@ issue_1750: {
     expect: {
         var a = 0, b = 1;
         true;
-        a, true;
         b = 2;
         console.log(a, b);
     }
@@ -963,6 +1236,7 @@ drop_switch_1: {
 
 drop_switch_2: {
     options = {
+        conditionals: true,
         dead_code: true,
         switches: true,
     }
@@ -1007,6 +1281,7 @@ drop_switch_3: {
 
 drop_switch_4: {
     options = {
+        conditionals: true,
         dead_code: true,
         switches: true,
     }
@@ -1028,3 +1303,308 @@ drop_switch_4: {
     }
     expect_stdout: "PASS"
 }
+
+drop_switch_5: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (A) {
+          case B:
+            x();
+          default:
+        }
+        switch (C) {
+          default:
+            y();
+          case D:
+        }
+    }
+    expect: {
+        A === B && x();
+        C !== D && y();
+    }
+}
+
+drop_switch_6: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (A) {
+          case B:
+          default:
+            x();
+        }
+        switch (C) {
+          default:
+          case D:
+            y();
+        }
+    }
+    expect: {
+        A;
+        B;
+        x();
+        C !== D;
+        y();
+    }
+}
+
+drop_switch_7: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (A) {
+          case B:
+            w();
+          default:
+            x();
+        }
+        switch (C) {
+          default:
+            y();
+          case D:
+            z();
+        }
+    }
+    expect: {
+        A === B && w();
+        x();
+        C !== D && y();
+        z();
+    }
+}
+
+drop_switch_8: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (A) {
+          case B:
+            w();
+            break;
+          default:
+            x();
+        }
+        switch (C) {
+          default:
+            y();
+            break;
+          case D:
+            z();
+        }
+    }
+    expect: {
+        (A === B ? w : x)();
+        (C !== D ? y : z)();
+    }
+}
+
+issue_4059: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        switch (0) {
+          default:
+          case 1:
+            break;
+          case a:
+            break;
+            var a;
+        }
+        console.log("PASS");
+    }
+    expect: {
+        switch (0) {
+          default:
+            break;
+          case a:
+            break;
+            var a;
+        }
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5008_1: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+        switches: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(function f() {
+            switch (f) {
+              case f:
+                return "PASS";
+              default:
+                return "FAIL";
+            }
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            switch (f) {
+              default:
+                return "PASS";
+            }
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5008_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+        switches: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(function(a) {
+            switch (a) {
+              case a:
+                return "PASS";
+              default:
+                return "FAIL";
+            }
+        }([]));
+    }
+    expect: {
+        console.log(function(a) {
+            switch (a) {
+              default:
+                return "PASS";
+            }
+        }([]));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5008_3: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+        switches: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(function(a) {
+            switch (a) {
+              case a:
+                return "PASS";
+              default:
+                return "FAIL";
+            }
+        }({}));
+    }
+    expect: {
+        console.log(function(a) {
+            switch (a) {
+              default:
+                return "PASS";
+            }
+        }({}));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5008_4: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+        switches: true,
+    }
+    input: {
+        console.log(function(a) {
+            switch (a) {
+              case a:
+                return "PASS";
+              default:
+                return "FAIL";
+            }
+        }(/foo/));
+    }
+    expect: {
+        console.log(function(a) {
+            switch (a) {
+              default:
+                return "PASS";
+            }
+        }(/foo/));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5010: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a;
+        switch (42) {
+          case console.log("PASS"):
+          case a:
+            console.log("FAIL");
+          case 42:
+        }
+    }
+    expect: {
+        var a;
+        switch (42) {
+          case console.log("PASS"):
+          case a:
+            console.log("FAIL");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5012: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        switch (void 0) {
+          case console.log("PASS"):
+            break;
+          case void 0:
+          case 42:
+            console.log("FAIL");
+        }
+    }
+    expect: {
+        switch (void 0) {
+          case console.log("PASS"):
+            break;
+          default:
+            console.log("FAIL");
+        }
+    }
+    expect_stdout: "PASS"
+}

test/compress/templates.js

@@ -0,0 +1,436 @@
+simple: {
+    input: {
+        console.log(`foo
+        bar\nbaz`);
+    }
+    expect_exact: "console.log(`foo\n        bar\\nbaz`);"
+    expect_stdout: [
+        "foo",
+        "        bar",
+        "baz",
+    ]
+    node_version: ">=4"
+}
+
+placeholder: {
+    input: {
+        console.log(`foo ${ function(a, b) {
+            return a * b;
+        }(6, 7) }`);
+    }
+    expect_exact: "console.log(`foo ${function(a,b){return a*b}(6,7)}`);"
+    expect_stdout: "foo 42"
+    node_version: ">=4"
+}
+
+nested: {
+    input: {
+        console.log(`P${`A${"S"}`}S`);
+    }
+    expect_exact: 'console.log(`P${`A${"S"}`}S`);'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+tagged: {
+    input: {
+        console.log(String.raw`foo\nbar`);
+    }
+    expect_exact: "console.log(String.raw`foo\\nbar`);"
+    expect_stdout: "foo\\nbar"
+    node_version: ">=4"
+}
+
+tagged_chain: {
+    input: {
+        function f(strings) {
+            return strings.join("") || f;
+        }
+        console.log(f```${42}``pass`.toUpperCase());
+    }
+    expect_exact: 'function f(strings){return strings.join("")||f}console.log(f```${42}``pass`.toUpperCase());'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+tag_parentheses_arrow: {
+    input: {
+        console.log((s => s.raw[0])`\tPASS`.slice(2));
+    }
+    expect_exact: "console.log((s=>s.raw[0])`\\tPASS`.slice(2));"
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+tag_parentheses_binary: {
+    options = {
+        collapse_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var f = function() {
+            console.log("PASS");
+        } || console
+        f``;
+    }
+    expect_exact: '(function(){console.log("PASS")}||console)``;'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+tag_parentheses_new: {
+    input: {
+        (new function() {
+            return console.log;
+        })`foo`;
+    }
+    expect_exact: "(new function(){return console.log})`foo`;"
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+tag_parentheses_sequence: {
+    input: {
+        var o = {
+            f() {
+                console.log(this === o ? "FAIL" : "PASS");
+            },
+        };
+        (42, o.f)``;
+    }
+    expect_exact: 'var o={f(){console.log(this===o?"FAIL":"PASS")}};(42,o.f)``;'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+tag_parentheses_unary: {
+    input: {
+        var a;
+        try {
+            (~a)``;
+            (a++)``;
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_exact: 'var a;try{(~a)``;(a++)``}catch(e){console.log("PASS")}'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+malformed_escape: {
+    input: {
+        (function(s) {
+            s.forEach((c, i) => console.log(i, c, s.raw[i]));
+            return () => console.log(arguments);
+        })`\uFo${42}`();
+    }
+    expect_exact: "(function(s){s.forEach((c,i)=>console.log(i,c,s.raw[i]));return()=>console.log(arguments)})`\\uFo${42}`();"
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+evaluate: {
+    options = {
+        evaluate: true,
+        templates: false,
+    }
+    input: {
+        console.log(`foo ${ function(a, b) {
+            return a * b;
+        }(6, 7) }`);
+    }
+    expect: {
+        console.log(`foo ${42}`);
+    }
+    expect_stdout: "foo 42"
+    node_version: ">=4"
+}
+
+evaluate_templates: {
+    options = {
+        evaluate: true,
+        templates: true,
+    }
+    input: {
+        console.log(`foo ${ function(a, b) {
+            return a * b;
+        }(6, 7) }`);
+    }
+    expect: {
+        console.log("foo 42");
+    }
+    expect_stdout: "foo 42"
+    node_version: ">=4"
+}
+
+partial_evaluate: {
+    options = {
+        evaluate: true,
+        templates: true,
+    }
+    input: {
+        console.log(`${6 * 7} foo ${console ? `PA` + "SS" : `FA` + `IL`}`);
+    }
+    expect: {
+        console.log(`42 foo ${console ? "PASS" : "FAIL"}`);
+    }
+    expect_stdout: "42 foo PASS"
+    node_version: ">=4"
+}
+
+malformed_evaluate_1: {
+    options = {
+        evaluate: true,
+        templates: true,
+    }
+    input: {
+        console.log(`\67 ${6 * 7}`);
+    }
+    expect: {
+        console.log(`\67 42`);
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+malformed_evaluate_2: {
+    options = {
+        evaluate: true,
+        templates: true,
+    }
+    input: {
+        console.log(`\u0${0}b${5}`);
+    }
+    expect: {
+        console.log(`\u0${0}b5`);
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+malformed_evaluate_3: {
+    options = {
+        evaluate: true,
+        templates: true,
+    }
+    input: {
+        console.log(`\u${0}b${5}`);
+    }
+    expect: {
+        console.log(`\u0b5`);
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+malformed_evaluate_4: {
+    options = {
+        evaluate: true,
+        templates: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(String.raw`\u0${0}b${5}`);
+    }
+    expect: {
+        console.log("\\u00b5");
+    }
+    expect_stdout: "\\u00b5"
+    node_version: ">=8"
+}
+
+unsafe_evaluate: {
+    options = {
+        evaluate: true,
+        templates: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(String.raw`\uFo`);
+    }
+    expect: {
+        console.log("\\uFo");
+    }
+    expect_stdout: "\\uFo"
+    node_version: ">=8"
+}
+
+side_effects_1: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        `42`;
+        `${console.log("foo")}`;
+        console.log`\nbar`;
+    }
+    expect: {
+        console.log("foo");
+        console.log`\nbar`;
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+side_effects_2: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        var o = {
+            f() {
+                console.log(this === o ? "FAIL" : "PASS");
+            },
+        };
+        (42, o.f)``;
+    }
+    expect: {
+        var o = {
+            f() {
+                console.log(this === o ? "FAIL" : "PASS");
+            },
+        };
+        (0, o.f)``;
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+unsafe_side_effects: {
+    options = {
+        side_effects: true,
+        unsafe: true,
+    }
+    input: {
+        `42`;
+        `${console.log("foo")}`;
+        String.raw`\nbar`;
+    }
+    expect: {
+        console.log("foo");
+    }
+    expect_stdout: "foo"
+    node_version: ">=4"
+}
+
+pure_funcs: {
+    options = {
+        pure_funcs: "Math.random",
+        side_effects: true,
+    }
+    input: {
+        Math.random`${console.log("PASS")}`;
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4604: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 0, log = console.log;
+        a = "FAIL";
+        (function() {
+            a = "PASS";
+        })``;
+        log(a);
+    }
+    expect: {
+        var a = 0, log = console.log;
+        a = "FAIL";
+        (function() {
+            a = "PASS";
+        })``;
+        log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4606: {
+    options = {
+        evaluate: true,
+        templates: true,
+    }
+    input: {
+        console.log(`${typeof A} ${"\r"} ${"\\"} ${"`"}`);
+    }
+    expect: {
+        console.log(`${typeof A} \r \\ \``);
+    }
+    expect_stdout: "undefined \r \\ `"
+    node_version: ">=4"
+}
+
+issue_4630: {
+    options = {
+        evaluate: true,
+        templates: true,
+    }
+    input: {
+        console.log(`${/PASS/}`);
+    }
+    expect: {
+        console.log("/PASS/");
+    }
+    expect_stdout: "/PASS/"
+    node_version: ">=4"
+}
+
+issue_4676: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        templates: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var b = `foo${a = "PASS"}`;
+            for (var c in f && b)
+                b.p;
+            return a;
+        }
+        console.log(f("FAIL"));
+    }
+    expect: {
+        console.log(function f(a) {
+            var b = "fooPASS";
+            for (var c in f, b)
+                b.p;
+            return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4931: {
+    options = {
+        evaluate: true,
+        templates: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(String.raw`${typeof A} ${"\r"}`);
+        console.log(String.raw`${"\\"} ${"`"}`);
+    }
+    expect: {
+        console.log(String.raw`${typeof A} ${"\r"}`);
+        console.log("\\ `");
+    }
+    expect_stdout: [
+        "undefined \r",
+        "\\ `",
+    ]
+    node_version: ">=4"
+}

test/compress/transform.js

@@ -95,7 +95,7 @@ while_if_break: {
         }
     }
     expect: {
-        for(; a && (b && c && d, !e););
+        for (; a && (b && c && d, !e););
     }
 }
 

test/compress/unicode.js

@@ -1,3 +1,37 @@
+ascii_only_false: {
+    options = {}
+    beautify = {
+        ascii_only: false,
+    }
+    input: {
+        console.log(
+            "\x000\x001\x007\x008\x00",
+            "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+            "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
+            "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff"
+        );
+    }
+    expect_exact: 'console.log("\\x000\\x001\\x007\\x008\\0","\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\f\\r\x0e\x0f","\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\');'
+    expect_stdout: true
+}
+
+ascii_only_true: {
+    options = {}
+    beautify = {
+        ascii_only: true,
+    }
+    input: {
+        console.log(
+            "\x000\x001\x007\x008\x00",
+            "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+            "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
+            "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff"
+        );
+    }
+    expect_exact: 'console.log("\\x000\\x001\\x007\\x008\\0","\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\f\\r\\x0e\\x0f","\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f",\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\');'
+    expect_stdout: true
+}
+
 unicode_parse_variables: {
     options = {}
     input: {
@@ -16,7 +50,7 @@ unicode_parse_variables: {
     }
 }
 
-unicode_escaped_identifier: {
+unicode_escaped_identifier_1: {
     input: {
         var \u0061 = "\ud800\udc00";
         console.log(a);
@@ -25,6 +59,17 @@ unicode_escaped_identifier: {
     expect_stdout: "\ud800\udc00"
 }
 
+unicode_escaped_identifier_2: {
+    input: {
+        var \u{61} = "foo";
+        var \u{10000} = "bar";
+        console.log(a, \u{10000});
+    }
+    expect_exact: 'var a="foo";var \u{10000}="bar";console.log(a,\u{10000});'
+    expect_stdout: "foo bar"
+    node_version: ">=4"
+}
+
 unicode_identifier_ascii_only: {
     beautify = {
         ascii_only: true,
@@ -141,3 +186,35 @@ issue_2569: {
     }
     expect_exact: 'new RegExp("[\\udc42-\\udcaa\\udd74-\\udd96\\ude45-\\ude4f\\udea3-\\udecc]");'
 }
+
+surrogate_pair: {
+    beautify = {
+        ascii_only: false,
+    }
+    input: {
+        var \u{2f800} = {
+            \u{2f801}: "\u{100000}",
+        };
+        \u{2f800}.\u{2f802} = "\u{100001}";
+        console.log(typeof \u{2f800}, \u{2f800}.\u{2f801}, \u{2f800}["\u{2f802}"]);
+    }
+    expect_exact: 'var \ud87e\udc00={"\ud87e\udc01":"\udbc0\udc00"};\ud87e\udc00.\ud87e\udc02="\udbc0\udc01";console.log(typeof \ud87e\udc00,\ud87e\udc00.\ud87e\udc01,\ud87e\udc00["\ud87e\udc02"]);'
+    expect_stdout: "object \udbc0\udc00 \udbc0\udc01"
+    node_version: ">=4"
+}
+
+surrogate_pair_ascii: {
+    beautify = {
+        ascii_only: true,
+    }
+    input: {
+        var \u{2f800} = {
+            \u{2f801}: "\u{100000}",
+        };
+        \u{2f800}.\u{2f802} = "\u{100001}";
+        console.log(typeof \u{2f800}, \u{2f800}.\u{2f801}, \u{2f800}["\u{2f802}"]);
+    }
+    expect_exact: 'var \\u{2f800}={"\\ud87e\\udc01":"\\udbc0\\udc00"};\\u{2f800}.\\u{2f802}="\\udbc0\\udc01";console.log(typeof \\u{2f800},\\u{2f800}.\\u{2f801},\\u{2f800}["\\ud87e\\udc02"]);'
+    expect_stdout: "object \udbc0\udc00 \udbc0\udc01"
+    node_version: ">=4"
+}

test/compress/varify.js

@@ -0,0 +1,615 @@
+reduce_merge_const: {
+    options = {
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        const a = console;
+        console.log(typeof a);
+        var b = typeof a;
+        console.log(b);
+    }
+    expect: {
+        var b = console;
+        console.log(typeof b);
+        b = typeof b;
+        console.log(b);
+    }
+    expect_stdout: [
+        "object",
+        "object",
+    ]
+}
+
+reduce_merge_let: {
+    options = {
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        let a = console;
+        console.log(typeof a);
+        var b = typeof a;
+        console.log(b);
+    }
+    expect: {
+        "use strict";
+        var b = console;
+        console.log(typeof b);
+        b = typeof b;
+        console.log(b);
+    }
+    expect_stdout: [
+        "object",
+        "object",
+    ]
+    node_version: ">=4"
+}
+
+reduce_block_const: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        {
+            const a = typeof console;
+            console.log(a);
+        }
+    }
+    expect: {
+        var a = typeof console;
+        console.log(a);
+    }
+    expect_stdout: "object"
+}
+
+reduce_block_let: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        {
+            let a = typeof console;
+            console.log(a);
+        }
+    }
+    expect: {
+        "use strict";
+        var a = typeof console;
+        console.log(a);
+    }
+    expect_stdout: "object"
+    node_version: ">=4"
+}
+
+hoist_props_const: {
+    options = {
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        {
+            const o = {
+                p: "PASS",
+            };
+            console.log(o.p);
+        }
+    }
+    expect: {
+        var o_p = "PASS";
+        console.log(o_p);
+    }
+    expect_stdout: "PASS"
+}
+
+hoist_props_let: {
+    options = {
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        {
+            let o = {
+                p: "PASS",
+            };
+            console.log(o.p);
+        }
+    }
+    expect: {
+        "use strict";
+        var o_p = "PASS";
+        console.log(o_p);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+scope_adjustment_const: {
+    options = {
+        conditionals: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        for (var k in [ 42 ])
+            console.log(function f() {
+                if (k) {
+                    const a = 0;
+                }
+            }());
+    }
+    expect: {
+        for (var k in [ 42 ])
+            console.log(void (k && 0));
+    }
+    expect_stdout: "undefined"
+}
+
+scope_adjustment_let: {
+    options = {
+        conditionals: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        for (var k in [ 42 ])
+            console.log(function f() {
+                if (k) {
+                    let a = 0;
+                }
+            }());
+    }
+    expect: {
+        "use strict";
+        for (var k in [ 42 ])
+            console.log(void (k && 0));
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_4191_const: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        const a = function() {};
+        console.log(typeof a, a());
+    }
+    expect: {
+        function a() {};
+        console.log(typeof a, a());
+    }
+    expect_stdout: "function undefined"
+}
+
+issue_4191_let: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        let a = function() {};
+        console.log(typeof a, a());
+    }
+    expect: {
+        "use strict";
+        function a() {};
+        console.log(typeof a, a());
+    }
+    expect_stdout: "function undefined"
+    node_version: ">=4"
+}
+
+forin_const_1: {
+    options = {
+        join_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        const o = {
+            foo: 42,
+            bar: "PASS",
+        };
+        for (const k in o)
+            console.log(k, o[k]);
+    }
+    expect: {
+        var o = {
+            foo: 42,
+            bar: "PASS",
+        };
+        for (const k in o)
+            console.log(k, o[k]);
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+forin_const_2: {
+    options = {
+        join_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        const o = {
+            p: 42,
+            q: "PASS",
+        };
+        for (const [ k ] in o)
+            console.log(k, o[k]);
+    }
+    expect: {
+        var o = {
+            p: 42,
+            q: "PASS",
+        }, k;
+        for ([ k ] in o)
+            console.log(k, o[k]);
+    }
+    expect_stdout: [
+        "p 42",
+        "q PASS",
+    ]
+    node_version: ">=6"
+}
+
+forin_let_1: {
+    options = {
+        join_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        let o = {
+            foo: 42,
+            bar: "PASS",
+        };
+        for (let k in o)
+            console.log(k, o[k]);
+    }
+    expect: {
+        "use strict";
+        var o = {
+            foo: 42,
+            bar: "PASS",
+        }, k;
+        for (k in o)
+            console.log(k, o[k]);
+    }
+    expect_stdout: [
+        "foo 42",
+        "bar PASS",
+    ]
+    node_version: ">=4"
+}
+
+forin_let_2: {
+    options = {
+        join_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        let o = {
+            p: 42,
+            q: "PASS",
+        };
+        for (let [ k ] in o)
+            console.log(k, o[k]);
+    }
+    expect: {
+        var o = {
+            p: 42,
+            q: "PASS",
+        }, k;
+        for ([ k ] in o)
+            console.log(k, o[k]);
+    }
+    expect_stdout: [
+        "p 42",
+        "q PASS",
+    ]
+    node_version: ">=6"
+}
+
+loop_scope_1: {
+    options = {
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        var o = { foo: 1, bar: 2 };
+        for (let i in o) {
+            console.log(i);
+        }
+        for (const j in o)
+            setTimeout(() => console.log(j), 0);
+        for (let k in o)
+            setTimeout(function() {
+                console.log(k);
+            }, 0);
+    }
+    expect: {
+        "use strict";
+        var o = { foo: 1, bar: 2 };
+        for (var i in o)
+            console.log(i);
+        for (const j in o)
+            setTimeout(() => console.log(j), 0);
+        for (let k in o)
+            setTimeout(function() {
+                console.log(k);
+            }, 0);
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "foo",
+        "bar",
+        "foo",
+        "bar",
+    ]
+    node_version: ">=4"
+}
+
+loop_scope_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        var a = [ "foo", "bar" ];
+        for (var i = 0; i < a.length; i++) {
+            const x = a[i];
+            console.log(x);
+            let y = a[i];
+            setTimeout(() => console.log(y), 0);
+            const z = a[i];
+            setTimeout(function() {
+                console.log(z);
+            }, 0);
+        }
+    }
+    expect: {
+        "use strict";
+        var a = [ "foo", "bar" ];
+        for (var i = 0; i < a.length; i++) {
+            var x = a[i];
+            console.log(x);
+            let y = a[i];
+            setTimeout(() => console.log(y), 0);
+            const z = a[i];
+            setTimeout(function() {
+                console.log(z);
+            }, 0);
+        }
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "foo",
+        "foo",
+        "bar",
+        "bar",
+    ]
+    node_version: ">=4"
+}
+
+issue_4290_1_const: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        const a = 0;
+        var a;
+    }
+    expect: {
+        const a = 0;
+        var a;
+    }
+    expect_stdout: true
+}
+
+issue_4290_1_let: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        let a = 0;
+        var a;
+    }
+    expect: {
+        "use strict";
+        let a = 0;
+        var a;
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+drop_forin_let: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        for (let a in console.log("PASS"));
+    }
+    expect: {
+        "use strict";
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+default_init: {
+    options = {
+        join_vars: true,
+        reduce_vars: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        A = "PASS";
+        (function() {
+            "use strict";
+            let a;
+            a = A;
+            console.log(a);
+        })();
+    }
+    expect: {
+        A = "PASS";
+        (function() {
+            "use strict";
+            var a = A;
+            console.log(a);
+        })();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4933_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        console.log(f());
+        function f() {
+            var a;
+            for (console in a = [ f ]) {
+                const b = a;
+            }
+        }
+    }
+    expect: {
+        console.log(function f() {
+            var a;
+            for (console in a = [ f ]) {
+                const b = a;
+            }
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4933_2: {
+    options = {
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        console.log(f());
+        function f() {
+            var a;
+            for (console in a = [ f ]) {
+                const b = a;
+            }
+        }
+    }
+    expect: {
+        console.log(function f() {
+            for (console in [ f ]);
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4954: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        (function() {
+            {
+                let a = console;
+                console.log(typeof a);
+            }
+            {
+                let a = function() {};
+                a && console.log(typeof a);
+            }
+        })();
+    }
+    expect: {
+        "use strict";
+        (function() {
+            var a = console;
+            console.log(typeof a);
+            {
+                let a = function() {};
+                a && console.log(typeof a);
+            }
+        })();
+    }
+    expect_stdout: [
+        "object",
+        "function",
+    ]
+    node_version: ">=4"
+}

test/compress/webkit.js

@@ -61,7 +61,7 @@ lambda_name_mangle: {
 
 lambda_name_mangle_ie8: {
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -95,7 +95,7 @@ function_name_mangle_ie8: {
         unused: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {

test/exports.js

@@ -1,5 +1,6 @@
 exports["Compressor"] = Compressor;
 exports["defaults"] = defaults;
+exports["is_statement"] = is_statement;
 exports["JS_Parse_Error"] = JS_Parse_Error;
 exports["List"] = List;
 exports["mangle_properties"] = mangle_properties;

test/input/invalid/assign_4.js

@@ -1 +1 @@
-++null
+console.log(4 || (null = 4));

test/input/invalid/assign_5.js

@@ -0,0 +1 @@
+console.log(5 || ([]?.length ^= 5));

test/input/invalid/destructured_var.js

@@ -0,0 +1,8 @@
+function f() {
+    var { eval } = null;
+}
+
+function g() {
+    "use strict";
+    var { eval } = 42;
+}

test/input/invalid/for-await.js

@@ -0,0 +1 @@
+for await (; console.log(42););

test/input/invalid/for-of_1.js

@@ -0,0 +1,3 @@
+var a = [ 1 ], b;
+for (b = 2 of a)
+    console.log(b);

test/input/invalid/for-of_2.js

@@ -0,0 +1,3 @@
+var a = [ 1 ];
+for (var b = 2 of a)
+    console.log(b);

test/input/invalid/switch.js

@@ -0,0 +1,4 @@
+switch (0) {
+  default:
+  default:
+}

test/input/issue-3040/input.js.map

@@ -1,11 +1,11 @@
-{
-    "version": 3,
-    "sources": [
-        "input.js"
-    ],
-    "names": [],
-    "mappings": ";;;;;;;;;;;;;;eAAc,OAAO,CAAC,KAAD,C;IAAd,G,YAAA,G;;gBACS,OAAO,CAAC,OAAD,C;IAAhB,K,aAAA,K;;AAEP,GAAG,CAAC,CAAJ,OAAA,GAAG,qBAAM,GAAG,CAAC,CAAJ,CAAM,KAAK,CAAC,CAAZ,CAAN,EAAH",
-    "sourcesContent": [
-        "const {foo} = require(\"bar\");\nconst {hello} = require(\"world\");\n\nfoo.x(...foo.y(hello.z));\n"
-    ]
-}
+{
+    "version": 3,
+    "sources": [
+        "input.js"
+    ],
+    "names": [],
+    "mappings": ";;;;;;;;;;;;;;eAAc,OAAO,CAAC,KAAD,C;IAAd,G,YAAA,G;;gBACS,OAAO,CAAC,OAAD,C;IAAhB,K,aAAA,K;;AAEP,GAAG,CAAC,CAAJ,OAAA,GAAG,qBAAM,GAAG,CAAC,CAAJ,CAAM,KAAK,CAAC,CAAZ,CAAN,EAAH",
+    "sourcesContent": [
+        "const {foo} = require(\"bar\");\nconst {hello} = require(\"world\");\n\nfoo.x(...foo.y(hello.z));\n"
+    ]
+}