v3.13.5

fixes #4876

.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'
+          - '--ie8 -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

@@ -7,13 +7,13 @@ 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 }}
@@ -29,20 +29,5 @@ jobs:
       - 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

@@ -2,7 +2,7 @@ name: Fuzzing
 on:
   pull_request:
   schedule:
-    - cron: "*/5 * * * *"
+    - cron: '*/5 * * * *'
 env:
   BASE_URL: https://api.github.com/repos/${{ github.repository }}
   CAUSE: ${{ github.event_name }}
@@ -13,30 +13,27 @@ jobs:
     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
+          . ./test/release/install.sh
           if [[ $CAUSE == "schedule" ]]; then
             node test/ufuzz/job $BASE_URL $TOKEN $RUN_NUM
           else

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
@@ -133,6 +137,10 @@ 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.
@@ -216,10 +224,10 @@ Example:
 To enable the mangler you need to pass `--mangle` (`-m`).  The following
 (comma-separated) options are supported:
 
-- `eval` (default `false`) -- mangle names visible in scopes where `eval` or
+- `eval` (default: `false`) — mangle names visible in scopes where `eval` or
   `with` are used.
 
-- `reserved` (default: `[]`) -- when mangling is enabled but you want to
+- `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:
 
@@ -486,44 +494,51 @@ 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.
+- `ie8` (default: `false`) — set to `true` to support IE8.
 
-- `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.
+- `webkit` (default: `false`) — enable workarounds for Safari/WebKit bugs.
   PhantomJS users should set this option to `true`.
 
 ## Minify options structure
@@ -608,109 +623,121 @@ 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 `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.
 
-- `merge_vars` (default: `true`) -- combine and reuse variables.
+- `merge_vars` (default: `true`) — combine and reuse variables.
 
-- `negate_iife` (default: `true`) -- negate "Immediately-Called Function Expressions"
+- `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
@@ -722,22 +749,24 @@ 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`
@@ -746,67 +775,68 @@ 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
+- `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)
+
+- `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.
 
-- `unsafe` (default: `false`) -- apply "unsafe" transformations (discussion below)
+- `unsafe` (default: `false`) — apply "unsafe" transformations (discussion below)
 
-- `unsafe_comps` (default: `false`) -- compress expressions like `a <= b` assuming
+- `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`
+- `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:
@@ -833,18 +863,18 @@ 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
@@ -853,77 +883,79 @@ 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;
   }
   ```
 
-- `galio` (default `false`) -- enable workarounds for ANT Galio bugs
+- `galio` (default: `false`) — enable workarounds for ANT Galio bugs
 
-- `indent_level` (default `4`)
+- `indent_level` (default: `4`)
 
-- `indent_start` (default `0`) -- prefix all lines by that many spaces
+- `indent_start` (default: `0`) — prefix all lines by that many spaces
 
-- `inline_script` (default `true`) -- escape HTML comments and the slash in
+- `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)
 
-- `v8` (default `false`) -- enable workarounds for Chrome & Node.js bugs
-
-- `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.
 
@@ -1124,25 +1156,21 @@ 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 });
 ```
 
@@ -1173,9 +1201,21 @@ 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:
-  ```js
+  ```javascript
   A = "FAIL";
   var B = "FAIL";
   // can be `global`, `self`, `window` etc.
@@ -1193,3 +1233,97 @@ To allow for better optimizations, the compiler makes various assumptions:
   `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.

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 = {
@@ -95,6 +95,8 @@ 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.",
@@ -113,6 +115,9 @@ function process_option(name, no_value) {
                 "  --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"));
         }
@@ -139,6 +144,7 @@ function process_option(name, no_value) {
       case "enclose":
         options[name] = read_value();
         break;
+      case "annotations":
       case "ie8":
       case "timings":
       case "toplevel":
@@ -146,6 +152,9 @@ function process_option(name, no_value) {
       case "webkit":
         options[name] = true;
         break;
+      case "no-annotations":
+        options.annotations = false;
+        break;
       case "keep-fnames":
         options.keep_fnames = true;
         break;
@@ -194,6 +203,7 @@ function process_option(name, no_value) {
       case "no-rename":
         options.rename = false;
         break;
+      case "in-situ":
       case "reduce-test":
       case "self":
         break;
@@ -225,10 +235,11 @@ if (options.mangle && options.mangle.properties) {
         });
     }
 }
-if (output == "ast") options.output = {
-    ast: true,
-    code: false,
-};
+if (/^ast|spidermonkey$/.test(output)) {
+    if (typeof options.output != "object") options.output = {};
+    options.output.ast = true;
+    options.output.code = false;
+}
 if (options.parse && (options.parse.acorn || options.parse.spidermonkey)
     && options.sourceMap && options.sourceMap.content == "inline") {
     fatal("inline source map only works with built-in parser");
@@ -254,18 +265,35 @@ if (specified["self"]) {
     if (!options.wrap) options.wrap = "UglifyJS";
     paths = UglifyJS.FILES;
 }
-if (paths.length) {
+if (specified["in-situ"]) {
+    if (output && output != "spidermonkey" || specified["reduce-test"] || specified["self"]) {
+        fatal("incompatible options specified");
+    }
+    paths.forEach(function(name) {
+        print(name);
+        if (/^ast|spidermonkey$/.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();
@@ -286,13 +314,43 @@ function run() {
     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 pos = node.start.parens;
+                        if (pos) for (var i = 0; !pure && i < pos.length; i++) {
+                            pure = list[pos[i]];
+                        }
+                    }
+                    if (pure) node.pure = pure;
+                }));
             } else if (options.parse.spidermonkey) {
                 files = convert_ast(function(toplevel, name) {
                     var obj = JSON.parse(files[name]);
@@ -360,14 +418,14 @@ function run() {
         }
         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;
@@ -384,16 +442,19 @@ 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

@@ -47,14 +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) {
@@ -75,6 +73,7 @@ function to_json(cache) {
 function minify(files, options) {
     try {
         options = defaults(options, {
+            annotations: undefined,
             compress: {},
             enclose: false,
             ie8: false,
@@ -87,22 +86,21 @@ 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" ]);
-        set_shorthand("webkit", options, [ "mangle", "output" ]);
+        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) set_shorthand("ie8", 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, [ "mangle", "output" ]);
         var quoted_props;
         if (options.mangle) {
             options.mangle = defaults(options.mangle, {
@@ -113,6 +111,7 @@ function minify(files, options) {
                 properties: false,
                 reserved: [],
                 toplevel: false,
+                v8: false,
                 webkit: false,
             }, true);
             if (options.mangle.properties) {
@@ -205,27 +204,29 @@ function minify(files, options) {
         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*$/, "");

lib/propmangle.js

@@ -81,7 +81,9 @@ var builtins = function() {
 
 function reserve_quoted_keys(ast, reserved) {
     ast.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_ObjectProperty) {
+        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);
@@ -163,6 +165,8 @@ function mangle_properties(ast, options) {
                 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) {
@@ -193,6 +197,8 @@ function mangle_properties(ast, options) {
                 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 (node instanceof AST_ObjectProperty) {
@@ -222,13 +228,11 @@ function mangle_properties(ast, options) {
     }
 
     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;
             }
@@ -236,6 +240,7 @@ 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;

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 ];
@@ -92,14 +92,28 @@ SymbolDef.prototype = {
     },
     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_SymbolLambda
-                    || this.orig[0] instanceof AST_SymbolDefun);
+                && (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,
@@ -109,15 +123,40 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     // pass 1: setup scope chaining and handle definitions
     var self = this;
     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_Defun) {
+        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_Definitions) {
+            var save_exported = exported;
+            exported = tw.parent() instanceof AST_ExportDeclaration;
+            descend();
+            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;
@@ -159,9 +198,12 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
         if (node instanceof AST_SymbolCatch) {
             scope.def_variable(node).defun = defun;
         } else if (node instanceof AST_SymbolConst) {
-            scope.def_variable(node).defun = defun;
+            var def = scope.def_variable(node);
+            def.defun = defun;
+            if (exported) def.exported = true;
         } else if (node instanceof AST_SymbolDefun) {
-            defun.def_function(node, tw.parent());
+            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);
@@ -170,9 +212,11 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             var def = defun.def_function(node, node.name == "arguments" ? undefined : defun);
             if (options.ie8) def.defun = defun.parent_scope.resolve();
         } else if (node instanceof AST_SymbolLet) {
-            scope.def_variable(node);
+            var def = scope.def_variable(node);
+            if (exported) def.exported = true;
         } else if (node instanceof AST_SymbolVar) {
-            defun.def_variable(node, null);
+            var def = defun.def_variable(node, node instanceof AST_SymbolImport ? undefined : null);
+            if (exported) def.exported = true;
             entangle(defun, scope);
         }
 
@@ -190,7 +234,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
         function entangle(defun, scope) {
             if (defun === scope) return;
             node.mark_enclosed(options);
-            var def = scope.find_variable(node);
+            var def = scope.find_variable(node.name);
             if (node.thedef === def) return;
             node.thedef = def;
             def.orig.push(node);
@@ -206,19 +250,50 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     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_body(node, tw);
+            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);
@@ -226,7 +301,9 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
                 i = in_arg.lastIndexOf(sym.scope, i - 1);
                 if (i < 0) break;
                 var decl = sym.orig[0];
-                if (decl instanceof AST_SymbolFunarg || decl instanceof AST_SymbolLambda) {
+                if (decl instanceof AST_SymbolCatch
+                    || decl instanceof AST_SymbolFunarg
+                    || decl instanceof AST_SymbolLambda) {
                     node.in_arg = true;
                     break;
                 }
@@ -234,9 +311,13 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             }
             if (!sym) {
                 sym = self.def_global(node);
-            } else if (name == "arguments" && sym.scope instanceof AST_Lambda) {
-                if (!(tw.parent() instanceof AST_PropAccess)) {
-                    sym.scope.uses_arguments = "d";
+            } 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;
                 }
@@ -254,25 +335,17 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
                     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;
-        }
-        // ensure compression works if `const` reuses a scope variable
-        if (node instanceof AST_SymbolConst) {
-            var redef = node.definition().redefined();
-            if (redef) redef.const_redefs = true;
-            return true;
-        }
     });
     self.walk(tw);
 
@@ -288,8 +361,9 @@ 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;
@@ -298,12 +372,18 @@ 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;
+        })) return false;
         var new_def = scope.find_variable(name);
         if (new_def) {
             var redef = new_def.redefined();
@@ -318,12 +398,12 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
         }
         old_def.defun = new_def.scope;
         old_def.forEach(function(node) {
-            node.redef = true;
+            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;
     }
 });
 
@@ -360,6 +440,13 @@ AST_BlockScope.DEFMETHOD("init_vars", function(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;
@@ -375,7 +462,9 @@ 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);
             });
@@ -390,14 +479,13 @@ AST_Symbol.DEFMETHOD("reference", function(options) {
 });
 
 AST_BlockScope.DEFMETHOD("find_variable", function(name) {
-    if (name instanceof AST_Symbol) name = name.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_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;
 });
@@ -406,7 +494,7 @@ 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);
@@ -486,6 +574,7 @@ function _default_mangler_options(options) {
         keep_fnames : false,
         reserved    : [],
         toplevel    : false,
+        v8          : false,
         webkit      : false,
     });
     if (!Array.isArray(options.reserved)) options.reserved = [];
@@ -517,7 +606,7 @@ 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_BlockScope) {
@@ -576,6 +665,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             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);
         }
@@ -590,6 +680,14 @@ 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) {

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);
@@ -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);
     });
@@ -162,6 +196,7 @@ TreeTransformer.prototype = new TreeWalker;
     });
     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);
@@ -169,6 +204,7 @@ TreeTransformer.prototype = new TreeWalker;
     });
     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);
@@ -177,6 +213,24 @@ TreeTransformer.prototype = new TreeWalker;
         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

@@ -238,21 +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": "3.12.1",
+  "version": "3.13.5",
   "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/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).");
@@ -209,7 +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;
             }
@@ -244,11 +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();
@@ -262,6 +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,
@@ -380,7 +381,7 @@ 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
@@ -409,7 +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 +1,473 @@
+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,
+        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,
@@ -412,7 +428,7 @@ issue_3273_global_strict_reduce_vars: {
     ]
 }
 
-issue_3273_keep_fargs_false: {
+issue_3273_drop_fargs_1: {
     options = {
         arguments: true,
         keep_fargs: false,
@@ -435,10 +451,10 @@ 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 +649,8 @@ 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 +672,8 @@ issue_3420_1: {
 issue_3420_2: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         var foo = function() {
@@ -675,7 +693,8 @@ issue_3420_2: {
 issue_3420_3: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         "use strict";
@@ -697,7 +716,8 @@ issue_3420_3: {
 issue_3420_4: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         !function() {
@@ -722,7 +742,8 @@ issue_3420_4: {
 issue_3420_5: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         "use strict";
@@ -749,7 +770,8 @@ issue_3420_5: {
 issue_3420_6: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         console.log(function() {
@@ -767,7 +789,8 @@ issue_3420_6: {
 issue_3420_7: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         "use strict";
@@ -811,7 +834,8 @@ issue_4200: {
 issue_4291_1: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         console.log(function() {
@@ -831,7 +855,8 @@ issue_4291_1: {
 issue_4291_2: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
+        reduce_vars: true,
     }
     input: {
         var a = function() {
@@ -842,8 +867,8 @@ issue_4291_2: {
         console.log(a[1], a[0], a.length);
     }
     expect: {
-        var a = function(argument_0) {
-            if (argument_0)
+        var a = function() {
+            if (arguments[0])
                 arguments[1] = "PASS";
             return arguments;
         }(42);
@@ -851,3 +876,160 @@ issue_4291_2: {
     }
     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 +1,816 @@
+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,
+        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"
+}
+
+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/assignments.js

@@ -461,3 +461,243 @@ 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"
+}

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

@@ -153,3 +153,31 @@ 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"
+}

test/compress/collapse_vars.js

@@ -958,8 +958,7 @@ collapse_vars_misc: {
     }
     expect: {
         function f0(o, a, h) {
-            var b = 3 - a;
-            return o.run(b)[7] = h;
+            return o.run(3 - a)[7] = h;
         }
         function f1(x) { return 5 - x }
         function f2(x) { return foo() / (5 - x) }
@@ -2276,8 +2275,8 @@ var_defs: {
     }
     expect: {
         var f1 = function(x, y) {
-            var r = x + y, z = r * r - r, b = 7;
-            console.log(z + b);
+            var r = x + y;
+            console.log(r * r - r + 7);
         };
         f1("1", 0);
     }
@@ -2869,7 +2868,7 @@ lvalues_def: {
     expect_stdout: true
 }
 
-compound_assignment: {
+compound_assignment_1: {
     options = {
         collapse_vars: true,
     }
@@ -2888,6 +2887,23 @@ compound_assignment: {
     expect_stdout: "4"
 }
 
+compound_assignment_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a;
+        a = 1;
+        for (a += a + 2; console.log(a););
+    }
+    expect: {
+        var a;
+        a = 1;
+        for (a += a + 2; console.log(a););
+    }
+    expect_stdout: "4"
+}
+
 issue_2187_1: {
     options = {
         collapse_vars: true,
@@ -2907,8 +2923,7 @@ issue_2187_1: {
         var a = 1;
         !function(foo) {
             foo();
-            var a = 2;
-            console.log(a);
+            console.log(2);
         }(function() {
             console.log(a);
         });
@@ -3145,8 +3160,8 @@ issue_2313_2: {
         var c = 0;
         !function a() {
             a && c++;
-            var a = 0;
-            a && c++;
+            var a;
+            (a = 0) && c++;
         }();
         console.log(c);
     }
@@ -4273,8 +4288,8 @@ issue_2436_14: {
         var b = {};
         (function() {
             a && function(c, d) {
-                console.log(c, d);
-            }(b, a);
+                console.log(b, d);
+            }(0, a);
         })();
     }
     expect_stdout: true
@@ -5502,8 +5517,7 @@ collapse_rhs_lhs_2: {
     expect: {
         var b = 1;
         (function f(f) {
-            f = b;
-            f[b] = 0;
+            b[b] = 0;
         })();
         console.log("PASS");
     }
@@ -5609,6 +5623,7 @@ collapse_rhs_array: {
 collapse_rhs_boolean_1: {
     options = {
         collapse_vars: true,
+        evaluate: true,
     }
     input: {
         var a, b;
@@ -5634,6 +5649,7 @@ collapse_rhs_boolean_1: {
 collapse_rhs_boolean_2: {
     options = {
         collapse_vars: true,
+        evaluate: true,
     }
     input: {
         var a;
@@ -5668,6 +5684,7 @@ collapse_rhs_boolean_3: {
         booleans: true,
         collapse_vars: true,
         conditionals: true,
+        evaluate: true,
     }
     input: {
         var a, f, g, h, i, n, s, t, x, y;
@@ -5721,6 +5738,7 @@ collapse_rhs_function: {
 collapse_rhs_number: {
     options = {
         collapse_vars: true,
+        evaluate: true,
     }
     input: {
         var a, b;
@@ -5800,6 +5818,7 @@ collapse_rhs_regexp: {
 collapse_rhs_string: {
     options = {
         collapse_vars: true,
+        evaluate: true,
     }
     input: {
         var a, b;
@@ -5875,6 +5894,7 @@ collapse_rhs_this: {
 collapse_rhs_undefined: {
     options = {
         collapse_vars: true,
+        side_effects: true,
     }
     input: {
         var a, b;
@@ -5996,7 +6016,7 @@ issue_3215_1: {
         }());
     }
     expect: {
-        console.log(typeof 42);
+        console.log("number");
     }
     expect_stdout: "number"
 }
@@ -6956,8 +6976,7 @@ sequence_in_iife_2: {
     }
     expect: {
         var a = "foo", b = 42;
-        b = a;
-        console.log(a, b);
+        console.log(a, b = a);
     }
     expect_stdout: "foo foo"
 }
@@ -8045,6 +8064,67 @@ mangleable_var: {
     expect_stdout: "PASS"
 }
 
+mangleable_assignment_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            p: function() {
+                return 6;
+            },
+        };
+        (function() {
+            var a, b = a = o.p();
+            console.log(a * (b / a + b));
+        })();
+    }
+    expect: {
+        var o = {
+            p: function() {
+                return 6;
+            },
+        };
+        (function() {
+            var a;
+            a = o.p();
+            console.log(a * (a / a + a));
+        })();
+    }
+    expect_stdout: "42"
+}
+
+mangleable_assignment_2: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            p: function() {
+                return 6;
+            },
+        };
+        (function(a, b) {
+            b = a = o.p();
+            console.log(a * (b / a + b));
+        })();
+    }
+    expect: {
+        var o = {
+            p: function() {
+                return 6;
+            },
+        };
+        (function(a, b) {
+            a = o.p();
+            console.log(a * (a / a + a));
+        })();
+    }
+    expect_stdout: "42"
+}
+
 issue_3884_1: {
     options = {
         collapse_vars: true,
@@ -8602,3 +8682,378 @@ issue_4248: {
     }
     expect_stdout: "1"
 }
+
+issue_4430_1: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+    }
+    input: {
+        function f(a) {
+            switch (a = 1, arguments[0]) {
+              case 1:
+                return "PASS";
+              case 2:
+                return "FAIL";
+            }
+        }
+        console.log(f(2));
+    }
+    expect: {
+        function f(a) {
+            switch (a = 1, arguments[0]) {
+              case 1:
+                return "PASS";
+              case 2:
+                return "FAIL";
+            }
+        }
+        console.log(f(2));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4430_2: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+    }
+    input: {
+        function f(a) {
+            switch (a = 0, arguments[0]) {
+              case 0:
+                return "PASS";
+              case 1:
+                return "FAIL";
+            }
+        }
+        console.log(f(1));
+    }
+    expect: {
+        function f(a) {
+            switch (arguments[a = 0]) {
+              case 0:
+                return "PASS";
+              case 1:
+                return "FAIL";
+            }
+        }
+        console.log(f(1));
+    }
+    expect_stdout: "PASS"
+}
+
+collapse_and_assign: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var log = console.log;
+        var a = {
+            p: "PASS",
+        };
+        console && (a = a.p);
+        log(a);
+    }
+    expect: {
+        var log = console.log;
+        var a = {
+            p: "PASS",
+        };
+        log(a = console ? a.p : a);
+    }
+    expect_stdout: "PASS"
+}
+
+collapse_or_assign: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var log = console.log;
+        var a = {
+            p: "PASS",
+        };
+        a.q || (a = a.p);
+        log(a);
+    }
+    expect: {
+        var log = console.log;
+        var a = {
+            p: "PASS",
+        };
+        log(a = !a.q ? a.p : a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4586_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 42;
+        (function f(b) {
+            var b = a;
+            if (b === arguments[0])
+                console.log("PASS");
+        })(console);
+    }
+    expect: {
+        var a = 42;
+        (function f(b) {
+            var b = a;
+            if (b === arguments[0])
+                console.log("PASS");
+        })(console);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4586_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 42;
+        (function f(b) {
+            b = a;
+            if (b === arguments[0])
+                console.log("PASS");
+        })(console);
+    }
+    expect: {
+        var a = 42;
+        (function f(b) {
+            if ((b = a) === arguments[0])
+                console.log("PASS");
+        })(console);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4732_1: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        (function(b) {
+            var b = a++;
+            var c = b ? b && console.log("PASS") : 0;
+        })(a++);
+    }
+    expect: {
+        var a = 0;
+        (function(b) {
+            (b = a++) && (b && console.log("PASS"));
+        })(a++);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4732_2: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        (function(b) {
+            var b = a++;
+            var c = b ? b && console.log("PASS") : 0;
+        })(a++);
+    }
+    expect: {
+        var a = 0;
+        (function(b) {
+            (b = a++) && b && console.log("PASS");
+        })(a++);
+    }
+    expect_stdout: "PASS"
+}
+
+dot_in_try: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var o, a = 6, b = 7, c;
+        try {
+            c = a * b;
+            o.p(c);
+        } catch (e) {
+            console.log(c);
+        }
+    }
+    expect: {
+        var o, a = 6, b = 7, c;
+        try {
+            c = a * b;
+            o.p(c);
+        } catch (e) {
+            console.log(c);
+        }
+    }
+    expect_stdout: "42"
+}
+
+dot_non_local: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var o, a = 6, b = 7, c;
+        function f() {
+            c = a * b;
+            o.p(c);
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log(c);
+        }
+    }
+    expect: {
+        var o, a = 6, b = 7, c;
+        function f() {
+            c = a * b;
+            o.p(c);
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log(c);
+        }
+    }
+    expect_stdout: "42"
+}
+
+issue_4806: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, o = {
+            f: function() {
+                console.log(this === o ? "FAIL" : "PASS");
+            },
+        };
+        (a = 42, o.f)(42);
+    }
+    expect: {
+        var a, o = {
+            f: function() {
+                console.log(this === o ? "FAIL" : "PASS");
+            },
+        };
+        (0, o.f)(a = 42);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4852: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "PASS";
+        (function(b) {
+            switch (b = a) {
+              case 42:
+                try {
+                    console;
+                } catch (b) {
+                    b.p;
+                }
+              case console.log(b):
+            }
+        })("FAIL");
+    }
+    expect: {
+        var a = "PASS";
+        (function(b) {
+            switch (a) {
+              case 42:
+                try {
+                    console;
+                } catch (b) {
+                    b.p;
+                }
+              case console.log(a):
+            }
+        })("FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4865: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var NaN;
+        var a = NaN = "PASS";
+        console.log(a, NaN);
+    }
+    expect: {
+        var NaN;
+        var a = NaN = "PASS";
+        console.log(a, NaN);
+    }
+    expect_stdout: true
+}
+
+issue_4868: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        (function(b) {
+            console.log(b[0]);
+        })(a = [ "PASS" ], a = [ "FAIL" ]);
+    }
+    expect: {
+        var a;
+        (function(b) {
+            console.log(b[0]);
+        })(a = [ "PASS" ], a = [ "FAIL" ]);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4874: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        a = null;
+        (function(b) {
+            for (var c in b = b && b[console.log("PASS")])
+                console;
+        })(a = 42);
+    }
+    expect: {
+        var a;
+        null;
+        (function(b) {
+            for (var c in a && a[console.log("PASS")])
+                console;
+        })(a = 42);
+    }
+    expect_stdout: "PASS"
+}

test/compress/conditionals.js

@@ -1861,3 +1861,39 @@ 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/const.js

@@ -658,6 +658,30 @@ legacy_scope: {
     expect_stdout: true
 }
 
+hoist_vars: {
+    options = {
+        hoist_vars: true,
+    }
+    input: {
+        {
+            const a = "FAIL";
+            var b = 42;
+        }
+        var a = "PASS";
+        console.log(a, b);
+    }
+    expect: {
+        var b;
+        {
+            const a = "FAIL";
+            b = 42;
+        }
+        var a = "PASS";
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
 issue_4191: {
     options = {
         functions: true,
@@ -1347,3 +1371,167 @@ issue_4305_2: {
     }
     expect_stdout: true
 }
+
+issue_4365_1: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        const arguments = 42;
+    }
+    expect: {
+        const arguments = 42;
+    }
+    expect_stdout: true
+}
+
+issue_4365_2: {
+    options = {
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        const arguments = 42;
+    }
+    expect: {
+        const arguments = 42;
+    }
+    expect_stdout: true
+}
+
+issue_4527: {
+    mangle = {}
+    input: {
+        (function() {
+            try {
+                throw 1;
+            } catch (a) {
+                try {
+                    const a = FAIL;
+                } finally {
+                    if (!b)
+                        return console.log("aaaa");
+                }
+            }
+            var b;
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                throw 1;
+            } catch (a) {
+                try {
+                    const a = FAIL;
+                } finally {
+                    if (!t)
+                        return console.log("aaaa");
+                }
+            }
+            var t;
+        })();
+    }
+    expect_stdout: "aaaa"
+}
+
+issue_4689: {
+    options = {
+        sequences: true,
+    }
+    input: {
+        "use strict";
+        var a = "PASS";
+        console.log(a);
+        for (const a in 42);
+    }
+    expect: {
+        "use strict";
+        var a = "PASS";
+        console.log(a);
+        for (const a in 42);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4691: {
+    options = {
+        if_return: true,
+        toplevel: true,
+    }
+    input: {
+        function A() {}
+        A.prototype.f = function() {
+            if (!this)
+                return;
+            const a = "PA";
+            function g(b) {
+                h(a + b);
+            }
+            [ "SS" ].forEach(function(c) {
+                g(c);
+            });
+        };
+        function h(d) {
+            console.log(d);
+        }
+        new A().f();
+    }
+    expect: {
+        function A() {}
+        A.prototype.f = function() {
+            if (this) {
+                const a = "PA";
+                [ "SS" ].forEach(function(c) {
+                    g(c);
+                });
+                function g(b) {
+                    h(a + b);
+                }
+            }
+        };
+        function h(d) {
+            console.log(d);
+        }
+        new A().f();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4848: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        function f(a) {
+            a(function() {
+                console.log(b);
+            });
+            if (!console)
+                return;
+            const b = "PASS";
+        }
+        var g;
+        f(function(h) {
+            g = h;
+        });
+        g();
+    }
+    expect: {
+        function f(a) {
+            a(function() {
+                console.log(b);
+            });
+            if (!console)
+                return;
+            const b = "PASS";
+        }
+        var g;
+        f(function(h) {
+            g = h;
+        });
+        g();
+    }
+    expect_stdout: "PASS"
+}

test/compress/dead-code.js

@@ -53,8 +53,10 @@ dead_code_2_should_warn: {
             g();
             x = 10;
             throw new Error("foo");
-            var x;
-            function g(){};
+            {
+                var x;
+                function g(){};
+            }
         }
         f();
     }
@@ -62,7 +64,6 @@ dead_code_2_should_warn: {
     expect_warnings: [
         "WARN: Dropping unreachable code [test/compress/dead-code.js:8,12]",
     ]
-    node_version: "<=4"
 }
 
 dead_code_constant_boolean_should_warn_more: {
@@ -88,8 +89,10 @@ 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 x = 10, y;
@@ -725,7 +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);
     }
@@ -1375,3 +1378,45 @@ issue_4051: {
     }
     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"
+}

test/compress/destructured.js

@@ -40,7 +40,7 @@ redefine_arguments_2: {
 
 redefine_arguments_3: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -188,7 +188,7 @@ funarg_side_effects_1: {
     }
     expect: {
         try {
-            (function({}) {})();
+            [ {} ] = [];
         } catch (e) {
             console.log("PASS");
         }
@@ -259,7 +259,7 @@ funarg_side_effects_3: {
 
 funarg_unused_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -318,7 +318,7 @@ funarg_unused_3: {
 
 funarg_unused_4: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: "strict",
         unused: true,
     }
@@ -384,7 +384,7 @@ funarg_unused_6_inline: {
 
 funarg_unused_6_keep_fargs: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -426,7 +426,7 @@ funarg_collapse_vars_1: {
 funarg_collapse_vars_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -505,7 +505,7 @@ funarg_reduce_vars_1: {
 funarg_reduce_vars_2: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: "strict",
         reduce_vars: true,
         unsafe: true,
@@ -682,7 +682,7 @@ funarg_inline: {
     }
     expect: {
         try {
-            (function({}) {})();
+            [ {} ] = [];
         } catch (e) {
             console.log("PASS");
         }
@@ -691,6 +691,28 @@ funarg_inline: {
     node_version: ">=6"
 }
 
+process_boolean_returns: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        console.log(function({ length }) {
+            return length ? "FAIL" : "PASS";
+        }(function() {
+            return 42;
+        }));
+    }
+    expect: {
+        console.log(function({ length }) {
+            return length ? "FAIL" : "PASS";
+        }(function() {
+            return 42;
+        }));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
 simple_const: {
     options = {
         evaluate: true,
@@ -750,6 +772,46 @@ simple_var: {
     node_version: ">=6"
 }
 
+drop_catch: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        try {} catch ({
+            [console.log("FAIL")]: e,
+        }) {} finally {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+drop_catch_var: {
+    options = {
+        unused: true,
+    }
+    input: {
+        try {
+            throw new Error("PASS");
+        } catch ({ name, message }) {
+            console.log(message);
+        }
+    }
+    expect: {
+        try {
+            throw new Error("PASS");
+        } catch ({ message }) {
+            console.log(message);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
 collapse_vars_1: {
     options = {
         collapse_vars: true,
@@ -1061,7 +1123,7 @@ join_vars: {
 
 keep_fargs: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1296,6 +1358,24 @@ fn_name_unused: {
     node_version: ">=6"
 }
 
+hoist_vars: {
+    options = {
+        hoist_vars: true,
+    }
+    input: {
+        var a = "PASS";
+        var [ b ] = [ 42 ];
+        console.log(a, b);
+    }
+    expect: {
+        var a = "PASS";
+        var [ b ] = [ 42 ];
+        console.log(a, b);
+    }
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
 issue_4280: {
     options = {
         evaluate: true,
@@ -1638,10 +1718,14 @@ issue_4312: {
     expect: {
         var a;
         b = "PASS",
-        (function({
-            [a = b]: d,
-        }){})((c = "FAIL") && c);
-        var b, c;
+        c = "FAIL",
+        [
+            {
+                [a = b]: d,
+            },
+        ] = [ c && c ],
+        void 0;
+        var b, c, d;
         console.log(a);
     }
     expect_stdout: "PASS"
@@ -1703,9 +1787,7 @@ issue_4319: {
         function f(a) {
             while (!a);
         }
-        console.log(function({}) {
-            return f(console);
-        }(0));
+        console.log(([ {} ] = [ 0 ], f(console)));
     }
     expect_stdout: "undefined"
     node_version: ">=6"
@@ -1714,7 +1796,7 @@ issue_4319: {
 issue_4321: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         try {
@@ -1729,11 +1811,9 @@ issue_4321: {
     }
     expect: {
         try {
-            console.log(function({}) {
-                return function() {
-                    while (!console);
-                }();
-            }());
+            console.log(([ {} ] = [], function() {
+                while (!console);
+            }()));
         } catch (e) {
             console.log("PASS");
         }
@@ -1764,11 +1844,15 @@ issue_4323: {
     }
     expect: {
         var a = 0;
-        (function({
-            [function a() {
-                console.log(typeof a);
-            }()]: d,
-        }) {})(0);
+        [
+            {
+                [function a() {
+                    console.log(typeof a);
+                }()]: d,
+            },
+        ] = [ 0 ],
+        void 0;
+        var d;
         e = 1,
         console.log,
         void e.p;
@@ -1777,3 +1861,698 @@ issue_4323: {
     expect_stdout: "function"
     node_version: ">=6"
 }
+
+issue_4355: {
+    options = {
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        (function({
+            [function() {
+                for (a in "foo");
+            }()]: b,
+        }) {
+            var a;
+        })(0);
+        console.log(a);
+    }
+    expect: {
+        var a;
+        (function({
+            [function() {
+                for (a in "foo");
+            }()]: b,
+        }) {})(0);
+        console.log(a);
+    }
+    expect_stdout: "2"
+    node_version: ">=6"
+}
+
+issue_4372_1: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        var a = "FAIL";
+        a += {
+            [console.log(a)]: a,
+        } = a = "PASS";
+    }
+    expect: {
+        var a = "FAIL";
+        a += {
+            [console.log(a)]: a,
+        } = a = "PASS";
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4372_2: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        var a;
+        [ a ] = a = [ "PASS", "FAIL" ];
+        console.log(a);
+    }
+    expect: {
+        var a;
+        [ a ] = [ "PASS", "FAIL" ];
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4383: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(function(a) {
+            [ a[0] ] = [];
+            return a.length;
+        }([]));
+    }
+    expect: {
+        console.log(function(a) {
+            [ a[0] ] = [];
+            return a.length;
+        }([]));
+    }
+    expect_stdout: "1"
+    node_version: ">=6"
+}
+
+issue_4386: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        function f({}) {
+            return arguments[0];
+        }
+        console.log(f("PASS"));
+    }
+    expect: {
+        function f({}) {
+            return arguments[0];
+        }
+        console.log(f("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4395: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        console.log(function(a, {}) {
+            a = "FAIL";
+            return arguments[0];
+        }("PASS", 42));
+    }
+    expect: {
+        console.log(function(a, {}) {
+            a = "FAIL";
+            return arguments[0];
+        }("PASS", 42));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4399: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        console.log(function({
+            [arguments[1]]: a,
+        }, b) {
+            return a;
+        }([ "PASS" ], 0));
+    }
+    expect: {
+        console.log(function({
+            [arguments[1]]: a,
+        }, b) {
+            return a;
+        }([ "PASS" ], 0));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4420: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var a = 1;
+            try {
+                throw [ "FAIL", "PASS" ];
+            } catch ({
+                [a]: b,
+            }) {
+                let a = 0;
+                return b;
+            }
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var a = 1;
+            try {
+                throw [ "FAIL", "PASS" ];
+            } catch ({
+                [a]: b,
+            }) {
+                return b;
+            }
+        }());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+issue_4425: {
+    rename = true
+    input: {
+        var a;
+        console.log(function() {
+            try {
+                try {
+                    throw 42;
+                } catch ({
+                    [a]: a,
+                }) {}
+                return "FAIL";
+            } catch (e) {
+                return "PASS";
+            }
+        }());
+    }
+    expect: {
+        var a;
+        console.log(function() {
+            try {
+                try {
+                    throw 42;
+                } catch ({
+                    [b]: b,
+                }) {}
+                return "FAIL";
+            } catch (c) {
+                return "PASS";
+            }
+        }());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+issue_4436_Infinity: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function({
+            [delete Infinity]: a,
+        }) {
+            var Infinity;
+            return a;
+        }({
+            true: "FAIL",
+            false: "PASS",
+        }));
+    }
+    expect: {
+        console.log(function({
+            [delete Infinity]: a,
+        }) {
+            return a;
+        }({
+            true: "FAIL",
+            false: "PASS",
+        }));
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_4436_NaN: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function({
+            [delete NaN]: a,
+        }) {
+            var NaN;
+            return a;
+        }({
+            true: "FAIL",
+            false: "PASS",
+        }));
+    }
+    expect: {
+        console.log(function({
+            [delete NaN]: a,
+        }) {
+            return a;
+        }({
+            true: "FAIL",
+            false: "PASS",
+        }));
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_4436_undefined: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function({
+            [delete undefined]: a,
+        }) {
+            var undefined;
+            return a;
+        }({
+            true: "FAIL",
+            false: "PASS",
+        }));
+    }
+    expect: {
+        console.log(function({
+            [delete undefined]: a,
+        }) {
+            return a;
+        }({
+            true: "FAIL",
+            false: "PASS",
+        }));
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_4446: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        a = "PASS";
+        var a = [ a[0] ] = [ a ];
+        console.log(a[0]);
+    }
+    expect: {
+        a = "PASS";
+        var a = [ a[0] ] = [ a ];
+        console.log(a[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4456: {
+    options = {
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        var o = {
+            set p(v) {
+                console.log(v);
+            },
+        };
+        [ function() {
+            try {
+                return o;
+            } catch ({}) {}
+        }().p ] = [ "PASS" ];
+    }
+    expect: {
+        var o = {
+            set p(v) {
+                console.log(v);
+            },
+        };
+        [ function() {
+            try {
+                return o;
+            } catch ({}) {}
+        }().p ] = [ "PASS" ];
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4485_1: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        (function([]) {
+            var arguments;
+            try {
+                arguments.length;
+            } catch (e) {
+                console.log("PASS");
+            }
+        })([]);
+    }
+    expect: {
+        (function([]) {
+            var arguments;
+            try {
+                arguments.length;
+            } catch (e) {
+                console.log("PASS");
+            }
+        })([]);
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_4485_2: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        (function([]) {
+            var arguments = null;
+            try {
+                arguments.length;
+            } catch (e) {
+                console.log("PASS");
+            }
+        })([]);
+    }
+    expect: {
+        (function([]) {
+            var arguments = null;
+            try {
+                arguments.length;
+            } catch (e) {
+                console.log("PASS");
+            }
+        })([]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4485_3: {
+    options = {
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        (function([]) {
+            var arguments;
+            try {
+                arguments.length;
+            } catch (e) {
+                console.log("PASS");
+            }
+        })([]);
+    }
+    expect: {
+        (function([]) {
+            var arguments;
+            try {
+                arguments.length;
+            } catch (e) {
+                console.log("PASS");
+            }
+        })([]);
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_4500: {
+    options = {
+        evaluate: true,
+        keep_fnames: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function f(b) {
+            return [ b ] = [], b;
+        }("FAIL");
+        console.log(a || "PASS");
+    }
+    expect: {
+        var a = function f(b) {
+            return [ b ] = [], b;
+        }("FAIL");
+        console.log(a || "PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4504: {
+    options = {
+        inline: true,
+        merge_vars: true,
+    }
+    input: {
+        A = "FAIL";
+        (function f(a) {
+            ({
+                [console.log(a)]: 0[(b => console + b)(A)]
+            } = 0);
+        })("PASS");
+    }
+    expect: {
+        A = "FAIL";
+        (function f(a) {
+            ({
+                [console.log(a)]: 0[b = A, console + b]
+            } = 0);
+            var b;
+        })("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4508: {
+    options = {
+        inline: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        for (var i = 0; i < 2; i++)
+            (function f([ a ]) {
+                var a = console.log(a) && b, b = null;
+            })([ "PASS" ]);
+    }
+    expect: {
+        for (var i = 0; i < 2; i++)
+            [ [ a ] ] = [ [ "PASS" ] ],
+            b = void 0,
+            a = console.log(a) && b,
+            b = null,
+            void 0;
+        var a, b;
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+    ]
+    node_version: ">=6"
+}
+
+issue_4512: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        console.log(function([ a, b = a ]) {}([]));
+    }
+    expect: {
+        console.log(function([ a, b = a ]) {}([]));
+    }
+    expect_stdout: "undefined"
+    node_version: ">=6"
+}
+
+issue_4519_1: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+    }
+    input: {
+        try {
+            (function() {
+                var [ arguments ] = [];
+                arguments[0];
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            (function() {
+                var [ arguments ] = [];
+                arguments[0];
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4519_2: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        try {
+            (function() {
+                var [ arguments ] = [];
+                arguments[0];
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            (function() {
+                var [ arguments ] = [];
+                arguments[0];
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4554: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        A = "PASS";
+        var a = "FAIL";
+        try {
+            (function({}, b) {
+                return b;
+            })(void 0, a = A);
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect: {
+        A = "PASS";
+        var a = "FAIL";
+        try {
+            (function({}, b) {
+                return b;
+            })(void 0, a = A);
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4584: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        try {
+            (function f({
+                [console.log(a = "FAIL")]: a,
+            }) {})(0);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            (function f({
+                [console.log(a = "FAIL")]: a,
+            }) {})(0);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4608_1: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+    }
+    input: {
+        (function() {
+            [ arguments ] = [ "foo" ];
+            console.log(arguments[0]);
+        })();
+    }
+    expect: {
+        (function() {
+            [ arguments ] = [ "foo" ];
+            console.log(arguments[0]);
+        })();
+    }
+    expect_stdout: "f"
+    node_version: ">=6"
+}
+
+issue_4608_2: {
+    options = {
+        arguments: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            [ arguments ] = [ "foo" ];
+            console.log(arguments[0]);
+        })();
+    }
+    expect: {
+        (function(a) {
+            [ arguments ] = [ "foo" ];
+            console.log(arguments[0]);
+        })();
+    }
+    expect_stdout: "f"
+    node_version: ">=6"
+}

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: {
@@ -2027,7 +1999,7 @@ issue_3192_1: {
 
 issue_3192_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -2166,6 +2138,7 @@ issue_3497: {
 issue_3515_1: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         reduce_vars: true,
         unused: true,
     }
@@ -2217,6 +2190,7 @@ issue_3515_2: {
 issue_3515_3: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         unused: true,
     }
     input: {
@@ -2284,6 +2258,7 @@ function_assign: {
 issue_3598: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         reduce_vars: true,
         unused: true,
     }
@@ -2396,6 +2371,7 @@ function_parameter_ie8: {
 issue_3664: {
     options = {
         pure_getters: "strict",
+        side_effects: true,
         unused: true,
     }
     input: {
@@ -2406,7 +2382,7 @@ issue_3664: {
     }
     expect: {
         console.log(function() {
-            var b = ([ b && console.log("FAIL") ].p = 0, 0);
+            var b = (b && console.log("FAIL"), 0, 0);
             return "PASS";
         }());
     }
@@ -2416,6 +2392,7 @@ issue_3664: {
 issue_3673: {
     options = {
         pure_getters: "strict",
+        sequences: true,
         side_effects: true,
         toplevel: true,
         unused: true,
@@ -2426,8 +2403,6 @@ issue_3673: {
         console.log("PASS");
     }
     expect: {
-        var a;
-        (a = [ a ]).p = 42;
         console.log("PASS");
     }
     expect_stdout: "PASS"
@@ -2435,7 +2410,7 @@ issue_3673: {
 
 issue_3746: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -2697,8 +2672,7 @@ issue_3956: {
         })();
     }
     expect: {
-        var c, d;
-        c += 0,
+        var d;
         console.log(NaN),
         d = 1 ^ console.log(1),
         console.log(d);
@@ -2713,7 +2687,7 @@ issue_3956: {
 issue_3962_1: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -2731,13 +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");
-        }(1), 0);
+        })(1);
         void 0;
     }
     expect_stdout: "PASS"
@@ -2745,7 +2719,7 @@ issue_3962_1: {
 
 issue_3962_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         side_effects: true,
         toplevel: true,
@@ -2764,13 +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");
-        }(1), 0);
+        })(1);
     }
     expect_stdout: "PASS"
 }
@@ -2827,7 +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"
@@ -2948,7 +2924,7 @@ issue_4133: {
 
 issue_4144: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -3112,3 +3088,303 @@ issue_4235: {
     }
     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,
+        ie8: 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"
+}

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 };
         }
     }
 }
@@ -703,6 +703,7 @@ prototype_function: {
         var g = 0();
         var h = 0();
     }
+    expect_stdout: true
 }
 
 call_args: {
@@ -846,6 +847,8 @@ unsafe_charAt_noop: {
         unsafe: true,
     }
     input: {
+        s = "foo";
+        x = 42;
         console.log(
             s.charAt(0),
             "string".charAt(x),
@@ -853,12 +856,15 @@ 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 +2806,7 @@ 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",
@@ -3074,3 +3080,104 @@ issue_4271: {
         "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"
+}

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, { foo: a } = 42;
+        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

@@ -1068,3 +1068,29 @@ 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"
+}

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 +134,163 @@ 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"
+}

test/compress/ie8.js

@@ -588,7 +588,6 @@ issue_3197_1: {
         ie8: false,
     }
     input: {
-        var window = {};
         !function() {
             function Foo() {
                 console.log(this instanceof Foo);
@@ -598,7 +597,6 @@ issue_3197_1: {
         new window.Foo();
     }
     expect: {
-        var window = {};
         window.Foo = function o() {
             console.log(this instanceof o);
         };
@@ -619,7 +617,6 @@ issue_3197_1_ie8: {
         ie8: true,
     }
     input: {
-        var window = {};
         !function() {
             function Foo() {
                 console.log(this instanceof Foo);
@@ -629,7 +626,6 @@ issue_3197_1_ie8: {
         new window.Foo();
     }
     expect: {
-        var window = {};
         window.Foo = function Foo() {
             console.log(this instanceof Foo);
         };
@@ -2904,3 +2900,48 @@ issue_4250: {
     }
     expect_stdout: "0"
 }
+
+issue_4568: {
+    options = {
+        ie8: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(typeof f, function(a) {
+            return a.length;
+        }([ function f() {} ]));
+    }
+    expect: {
+        console.log(typeof f, function(a) {
+            return a.length;
+        }([ function f() {} ]));
+    }
+    expect_stdout: "undefined 1"
+}
+
+issue_4729: {
+    options = {
+        ie8: true,
+        pure_getters: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            f;
+        } catch (e) {
+            var a = a && a[function f() {}];
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            f;
+        } catch (e) {
+            (function f() {});
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}

test/compress/imports.js

@@ -0,0 +1,211 @@
+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, bar as d } from "baz";
+        console.log(c);
+    }
+    expect: {
+        import "foo";
+        import { c as c } from "baz";
+        console.log(c);
+    }
+}
+
+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-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-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

@@ -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,
@@ -1055,3 +1055,75 @@ issue_3916: {
     }
     expect_stdout: "object PASS true PASS"
 }
+
+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,
     }
@@ -202,7 +115,7 @@ replace_index_strict: {
 issue_1858: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: true,
         unused: true,
     }
@@ -224,7 +137,7 @@ issue_1858: {
 issue_2187_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -245,7 +158,7 @@ issue_2187_2: {
 issue_2203_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -280,7 +193,7 @@ issue_2203_2: {
 issue_2298: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -323,7 +236,7 @@ issue_2298: {
 issue_2319_1: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -346,7 +259,7 @@ issue_2319_1: {
 issue_2319_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -371,7 +284,7 @@ issue_2319_2: {
 issue_2319_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -396,7 +309,7 @@ issue_2319_3: {
 issue_2425_1: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -419,7 +332,7 @@ issue_2425_1: {
 issue_2425_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -442,7 +355,7 @@ issue_2425_2: {
 issue_2425_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -465,7 +378,7 @@ issue_2425_3: {
 issue_2436_13: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -499,7 +412,7 @@ issue_2436_13: {
 issue_2506: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -525,7 +438,7 @@ issue_2506: {
         function f0(bar) {
             (function() {
                 (function() {
-                    if (false <= NaN & this >> 1 >= 0)
+                    if (false <= 0/0 & this >> 1 >= 0)
                         c++;
                 })(c++);
             })();
@@ -538,7 +451,7 @@ issue_2506: {
 
 issue_2226_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -585,7 +498,7 @@ issue_2226_1: {
 issue_2226_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         sequences: true,
         side_effects: true,
         unused: true,
@@ -607,7 +520,7 @@ issue_2226_2: {
 issue_2226_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -627,7 +540,7 @@ issue_2226_3: {
 
 issue_3192: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -657,7 +570,7 @@ issue_3192: {
 if_increment: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -679,7 +592,7 @@ if_increment: {
 try_increment: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -703,7 +616,7 @@ try_increment: {
 issue_2630_3: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -740,7 +653,7 @@ issue_2630_3: {
 issue_3364: {
     options = {
         functions: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -805,7 +718,7 @@ issue_3364: {
 
 defun_label: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -837,7 +750,7 @@ defun_label: {
 
 iife_func_side_effects: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -889,7 +802,7 @@ iife_func_side_effects: {
 issue_1595_1: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -909,7 +822,7 @@ issue_1595_1: {
 issue_1595_2: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -929,7 +842,7 @@ issue_1595_2: {
 issue_1595_3: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -950,7 +863,7 @@ issue_1595_3: {
 issue_1595_4: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -972,7 +885,7 @@ issue_1595_4: {
 
 duplicate_lambda_defun_name_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
     }
     input: {
@@ -992,7 +905,7 @@ duplicate_lambda_defun_name_1: {
 
 duplicate_lambda_defun_name_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -1013,7 +926,7 @@ duplicate_lambda_defun_name_2: {
 
 function_name_mangle: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         keep_fnames: true,
         reduce_vars: true,
         unused: true,
@@ -1031,7 +944,7 @@ function_name_mangle: {
 
 function_name_mangle_ie8: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         keep_fnames: true,
         reduce_vars: true,
         unused: true,
@@ -1052,7 +965,7 @@ function_name_mangle_ie8: {
 
 issue_3420_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1075,7 +988,7 @@ issue_3420_1: {
 issue_3420_2: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1096,7 +1009,7 @@ issue_3420_2: {
 issue_3420_3: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1118,7 +1031,7 @@ issue_3420_3: {
 
 issue_3423_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1138,7 +1051,7 @@ issue_3423_1: {
 
 issue_3423_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1165,7 +1078,7 @@ 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,
@@ -1212,7 +1125,7 @@ collapse_vars_repeated: {
 chained_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1236,7 +1149,7 @@ replace_all_var_scope: {
     rename = true
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     mangle = {}
@@ -1265,7 +1178,7 @@ replace_all_var_scope: {
 
 issue_1583: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -1302,7 +1215,7 @@ issues_3267_1: {
         dead_code: true,
         evaluate: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         side_effects: true,
@@ -1331,7 +1244,7 @@ issues_3267_1: {
 
 trailing_argument_side_effects: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1355,7 +1268,7 @@ trailing_argument_side_effects: {
 
 recursive_iife_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1374,7 +1287,7 @@ recursive_iife_1: {
 
 recursive_iife_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1452,3 +1365,37 @@ 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/let.js

@@ -359,6 +359,108 @@ reduce_block_2_toplevel: {
     node_version: ">=4"
 }
 
+reduce_vars_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        let a = "PASS";
+        console.log(a);
+        a = "FAIL";
+    }
+    expect: {
+        "use strict";
+        console.log("PASS");
+        "FAIL";
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+reduce_vars_2: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        (function() {
+            function f() {
+                console.log(typeof a);
+            }
+            for (let a in [ 42 ])
+                f();
+        })();
+    }
+    expect: {
+        "use strict";
+        (function() {
+            function f() {
+                console.log(typeof a);
+            }
+            for (let a in [ 42 ])
+                f();
+        })();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+reduce_vars_3: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        (function(a) {
+            let i = 1;
+            function f() {
+                i = 0;
+            }
+            for (let i = 0, x = 0; i < a.length; i++, x++) {
+                if (x != i) {
+                    console.log("FAIL");
+                    break;
+                }
+                f();
+                console.log(a[i]);
+            }
+            console.log(i);
+        })([ 4, 2 ]);
+    }
+    expect: {
+        "use strict";
+        (function(a) {
+            let i = 1;
+            function f() {
+                i = 0;
+            }
+            for (let i = 0, x = 0; i < a.length; i++, x++) {
+                if (x != i) {
+                    console.log("FAIL");
+                    break;
+                }
+                f();
+                console.log(a[i]);
+            }
+            console.log(i);
+        })([ 4, 2 ]);
+    }
+    expect_stdout: [
+        "4",
+        "2",
+        "0",
+    ]
+    node_version: ">=4"
+}
+
 hoist_props: {
     options = {
         hoist_props: true,
@@ -588,6 +690,28 @@ drop_unused: {
     node_version: ">=4"
 }
 
+default_init: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        let a;
+        a = "PASS";
+        console.log(a);
+    }
+    expect: {
+        "use strict";
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
 issue_4191: {
     options = {
         functions: true,
@@ -1228,3 +1352,197 @@ issue_1753_toplevel: {
     expect_stdout: "0"
     node_version: ">=4"
 }
+
+issue_4438: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        function f() {
+            if (console) {
+                {
+                    let a = console.log;
+                    return void a("PASS");
+                }
+            }
+        }
+        f();
+    }
+    expect: {
+        "use strict";
+        function f() {
+            if (!console)
+                ;
+            else {
+                let a = console.log;
+                a("PASS");
+            }
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4531_1: {
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        "use strict";
+        var a;
+        console.log(function a() {
+            let a;
+            var b;
+        }());
+    }
+    expect: {
+        "use strict";
+        var o;
+        console.log(function o() {
+            let o;
+            var t;
+        }());
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_4531_2: {
+    options = {
+        evaluate: true,
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var a = console;
+        console.log(typeof a, function a() {
+            let { [console]: a } = 0 && a;
+            var b = console;
+            while (!b);
+        }());
+    }
+    expect: {
+        var o = console;
+        console.log(typeof o, function o() {
+            let { [console]: o } = 0;
+            var e = console;
+            while (!e);
+        }());
+    }
+    expect_stdout: "object undefined"
+    node_version: ">=6"
+}
+
+issue_4689: {
+    options = {
+        sequences: true,
+    }
+    input: {
+        "use strict";
+        var a = "PASS";
+        console.log(a);
+        for (let a in 42);
+    }
+    expect: {
+        "use strict";
+        var a = "PASS";
+        console.log(a);
+        for (let a in 42);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4691: {
+    options = {
+        if_return: true,
+        toplevel: true,
+    }
+    input: {
+        "use strict";
+        function A() {}
+        A.prototype.f = function() {
+            if (!this)
+                return;
+            let a = "PA";
+            function g(b) {
+                h(a + b);
+            }
+            [ "SS" ].forEach(function(c) {
+                g(c);
+            });
+        };
+        function h(d) {
+            console.log(d);
+        }
+        new A().f();
+    }
+    expect: {
+        "use strict";
+        function A() {}
+        A.prototype.f = function() {
+            if (this) {
+                let a = "PA";
+                [ "SS" ].forEach(function(c) {
+                    g(c);
+                });
+                function g(b) {
+                    h(a + b);
+                }
+            }
+        };
+        function h(d) {
+            console.log(d);
+        }
+        new A().f();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4848: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        function f(a) {
+            a(function() {
+                console.log(b);
+            });
+            if (!console)
+                return;
+            let b = "PASS";
+        }
+        var g;
+        f(function(h) {
+            g = h;
+        });
+        g();
+    }
+    expect: {
+        "use strict";
+        function f(a) {
+            a(function() {
+                console.log(b);
+            });
+            if (!console)
+                return;
+            let b = "PASS";
+        }
+        var g;
+        f(function(h) {
+            g = h;
+        });
+        g();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}

test/compress/loops.js

@@ -501,14 +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;);
     }
@@ -828,6 +828,44 @@ empty_for_in_prop_init: {
     ]
 }
 
+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,
@@ -1026,7 +1064,7 @@ issue_4075: {
 
 issue_4082: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         loops: true,
         unused: true,
     }
@@ -1050,9 +1088,8 @@ issue_4082: {
 
 issue_4084: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         loops: true,
-        passes: 2,
         reduce_vars: true,
         unused: true,
     }
@@ -1255,3 +1292,59 @@ issue_4240: {
     }
     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/merge_vars.js

@@ -327,7 +327,7 @@ issue_4103: {
 
 issue_4107: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         merge_vars: true,
         reduce_vars: true,
         unused: true,
@@ -2620,9 +2620,9 @@ issue_4126_1: {
             try {
                 console.log("PASS");
             } catch (e) {
-                var b = a;
+                var c = a;
             } finally {
-                var c = b;
+                var c = c;
             }
             console.log(c);
         }
@@ -3183,3 +3183,121 @@ issue_4257: {
         "1",
     ]
 }
+
+issue_4628: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        (function() {
+            try {
+                console;
+            } finally {
+                var b = a;
+            }
+            for (var a in "foo");
+            console.log(b);
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                console;
+            } finally {
+                var b = a;
+            }
+            for (var a in "foo");
+            console.log(b);
+        })();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4653: {
+    options = {
+        evaluate: true,
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1, b;
+        function f(c, d) {
+            c || console.log(d);
+        }
+        f(a++ + (b = b), b |= console.log(a));
+    }
+    expect: {
+        var b = 1;
+        (function(c, d) {
+            c || console.log(d);
+        })(+b + (b = void 0), b |= console.log(2));
+    }
+    expect_stdout: [
+        "2",
+        "0",
+    ]
+}
+
+issue_4759: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var i = 2, a = 1, b, c, d;
+        while (i--) {
+            try {
+                if (1 != b) {
+                    d = [];
+                    null.p;
+                    c = d;
+                } else {
+                    b = 0;
+                    a = c;
+                }
+            } catch (e) {}
+            b = a;
+        }
+        console.log(a);
+    }
+    expect: {
+        var i = 2, a = 1, b, c, d;
+        while (i--) {
+            try {
+                if (1 != b) {
+                    d = [];
+                    null.p;
+                    c = d;
+                } else {
+                    b = 0;
+                    a = c;
+                }
+            } catch (e) {}
+            b = a;
+        }
+        console.log(a);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4761: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL", b;
+        try {
+            !a && --a && (b = 0)[console] || console.log(b);
+        } catch (e) {}
+    }
+    expect: {
+        var a = "FAIL", b;
+        try {
+            !a && --a && (b = 0)[console] || console.log(b);
+        } catch (e) {}
+    }
+    expect_stdout: "undefined"
+}

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 +1,130 @@
+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"
+}
+
+issue_4679: {
+    options = {
+        comparisons: true,
+        ie8: 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

@@ -1,3 +1,10 @@
+literal_infinity: {
+    input: {
+        console.log(2e308, -1e2345);
+    }
+    expect_exact: "console.log(1/0,-(1/0));"
+}
+
 parentheses_for_prototype_functions: {
     beautify = {
         beautify: true,
@@ -97,6 +104,40 @@ parentheses_for_prototype_functions_galio: {
     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: {
     options = {
         comparisons: true,
@@ -338,7 +379,7 @@ evaluate_3: {
         console.log(1 + Number(x) + 2);
     }
     expect: {
-        console.log(+x + 3);
+        console.log(+("" + x) + 3);
     }
 }
 
@@ -777,7 +818,7 @@ issue_1710: {
     expect_stdout: true
 }
 
-unary_binary_parenthesis: {
+unary_binary_parentheses: {
     options = {
         evaluate: true,
     }
@@ -1386,3 +1427,75 @@ issue_4142: {
     }
     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]);
@@ -257,6 +257,95 @@ keep_computed_key: {
     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,
@@ -323,8 +412,8 @@ issue_4269_3: {
     }
     expect: {
         console.log({
-            ["foo"]: "bar",
-            get 42() {
+            foo: "bar",
+            get [42]() {
                 return "FAIL";
             },
             42: "PASS",
@@ -353,10 +442,82 @@ issue_4269_4: {
             get 42() {
                 return "FAIL";
             },
-            ["foo"]: "bar",
+            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/properties.js

@@ -1378,3 +1378,71 @@ 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"
+}

test/compress/pure_funcs.js

@@ -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,
@@ -979,6 +1008,7 @@ collapse_vars_2_strict: {
 collapse_rhs_true: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         pure_getters: true,
     }
     input: {
@@ -1015,6 +1045,7 @@ collapse_rhs_true: {
 collapse_rhs_false: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         pure_getters: false,
     }
     input: {
@@ -1051,6 +1082,7 @@ collapse_rhs_false: {
 collapse_rhs_strict: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         pure_getters: "strict",
     }
     input: {
@@ -1087,6 +1119,7 @@ collapse_rhs_strict: {
 collapse_rhs_setter: {
     options = {
         collapse_vars: true,
+        evaluate: true,
         pure_getters: "strict",
     }
     input: {
@@ -1187,13 +1220,110 @@ 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,
@@ -1208,3 +1338,303 @@ 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"
+}

test/compress/reduce_vars.js

@@ -2373,7 +2373,7 @@ redefine_farg_1: {
         function f(a) {
             return typeof a;
         }
-        function g() {
+        function g(a) {
             return "number";
         }
         function h(a, b) {
@@ -2460,6 +2460,7 @@ delay_def: {
         evaluate: true,
         reduce_funcs: true,
         reduce_vars: true,
+        side_effects: true,
         unused: true,
     }
     input: {
@@ -6928,7 +6929,7 @@ issue_3622: {
     options = {
         evaluate: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         toplevel: true,
@@ -7196,7 +7197,7 @@ issue_3894: {
 issue_3922: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: "strict",
         reduce_vars: true,
         side_effects: true,
@@ -7601,3 +7602,32 @@ issue_4188_2: {
     }
     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"
+}

test/compress/rests.js

@@ -0,0 +1,786 @@
+arrow_1: {
+    input: {
+        console.log.apply(console, ((...a) => a)("PASS", 42));
+    }
+    expect_exact: 'console.log.apply(console,((...a)=>a)("PASS",42));'
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+arrow_2: {
+    input: {
+        console.log.apply(console, ((a, ...b) => b)("FAIL", "PASS", 42));
+    }
+    expect_exact: 'console.log.apply(console,((a,...b)=>b)("FAIL","PASS",42));'
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+arrow_destructured_array_1: {
+    input: {
+        console.log.apply(console, (([ ...a ]) => a)("PASS"));
+    }
+    expect_exact: 'console.log.apply(console,(([...a])=>a)("PASS"));'
+    expect_stdout: "P A S S"
+    node_version: ">=6"
+}
+
+arrow_destructured_array_2: {
+    input: {
+        console.log.apply(console, (([ a, ...b ]) => b)([ "FAIL", "PASS", 42 ]));
+    }
+    expect_exact: 'console.log.apply(console,(([a,...b])=>b)(["FAIL","PASS",42]));'
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+arrow_destructured_array_3: {
+    input: {
+        console.log((([ [ ...a ] = "FAIL" ]) => a)([ "PASS" ]).join("|"));
+    }
+    expect_exact: 'console.log((([[...a]="FAIL"])=>a)(["PASS"]).join("|"));'
+    expect_stdout: "P|A|S|S"
+    node_version: ">=6"
+}
+
+arrow_destructured_object_1: {
+    input: {
+        var f = ({ ...a }) => a, o = f({ PASS: 42 });
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect_exact: "var f=({...a})=>a,o=f({PASS:42});for(var k in o)console.log(k,o[k]);"
+    expect_stdout: "PASS 42"
+    node_version: ">=8"
+}
+
+arrow_destructured_object_2: {
+    input: {
+        var f = ({ FAIL: a, ...b }) => b, o = f({ PASS: 42, FAIL: null });
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect_exact: "var f=({FAIL:a,...b})=>b,o=f({PASS:42,FAIL:null});for(var k in o)console.log(k,o[k]);"
+    expect_stdout: "PASS 42"
+    node_version: ">=8"
+}
+
+arrow_destructured_object_3: {
+    input: {
+        var f = ([ { ...a } = [ "FAIL" ] ]) => a;
+        var o = f([ "PASS" ]);
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect_exact: 'var f=([{...a}=["FAIL"]])=>a;var o=f(["PASS"]);for(var k in o)console.log(k,o[k]);'
+    expect_stdout: [
+        "0 P",
+        "1 A",
+        "2 S",
+        "3 S",
+    ]
+    node_version: ">=8"
+}
+
+funarg_1: {
+    input: {
+        console.log.apply(console, function(...a) {
+            return a;
+        }("PASS", 42));
+    }
+    expect_exact: 'console.log.apply(console,function(...a){return a}("PASS",42));'
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+funarg_2: {
+    input: {
+        console.log.apply(console, function(a, ...b) {
+            return b;
+        }("FAIL", "PASS", 42));
+    }
+    expect_exact: 'console.log.apply(console,function(a,...b){return b}("FAIL","PASS",42));'
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+destructured_array_1: {
+    input: {
+        var [ ...a ] = [ "PASS", 42 ];
+        console.log.apply(console, a);
+    }
+    expect_exact: 'var[...a]=["PASS",42];console.log.apply(console,a);'
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+destructured_array_2: {
+    input: {
+        var [ a, ...b ] = [ "FAIL", "PASS", 42 ];
+        console.log.apply(console, b);
+    }
+    expect_exact: 'var[a,...b]=["FAIL","PASS",42];console.log.apply(console,b);'
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+destructured_object_1: {
+    input: {
+        var { ...a } = [ "FAIL", "PASS", 42 ];
+        console.log(a[1], a[2]);
+    }
+    expect_exact: 'var{...a}=["FAIL","PASS",42];console.log(a[1],a[2]);'
+    expect_stdout: "PASS 42"
+    node_version: ">=8"
+}
+
+destructured_object_2: {
+    input: {
+        var { 0: a, ...b } = [ "FAIL", "PASS", 42 ];
+        console.log(b[1], b[2]);
+    }
+    expect_exact: 'var{0:a,...b}=["FAIL","PASS",42];console.log(b[1],b[2]);'
+    expect_stdout: "PASS 42"
+    node_version: ">=8"
+}
+
+drop_fargs: {
+    options = {
+        keep_fargs: false,
+        rests: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a, ...b) {
+            return b[0];
+        }("FAIL", "PASS"));
+    }
+    expect: {
+        console.log(function(b) {
+            return b[0];
+        }([ "PASS" ]));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+inline: {
+    options = {
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        console.log(function(a, ...[ b, c ]) {
+            return c + b + a;
+        }("SS", "A", "P"));
+    }
+    expect: {
+        console.log(([ a, ...[ b, c ] ] = [ "SS", "A", "P" ], c + b + a));
+        var a, b, c;
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+retain_var: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var [ ...a ] = [ "PASS" ];
+        console.log(a[0]);
+    }
+    expect: {
+        var [ ...a ] = [ "PASS" ];
+        console.log(a[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+reduce_destructured_array: {
+    options = {
+        reduce_vars: true,
+        rests: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var [ ...a ] = [ "PASS" ];
+        console.log(a[0]);
+    }
+    expect: {
+        console.log([ "PASS" ][0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+reduce_destructured_object: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var { ...a } = [ "PASS" ];
+        console.log(a[0]);
+    }
+    expect: {
+        var { ...a } = [ "PASS" ];
+        console.log(a[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+retain_destructured_array: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var [ a, ...b ] = [ "FAIL", "PASS", 42 ];
+        console.log.apply(console, b);
+    }
+    expect: {
+        var [ , ...b ] = [ "FAIL", "PASS", 42 ];
+        console.log.apply(console, b);
+    }
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+retain_destructured_object_1: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var { 0: a, ...b } = [ "FAIL", "PASS", 42 ];
+        for (var k in b)
+            console.log(k, b[k]);
+    }
+    expect: {
+        var { 0: a, ...b } = [ "FAIL", "PASS", 42 ];
+        for (var k in b)
+            console.log(k, b[k]);
+    }
+    expect_stdout: [
+        "1 PASS",
+        "2 42",
+    ]
+    node_version: ">=8"
+}
+
+retain_destructured_object_2: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var { foo: [ a ], ...b } = { foo: [ "FAIL" ], bar: "PASS", baz: 42 };
+        for (var k in b)
+            console.log(k, b[k]);
+    }
+    expect: {
+        var { foo: [], ...b } = { foo: [ "FAIL" ], bar: "PASS", baz: 42 };
+        for (var k in b)
+            console.log(k, b[k]);
+    }
+    expect_stdout: [
+        "bar PASS",
+        "baz 42",
+    ]
+    node_version: ">=8"
+}
+
+retain_funarg_destructured_array_1: {
+    options = {
+        inline: true,
+        keep_fargs: false,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        console.log((([ ...a ]) => a)([ "PASS" ])[0]);
+    }
+    expect: {
+        console.log((([ ...a ]) => a)([ "PASS" ])[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+retain_funarg_destructured_array_2: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function([ a, ...b ]) {
+            return b;
+        }("bar")[1]);
+    }
+    expect: {
+        console.log(function([ , ...b ]) {
+            return b;
+        }("bar")[1]);
+    }
+    expect_stdout: "r"
+    node_version: ">=6"
+}
+
+retain_funarg_destructured_object_1: {
+    options = {
+        inline: true,
+        keep_fargs: false,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        console.log((({ ...a }) => a)([ "PASS" ])[0]);
+    }
+    expect: {
+        console.log((({ ...a }) => a)([ "PASS" ])[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+retain_funarg_destructured_object_2: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function({ p: a, ... b }) {
+            return b;
+        }({ p: "FAIL" }).p || "PASS");
+    }
+    expect: {
+        console.log(function({ p: a, ... b }) {
+            return b;
+        }({ p: "FAIL" }).p || "PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+drop_unused_call_args_1: {
+    options = {
+        rests: true,
+        unused: true,
+    }
+    input: {
+        (function(...a) {
+            console.log(a[0]);
+        })(42, console.log("PASS"));
+    }
+    expect: {
+        (function(a) {
+            console.log(a[0]);
+        })([ 42, console.log("PASS") ]);
+    }
+    expect_stdout: [
+        "PASS",
+        "42",
+    ]
+    node_version: ">=6"
+}
+
+drop_unused_call_args_2: {
+    options = {
+        keep_fargs: false,
+        rests: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a, ...b) {
+            return b;
+        }(console).length);
+    }
+    expect: {
+        console.log(function(b) {
+            return b;
+        }((console, [])).length);
+    }
+    expect_stdout: "0"
+    node_version: ">=6"
+}
+
+merge_funarg: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        (function(...a) {
+            var b = a.length;
+            console.log(b);
+        })();
+    }
+    expect: {
+        (function(...b) {
+            var b = b.length;
+            console.log(b);
+        })();
+    }
+    expect_stdout: "0"
+    node_version: ">=6"
+}
+
+merge_funarg_destructured_array: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        (function([ ...a ]) {
+            var b = a.length;
+            console.log(b);
+        })([]);
+    }
+    expect: {
+        (function([ ...b ]) {
+            var b = b.length;
+            console.log(b);
+        })([]);
+    }
+    expect_stdout: "0"
+    node_version: ">=6"
+}
+
+merge_funarg_destructured_object: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        (function({ ...a }) {
+            var b = a[0];
+            console.log(b);
+        })([ "PASS" ]);
+    }
+    expect: {
+        (function({ ...b }) {
+            var b = b[0];
+            console.log(b);
+        })([ "PASS" ]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+keep_arguments: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+    }
+    input: {
+        (function(...[ {} ]) {
+            console.log(arguments[0]);
+        })("PASS");
+    }
+    expect: {
+        (function(...[ {} ]) {
+            console.log(arguments[0]);
+        })("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+drop_rest_array: {
+    options = {
+        rests: true,
+    }
+    input: {
+        var [ ...[ a ]] = [ "PASS" ];
+        console.log(a);
+    }
+    expect: {
+        var [ a ] = [ "PASS" ];
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+drop_rest_arrow: {
+    options = {
+        arrows: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        rests: true,
+    }
+    input: {
+        console.log(((...[ a ]) => a)("PASS"));
+    }
+    expect: {
+        console.log((a => a)("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+drop_rest_lambda: {
+    options = {
+        keep_fargs: false,
+        reduce_vars: true,
+        rests: true,
+        toplevel: true,
+    }
+    input: {
+        function f(...[ a ]) {
+            return a;
+        }
+        console.log(f("PASS"), f(42));
+    }
+    expect: {
+        function f(a) {
+            return a;
+        }
+        console.log(f("PASS"), f(42));
+    }
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+issue_4525_1: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        console.log(function(a, ...[]) {
+            a = "FAIL";
+            return arguments[0];
+        }("PASS"));
+    }
+    expect: {
+        console.log(function(a, ...[]) {
+            a = "FAIL";
+            return arguments[0];
+        }("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4525_2: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function(a, ...[]) {
+            a = "FAIL";
+            return arguments[0];
+        }("PASS"));
+    }
+    expect: {
+        console.log(function(a, ...[]) {
+            a = "FAIL";
+            return arguments[0];
+        }("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4538: {
+    options = {
+        rests: true,
+        unused: true,
+    }
+    input: {
+        console.log(typeof function f(...a) {
+            return a.p, f;
+        }()());
+    }
+    expect: {
+        console.log(typeof function f(...a) {
+            return a.p, f;
+        }()());
+    }
+    expect_stdout: "function"
+    node_version: ">=6"
+}
+
+issue_4544_1: {
+    options = {
+        keep_fnames: true,
+        side_effects: true,
+    }
+    input: {
+        try {
+            (function f(...[ {} ]) {})();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            [ ...[ {} ] ] = [];
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4544_2: {
+    options = {
+        keep_fnames: true,
+        side_effects: true,
+    }
+    input: {
+        try {
+            (function f(a, ...[ {} ]) {})([]);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            [ , ...[ {} ] ] = [ [] ];
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4562: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        rests: true,
+        unsafe: true,
+    }
+    input: {
+        console.log((([ ...[ a ] ]) => a)("foo"));
+    }
+    expect: {
+        console.log((([ a ]) => a)("foo"));
+    }
+    expect_stdout: "f"
+    node_version: ">=6"
+}
+
+issue_4575: {
+    options = {
+        collapse_vars: true,
+        ie8: true,
+        reduce_vars: true,
+        rests: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            var b = a;
+            var c = function a(...d) {
+                console.log(d.length);
+            }();
+        })();
+    }
+    expect: {
+        (function(a) {
+            (function a(...d) {
+                console.log(d.length);
+            })();
+        })();
+    }
+    expect_stdout: "0"
+    node_version: ">=6"
+}
+
+issue_4621: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        (function f(a, ...{
+            [console.log(a)]: b,
+        }) {})("PASS");
+    }
+    expect: {
+        (function f(a, ...{
+            [console.log(a)]: b,
+        }) {})("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4644_1: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        var a = "FAIL";
+        (function f(b, ...{
+            [a = "PASS"]: c,
+        }) {
+            return b;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        (function f(b, ...{
+            [a = "PASS"]: c,
+        }) {
+            return b;
+        })();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_4644_2: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(function(...a) {
+            return a[1];
+        }("FAIL", "PASS"), function(...b) {
+            return b.length;
+        }(), function(c, ...d) {
+            return d[0];
+        }("FAIL"));
+    }
+    expect: {
+        console.log("PASS", 0, function(c, ...d) {
+            return d[0];
+        }("FAIL"));
+    }
+    expect_stdout: "PASS 0 undefined"
+    node_version: ">=6"
+}
+
+issue_4666: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        rests: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = 0, b = 0;
+        var o = ((...c) => a++ + c)(b);
+        for (var k in o)
+            b++;
+        console.log(a, b);
+    }
+    expect: {
+        var a = 0, b = 0;
+        var o = (c => +a + c)([ b ]);
+        for(var k in o)
+            b++;
+        console.log(1, b);
+    }
+    expect_stdout: "1 2"
+    node_version: ">=6"
+}

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,
@@ -81,6 +98,63 @@ 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({
@@ -98,3 +172,32 @@ issue_4054: {
     }
     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: {

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,
@@ -348,8 +378,6 @@ issue_3983_1: {
     }
     expect: {
         var a = "PASS";
-        g();
-        function g() {}
         console.log(a);
     }
     expect_stdout: "PASS"
@@ -436,7 +464,7 @@ trim_new: {
 
 issue_4325: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         pure_getters: "strict",
         reduce_vars: true,
@@ -458,15 +486,162 @@ issue_4325: {
     }
     expect: {
         (function() {
-            (function() {
+            (function(c) {
                 try {
-                    (void 0).p = 0;
+                    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/templates.js

@@ -0,0 +1,368 @@
+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```${42}``pass`.toUpperCase());'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+tag_parentheses_arrow: {
+    input: {
+        console.log((s => s.raw[0])`\tPASS`.slice(2));
+    }
+    expect_exact: "console.log((s=>s.raw[0])`\\tPASS`.slice(2));"
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+tag_parentheses_new: {
+    input: {
+        (new function() {
+            return console.log;
+        })`foo`;
+    }
+    expect_exact: "(new function(){return console.log})`foo`;"
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+tag_parentheses_sequence: {
+    input: {
+        var o = {
+            f() {
+                console.log(this === o ? "FAIL" : "PASS");
+            },
+        };
+        (42, o.f)``;
+    }
+    expect_exact: 'var o={f(){console.log(this===o?"FAIL":"PASS")}};(42,o.f)``;'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+malformed_escape: {
+    input: {
+        (function(s) {
+            s.forEach((c, i) => console.log(i, c, s.raw[i]));
+            return () => console.log(arguments);
+        })`\uFo${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"
+}
+
+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"
+}

test/compress/unicode.js

@@ -50,7 +50,7 @@ unicode_parse_variables: {
     }
 }
 
-unicode_escaped_identifier: {
+unicode_escaped_identifier_1: {
     input: {
         var \u0061 = "\ud800\udc00";
         console.log(a);
@@ -59,6 +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,

test/compress/varify.js

@@ -354,6 +354,92 @@ forin_let_2: {
     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,
@@ -409,3 +495,31 @@ drop_forin_let: {
     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"
+}

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/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/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"
+    ]
+}

test/input/issue-3315/config.json

@@ -1,8 +1,8 @@
-{
-    "compress": false,
-    "mangle": {
-        "properties": {
-            "regex": "/^_/"
-        }
-    }
-}
+{
+    "compress": false,
+    "mangle": {
+        "properties": {
+            "regex": "/^_/"
+        }
+    }
+}

test/input/reduce/destructured_assign.js

@@ -0,0 +1,3 @@
+var o = {};
+[ o[1 + .1 + .1] ] = [ 42 ];
+console.log(o[1.2]);

test/input/reduce/destructured_assign.reduced.js

@@ -0,0 +1,17 @@
+// (beautified)
+var o = {};
+
+[ o[1 + .1 + .1] ] = [];
+
+console.log(o);
+// output: { '1.2000000000000002': undefined }
+// 
+// minify: { '1.2': undefined }
+// 
+// options: {
+//   "compress": {
+//     "unsafe_math": true
+//   },
+//   "mangle": false,
+//   "validate": true
+// }

test/input/reduce/destructured_catch.js

@@ -0,0 +1,7 @@
+try {
+    "foo" in 42;
+} catch ({
+    message,
+}) {
+    console.log(message);
+}

test/input/reduce/destructured_catch.reduced.js

@@ -0,0 +1,13 @@
+// (beautified)
+try {
+    1 in 0;
+} catch (message) {
+    console.log(message);
+}
+// output: TypeError: Cannot use 'in' operator to search for '1' in 0
+// 
+// minify: TypeError: Cannot use 'in' operator to search for '0' in 0
+// 
+// options: {
+//   "mangle": false
+// }

test/input/reduce/diff_error.js

@@ -1,5 +1,5 @@
-(function f(a) {
-    do {
-        console.log(f.length);
-    } while (console.log(f += 0));
-})();
+console.log(function(undefined) {
+    return undefined[function() {
+        {}
+    }] || 1 + .1 + .1;
+}(42));

test/input/reduce/diff_error.reduced.js

@@ -1,19 +1,14 @@
 // (beautified)
-(function f(a) {
-    do {
-        console.log(f.length);
-    } while (console.log(f += 0));
-})();
-// output: 1
-// function(){}0
+console.log(function() {
+    return 1 + .1 + .1;
+}());
+// output: 1.2000000000000002
 // 
-// minify: 0
-// function(){}0
+// minify: 1.2
 // 
 // options: {
 //   "compress": {
-//     "keep_fargs": false,
-//     "unsafe": true
+//     "unsafe_math": true
 //   },
 //   "mangle": false
 // }

test/input/reduce/setter.js

@@ -1,8 +1,5 @@
-console.log(function f(a) {
-    ({
-        set p(v) {
-            f++;
-        }
-    });
-    return f.length;
-}());
+({
+    set p(v) {
+        console.log(+v + .1 + .1);
+    }
+}).p = 1;

test/input/reduce/setter.reduced.js

@@ -1,20 +1,16 @@
 // (beautified)
-console.log(function f(a) {
-    ({
-        set p(v) {
-            f++;
-        }
-    });
-    return f.length;
-}());
-// output: 1
+({
+    set p(v) {
+        console.log(1 + .1 + .1);
+    }
+}).p = 0;
+// output: 1.2000000000000002
 // 
-// minify: 0
+// minify: 1.2
 // 
 // options: {
 //   "compress": {
-//     "keep_fargs": false,
-//     "unsafe": true
+//     "unsafe_math": true
 //   },
 //   "mangle": false
 // }

test/jetstream.js

@@ -5,7 +5,7 @@
 
 var site = "https://browserbench.org/JetStream1.1";
 if (typeof phantom == "undefined") {
-    require("../tools/exit");
+    require("../tools/tty");
     var args = process.argv.slice(2);
     var debug = args.indexOf("--debug");
     if (debug < 0) {

test/mocha/awaits.js

@@ -0,0 +1,65 @@
+var assert = require("assert");
+var UglifyJS = require("../node");
+
+describe("async", function() {
+    it("Should reject `await` as symbol name within async functions only", function() {
+        [
+            "function await() {}",
+            "function(await) {}",
+            "function() { await; }",
+            "function() { await:{} }",
+            "function() { var await; }",
+            "function() { function await() {} }",
+            "function() { try {} catch (await) {} }",
+        ].forEach(function(code) {
+            var ast = UglifyJS.parse("(" + code + ")();");
+            assert.strictEqual(ast.TYPE, "Toplevel");
+            assert.strictEqual(ast.body.length, 1);
+            assert.strictEqual(ast.body[0].TYPE, "SimpleStatement");
+            assert.strictEqual(ast.body[0].body.TYPE, "Call");
+            assert.strictEqual(ast.body[0].body.expression.TYPE, "Function");
+            assert.throws(function() {
+                UglifyJS.parse("(async " + code + ")();");
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+    it("Should reject `await` expression outside of async functions", function() {
+        [
+            "await 42;",
+            "function f() { await 42; }",
+            "async function f() { function g() { await 42; } }",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+    it("Should reject `await` expression directly on computed key of function argument", function() {
+        [
+            "function f({ [await 42]: a }) {}",
+            "async function f({ [await 42]: a }) {}",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+    it("Should accept `await` expression nested within computed key of function argument", function() {
+        [
+            "function f({ [async function() { await 42; }()]: a }) {}",
+            "async function f({ [async function() { await 42; }()]: a }) {}",
+        ].forEach(function(code) {
+            var ast = UglifyJS.parse(code);
+            assert.strictEqual(ast.TYPE, "Toplevel");
+            assert.strictEqual(ast.body.length, 1);
+            assert.strictEqual(ast.body[0].argnames.length, 1);
+            assert.strictEqual(ast.body[0].argnames[0].TYPE, "DestructuredObject");
+        });
+    });
+});

test/mocha/bug-report.js

@@ -0,0 +1,40 @@
+var assert = require("assert");
+var exec = require("child_process").exec;
+
+describe("UGLIFY_BUG_REPORT", function() {
+    var env = Object.create(process.env);
+    env.UGLIFY_BUG_REPORT = 1;
+    it("Should generate bug report via API", function(done) {
+        exec('"' + process.argv[0] + '"', { env: env }, function(err, stdout) {
+            if (err) throw err;
+            assert.strictEqual(stdout, [
+                "// UGLIFY_BUG_REPORT",
+                "// <<undefined>>",
+                "",
+                "//-------------------------------------------------------------",
+                "// INPUT CODE",
+                "...---...",
+                "",
+            ].join("\n"));
+            done();
+        }).stdin.end('console.log(require("./").minify("...---...").code);');
+    });
+    it("Should generate bug report via CLI", function(done) {
+        exec('"' + process.argv[0] + '" bin/uglifyjs -mc', { env: env }, function(err, stdout) {
+            if (err) throw err;
+            assert.strictEqual(stdout, [
+                "// UGLIFY_BUG_REPORT",
+                "// {",
+                '//   "mangle": {},',
+                '//   "compress": {}',
+                "// }",
+                "",
+                "//-------------------------------------------------------------",
+                "// STDIN",
+                "...---...",
+                "",
+            ].join("\n"));
+            done();
+        }).stdin.end("...---...");
+    });
+});

test/mocha/cli.js

@@ -29,7 +29,7 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + ' test/input/comments/filter.js --comments all';
         exec(command, function(err, stdout) {
             if (err) throw err;
-            assert.strictEqual(stdout, "// foo\n/*@preserve*/\n// bar\n\n");
+            assert.strictEqual(stdout, "// foo\n/*@preserve*/\n// bar\n");
             done();
         });
     });
@@ -37,7 +37,7 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + ' test/input/comments/filter.js --comments /r/';
         exec(command, function(err, stdout) {
             if (err) throw err;
-            assert.strictEqual(stdout, "/*@preserve*/\n// bar\n\n");
+            assert.strictEqual(stdout, "/*@preserve*/\n// bar\n");
             done();
         });
     });
@@ -45,7 +45,7 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + ' test/input/comments/filter.js --comments';
         exec(command, function(err, stdout) {
             if (err) throw err;
-            assert.strictEqual(stdout, "/*@preserve*/\n\n");
+            assert.strictEqual(stdout, "/*@preserve*/\n");
             done();
         });
     });
@@ -56,7 +56,7 @@ describe("bin/uglifyjs", function() {
             "--source-map", [
                 "names=true",
                 "url=inline",
-            ].join(","),
+            ].join(),
         ].join(" "), function(err, stdout) {
             if (err) throw err;
             var expected = [
@@ -84,7 +84,7 @@ describe("bin/uglifyjs", function() {
             "--source-map", [
                 "names=false",
                 "url=inline",
-            ].join(","),
+            ].join(),
         ].join(" "), function(err, stdout) {
             if (err) throw err;
             var expected = [
@@ -171,7 +171,7 @@ describe("bin/uglifyjs", function() {
                 "content=" + mapFile,
                 "includeSources",
                 "url=inline",
-            ].join(","),
+            ].join(),
         ].join(" ");
 
         var child = exec(command, function(err, stdout) {
@@ -333,11 +333,13 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + " test/input/invalid/simple.js";
         exec(command, function(err, stdout, stderr) {
             assert.ok(err);
-            var lines = stderr.split(/\n/);
-            assert.strictEqual(lines[0], "Parse error at test/input/invalid/simple.js:1,12");
-            assert.strictEqual(lines[1], "function f(a{}");
-            assert.strictEqual(lines[2], "            ^");
-            assert.strictEqual(lines[3], "ERROR: Unexpected token: punc «{», expected: punc «,»");
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/simple.js:1,12",
+                "function f(a{}",
+                "            ^",
+                "ERROR: Unexpected token: punc «{», expected: punc «,»",
+            ].join("\n"));
             done();
         });
     });
@@ -345,11 +347,13 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + " test/input/invalid/tab.js";
         exec(command, function(err, stdout, stderr) {
             assert.ok(err);
-            var lines = stderr.split(/\n/);
-            assert.strictEqual(lines[0], "Parse error at test/input/invalid/tab.js:1,12");
-            assert.strictEqual(lines[1], "\t\tfoo(\txyz, 0abc);");
-            assert.strictEqual(lines[2], "\t\t    \t     ^");
-            assert.strictEqual(lines[3], "ERROR: Invalid syntax: 0abc");
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/tab.js:1,12",
+                "\t\tfoo(\txyz, 0abc);",
+                "\t\t    \t     ^",
+                "ERROR: Invalid syntax: 0abc",
+            ].join("\n"));
             done();
         });
     });
@@ -357,11 +361,13 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + " test/input/invalid/eof.js";
         exec(command, function(err, stdout, stderr) {
             assert.ok(err);
-            var lines = stderr.split(/\n/);
-            assert.strictEqual(lines[0], "Parse error at test/input/invalid/eof.js:2,0");
-            assert.strictEqual(lines[1], "foo, bar(");
-            assert.strictEqual(lines[2], "         ^");
-            assert.strictEqual(lines[3], "ERROR: Unexpected token: eof");
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/eof.js:2,0",
+                "foo, bar(",
+                "         ^",
+                "ERROR: Unexpected token: eof",
+            ].join("\n"));
             done();
         });
     });
@@ -369,11 +375,13 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + " test/input/invalid/loop-no-body.js";
         exec(command, function(err, stdout, stderr) {
             assert.ok(err);
-            var lines = stderr.split(/\n/);
-            assert.strictEqual(lines[0], "Parse error at test/input/invalid/loop-no-body.js:2,0");
-            assert.strictEqual(lines[1], "for (var i = 0; i < 1; i++) ");
-            assert.strictEqual(lines[2], "                            ^");
-            assert.strictEqual(lines[3], "ERROR: Unexpected token: eof");
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/loop-no-body.js:2,0",
+                "for (var i = 0; i < 1; i++) ",
+                "                            ^",
+                "ERROR: Unexpected token: eof",
+            ].join("\n"));
             done();
         });
     });
@@ -386,7 +394,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/assign_1.js:1,18",
                 "console.log(1 || 5--);",
                 "                  ^",
-                "ERROR: Invalid use of -- operator"
+                "ERROR: Invalid use of -- operator",
             ].join("\n"));
             done();
         });
@@ -400,7 +408,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/assign_2.js:1,32",
                 "console.log(2 || (Math.random() /= 2));",
                 "                                ^",
-                "ERROR: Invalid assignment"
+                "ERROR: Invalid assignment",
             ].join("\n"));
             done();
         });
@@ -414,7 +422,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/assign_3.js:1,17",
                 "console.log(3 || ++this);",
                 "                 ^",
-                "ERROR: Invalid use of ++ operator"
+                "ERROR: Invalid use of ++ operator",
             ].join("\n"));
             done();
         });
@@ -428,7 +436,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/assign_4.js:1,0",
                 "++null",
                 "^",
-                "ERROR: Invalid use of ++ operator"
+                "ERROR: Invalid use of ++ operator",
             ].join("\n"));
             done();
         });
@@ -442,7 +450,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/dot_1.js:1,2",
                 "a.=",
                 "  ^",
-                "ERROR: Unexpected token: operator «=», expected: name"
+                "ERROR: Unexpected token: operator «=», expected: name",
             ].join("\n"));
             done();
         });
@@ -456,7 +464,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/dot_2.js:1,0",
                 "%.a;",
                 "^",
-                "ERROR: Unexpected token: operator «%»"
+                "ERROR: Unexpected token: operator «%»",
             ].join("\n"));
             done();
         });
@@ -470,7 +478,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/dot_3.js:1,2",
                 "a./();",
                 "  ^",
-                "ERROR: Unexpected token: operator «/», expected: name"
+                "ERROR: Unexpected token: operator «/», expected: name",
             ].join("\n"));
             done();
         });
@@ -484,7 +492,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/object.js:1,13",
                 "console.log({%: 1});",
                 "             ^",
-                "ERROR: Unexpected token: operator «%»"
+                "ERROR: Unexpected token: operator «%»",
             ].join("\n"));
             done();
         });
@@ -498,7 +506,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/delete.js:13,11",
                 "    delete x;",
                 "           ^",
-                "ERROR: Calling delete on expression not allowed in strict mode"
+                "ERROR: Calling delete on expression not allowed in strict mode",
             ].join("\n"));
             done();
         });
@@ -512,7 +520,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/function_1.js:4,11",
                 "function g(arguments) {",
                 "           ^",
-                "ERROR: Unexpected arguments in strict mode"
+                "ERROR: Unexpected arguments in strict mode",
             ].join("\n"));
             done();
         });
@@ -526,7 +534,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/function_2.js:4,9",
                 "function eval() {",
                 "         ^",
-                "ERROR: Unexpected eval in strict mode"
+                "ERROR: Unexpected eval in strict mode",
             ].join("\n"));
             done();
         });
@@ -540,7 +548,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/function_3.js:4,10",
                 "!function arguments() {",
                 "          ^",
-                "ERROR: Unexpected arguments in strict mode"
+                "ERROR: Unexpected arguments in strict mode",
             ].join("\n"));
             done();
         });
@@ -554,7 +562,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/try.js:7,18",
                 "    try {} catch (eval) {}",
                 "                  ^",
-                "ERROR: Unexpected eval in strict mode"
+                "ERROR: Unexpected eval in strict mode",
             ].join("\n"));
             done();
         });
@@ -568,7 +576,21 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/var.js:7,8",
                 "    var eval;",
                 "        ^",
-                "ERROR: Unexpected eval in strict mode"
+                "ERROR: Unexpected eval in strict mode",
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (var { eval })", function(done) {
+        var command = uglifyjscmd + " test/input/invalid/destructured_var.js";
+        exec(command, function(err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/destructured_var.js:7,10",
+                "    var { eval } = 42;",
+                "          ^",
+                "ERROR: Unexpected eval in strict mode",
             ].join("\n"));
             done();
         });
@@ -582,7 +604,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/else.js:1,7",
                 "if (0) else 1;",
                 "       ^",
-                "ERROR: Unexpected token: keyword «else»"
+                "ERROR: Unexpected token: keyword «else»",
             ].join("\n"));
             done();
         });
@@ -596,7 +618,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/return.js:1,0",
                 "return 42;",
                 "^",
-                "ERROR: 'return' outside of function"
+                "ERROR: 'return' outside of function",
             ].join("\n"));
             done();
         });
@@ -610,7 +632,7 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/for-in_1.js:2,5",
                 "for (1, 2, a in b) {",
                 "     ^",
-                "ERROR: Invalid left-hand side in for..in loop"
+                "ERROR: Invalid left-hand side in for..in/of loop",
             ].join("\n"));
             done();
         });
@@ -624,7 +646,49 @@ describe("bin/uglifyjs", function() {
                 "Parse error at test/input/invalid/for-in_2.js:2,5",
                 "for (var a, b in c) {",
                 "     ^",
-                "ERROR: Only one variable declaration allowed in for..in loop"
+                "ERROR: Only one variable declaration allowed in for..in/of loop",
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (for-of init)", function(done) {
+        var command = uglifyjscmd + " test/input/invalid/for-of_1.js";
+        exec(command, function(err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/for-of_1.js:2,5",
+                "for (b = 2 of a)",
+                "     ^",
+                "ERROR: Invalid left-hand side in for..in/of loop",
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (for-of var)", function(done) {
+        var command = uglifyjscmd + " test/input/invalid/for-of_2.js";
+        exec(command, function(err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/for-of_2.js:2,13",
+                "for (var b = 2 of a)",
+                "             ^",
+                "ERROR: No initializers allowed in for..of loop",
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (for-await)", function(done) {
+        var command = uglifyjscmd + " test/input/invalid/for-await.js";
+        exec(command, function(err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/for-await.js:1,11",
+                "for await (; console.log(42););",
+                "           ^",
+                "ERROR: Unexpected token: punc «;»",
             ].join("\n"));
             done();
         });
@@ -633,11 +697,13 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + " test/input/invalid/switch.js";
         exec(command, function(err, stdout, stderr) {
             assert.ok(err);
-            var lines = stderr.split(/\n/);
-            assert.strictEqual(lines[0], "Parse error at test/input/invalid/switch.js:3,2");
-            assert.strictEqual(lines[1], "  default:");
-            assert.strictEqual(lines[2], "  ^");
-            assert.strictEqual(lines[3], "ERROR: More than one default clause in switch statement");
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/switch.js:3,2",
+                "  default:",
+                "  ^",
+                "ERROR: More than one default clause in switch statement",
+            ].join("\n"));
             done();
         });
     });

test/mocha/comments.js

@@ -259,7 +259,7 @@ describe("comments", function() {
         assert.strictEqual(result.code, code);
     });
 
-    it("Should handle comments around parenthesis correctly", function() {
+    it("Should handle comments around parentheses correctly", function() {
         var code = [
             "a();",
             "/* foo */",
@@ -392,12 +392,12 @@ describe("comments", function() {
     describe("comment filters", function() {
         it("Should be able to filter comments by passing regexp", function() {
             var ast = UglifyJS.parse("/*!test1*/\n/*test2*/\n//!test3\n//test4\n<!--test5\n<!--!test6\n-->test7\n-->!test8");
-            assert.strictEqual(ast.print_to_string({comments: /^!/}), "/*!test1*/\n//!test3\n//!test6\n//!test8\n");
+            assert.strictEqual(ast.print_to_string({comments: /^!/}), "/*!test1*/\n//!test3\n//!test6\n//!test8");
         });
 
         it("Should be able to filter comments with the 'all' option", function() {
             var ast = UglifyJS.parse("/*!test1*/\n/*test2*/\n//!test3\n//test4\n<!--test5\n<!--!test6\n-->test7\n-->!test8");
-            assert.strictEqual(ast.print_to_string({comments: "all"}), "/*!test1*/\n/*test2*/\n//!test3\n//test4\n//test5\n//!test6\n//test7\n//!test8\n");
+            assert.strictEqual(ast.print_to_string({comments: "all"}), "/*!test1*/\n/*test2*/\n//!test3\n//test4\n//test5\n//!test6\n//test7\n//!test8");
         });
 
         it("Should be able to filter commments with the 'some' option", function() {
@@ -410,13 +410,12 @@ describe("comments", function() {
             var f = function(node, comment) {
                 return comment.value.length === 8;
             };
-
-            assert.strictEqual(ast.print_to_string({comments: f}), "/*TEST 123*/\n//8 chars.\n");
+            assert.strictEqual(ast.print_to_string({comments: f}), "/*TEST 123*/\n//8 chars.");
         });
 
         it("Should be able to filter comments by passing regex in string format", function() {
             var ast = UglifyJS.parse("/*!test1*/\n/*test2*/\n//!test3\n//test4\n<!--test5\n<!--!test6\n-->test7\n-->!test8");
-            assert.strictEqual(ast.print_to_string({comments: "/^!/"}), "/*!test1*/\n//!test3\n//!test6\n//!test8\n");
+            assert.strictEqual(ast.print_to_string({comments: "/^!/"}), "/*!test1*/\n//!test3\n//!test6\n//!test8");
         });
 
         it("Should be able to get the comment and comment type when using a function", function() {
@@ -424,14 +423,12 @@ describe("comments", function() {
             var f = function(node, comment) {
                 return comment.type == "comment1" || comment.type == "comment3";
             };
-
-            assert.strictEqual(ast.print_to_string({comments: f}), "//!test3\n//test4\n//test5\n//!test6\n");
+            assert.strictEqual(ast.print_to_string({comments: f}), "//!test3\n//test4\n//test5\n//!test6");
         });
 
         it("Should be able to filter comments by passing a boolean", function() {
             var ast = UglifyJS.parse("/*!test1*/\n/*test2*/\n//!test3\n//test4\n<!--test5\n<!--!test6\n-->test7\n-->!test8");
-
-            assert.strictEqual(ast.print_to_string({comments: true}), "/*!test1*/\n/*test2*/\n//!test3\n//test4\n//test5\n//!test6\n//test7\n//!test8\n");
+            assert.strictEqual(ast.print_to_string({comments: true}), "/*!test1*/\n/*test2*/\n//!test3\n//test4\n//test5\n//!test6\n//test7\n//!test8");
             assert.strictEqual(ast.print_to_string({comments: false}), "");
         });
 
@@ -439,10 +436,8 @@ describe("comments", function() {
             var ast = UglifyJS.parse("#!Random comment\n//test1\n/*test2*/");
             var f = function(node, comment) {
                 assert.strictEqual(comment.type === "comment5", false);
-
                 return true;
             };
-
             assert.strictEqual(ast.print_to_string({comments: f}), "#!Random comment\n//test1\n/*test2*/");
         });
 
@@ -453,9 +448,8 @@ describe("comments", function() {
 
         it("Should have no problem on multiple calls", function() {
             const options = {
-                comments: /ok/
+                comments: /ok/,
             };
-
             assert.strictEqual(UglifyJS.parse("/* ok */ function a(){}").print_to_string(options), "/* ok */function a(){}");
             assert.strictEqual(UglifyJS.parse("/* ok */ function a(){}").print_to_string(options), "/* ok */function a(){}");
             assert.strictEqual(UglifyJS.parse("/* ok */ function a(){}").print_to_string(options), "/* ok */function a(){}");
@@ -463,14 +457,14 @@ describe("comments", function() {
 
         it("Should handle shebang and preamble correctly", function() {
             var code = UglifyJS.minify("#!/usr/bin/node\nvar x = 10;", {
-                output: { preamble: "/* Build */" }
+                output: { preamble: "/* Build */" },
             }).code;
             assert.strictEqual(code, "#!/usr/bin/node\n/* Build */\nvar x=10;");
         });
 
         it("Should handle preamble without shebang correctly", function() {
             var code = UglifyJS.minify("var x = 10;", {
-                output: { preamble: "/* Build */" }
+                output: { preamble: "/* Build */" },
             }).code;
             assert.strictEqual(code, "/* Build */\nvar x=10;");
         });

test/mocha/exports.js

@@ -0,0 +1,71 @@
+var assert = require("assert");
+var UglifyJS = require("../node");
+
+describe("export", function() {
+    it("Should reject invalid `export ...` statement syntax", function() {
+        [
+            "export *;",
+            "export A;",
+            "export 42;",
+            "export var;",
+            "export * as A;",
+            "export A as B;",
+            "export const A;",
+            "export function(){};",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+    it("Should reject invalid `export { ... }` statement syntax", function() {
+        [
+            "export { * };",
+            "export { * as A };",
+            "export { 42 as A };",
+            "export { A as B-C };",
+            "export { default as A };",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+    it("Should reject invalid `export default ...` statement syntax", function() {
+        [
+            "export default *;",
+            "export default var;",
+            "export default A as B;",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+    it("Should reject invalid `export ... from ...` statement syntax", function() {
+        [
+            "export from 'path';",
+            "export * from `path`;",
+            "export A as B from 'path';",
+            "export default from 'path';",
+            "export { A }, B from 'path';",
+            "export * as A, B from 'path';",
+            "export * as A, {} from 'path';",
+            "export { * as A } from 'path';",
+            "export { 42 as A } from 'path';",
+            "export { A-B as C } from 'path';",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+});

test/mocha/getter-setter.js

@@ -3,7 +3,7 @@ var UglifyJS = require("../node");
 
 describe("Getters and setters", function() {
     it("Should not accept operator symbols as getter/setter name", function() {
-        var illegalOperators = [
+        [
             "++",
             "--",
             "+",
@@ -42,43 +42,26 @@ describe("Getters and setters", function() {
             "&=",
             "&&",
             "||"
-        ];
-        var generator = function() {
-            var results = [];
-
-            for (var i in illegalOperators) {
-                results.push({
-                    code: "var obj = { get " + illegalOperators[i] + "() { return test; }};",
-                    operator: illegalOperators[i],
-                    method: "get"
-                });
-                results.push({
-                    code: "var obj = { set " + illegalOperators[i] + "(value) { test = value}};",
-                    operator: illegalOperators[i],
-                    method: "set"
-                });
-            }
-
-            return results;
-        };
-        var testCase = function(data) {
-            return function() {
-                UglifyJS.parse(data.code);
-            };
-        };
-        var fail = function(data) {
-            return function(e) {
+        ].reduce(function(tests, illegalOperator) {
+            tests.push({
+                code: "var obj = { get " + illegalOperator + "() { return test; }};",
+                operator: illegalOperator,
+            });
+            tests.push({
+                code: "var obj = { set " + illegalOperator + "(value) { test = value; }};",
+                operator: illegalOperator,
+            });
+            return tests;
+        }, []).forEach(function(test) {
+            assert.throws(function() {
+                UglifyJS.parse(test.code);
+            }, test.operator == "=" ? function(e) {
                 return e instanceof UglifyJS.JS_Parse_Error
-                    && e.message === "Unexpected token: operator «" + data.operator + "»";
-            };
-        };
-        var errorMessage = function(data) {
-            return "Expected but didn't get a syntax error while parsing following line:\n" + data.code;
-        };
-        var tests = generator();
-        for (var i = 0; i < tests.length; i++) {
-            var test = tests[i];
-            assert.throws(testCase(test), fail(test), errorMessage(test));
-        }
+                    && /^Unexpected token: punc «{», expected: punc «.*?»$/.test(e.message);
+            } : function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error
+                    && e.message === "Unexpected token: operator «" + test.operator + "»";
+            }, "Expected but didn't get a syntax error while parsing following line:\n" + test.code);
+        });
     });
 });

test/mocha/imports.js

@@ -0,0 +1,28 @@
+var assert = require("assert");
+var UglifyJS = require("../node");
+
+describe("import", function() {
+    it("Should reject invalid `import` statement syntax", function() {
+        [
+            "import *;",
+            "import A;",
+            "import {};",
+            "import `path`;",
+            "import from 'path';",
+            "import * from 'path';",
+            "import A as B from 'path';",
+            "import { A }, B from 'path';",
+            "import * as A, B from 'path';",
+            "import * as A, {} from 'path';",
+            "import { * as A } from 'path';",
+            "import { 42 as A } from 'path';",
+            "import { A-B as C } from 'path';",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+});

test/mocha/minify.js

@@ -235,8 +235,8 @@ describe("minify", function() {
                 }
             });
             var code = result.code;
-            assert.strictEqual(code, "var a=/* */function(){foo()}();");
-        })
+            assert.strictEqual(code, "var a=function(){foo()}();");
+        });
     });
 
     describe("JS_Parse_Error", function() {

test/mocha/number-literal.js

@@ -89,4 +89,13 @@ describe("Number literals", function() {
             }, code);
         });
     });
+    it("Should reject invalid syntax under expression=true", function() {
+        assert.throws(function() {
+            UglifyJS.parse("42.g", {
+                expression: true,
+            });
+        }, function(e) {
+            return e instanceof UglifyJS.JS_Parse_Error;
+        });
+    });
 });

test/mocha/parentheses.js

@@ -84,7 +84,7 @@ describe("parentheses", function() {
         }
     });
 
-    it("Should compress leading parenthesis with reasonable performance", function() {
+    it("Should compress leading parentheses with reasonable performance", function() {
         this.timeout(30000);
         var code = [
             "({}?0:1)&&x();",

test/mocha/reduce.js

@@ -37,8 +37,7 @@ describe("test/reduce.js", function() {
     it("Should retain setter arguments", function() {
         var result = reduce_test(read("test/input/reduce/setter.js"), {
             compress: {
-                keep_fargs: false,
-                unsafe: true,
+                unsafe_math: true,
             },
             mangle: false,
         }, {
@@ -110,28 +109,24 @@ describe("test/reduce.js", function() {
     });
     it("Should print correct output for irreducible test case", function() {
         var result = reduce_test([
-            "console.log(function f(a) {",
-            "    return f.length;",
-            "}());",
+            "console.log(1 + .1 + .1);",
         ].join("\n"), {
             compress: {
-                keep_fargs: false,
+                unsafe_math: true,
             },
             mangle: false,
         });
         if (result.error) throw result.error;
         assert.strictEqual(result.code, [
             "// (beautified)",
-            "console.log(function f(a) {",
-            "    return f.length;",
-            "}());",
-            "// output: 1",
+            "console.log(1 + .1 + .1);",
+            "// output: 1.2000000000000002",
             "// ",
-            "// minify: 0",
+            "// minify: 1.2",
             "// ",
             "// options: {",
             '//   "compress": {',
-            '//     "keep_fargs": false',
+            '//     "unsafe_math": true',
             "//   },",
             '//   "mangle": false',
             "// }",
@@ -188,6 +183,24 @@ describe("test/reduce.js", function() {
             "// }",
         ].join("\n"));
     });
+    it("Should reduce `for (const ... in ...)` without invalid intermediate AST", function() {
+        if (semver.satisfies(process.version, "<4")) return;
+        var code = [
+            "var a = 0;",
+            "",
+            "for (const b in [ 1, 2, 3 ]) {",
+            "    a = +a + 1 - .2;",
+            "    console.log(a);",
+            "}",
+        ].join("\n");
+        var result = reduce_test(code, {
+            compress: {
+                unsafe_math: true,
+            },
+        });
+        if (result.error) throw result.error;
+        assert.deepEqual(result.warnings, []);
+    });
     it("Should reduce infinite loops with reasonable performance", function() {
         if (semver.satisfies(process.version, "<=0.10")) return;
         this.timeout(120000);
@@ -299,12 +312,45 @@ describe("test/reduce.js", function() {
             "// }",
         ]).join("\n"));
     });
+    it("Should maintain block-scope for const/let", function() {
+        if (semver.satisfies(process.version, "<4")) return;
+        this.timeout(120000);
+        var code = [
+            '"use strict";',
+            "",
+            "L: for (let a = (1 - .8).toString(); ;) {",
+            "    if (!console.log(a)) {",
+            "        break L;",
+            "    }",
+            "}",
+        ].join("\n");
+        var result = reduce_test(code, {
+            compress: {
+                unsafe_math: true,
+            },
+            mangle: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "// (beautified)",
+            code,
+            "// output: 0.19999999999999996",
+            "// ",
+            "// minify: 0.2",
+            "// ",
+            "// options: {",
+            '//   "compress": {',
+            '//     "unsafe_math": true',
+            '//   },',
+            '//   "mangle": false',
+            "// }",
+        ].join("\n"));
+    });
     it("Should handle corner cases when intermediate case differs only in Error.message", function() {
         if (semver.satisfies(process.version, "<=0.10")) return;
         var result = reduce_test(read("test/input/reduce/diff_error.js"), {
             compress: {
-                keep_fargs: false,
-                unsafe: true,
+                unsafe_math: true,
             },
             mangle: false,
         }, {
@@ -313,4 +359,59 @@ describe("test/reduce.js", function() {
         if (result.error) throw result.error;
         assert.strictEqual(result.code, read("test/input/reduce/diff_error.reduced.js"));
     });
+    it("Should maintain valid LHS in destructuring assignments", function() {
+        if (semver.satisfies(process.version, "<6")) return;
+        var result = reduce_test(read("test/input/reduce/destructured_assign.js"), {
+            compress: {
+                unsafe_math: true,
+            },
+            mangle: false,
+            validate: true,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, read("test/input/reduce/destructured_assign.reduced.js"));
+    });
+    it("Should handle destructured catch expressions", function() {
+        if (semver.satisfies(process.version, "<6")) return;
+        var result = reduce_test(read("test/input/reduce/destructured_catch.js"), {
+            mangle: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, read("test/input/reduce/destructured_catch.reduced.js"));
+    });
+    it("Should not enumerate `toString` over global context", function() {
+        if (semver.satisfies(process.version, "<8")) return;
+        var code = [
+            "(async function() {});",
+            "for (var k in this);",
+            "console.log(k, 42 + this);",
+        ].join("\n");
+        var result = reduce_test(code, {
+            mangle: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "// Can't reproduce test failure",
+            "// minify options: {",
+            '//   "mangle": false',
+            "// }",
+        ].join("\n"));
+    });
+    it("Should reduce object with method syntax without invalid intermediate AST", function() {
+        if (semver.satisfies(process.version, "<4")) return;
+        var code = [
+            "console.log({",
+            "    f() {",
+            "        return 1 - .8;",
+            "    },",
+            "}.f());",
+        ].join("\n");
+        var result = reduce_test(code, {
+            compress: {
+                unsafe_math: true,
+            },
+        });
+        if (result.error) throw result.error;
+        assert.deepEqual(result.warnings, []);
+    });
 });