v3.17.4

fixes #5716

.github/ISSUE_TEMPLATE.md

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

.github/ISSUE_TEMPLATE/bug_report.md

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

.github/workflows/build.yml

@@ -0,0 +1,58 @@
+name: Build testing
+on:
+  pull_request:
+  push:
+    branches: [ master ]
+jobs:
+  ufuzz:
+    strategy:
+      fail-fast: false
+      matrix:
+        options:
+          - '-mb braces'
+          - '--ie -c'
+          - '-mc'
+          - '-p acorn --toplevel -mco spidermonkey'
+          - '--toplevel -mc passes=3,pure_getters,unsafe'
+        script:
+          - acorn.sh
+          - bootstrap.sh
+          - buble.sh
+          - butternut.sh
+          - mathjs.sh
+          - rollup-es.sh
+          - rollup-ts.sh
+          - sucrase.sh
+          - web-tooling-benchmark.sh
+        include:
+          - node: '14'
+            script: acorn.sh
+          - node: '14'
+            script: bootstrap.sh
+          - node: '14'
+            script: buble.sh
+          - node: '14'
+            script: butternut.sh
+          - node: '14'
+            script: mathjs.sh
+          - node: '8'
+            script: rollup-es.sh
+          - node: '14'
+            script: rollup-ts.sh
+          - node: '14'
+            script: sucrase.sh
+          - node: '14'
+            script: web-tooling-benchmark.sh
+    name: ${{ matrix.script }} ${{ matrix.options }}
+    runs-on: ubuntu-latest
+    env:
+      NODE: ${{ matrix.node }}
+      OPTIONS: ${{ matrix.options }}
+      SCRIPT: ${{ matrix.script }}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Perform uglify, build & test
+        shell: bash
+        run: |
+          . ./test/release/install.sh
+          ./test/release/$SCRIPT $OPTIONS

.github/workflows/ci.yml

@@ -0,0 +1,29 @@
+name: CI
+on:
+  pull_request:
+  push:
+    branches: [ master ]
+jobs:
+  test:
+    strategy:
+      matrix:
+        node: [ '0.10', '0.12', '4', '6', '8', '10', '12', '14', '16', latest ]
+        os: [ ubuntu-latest, windows-latest ]
+        script: [ compress, mocha, release/benchmark, release/jetstream ]
+    name: ${{ matrix.node }} ${{ matrix.os }} ${{ matrix.script }}
+    runs-on: ${{ matrix.os }}
+    env:
+      NODE: ${{ matrix.node }}
+      TYPE: ${{ matrix.script }}
+      UGLIFY_GITHUB_LAG: 10000
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/cache@v3
+        with:
+          path: tmp
+          key: tmp ${{ matrix.script }}
+      - name: Perform tests
+        shell: bash
+        run: |
+          . ./test/release/install.sh
+          node test/$TYPE

.github/workflows/ufuzz.yml

@@ -0,0 +1,44 @@
+name: Fuzzing
+on:
+  pull_request:
+  schedule:
+    - cron: '*/15 * * * *'
+  workflow_dispatch:
+  workflow_run:
+    branches: [ master ]
+    types: [ completed ]
+    workflows: [ 'Build testing', CI ]
+env:
+  BASE_URL: https://api.github.com/repos/${{ github.repository }}
+  TOKEN: ${{ github.token }}
+jobs:
+  ufuzz:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - node: '16'
+            os: macos-latest
+          - node: '12'
+            os: ubuntu-latest
+          - node: '8'
+            os: ubuntu-latest
+          - node: '12'
+            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@v3
+      - name: Perform fuzzing
+        shell: bash
+        run: |
+          . ./test/release/install.sh
+          if [[ $GITHUB_EVENT_NAME == "pull_request" ]]; then
+            node test/ufuzz/job 5000
+          else
+            node test/ufuzz/job $BASE_URL $TOKEN $GITHUB_RUN_NUMBER
+          fi

.travis.yml

@@ -1,34 +0,0 @@
-addons:
-  apt:
-    sources:
-      - ubuntu-toolchain-r-test
-    packages:
-      - libstdc++-4.9-dev
-cache:
-  directories: tmp
-language: generic
-matrix:
-  fast_finish: true
-sudo: false
-env:
-  global:
-    - UGLIFYJS_TEST_ALL=1
-  matrix:
-    - NODEJS_VER=node/0.10
-    - NODEJS_VER=node/0.12
-    - NODEJS_VER=node/4
-    - NODEJS_VER=node/6
-    - NODEJS_VER=node/8
-    - NODEJS_VER=node/latest
-before_install:
-  - git clone --branch v1.4.2 --depth 1 https://github.com/jasongin/nvs.git ~/.nvs
-  - . ~/.nvs/nvs.sh
-  - nvs --version
-install:
-  - nvs add $NODEJS_VER
-  - nvs use $NODEJS_VER
-  - node --version
-  - npm --version --no-update-notifier
-  - npm install --no-optional --no-save --no-update-notifier
-script:
-  - npm test --no-update-notifier

CONTRIBUTING.md

@@ -3,7 +3,7 @@ Contributing
 
 ## Documentation
 
-Every new feature and API change should be accompanied by a README additon.
+Every new feature and API change should be accompanied by a README addition.
 
 ## Testing
 

LICENSE

@@ -1,6 +1,6 @@
 UglifyJS is released under the BSD license:
 
-Copyright 2012-2018 (c) Mihai Bazon <mihai.bazon@gmail.com>
+Copyright 2012-2019 (c) Mihai Bazon <mihai.bazon@gmail.com>
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions

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/UglifyJS2/tree/v2.x)**.
-- **Documentation for UglifyJS `2.x` releases can be found [here](https://github.com/mishoo/UglifyJS2/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
 -------
@@ -53,8 +54,6 @@ a double dash to prevent input files being used as option arguments:
                                                 modules and Userscripts that may
                                                 be anonymous function wrapped (IIFE)
                                                 by the .user.js engine `caller`.
-                                `expression`  Parse a single expression, rather than
-                                              a program (for parsing JSON).
                                 `spidermonkey`  Assume input files are SpiderMonkey
                                                 AST format (as JSON).
     -c, --compress [options]    Enable compressor/specify compressor options:
@@ -84,12 +83,16 @@ 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
@@ -106,12 +109,16 @@ a double dash to prevent input files being used as option arguments:
     -d, --define <expr>[=value] Global definitions.
     -e, --enclose [arg[:value]] Embed everything in a big function, with configurable
                                 argument(s) & value(s).
-    --ie8                       Support non-standard Internet Explorer 8.
-                                Equivalent to setting `ie8: true` in `minify()`
+    --expression                Parse a single expression, rather than a program
+                                (for parsing JSON).
+    --ie                        Support non-standard Internet Explorer.
+                                Equivalent to setting `ie: true` in `minify()`
                                 for `compress`, `mangle` and `output` options.
                                 By default UglifyJS will not try to be IE-proof.
+    --keep-fargs                Do not mangle/drop function arguments.
     --keep-fnames               Do not mangle/drop function names.  Useful for
                                 code relying on Function.prototype.name.
+    --module                    Process input as ES module (implies --toplevel)
     --name-cache <file>         File to hold mangled name mappings.
     --self                      Build UglifyJS as a library (implies --wrap UglifyJS)
     --source-map [options]      Enable source map/specify source map options:
@@ -125,14 +132,23 @@ a double dash to prevent input files being used as option arguments:
                                 `includeSources`  Pass this flag if you want to include
                                                   the content of source files in the
                                                   source map as sourcesContent property.
+                                `names` Include symbol names in the source map.
                                 `root`  Path to the original source to be included in
                                         the source map.
                                 `url`  If specified, path to the source map to append in
                                        `//# sourceMappingURL`.
     --timings                   Display operations run time on STDERR.
     --toplevel                  Compress and/or mangle variables in top level scope.
+    --v8                        Support non-standard Chrome & Node.js
+                                Equivalent to setting `v8: true` in `minify()`
+                                for `mangle` and `output` options.
+                                By default UglifyJS will not try to be v8-proof.
     --verbose                   Print diagnostic messages.
     --warn                      Print warning messages.
+    --webkit                    Support non-standard Safari/Webkit.
+                                Equivalent to setting `webkit: true` in `minify()`
+                                for `compress`, `mangle` and `output` options.
+                                By default UglifyJS will not try to be Safari-proof.
     --wrap <name>               Embed everything in a big function, making the
                                 “exports” and “global” variables available. You
                                 need to pass an argument to this option to
@@ -158,6 +174,9 @@ Additional options:
 
 - `--source-map "root='<URL>'"` to pass the URL where the original files can be found.
 
+- `--source-map "names=false"` to omit symbol names if you want to reduce size
+  of the source map file.
+
 - `--source-map "url='<URL>'"` to specify the URL where the source map can be found.
   Otherwise UglifyJS assumes HTTP `X-SourceMap` is being used and will omit the
   `//# sourceMappingURL=` directive.
@@ -207,17 +226,16 @@ Example:
 To enable the mangler you need to pass `--mangle` (`-m`).  The following
 (comma-separated) options are supported:
 
-- `toplevel` (default `false`) -- mangle names declared in the top level scope.
+- `eval` (default: `false`) — mangle names visible in scopes where `eval` or
+  `with` are used.
 
-- `eval` (default `false`) -- mangle names visible in scopes where `eval` or `with` are used.
+- `reserved` (default: `[]`) — when mangling is enabled but you want to
+  prevent certain names from being mangled, you can declare those names with
+  `--mangle reserved` — pass a comma-separated list of names.  For example:
 
-When mangling is enabled but you want to prevent certain names from being
-mangled, you can declare those names with `--mangle reserved` — pass a
-comma-separated list of names.  For example:
+      uglifyjs ... -m reserved=['$','require','exports']
 
-    uglifyjs ... -m reserved=['$','require','exports']
-
-to prevent the `require`, `exports` and `$` names from being changed.
+  to prevent the `require`, `exports` and `$` names from being changed.
 
 ### CLI mangling property names (`--mangle-props`)
 
@@ -309,7 +327,7 @@ unquoted style (`o.foo`). Example:
 // stuff.js
 var o = {
     "foo": 1,
-    bar: 3
+    bar: 3,
 };
 o.foo += o.bar;
 console.log(o.foo);
@@ -321,6 +339,16 @@ $ uglifyjs stuff.js --mangle-props keep_quoted -c -m
 var o={foo:1,o:3};o.foo+=o.o,console.log(o.foo);
 ```
 
+If the minified output will be processed again by UglifyJS, consider specifying
+`keep_quoted_props` so the same property names are preserved:
+
+```bash
+$ uglifyjs stuff.js --mangle-props keep_quoted -c -m -O keep_quoted_props
+```
+```javascript
+var o={"foo":1,o:3};o.foo+=o.o,console.log(o.foo);
+```
+
 ### Debugging property name mangling
 
 You can also pass `--mangle-props debug` in order to mangle property names
@@ -478,42 +506,61 @@ if (result.error) throw result.error;
 
 ## Minify options
 
-- `warnings` (default `false`) — pass `true` to return compressor warnings
-  in `result.warnings`. Use the value `"verbose"` for more detailed warnings.
+- `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.
 
-- `parse` (default `{}`) — pass an object if you wish to specify some
-  additional [parse options](#parse-options).
-
-- `compress` (default `{}`) — pass `false` to skip compressing entirely.
+- `compress` (default: `{}`) — pass `false` to skip compressing entirely.
   Pass an object to specify custom [compress options](#compress-options).
 
-- `mangle` (default `true`) — pass `false` to skip mangling names, or pass
+- `expression` (default: `false`) — parse as a single expression, e.g. JSON.
+
+- `ie` (default: `false`) — enable workarounds for Internet Explorer bugs.
+
+- `keep_fargs` (default: `false`) — pass `true` to prevent discarding or mangling
+  of function arguments.
+
+- `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
   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).
 
-- `output` (default `null`) — pass an object if you wish to specify
-  additional [output options](#output-options).  The defaults are optimized
-  for best compression.
+- `module` (default: `false`) — set to `true` if you wish to process input as
+  ES module, i.e. implicit `"use strict";` and support for top-level `await`,
+  alongside with `toplevel` enabled.
 
-- `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
-  variable and function name mangling and to drop unused variables and functions.
-
-- `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.
 
-- `ie8` (default `false`) - set to `true` to support IE8.
+- `output` (default: `null`) — pass an object if you wish to specify
+  additional [output options](#output-options).  The defaults are optimized
+  for best compression.
 
-- `keep_fnames` (default: `false`) - pass `true` to prevent discarding or mangling
-  of function names.  Useful for code relying on `Function.prototype.name`.
+- `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
+  [source map options](#source-map-options).
+
+- `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.
+
+- `v8` (default: `false`) — enable workarounds for Chrome & Node.js bugs.
+
+- `warnings` (default: `false`) — pass `true` to return compressor warnings
+  in `result.warnings`. Use the value `"verbose"` for more detailed warnings.
+
+- `webkit` (default: `false`) — enable workarounds for Safari/WebKit bugs.
+  PhantomJS users should set this option to `true`.
 
 ## Minify options structure
 
@@ -540,7 +587,6 @@ if (result.error) throw result.error;
     },
     nameCache: null, // or specify a name cache object
     toplevel: false,
-    ie8: false,
     warnings: false,
 }
 ```
@@ -592,98 +638,134 @@ var result = UglifyJS.minify({"compiled.js": "compiled code"}, {
 
 If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.url`.
 
+If you wish to reduce file size of the source map, set option `sourceMap.names`
+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`) — process HTML comment as workaround for
+  browsers which do not recognize `<script>` tags
 
-- `shebang` (default `true`) -- support `#!command` as the first line
+- `module` (default: `false`) — set to `true` if you wish to process input as
+  ES module, i.e. implicit `"use strict";` and support for top-level `await`.
+
+- `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.
 
-- `booleans` (default: `true`) -- various optimizations for boolean context,
+- `arrows` (default: `true`) — apply optimizations to arrow functions
+
+- `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`) -- attempt to evaluate constant expressions
+- `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.
 
-- `global_defs` (default: `{}`) -- see [conditional compilation](#conditional-compilation)
+- `functions` (default: `true`) — convert declarations from `var` to `function`
+  whenever possible.
 
-- `hoist_funs` (default: `false`) -- hoist function declarations
+- `global_defs` (default: `{}`) — see [conditional compilation](#conditional-compilation)
 
-- `hoist_props` (default: `true`) -- hoist properties from constant object and
+- `hoist_exports` (default: `true`) — hoist `export` statements to facilitate
+  various `compress` and `mangle` optimizations.
+
+- `hoist_funs` (default: `false`) — hoist function declarations
+
+- `hoist_props` (default: `true`) — hoist properties from constant object and
   array literals into regular variables subject to a set of constraints. For example:
   `var o={p:1, q:2}; f(o.p, o.q);` is converted to `f(1, 2);`. Note: `hoist_props`
-  works best with `mangle` enabled, the `compress` option `passes` set to `2` or higher,
-  and the `compress` option `toplevel` enabled.
+  works best with `toplevel` and `mangle` enabled, alongside with `compress` option
+  `passes` set to `2` or higher.
 
-- `hoist_vars` (default: `false`) -- hoist `var` declarations (this is `false`
+- `hoist_vars` (default: `false`) — hoist `var` declarations (this is `false`
   by default because it seems to increase the size of the output in general)
 
-- `if_return` (default: `true`) -- optimizations for if/return and if/continue
+- `if_return` (default: `true`) — optimizations for if/return and if/continue
 
-- `inline` (default: `true`) -- inline calls to function with simple/`return` statement:
-  - `false` -- same as `0`
-  - `0` -- disabled inlining
-  - `1` -- inline simple functions
-  - `2` -- inline functions with arguments
-  - `3` -- inline functions with arguments and variables
-  - `true` -- same as `3`
+- `imports` (default: `true`) — drop unreferenced import symbols when used with `unused`
 
-- `join_vars` (default: `true`) -- join consecutive `var` statements
+- `inline` (default: `true`) — inline calls to function with simple/`return` statement:
+  - `false` — same as `0`
+  - `0` — disabled inlining
+  - `1` — inline simple functions
+  - `2` — inline functions with arguments
+  - `3` — inline functions with arguments and variables
+  - `4` — inline functions with arguments, variables and statements
+  - `true` — same as `4`
 
-- `keep_fargs` (default: `true`) -- Prevents the compressor from discarding unused
-  function arguments.  You need this for code which relies on `Function.length`.
+- `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).
+- `keep_fargs` (default: `false`) — discard unused function arguments except
+  when unsafe to do so, e.g. code which relies on `Function.prototype.length`.
+  Pass `true` to always retain function arguments.
 
-- `keep_infinity` (default: `false`) -- Pass `true` to prevent `Infinity` from
+- `keep_infinity` (default: `false`) — Pass `true` to prevent `Infinity` from
   being compressed into `1/0`, which may cause performance issues on Chrome.
 
-- `loops` (default: `true`) -- optimizations for `do`, `while` and `for` loops
+- `loops` (default: `true`) — optimizations for `do`, `while` and `for` loops
   when we can statically determine the condition.
 
-- `negate_iife` (default: `true`) -- negate "Immediately-Called Function Expressions"
-  where the return value is discarded, to avoid the parens that the
+- `merge_vars` (default: `true`) — combine and reuse variables.
+
+- `module` (default: `false`) — set to `true` if you wish to process input as
+  ES module, i.e. implicit `"use strict";` alongside with `toplevel` enabled.
+
+- `negate_iife` (default: `true`) — negate "Immediately-Called Function Expressions"
+  where the return value is discarded, to avoid the parentheses that the
   code generator would insert.
 
-- `passes` (default: `1`) -- The maximum number of times to run compress.
+- `objects` (default: `true`) — compact duplicate keys in object literals.
+
+- `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
@@ -695,22 +777,24 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   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`
@@ -719,65 +803,68 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   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.
 
-- `switches` (default: `true`) -- de-duplicate and remove unreachable `switch` branches
+- `spreads` (default: `true`) — flatten spread expressions.
 
-- `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)
+- `strings` (default: `true`) — compact string concatenations.
 
-- `top_retain` (default: `null`) -- prevent specific toplevel functions and
+- `switches` (default: `true`) — de-duplicate and remove unreachable `switch` branches
+
+- `templates` (default: `true`) — compact template literals by embedding expressions
+  and/or converting to string literals, e.g. `` `foo ${42}` → "foo 42"``
+
+- `top_retain` (default: `null`) — prevent specific toplevel functions and
   variables from `unused` removal (can be array, comma-separated, RegExp or
   function. Implies `toplevel`)
 
-- `typeofs` (default: `true`) -- Transforms `typeof foo == "undefined"` into
-  `foo === void 0`.  Note: recommend to set this value to `false` for IE10 and
-  earlier versions due to known issues.
+- `toplevel` (default: `false`) — drop unreferenced functions (`"funcs"`) and/or
+  variables (`"vars"`) in the top level scope (`false` by default, `true` to drop
+  both unreferenced functions and variables)
 
-- `unsafe` (default: `false`) -- apply "unsafe" transformations (discussion below)
+- `typeofs` (default: `true`) — compress `typeof` expressions, e.g.
+  `typeof foo == "undefined" → void 0 === foo`
 
-- `unsafe_comps` (default: `false`) -- compress expressions like `a <= b` assuming
-  none of the operands can be (coerced to) `NaN`.
+- `unsafe` (default: `false`) — apply "unsafe" transformations (discussion below)
 
-- `unsafe_Function` (default: `false`) -- compress and mangle `Function(args, code)`
+- `unsafe_comps` (default: `false`) — assume operands cannot be (coerced to) `NaN`
+  in numeric comparisons, e.g. `a <= b`. In addition, expressions involving `in`
+  or `instanceof` would never throw.
+
+- `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"`)
 
-- `warnings` (default: `false`) -- display warnings when dropping unreachable
-  code or unused declarations etc.
+- `varify` (default: `true`) — convert block-scoped declarations 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:
@@ -804,18 +891,24 @@ UglifyJS.minify(code, { mangle: { toplevel: true } }).code;
 
 ### Mangle properties options
 
-- `builtins` (default: `false`) -- Use `true` to allow the mangling of builtin
-  DOM properties. Not recommended to override this setting.
+- `builtins` (default: `false`) — Use `true` to allow the mangling of built-in
+  properties of JavaScript API. 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.
+- `domprops` (default: `false`) — Use `true` to allow the mangling of properties
+  commonly found in Document Object Model. Not recommended to override this setting.
 
-- `regex` (default: `null`) -— Pass a RegExp literal to only mangle property
+- `keep_fargs` (default: `false`) — Use `true` to prevent mangling of function
+  arguments.
+
+- `keep_quoted` (default: `false`) — Only mangle unquoted property names.
+
+- `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
@@ -824,72 +917,86 @@ 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, `"some"` to preserve some comments, a regular expression string
-  (e.g. `/^!/`) or a function.
+- `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.
+  ```javascript
+  function(node, comment) {
+      return comment.value.indexOf("@type " + node.TYPE) >= 0;
+  }
+  ```
 
-- `indent_level` (default `4`)
+- `extendscript` (default: `false`) — enable workarounds for Adobe ExtendScript
+  bugs
 
-- `indent_start` (default `0`) -- prefix all lines by that many spaces
+- `galio` (default: `false`) — enable workarounds for ANT Galio bugs
 
-- `inline_script` (default `true`) -- escape HTML comments and the slash in
+- `indent_level` (default: `4`) — indent by specified number of spaces or the
+  exact whitespace sequence supplied, e.g. `"\t"`.
+
+- `indent_start` (default: `0`) — prefix all lines by whitespace sequence
+  specified in the same format as `indent_level`.
+
+- `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 preserve lines, but it
-  only works if `beautify` is set to `false`.
+- `preserve_line` (default: `false`) — pass `true` to retain line numbering on
+  a best effort basis.
 
-- `quote_keys` (default `false`) -- pass `true` to quote all keys in literal
+- `quote_keys` (default: `false`) — pass `true` to quote all keys in literal
   objects
 
-- `quote_style` (default `0`) -- preferred quote style for strings (affects
+- `quote_style` (default: `0`) — preferred quote style for strings (affects
   quoted property names and directives as well):
-  - `0` -- prefers double quotes, switches to single quotes when there are
+  - `0` — prefers double quotes, switches to single quotes when there are
     more double quotes in the string itself. `0` is best for gzip size.
-  - `1` -- always use single quotes
-  - `2` -- always use double quotes
-  - `3` -- always use the original quotes
+  - `1` — always use single quotes
+  - `2` — always use double quotes
+  - `3` — always use the original quotes
 
-- `semicolons` (default `true`) -- separate statements with semicolons.  If
+- `semicolons` (default: `true`) — separate statements with semicolons.  If
   you pass `false` then whenever possible we will use a newline instead of a
   semicolon, leading to more readable output of uglified code (size before
   gzip could be smaller; size after gzip insignificantly larger).
 
-- `shebang` (default `true`) -- preserve shebang `#!` in preamble (bash scripts)
+- `shebang` (default: `true`) — preserve shebang `#!` in preamble (bash scripts)
 
-- `webkit` (default `false`) -- enable workarounds for WebKit bugs.
-  PhantomJS users should set this option to `true`.
-
-- `width` (default `80`) -- only takes effect when beautification is on, this
+- `width` (default: `80`) — only takes effect when beautification is on, this
   specifies an (orientative) line width that the beautifier will try to
   obey.  It refers to the width of the line text (excluding indentation).
   It doesn't work very well currently, but it does make the code generated
   by UglifyJS more readable.
 
-- `wrap_iife` (default `false`) -- pass `true` to wrap immediately invoked
+- `wrap_iife` (default: `false`) — pass `true` to wrap immediately invoked
   function expressions. See
-  [#640](https://github.com/mishoo/UglifyJS2/issues/640) for more details.
+  [#640](https://github.com/mishoo/UglifyJS/issues/640) for more details.
 
 # Miscellaneous
 
@@ -1048,8 +1155,8 @@ var result = UglifyJS.minify(ast, {
 ### Working with Uglify AST
 
 Transversal and transformation of the native AST can be performed through
-[`TreeWalker`](https://github.com/mishoo/UglifyJS2/blob/master/lib/ast.js) and
-[`TreeTransformer`](https://github.com/mishoo/UglifyJS2/blob/master/lib/transform.js)
+[`TreeWalker`](https://github.com/mishoo/UglifyJS/blob/master/lib/ast.js) and
+[`TreeTransformer`](https://github.com/mishoo/UglifyJS/blob/master/lib/transform.js)
 respectively.
 
 ### ESTree / SpiderMonkey AST
@@ -1088,29 +1195,25 @@ in total it's a bit more than just using UglifyJS's own parser.
 It's not well known, but whitespace removal and symbol mangling accounts
 for 95% of the size reduction in minified code for most JavaScript - not
 elaborate code transforms. One can simply disable `compress` to speed up
-Uglify builds by 3 to 4 times. In this fast `mangle`-only mode Uglify has
-comparable minify speeds and gzip sizes to
-[`butternut`](https://www.npmjs.com/package/butternut):
+Uglify builds by 3 to 5 times.
 
 | d3.js | minify size | gzip size | minify time (seconds) |
 | --- | ---: | ---: | ---: |
-| original | 451,131 | 108,733 | - |
-| uglify-js@3.0.24 mangle=false, compress=false | 316,600 | 85,245 | 0.70 |
-| uglify-js@3.0.24 mangle=true, compress=false | 220,216 | 72,730 | 1.13 |
-| butternut@0.4.6 | 217,568 | 72,738 | 1.41 |
-| uglify-js@3.0.24 mangle=true, compress=true | 212,511 | 71,560 | 3.36 |
-| babili@0.1.4 | 210,713 | 72,140 | 12.64 |
+| original | 511,371 | 119,932 | - |
+| uglify-js@3.13.0 mangle=false, compress=false | 363,988 | 95,695 | 0.56 |
+| uglify-js@3.13.0 mangle=true, compress=false | 253,305 | 81,281 | 0.99 |
+| uglify-js@3.13.0 mangle=true, compress=true | 244,436 | 79,854 | 5.30 |
 
 To enable fast minify mode from the CLI use:
 ```
 uglifyjs file.js -m
 ```
 To enable fast minify mode with the API use:
-```js
+```javascript
 UglifyJS.minify(code, { compress: false, mangle: true });
 ```
 
-#### Source maps and debugging
+### Source maps and debugging
 
 Various `compress` transforms that simplify, rearrange, inline and remove code
 are known to have an adverse effect on debugging with source maps. This is
@@ -1122,6 +1225,10 @@ disable the Uglify `compress` option and just use `mangle`.
 
 To allow for better optimizations, the compiler makes various assumptions:
 
+- The code does not rely on preserving its runtime performance characteristics.
+  Typically uglified code will run faster due to less instructions and easier
+  inlining, but may be slower on rare occasions for a specific platform, e.g.
+  see [`reduce_funcs`](#compress-options).
 - `.toString()` and `.valueOf()` don't have side effects, and for built-in
   objects they have not been overridden.
 - `undefined`, `NaN` and `Infinity` have not been externally redefined.
@@ -1133,3 +1240,239 @@ 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()`).
+- If array destructuring is present, index-like properties in `Array.prototype`
+  have not been overridden:
+  ```javascript
+  Object.prototype[0] = 42;
+  var [ a ] = [];
+  var { 0: b } = {};
+  // 42 undefined
+  console.log([][0], a);
+  // 42 42
+  console.log({}[0], b);
+  ```
+- Earlier versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  ({
+      p: 42,
+      get p() {},
+  });
+  // SyntaxError: Object literal may not have data and accessor property with
+  //              the same name
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Iteration order of keys over an object which contains spread syntax in later
+  versions of Chrome and Node.js may be altered.
+- When `toplevel` is enabled, UglifyJS effectively assumes input code is wrapped
+  within `function(){ ... }`, thus forbids aliasing of declared global variables:
+  ```javascript
+  A = "FAIL";
+  var B = "FAIL";
+  // can be `global`, `self`, `window` etc.
+  var top = function() {
+      return this;
+  }();
+  // "PASS"
+  top.A = "PASS";
+  console.log(A);
+  // "FAIL" after compress and/or mangle
+  top.B = "PASS";
+  console.log(B);
+  ```
+- Use of `arguments` alongside destructuring as function parameters, e.g.
+  `function({}, arguments) {}` will result in `SyntaxError` in earlier versions
+  of Chrome and Node.js - UglifyJS may modify the input which in turn may
+  suppress those errors.
+- Earlier versions of Chrome and Node.js will throw `ReferenceError` with the
+  following:
+  ```javascript
+  var a;
+  try {
+      throw 42;
+  } catch ({
+      [a]: b,
+      // ReferenceError: a is not defined
+  }) {
+      let a;
+  }
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  a => {
+      let a;
+  };
+  // SyntaxError: Identifier 'a' has already been declared
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  try {
+      // ...
+  } catch ({ message: a }) {
+      var a;
+  }
+  // SyntaxError: Identifier 'a' has already been declared
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of Chrome and Node.js will throw `ReferenceError` with the
+  following:
+  ```javascript
+  console.log(((a, b = function() {
+      return a;
+      // ReferenceError: a is not defined
+  }()) => b)());
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some arithmetic operations with `BigInt` may throw `TypeError`:
+  ```javascript
+  1n + 1;
+  // TypeError: can't convert BigInt to number
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of JavaScript will throw `SyntaxError` with the
+  following:
+  ```javascript
+  console.log(String.raw`\uFo`);
+  // SyntaxError: Invalid Unicode escape sequence
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of JavaScript will throw `SyntaxError` with the
+  following:
+  ```javascript
+  try {} catch (e) {
+      for (var e of []);
+  }
+  // SyntaxError: Identifier 'e' has already been declared
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of Chrome and Node.js will give incorrect results with the
+  following:
+  ```javascript
+  console.log({
+      ...{
+          set 42(v) {},
+          42: "PASS",
+      },
+  });
+  // Expected: { '42': 'PASS' }
+  // Actual:   { '42': undefined }
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  var await;
+  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.
+- Some versions of Chrome and Node.js will give incorrect results with the
+  following:
+  ```javascript
+  console.log({
+      ...console,
+      get 42() {
+          return "FAIL";
+      },
+      [42]: "PASS",
+  }[42], {
+      ...console,
+      get 42() {
+          return "FAIL";
+      },
+      42: "PASS",
+  }[42]);
+  // Expected: "PASS PASS"
+  // Actual:   "PASS FAIL"
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Earlier versions of JavaScript will throw `TypeError` with the following:
+  ```javascript
+  (function() {
+      {
+          const a = "foo";
+      }
+      {
+          const a = "bar";
+      }
+  })();
+  // TypeError: const 'a' has already been declared
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of Chrome and Node.js will give incorrect results with the
+  following:
+  ```javascript
+  try {
+      class A {
+          static 42;
+          static get 42() {}
+      }
+      console.log("PASS");
+  } catch (e) {
+      console.log("FAIL");
+  }
+  // Expected: "PASS"
+  // Actual:   "FAIL"
+  ```
+  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
+  (async function(a) {
+      (function() {
+          var b = await => console.log("PASS");
+          b();
+      })();
+  })().catch(console.error);
+  // Expected: "PASS"
+  // Actual:   SyntaxError: Unexpected reserved word
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of Chrome and Node.js will give incorrect results with the
+  following:
+  ```javascript
+  try {
+      f();
+      function f() {
+          throw 42;
+      }
+  } catch (e) {
+      console.log(typeof f, e);
+  }
+  // Expected: "function 42"
+  // Actual:   "undefined 42"
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  "use strict";
+  console.log(function f() {
+      return f = "PASS";
+  }());
+  // Expected: "PASS"
+  // Actual:   TypeError: invalid assignment to const 'f'
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Adobe ExtendScript will give incorrect results with the following:
+  ```javascript
+  alert(true ? "PASS" : false ? "FAIL" : null);
+  // Expected: "PASS"
+  // Actual:   "FAIL"
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Adobe ExtendScript will give incorrect results with the following:
+  ```javascript
+  alert(42 ? null ? "FAIL" : "PASS" : "FAIL");
+  // Expected: "PASS"
+  // Actual:   SyntaxError: Expected: :
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.

appveyor.yml

@@ -1,25 +0,0 @@
-environment:
-  UGLIFYJS_TEST_ALL: 1
-  matrix:
-    - NODEJS_VER: node/0.10
-    - NODEJS_VER: node/0.12
-    - NODEJS_VER: node/4
-    - NODEJS_VER: node/6
-    - NODEJS_VER: node/8
-    - NODEJS_VER: node/latest
-install:
-  - git clone --branch v1.4.2 --depth 1 https://github.com/jasongin/nvs.git %LOCALAPPDATA%\nvs
-  - set PATH=%LOCALAPPDATA%\nvs;%PATH%
-  - nvs --version
-  - nvs add %NODEJS_VER%
-  - nvs use %NODEJS_VER%
-  - node --version
-  - npm --version --no-update-notifier
-  - npm install --no-optional --no-save --no-update-notifier
-build: off
-cache:
-  - tmp
-matrix:
-  fast_finish: true
-test_script:
-  - npm test --no-update-notifier

bin/uglifyjs

@@ -3,168 +3,302 @@
 
 "use strict";
 
-require("../tools/exit");
+require("../tools/tty");
 
 var fs = require("fs");
 var info = require("../package.json");
 var path = require("path");
-var program = require("commander");
 var UglifyJS = require("../tools/node");
 
-var skip_keys = [ "cname", "inlined", "parent_scope", "scope", "uses_eval", "uses_with" ];
+var skip_keys = [ "cname", "fixed", "in_arg", "inlined", "length_read", "parent_scope", "redef", "scope", "unused" ];
+var truthy_keys = [ "optional", "pure", "terminal", "uses_arguments", "uses_eval", "uses_with" ];
+
 var files = {};
-var options = {
-    compress: false,
-    mangle: false
+var options = {};
+var short_forms = {
+    b: "beautify",
+    c: "compress",
+    d: "define",
+    e: "enclose",
+    h: "help",
+    m: "mangle",
+    o: "output",
+    O: "output-opts",
+    p: "parse",
+    v: "version",
+    V: "version",
 };
-program.version(info.name + " " + info.version);
-program.parseArgv = program.parse;
-program.parse = undefined;
-if (process.argv.indexOf("ast") >= 0) program.helpInformation = UglifyJS.describe_ast;
-else if (process.argv.indexOf("options") >= 0) program.helpInformation = function() {
-    var text = [];
-    var options = UglifyJS.default_options();
-    for (var option in options) {
-        text.push("--" + (option == "output" ? "beautify" : option == "sourceMap" ? "source-map" : option) + " options:");
-        text.push(format_object(options[option]));
-        text.push("");
-    }
-    return text.join("\n");
-};
-program.option("-p, --parse <options>", "Specify parser options.", parse_js());
-program.option("-c, --compress [options]", "Enable compressor/specify compressor options.", parse_js());
-program.option("-m, --mangle [options]", "Mangle names/specify mangler options.", parse_js());
-program.option("--mangle-props [options]", "Mangle properties/specify mangler options.", parse_js());
-program.option("-b, --beautify [options]", "Beautify output/specify output options.", parse_js());
-program.option("-o, --output <file>", "Output file (default STDOUT).");
-program.option("--comments [filter]", "Preserve copyright comments in the output.");
-program.option("--config-file <file>", "Read minify() options from JSON file.");
-program.option("-d, --define <expr>[=value]", "Global definitions.", parse_js("define"));
-program.option("-e, --enclose [arg[,...][:value[,...]]]", "Embed everything in a big function, with configurable argument(s) & value(s).");
-program.option("--ie8", "Support non-standard Internet Explorer 8.");
-program.option("--keep-fnames", "Do not mangle/drop function names. Useful for code relying on Function.prototype.name.");
-program.option("--name-cache <file>", "File to hold mangled name mappings.");
-program.option("--rename", "Force symbol expansion.");
-program.option("--no-rename", "Disable symbol expansion.");
-program.option("--self", "Build UglifyJS as a library (implies --wrap UglifyJS)");
-program.option("--source-map [options]", "Enable source map/specify source map options.", parse_js());
-program.option("--timings", "Display operations run time on STDERR.");
-program.option("--toplevel", "Compress and/or mangle variables in toplevel scope.");
-program.option("--verbose", "Print diagnostic messages.");
-program.option("--warn", "Print warning messages.");
-program.option("--wrap <name>", "Embed everything as a function with “exports” corresponding to “name” globally.");
-program.arguments("[files...]").parseArgv(process.argv);
-if (program.configFile) {
-    options = JSON.parse(read_file(program.configFile));
+var args = process.argv.slice(2);
+var paths = [];
+var output, nameCache;
+var specified = {};
+while (args.length) {
+    var arg = args.shift();
+    if (arg[0] != "-") {
+        paths.push(arg);
+    } else if (arg == "--") {
+        paths = paths.concat(args);
+        break;
+    } else if (arg[1] == "-") {
+        process_option(arg.slice(2));
+    } else [].forEach.call(arg.slice(1), function(letter, index, arg) {
+        if (!(letter in short_forms)) fatal("invalid option -" + letter);
+        process_option(short_forms[letter], index + 1 < arg.length);
+    });
 }
-if (!program.output && program.sourceMap && program.sourceMap.url != "inline") {
-    fatal("ERROR: cannot write source map to STDOUT");
-}
-[
-    "compress",
-    "enclose",
-    "ie8",
-    "mangle",
-    "sourceMap",
-    "toplevel",
-    "wrap"
-].forEach(function(name) {
-    if (name in program) {
-        options[name] = program[name];
+
+function process_option(name, no_value) {
+    specified[name] = true;
+    switch (name) {
+      case "help":
+        switch (read_value()) {
+          case "ast":
+            print(UglifyJS.describe_ast());
+            break;
+          case "options":
+            var text = [];
+            var toplevels = [];
+            var padding = "";
+            var defaults = UglifyJS.default_options();
+            for (var name in defaults) {
+                var option = defaults[name];
+                if (option && typeof option == "object") {
+                    text.push("--" + ({
+                        output: "beautify",
+                        sourceMap: "source-map",
+                    }[name] || name) + " options:");
+                    text.push(format_object(option));
+                    text.push("");
+                } else {
+                    if (padding.length < name.length) padding = Array(name.length + 1).join(" ");
+                    toplevels.push([ {
+                        keep_fargs: "keep-fargs",
+                        keep_fnames: "keep-fnames",
+                        nameCache: "name-cache",
+                    }[name] || name, option ]);
+                }
+            }
+            toplevels.forEach(function(tokens) {
+                text.push("--" + tokens[0] + padding.slice(tokens[0].length - 2) + tokens[1]);
+            });
+            print(text.join("\n"));
+            break;
+          default:
+            print([
+                "Usage: uglifyjs [files...] [options]",
+                "",
+                "Options:",
+                "  -h, --help                               Print usage information.",
+                "                                           `--help options` for details on available options.",
+                "  -v, -V, --version                        Print version number.",
+                "  -p, --parse <options>                    Specify parser options.",
+                "  -c, --compress [options]                 Enable compressor/specify compressor options.",
+                "  -m, --mangle [options]                   Mangle names/specify mangler options.",
+                "  --mangle-props [options]                 Mangle properties/specify mangler options.",
+                "  -b, --beautify [options]                 Beautify output/specify output options.",
+                "  -O, --output-opts <options>              Output options (beautify disabled).",
+                "  -o, --output <file>                      Output file (default STDOUT).",
+                "  --annotations                            Process and preserve comment annotations.",
+                "  --no-annotations                         Ignore and discard comment annotations.",
+                "  --comments [filter]                      Preserve copyright comments in the output.",
+                "  --config-file <file>                     Read minify() options from JSON file.",
+                "  -d, --define <expr>[=value]              Global definitions.",
+                "  -e, --enclose [arg[,...][:value[,...]]]  Embed everything in a big function, with configurable argument(s) & value(s).",
+                "  --expression                             Parse a single expression, rather than a program.",
+                "  --ie                                     Support non-standard Internet Explorer.",
+                "  --keep-fargs                             Do not mangle/drop function arguments.",
+                "  --keep-fnames                            Do not mangle/drop function names. Useful for code relying on Function.prototype.name.",
+                "  --module                                 Process input as ES module (implies --toplevel)",
+                "  --name-cache <file>                      File to hold mangled name mappings.",
+                "  --rename                                 Force symbol expansion.",
+                "  --no-rename                              Disable symbol expansion.",
+                "  --self                                   Build UglifyJS as a library (implies --wrap UglifyJS)",
+                "  --source-map [options]                   Enable source map/specify source map options.",
+                "  --timings                                Display operations run time on STDERR.",
+                "  --toplevel                               Compress and/or mangle variables in toplevel scope.",
+                "  --v8                                     Support non-standard Chrome & Node.js.",
+                "  --validate                               Perform validation during AST manipulations.",
+                "  --verbose                                Print diagnostic messages.",
+                "  --warn                                   Print warning messages.",
+                "  --webkit                                 Support non-standard Safari/Webkit.",
+                "  --wrap <name>                            Embed everything as a function with “exports” corresponding to “name” globally.",
+                "",
+                "(internal debug use only)",
+                "  --in-situ                                Warning: replaces original source files with minified output.",
+                "  --reduce-test                            Reduce a standalone test case (assumes cloned repository).",
+            ].join("\n"));
+        }
+        process.exit();
+      case "version":
+        print(info.name + " " + info.version);
+        process.exit();
+      case "config-file":
+        var config = JSON.parse(read_file(read_value(true)));
+        if (config.mangle && config.mangle.properties && config.mangle.properties.regex) {
+            config.mangle.properties.regex = UglifyJS.parse(config.mangle.properties.regex, {
+                expression: true,
+            }).value;
+        }
+        for (var key in config) if (!(key in options)) options[key] = config[key];
+        break;
+      case "compress":
+      case "mangle":
+        options[name] = parse_js(read_value(), options[name]);
+        break;
+      case "source-map":
+        options.sourceMap = parse_js(read_value(), options.sourceMap);
+        break;
+      case "enclose":
+        options[name] = read_value();
+        break;
+      case "annotations":
+      case "expression":
+      case "ie":
+      case "ie8":
+      case "module":
+      case "timings":
+      case "toplevel":
+      case "v8":
+      case "validate":
+      case "webkit":
+        options[name] = true;
+        break;
+      case "no-annotations":
+        options.annotations = false;
+        break;
+      case "keep-fargs":
+        options.keep_fargs = true;
+        break;
+      case "keep-fnames":
+        options.keep_fnames = true;
+        break;
+      case "wrap":
+        options[name] = read_value(true);
+        break;
+      case "verbose":
+        options.warnings = "verbose";
+        break;
+      case "warn":
+        if (!options.warnings) options.warnings = true;
+        break;
+      case "beautify":
+        options.output = parse_js(read_value(), options.output);
+        if (!("beautify" in options.output)) options.output.beautify = true;
+        break;
+      case "output-opts":
+        options.output = parse_js(read_value(true), options.output);
+        break;
+      case "comments":
+        if (typeof options.output != "object") options.output = {};
+        options.output.comments = read_value();
+        if (options.output.comments === true) options.output.comments = "some";
+        break;
+      case "define":
+        if (typeof options.compress != "object") options.compress = {};
+        options.compress.global_defs = parse_js(read_value(true), options.compress.global_defs, "define");
+        break;
+      case "mangle-props":
+        if (typeof options.mangle != "object") options.mangle = {};
+        options.mangle.properties = parse_js(read_value(), options.mangle.properties);
+        break;
+      case "name-cache":
+        nameCache = read_value(true);
+        options.nameCache = JSON.parse(read_file(nameCache, "{}"));
+        break;
+      case "output":
+        output = read_value(true);
+        break;
+      case "parse":
+        options.parse = parse_js(read_value(true), options.parse);
+        break;
+      case "rename":
+        options.rename = true;
+        break;
+      case "no-rename":
+        options.rename = false;
+        break;
+      case "in-situ":
+      case "reduce-test":
+      case "self":
+        break;
+      default:
+        fatal("invalid option --" + name);
     }
+
+    function read_value(required) {
+        if (no_value || !args.length || args[0][0] == "-") {
+            if (required) fatal("missing option argument for --" + name);
+            return true;
+        }
+        return args.shift();
+    }
+}
+if (!output && options.sourceMap && options.sourceMap.url != "inline") fatal("cannot write source map to STDOUT");
+if (specified["beautify"] && specified["output-opts"]) fatal("--beautify cannot be used with --output-opts");
+[ "compress", "mangle" ].forEach(function(name) {
+    if (!(name in options)) options[name] = false;
 });
-if (program.beautify) {
-    options.output = typeof program.beautify == "object" ? program.beautify : {};
-    if (!("beautify" in options.output)) {
-        options.output.beautify = true;
-    }
-}
-if (program.comments) {
+if (/^ast|spidermonkey$/.test(output)) {
     if (typeof options.output != "object") options.output = {};
-    options.output.comments = typeof program.comments == "string" ? program.comments : "some";
+    options.output.ast = true;
+    options.output.code = false;
 }
-if (program.define) {
-    if (typeof options.compress != "object") options.compress = {};
-    if (typeof options.compress.global_defs != "object") options.compress.global_defs = {};
-    for (var expr in program.define) {
-        options.compress.global_defs[expr] = program.define[expr];
-    }
+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");
 }
-if (program.keepFnames) {
-    options.keep_fnames = true;
-}
-if (program.mangleProps) {
-    if (program.mangleProps.domprops) {
-        delete program.mangleProps.domprops;
-    } else {
-        if (typeof program.mangleProps != "object") program.mangleProps = {};
-        if (!Array.isArray(program.mangleProps.reserved)) program.mangleProps.reserved = [];
-        require("../tools/domprops").forEach(function(name) {
-            UglifyJS._push_uniq(program.mangleProps.reserved, name);
-        });
-    }
-    if (typeof options.mangle != "object") options.mangle = {};
-    options.mangle.properties = program.mangleProps;
-}
-if (program.nameCache) {
-    options.nameCache = JSON.parse(read_file(program.nameCache, "{}"));
-}
-if (program.output == "ast") {
-    options.output = {
-        ast: true,
-        code: false
-    };
-}
-if (program.parse) {
-    if (!program.parse.acorn && !program.parse.spidermonkey) {
-        options.parse = program.parse;
-    } else if (program.sourceMap && program.sourceMap.content == "inline") {
-        fatal("ERROR: inline source map only works with built-in parser");
-    }
-}
-if (~program.rawArgs.indexOf("--rename")) {
-    options.rename = true;
-} else if (!program.rename) {
-    options.rename = false;
+if (options.warnings) {
+    UglifyJS.AST_Node.log_function(print_error, options.warnings == "verbose");
+    delete options.warnings;
 }
 var convert_path = function(name) {
     return name;
 };
-if (typeof program.sourceMap == "object" && "base" in program.sourceMap) {
+if (typeof options.sourceMap == "object" && "base" in options.sourceMap) {
     convert_path = function() {
-        var base = program.sourceMap.base;
+        var base = options.sourceMap.base;
         delete options.sourceMap.base;
         return function(name) {
             return path.relative(base, name);
         };
     }();
 }
-if (program.verbose) {
-    options.warnings = "verbose";
-} else if (program.warn) {
-    options.warnings = true;
-}
-if (program.self) {
-    if (program.args.length) {
-        print_error("WARN: Ignoring input files since --self was passed");
-    }
+if (specified["self"]) {
+    if (paths.length) UglifyJS.AST_Node.warn("Ignoring input files since --self was passed");
     if (!options.wrap) options.wrap = "UglifyJS";
-    simple_glob(UglifyJS.FILES).forEach(function(name) {
+    paths = UglifyJS.FILES;
+} else if (paths.length) {
+    paths = simple_glob(paths);
+}
+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();
     });
-    run();
-} else if (program.args.length) {
-    simple_glob(program.args).forEach(function(name) {
+} else if (paths.length) {
+    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();
@@ -175,26 +309,54 @@ function convert_ast(fn) {
 }
 
 function run() {
-    UglifyJS.AST_Node.warn_function = function(msg) {
-        print_error("WARN: " + msg);
-    };
-    var content = program.sourceMap && program.sourceMap.content;
+    var content = options.sourceMap && options.sourceMap.content;
     if (content && content != "inline") {
-        print_error("INFO: Using input source map: " + content);
+        UglifyJS.AST_Node.info("Using input source map: {content}", {
+            content : content,
+        });
         options.sourceMap.content = read_file(content, content);
     }
-    if (program.timings) options.timings = true;
     try {
-        if (program.parse) {
-            if (program.parse.acorn) {
+        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",
                     });
                 });
-            } else if (program.parse.spidermonkey) {
+                files.walk(new UglifyJS.TreeWalker(function(node) {
+                    if (!(node instanceof UglifyJS.AST_Call)) return;
+                    var list = annotations[node.start.file];
+                    var pure = list[node.start.pos];
+                    if (!pure) {
+                        var tokens = node.start.parens;
+                        if (tokens) for (var i = 0; !pure && i < tokens.length; i++) {
+                            pure = list[tokens[i].pos];
+                        }
+                    }
+                    if (pure) node.pure = pure;
+                }));
+            } else if (options.parse.spidermonkey) {
                 files = convert_ast(function(toplevel, name) {
                     var obj = JSON.parse(files[name]);
                     if (!toplevel) return obj;
@@ -206,49 +368,71 @@ function run() {
     } catch (ex) {
         fatal(ex);
     }
-    var result = UglifyJS.minify(files, options);
+    var result;
+    if (specified["reduce-test"]) {
+        // load on demand - assumes cloned repository
+        var reduce_test = require("../test/reduce");
+        if (Object.keys(files).length != 1) fatal("can only test on a single file");
+        result = reduce_test(files[Object.keys(files)[0]], options, {
+            log: print_error,
+            verbose: true,
+        });
+    } else {
+        result = UglifyJS.minify(files, options);
+    }
     if (result.error) {
         var ex = result.error;
         if (ex.name == "SyntaxError") {
             print_error("Parse error at " + ex.filename + ":" + ex.line + "," + ex.col);
-            var col = ex.col;
-            var lines = files[ex.filename].split(/\r?\n/);
-            var line = lines[ex.line - 1];
-            if (!line && !col) {
-                line = lines[ex.line - 2];
-                col = line.length;
-            }
-            if (line) {
-                var limit = 70;
-                if (col > limit) {
-                    line = line.slice(col - limit);
-                    col = limit;
+            var file = files[ex.filename];
+            if (file) {
+                var col = ex.col;
+                var lines = file.split(/\r?\n/);
+                var line = lines[ex.line - 1];
+                if (!line && !col) {
+                    line = lines[ex.line - 2];
+                    col = line.length;
+                }
+                if (line) {
+                    var limit = 70;
+                    if (col > limit) {
+                        line = line.slice(col - limit);
+                        col = limit;
+                    }
+                    print_error(line.slice(0, 80));
+                    print_error(line.slice(0, col).replace(/\S/g, " ") + "^");
                 }
-                print_error(line.slice(0, 80));
-                print_error(line.slice(0, col).replace(/\S/g, " ") + "^");
             }
-        }
-        if (ex.defs) {
+        } else if (ex.defs) {
             print_error("Supported options:");
             print_error(format_object(ex.defs));
         }
         fatal(ex);
-    } else if (program.output == "ast") {
+    } else if (output == "ast") {
         if (!options.compress && !options.mangle) {
-            result.ast.figure_out_scope({});
+            var toplevel = result.ast;
+            if (!(toplevel instanceof UglifyJS.AST_Toplevel)) {
+                if (!(toplevel instanceof UglifyJS.AST_Statement)) toplevel = new UglifyJS.AST_SimpleStatement({
+                    body: toplevel,
+                });
+                toplevel = new UglifyJS.AST_Toplevel({
+                    body: [ toplevel ],
+                });
+            }
+            toplevel.figure_out_scope({});
         }
         print(JSON.stringify(result.ast, function(key, value) {
             if (value) switch (key) {
-              case "thedef":
-                return symdef(value);
               case "enclosed":
                 return value.length ? value.map(symdef) : undefined;
-              case "variables":
               case "functions":
               case "globals":
+              case "variables":
                 return value.size() ? value.map(symdef) : undefined;
+              case "thedef":
+                return symdef(value);
             }
-            if (skip_key(key)) return;
+            if (skip_property(key, value)) return;
             if (value instanceof UglifyJS.AST_Token) return;
             if (value instanceof UglifyJS.Dictionary) return;
             if (value instanceof UglifyJS.AST_Node) {
@@ -262,66 +446,78 @@ function run() {
             }
             return value;
         }, 2));
-    } else if (program.output == "spidermonkey") {
-        print(JSON.stringify(UglifyJS.minify(result.code, {
-            compress: false,
-            mangle: false,
-            output: {
-                ast: true,
-                code: false
+    } else if (output == "spidermonkey") {
+        print(JSON.stringify(result.ast.to_mozilla_ast(), null, 2));
+    } else if (output) {
+        var code;
+        if (result.ast) {
+            var opts = {};
+            for (var name in options.output) {
+                if (!/^ast|code$/.test(name)) opts[name] = options.output[name];
             }
-        }).ast.to_mozilla_ast(), null, 2));
-    } else if (program.output) {
-        fs.writeFileSync(program.output, result.code);
-        if (result.map) {
-            fs.writeFileSync(program.output + ".map", result.map);
+            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);
     }
-    if (program.nameCache) {
-        fs.writeFileSync(program.nameCache, JSON.stringify(options.nameCache));
-    }
+    if (nameCache) fs.writeFileSync(nameCache, JSON.stringify(options.nameCache));
     if (result.timings) for (var phase in result.timings) {
         print_error("- " + phase + ": " + result.timings[phase].toFixed(3) + "s");
     }
 }
 
 function fatal(message) {
-    if (message instanceof Error) message = message.stack.replace(/^\S*?Error:/, "ERROR:")
+    if (message instanceof Error) {
+        message = message.stack.replace(/^\S*?Error:/, "ERROR:")
+    } else {
+        message = "ERROR: " + message;
+    }
     print_error(message);
     process.exit(1);
 }
 
 // A file glob function that only supports "*" and "?" wildcards in the basename.
 // Example: "foo/bar/*baz??.*.js"
-// Argument `glob` may be a string or an array of strings.
+// Argument `paths` must be an array of strings.
 // Returns an array of strings. Garbage in, garbage out.
-function simple_glob(glob) {
-    if (Array.isArray(glob)) {
-        return [].concat.apply([], glob.map(simple_glob));
-    }
-    if (glob.match(/\*|\?/)) {
-        var dir = path.dirname(glob);
-        try {
-            var entries = fs.readdirSync(dir);
-        } catch (ex) {}
-        if (entries) {
-            var pattern = "^" + path.basename(glob)
-                .replace(/[.+^$[\]\\(){}]/g, "\\$&")
-                .replace(/\*/g, "[^/\\\\]*")
-                .replace(/\?/g, "[^/\\\\]") + "$";
-            var mod = process.platform === "win32" ? "i" : "";
-            var rx = new RegExp(pattern, mod);
-            var results = entries.filter(function(name) {
-                return rx.test(name);
-            }).map(function(name) {
-                return path.join(dir, name);
-            });
-            if (results.length) return results;
+function simple_glob(paths) {
+    return paths.reduce(function(paths, glob) {
+        if (/\*|\?/.test(glob)) {
+            var dir = path.dirname(glob);
+            try {
+                var entries = fs.readdirSync(dir).filter(function(name) {
+                    try {
+                        return fs.statSync(path.join(dir, name)).isFile();
+                    } catch (ex) {
+                        return false;
+                    }
+                });
+            } catch (ex) {}
+            if (entries) {
+                var pattern = "^" + path.basename(glob)
+                    .replace(/[.+^$[\]\\(){}]/g, "\\$&")
+                    .replace(/\*/g, "[^/\\\\]*")
+                    .replace(/\?/g, "[^/\\\\]") + "$";
+                var mod = process.platform === "win32" ? "i" : "";
+                var rx = new RegExp(pattern, mod);
+                var results = entries.filter(function(name) {
+                    return rx.test(name);
+                }).sort().map(function(name) {
+                    return path.join(dir, name);
+                });
+                if (results.length) {
+                    [].push.apply(paths, results);
+                    return paths;
+                }
+            }
         }
-    }
-    return [ glob ];
+        paths.push(glob);
+        return paths;
+    }, []);
 }
 
 function read_file(path, default_value) {
@@ -333,59 +529,51 @@ function read_file(path, default_value) {
     }
 }
 
-function parse_js(flag) {
-    return function(value, options) {
-        options = options || {};
-        try {
-            UglifyJS.minify(value, {
-                parse: {
-                    expression: true
-                },
-                compress: false,
-                mangle: false,
-                output: {
-                    ast: true,
-                    code: false
+function parse_js(value, options, flag) {
+    if (!options || typeof options != "object") options = Object.create(null);
+    if (typeof value == "string") try {
+        UglifyJS.parse(value, {
+            expression: true
+        }).walk(new UglifyJS.TreeWalker(function(node) {
+            if (node instanceof UglifyJS.AST_Assign) {
+                var name = node.left.print_to_string();
+                var value = node.right;
+                if (flag) {
+                    options[name] = value;
+                } else if (value instanceof UglifyJS.AST_Array) {
+                    options[name] = value.elements.map(to_string);
+                } else {
+                    options[name] = to_string(value);
                 }
-            }).ast.walk(new UglifyJS.TreeWalker(function(node) {
-                if (node instanceof UglifyJS.AST_Assign) {
-                    var name = node.left.print_to_string();
-                    var value = node.right;
-                    if (flag) {
-                        options[name] = value;
-                    } else if (value instanceof UglifyJS.AST_Array) {
-                        options[name] = value.elements.map(to_string);
-                    } else {
-                        options[name] = to_string(value);
-                    }
-                    return true;
-                }
-                if (node instanceof UglifyJS.AST_Symbol || node instanceof UglifyJS.AST_PropAccess) {
-                    var name = node.print_to_string();
-                    options[name] = true;
-                    return true;
-                }
-                if (!(node instanceof UglifyJS.AST_Sequence)) throw node;
-
-                function to_string(value) {
-                    return value instanceof UglifyJS.AST_Constant ? value.getValue() : value.print_to_string({
-                        quote_keys: true
-                    });
-                }
-            }));
-        } catch(ex) {
-            if (flag) {
-                fatal("Error parsing arguments for '" + flag + "': " + value);
-            } else {
-                options[value] = null;
+                return true;
             }
+            if (node instanceof UglifyJS.AST_Symbol || node instanceof UglifyJS.AST_PropAccess) {
+                var name = node.print_to_string();
+                options[name] = true;
+                return true;
+            }
+            if (!(node instanceof UglifyJS.AST_Sequence)) throw node;
+
+            function to_string(value) {
+                return value instanceof UglifyJS.AST_Constant ? value.value : value.print_to_string({
+                    quote_keys: true
+                });
+            }
+        }));
+    } catch (ex) {
+        if (flag) {
+            fatal("cannot parse arguments for '" + flag + "': " + value);
+        } else {
+            options[value] = null;
         }
-        return options;
     }
+    return options;
 }
 
-function skip_key(key) {
-    return skip_keys.indexOf(key) >= 0;
+function skip_property(key, value) {
+    return skip_keys.indexOf(key) >= 0
+        // only skip truthy_keys if their value is falsy
+        || truthy_keys.indexOf(key) >= 0 && !value;
 }
 
 function symdef(def) {

lib/minify.js

@@ -1,19 +1,41 @@
 "use strict";
 
-var to_ascii = typeof atob == "undefined" ? function(b64) {
-    return new Buffer(b64, "base64").toString();
-} : atob;
-var to_base64 = typeof btoa == "undefined" ? function(str) {
-    return new Buffer(str).toString("base64");
-} : btoa;
+var to_ascii, to_base64;
+if (typeof Buffer == "undefined") {
+    to_ascii = atob;
+    to_base64 = btoa;
+} else if (typeof Buffer.alloc == "undefined") {
+    to_ascii = function(b64) {
+        return new Buffer(b64, "base64").toString();
+    };
+    to_base64 = function(str) {
+        return new Buffer(str).toString("base64");
+    };
+} else {
+    to_ascii = function(b64) {
+        return Buffer.from(b64, "base64").toString();
+    };
+    to_base64 = function(str) {
+        return Buffer.from(str).toString("base64");
+    };
+}
 
-function read_source_map(name, code) {
-    var match = /\n\/\/# sourceMappingURL=data:application\/json(;.*?)?;base64,(.*)/.exec(code);
-    if (!match) {
-        AST_Node.warn("inline source map not found: " + name);
-        return null;
+function read_source_map(name, toplevel) {
+    var comments = toplevel.end.comments_after;
+    for (var i = comments.length; --i >= 0;) {
+        var comment = comments[i];
+        if (comment.type != "comment1") break;
+        var match = /^# ([^\s=]+)=(\S+)\s*$/.exec(comment.value);
+        if (!match) break;
+        if (match[1] == "sourceMappingURL") {
+            match = /^data:application\/json(;.*?)?;base64,([^,]+)$/.exec(match[2]);
+            if (!match) break;
+            return to_ascii(match[2]);
+        }
     }
-    return to_ascii(match[2]);
+    AST_Node.warn("inline source map not found: {name}", {
+        name: name,
+    });
 }
 
 function parse_source_map(content) {
@@ -25,14 +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) {
@@ -51,44 +71,56 @@ function to_json(cache) {
 }
 
 function minify(files, options) {
-    var warn_function = AST_Node.warn_function;
     try {
         options = defaults(options, {
+            annotations: undefined,
             compress: {},
             enclose: false,
+            expression: false,
+            ie: false,
             ie8: false,
+            keep_fargs: false,
             keep_fnames: false,
             mangle: {},
+            module: false,
             nameCache: null,
             output: {},
             parse: {},
             rename: undefined,
             sourceMap: false,
             timings: false,
-            toplevel: false,
+            toplevel: !!(options && options["module"]),
+            v8: false,
+            validate: false,
             warnings: false,
+            webkit: false,
             wrap: false,
         }, true);
-        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("warnings", options, [ "compress" ]);
+        if (options.validate) AST_Node.enable_validation();
+        var timings = options.timings && { start: Date.now() };
+        if (options.annotations !== undefined) set_shorthand("annotations", options, [ "compress", "output" ]);
+        if (options.expression) set_shorthand("expression", options, [ "compress", "parse" ]);
+        if (options.ie8) options.ie = options.ie || options.ie8;
+        if (options.ie) set_shorthand("ie", options, [ "compress", "mangle", "output", "rename" ]);
+        if (options.keep_fargs) set_shorthand("keep_fargs", options, [ "compress", "mangle", "rename" ]);
+        if (options.keep_fnames) set_shorthand("keep_fnames", options, [ "compress", "mangle", "rename" ]);
+        if (options.module) set_shorthand("module", options, [ "compress", "parse" ]);
+        if (options.toplevel) set_shorthand("toplevel", options, [ "compress", "mangle", "rename" ]);
+        if (options.v8) set_shorthand("v8", options, [ "mangle", "output", "rename" ]);
+        if (options.webkit) set_shorthand("webkit", options, [ "compress", "mangle", "output", "rename" ]);
         var quoted_props;
         if (options.mangle) {
             options.mangle = defaults(options.mangle, {
                 cache: options.nameCache && (options.nameCache.vars || {}),
                 eval: false,
-                ie8: false,
+                ie: false,
+                keep_fargs: false,
                 keep_fnames: false,
                 properties: false,
                 reserved: [],
                 toplevel: false,
+                v8: false,
+                webkit: false,
             }, true);
             if (options.mangle.properties) {
                 if (typeof options.mangle.properties != "object") {
@@ -106,68 +138,65 @@ function minify(files, options) {
             init_cache(options.mangle.cache);
             init_cache(options.mangle.properties.cache);
         }
+        if (options.rename === undefined) options.rename = options.compress && options.mangle;
         if (options.sourceMap) {
             options.sourceMap = defaults(options.sourceMap, {
                 content: null,
                 filename: null,
                 includeSources: false,
+                names: true,
                 root: null,
                 url: null,
             }, true);
         }
         var warnings = [];
-        if (options.warnings && !AST_Node.warn_function) {
-            AST_Node.warn_function = function(warning) {
-                warnings.push(warning);
-            };
-        }
+        if (options.warnings) AST_Node.log_function(function(warning) {
+            warnings.push(warning);
+        }, options.warnings == "verbose");
         if (timings) timings.parse = Date.now();
-        var source_maps, toplevel;
-        if (files instanceof AST_Toplevel) {
+        var toplevel;
+        options.parse = options.parse || {};
+        if (files instanceof AST_Node) {
             toplevel = files;
         } else {
-            if (typeof files == "string") {
-                files = [ files ];
-            }
-            options.parse = options.parse || {};
+            if (typeof files == "string") files = [ files ];
             options.parse.toplevel = null;
             var source_map_content = options.sourceMap && options.sourceMap.content;
             if (typeof source_map_content == "string" && source_map_content != "inline") {
                 source_map_content = parse_source_map(source_map_content);
             }
-            source_maps = source_map_content && Object.create(null);
+            if (source_map_content) options.sourceMap.orig = Object.create(null);
             for (var name in files) if (HOP(files, name)) {
                 options.parse.filename = name;
-                options.parse.toplevel = parse(files[name], options.parse);
-                if (source_maps) {
-                    if (source_map_content == "inline") {
-                        var inlined_content = read_source_map(name, files[name]);
-                        if (inlined_content) {
-                            source_maps[name] = parse_source_map(inlined_content);
-                        }
-                    } else {
-                        source_maps[name] = source_map_content;
-                    }
+                options.parse.toplevel = toplevel = parse(files[name], options.parse);
+                if (source_map_content == "inline") {
+                    var inlined_content = read_source_map(name, toplevel);
+                    if (inlined_content) options.sourceMap.orig[name] = parse_source_map(inlined_content);
+                } else if (source_map_content) {
+                    options.sourceMap.orig[name] = source_map_content;
                 }
             }
-            toplevel = options.parse.toplevel;
-        }
-        if (quoted_props) {
-            reserve_quoted_keys(toplevel, quoted_props);
-        }
-        if (options.wrap) {
-            toplevel = toplevel.wrap_commonjs(options.wrap);
-        }
-        if (options.enclose) {
-            toplevel = toplevel.wrap_enclose(options.enclose);
         }
+        if (options.parse.expression) toplevel = toplevel.wrap_expression();
+        if (quoted_props) reserve_quoted_keys(toplevel, quoted_props);
+        [ "enclose", "wrap" ].forEach(function(action) {
+            var option = options[action];
+            if (!option) return;
+            var orig = toplevel.print_to_string().slice(0, -1);
+            toplevel = toplevel[action](option);
+            files[toplevel.start.file] = toplevel.print_to_string().replace(orig, "");
+        });
+        if (options.validate) toplevel.validate_ast();
         if (timings) timings.rename = Date.now();
         if (options.rename) {
-            toplevel.figure_out_scope(options.mangle);
-            toplevel.expand_names(options.mangle);
+            toplevel.figure_out_scope(options.rename);
+            toplevel.expand_names(options.rename);
         }
         if (timings) timings.compress = Date.now();
-        if (options.compress) toplevel = new Compressor(options.compress).compress(toplevel);
+        if (options.compress) {
+            toplevel = new Compressor(options.compress).compress(toplevel);
+            if (options.validate) toplevel.validate_ast();
+        }
         if (timings) timings.scope = Date.now();
         if (options.mangle) toplevel.figure_out_scope(options.mangle);
         if (timings) timings.mangle = Date.now();
@@ -176,42 +205,42 @@ function minify(files, options) {
             toplevel.mangle_names(options.mangle);
         }
         if (timings) timings.properties = Date.now();
-        if (options.mangle && options.mangle.properties) {
-            toplevel = mangle_properties(toplevel, options.mangle.properties);
-        }
+        if (quoted_props) reserve_quoted_keys(toplevel, quoted_props);
+        if (options.mangle && options.mangle.properties) mangle_properties(toplevel, options.mangle.properties);
+        if (options.parse.expression) toplevel = toplevel.unwrap_expression();
         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({
-                    file: options.sourceMap.filename,
-                    orig: source_maps,
-                    root: options.sourceMap.root
-                });
+                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.get().setSourceContent(name, files[name]);
+                        output.source_map.setSourceContent(name, files[name]);
                     }
-                } else {
-                    options.output.source_map.get()._sourcesContents = null;
                 }
             }
-            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();
-                if (options.sourceMap.url == "inline") {
-                    result.code += "\n//# sourceMappingURL=data:application/json;charset=utf-8;base64," + to_base64(result.map);
-                } else if (options.sourceMap.url) {
-                    result.code += "\n//# sourceMappingURL=" + options.sourceMap.url;
+                result.map = output.source_map.toString();
+                var url = options.sourceMap.url;
+                if (url) {
+                    result.code = result.code.replace(/\n\/\/# sourceMappingURL=\S+\s*$/, "");
+                    if (url == "inline") {
+                        result.code += "\n//# sourceMappingURL=data:application/json;charset=utf-8;base64," + to_base64(result.map);
+                    } else {
+                        result.code += "\n//# sourceMappingURL=" + url;
+                    }
                 }
             }
         }
@@ -232,7 +261,7 @@ function minify(files, options) {
                 properties: 1e-3 * (timings.output - timings.properties),
                 output: 1e-3 * (timings.end - timings.output),
                 total: 1e-3 * (timings.end - timings.start)
-            }
+            };
         }
         if (warnings.length) {
             result.warnings = warnings;
@@ -241,6 +270,7 @@ function minify(files, options) {
     } catch (ex) {
         return { error: ex };
     } finally {
-        AST_Node.warn_function = warn_function;
+        AST_Node.log_function();
+        AST_Node.disable_validation();
     }
 }

lib/propmangle.js

@@ -1,7 +1,7 @@
 /***********************************************************************
 
   A JavaScript tokenizer / parser / beautifier / compressor.
-  https://github.com/mishoo/UglifyJS2
+  https://github.com/mishoo/UglifyJS
 
   -------------------------------- (C) ---------------------------------
 
@@ -43,9 +43,11 @@
 
 "use strict";
 
-function find_builtins(reserved) {
-    // NaN will be included due to Number.NaN
+function get_builtins() {
+    var names = new Dictionary();
+    // constants
     [
+        "NaN",
         "null",
         "true",
         "false",
@@ -53,46 +55,104 @@ function find_builtins(reserved) {
         "-Infinity",
         "undefined",
     ].forEach(add);
-    [ Object, Array, Function, Number,
-      String, Boolean, Error, Math,
-      Date, RegExp
-    ].forEach(function(ctor) {
+    // global functions
+    [
+        "encodeURI",
+        "encodeURIComponent",
+        "escape",
+        "eval",
+        "decodeURI",
+        "decodeURIComponent",
+        "isFinite",
+        "isNaN",
+        "parseFloat",
+        "parseInt",
+        "unescape",
+    ].forEach(add);
+    // global constructors & objects
+    var global = Function("return this")();
+    [
+        "Array",
+        "ArrayBuffer",
+        "Atomics",
+        "BigInt",
+        "Boolean",
+        "console",
+        "DataView",
+        "Date",
+        "Error",
+        "Function",
+        "Int8Array",
+        "Intl",
+        "JSON",
+        "Map",
+        "Math",
+        "Number",
+        "Object",
+        "Promise",
+        "Proxy",
+        "Reflect",
+        "RegExp",
+        "Set",
+        "String",
+        "Symbol",
+        "WebAssembly",
+    ].forEach(function(name) {
+        add(name);
+        var ctor = global[name];
+        if (!ctor) return;
         Object.getOwnPropertyNames(ctor).map(add);
-        if (ctor.prototype) {
-            Object.getOwnPropertyNames(ctor.prototype).map(add);
+        if (typeof ctor != "function") return;
+        if (ctor.__proto__) Object.getOwnPropertyNames(ctor.__proto__).map(add);
+        if (ctor.prototype) Object.getOwnPropertyNames(ctor.prototype).map(add);
+        try {
+            Object.getOwnPropertyNames(new ctor()).map(add);
+        } catch (e) {
+            try {
+                Object.getOwnPropertyNames(ctor()).map(add);
+            } catch (e) {}
         }
     });
+    return (get_builtins = function() {
+        return names.clone();
+    })();
+
     function add(name) {
-        push_uniq(reserved, name);
+        names.set(name, true);
     }
 }
 
 function reserve_quoted_keys(ast, reserved) {
-    function add(name) {
-        push_uniq(reserved, name);
-    }
-
     ast.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_ObjectKeyVal && node.quote) {
-            add(node.key);
+        if (node instanceof AST_ClassProperty
+            || node instanceof AST_DestructuredKeyVal
+            || node instanceof AST_ObjectProperty) {
+            if (node.key instanceof AST_Node) {
+                addStrings(node.key, add);
+            } else if (node.start && node.start.quote) {
+                add(node.key);
+            }
+        } else if (node instanceof AST_Dot) {
+            if (node.quoted) add(node.property);
         } else if (node instanceof AST_Sub) {
             addStrings(node.property, add);
         }
     }));
+
+    function add(name) {
+        push_uniq(reserved, name);
+    }
 }
 
 function addStrings(node, add) {
-    node.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_Sequence) {
-            addStrings(node.tail_node(), add);
-        } else if (node instanceof AST_String) {
-            add(node.value);
-        } else if (node instanceof AST_Conditional) {
-            addStrings(node.consequent, add);
-            addStrings(node.alternative, add);
-        }
-        return true;
-    }));
+    if (node instanceof AST_Conditional) {
+        addStrings(node.consequent, add);
+        addStrings(node.alternative, add);
+    } else if (node instanceof AST_Sequence) {
+        addStrings(node.tail_node(), add);
+    } else if (node instanceof AST_String) {
+        add(node.value);
+    }
 }
 
 function mangle_properties(ast, options) {
@@ -100,22 +160,26 @@ function mangle_properties(ast, options) {
         builtins: false,
         cache: null,
         debug: false,
+        domprops: false,
         keep_quoted: false,
-        only_cache: false,
         regex: null,
         reserved: null,
     }, true);
 
-    var reserved = options.reserved;
-    if (!Array.isArray(reserved)) reserved = [];
-    if (!options.builtins) find_builtins(reserved);
+    var reserved = options.builtins ? new Dictionary() : get_builtins();
+    if (!options.domprops && typeof domprops !== "undefined") domprops.forEach(function(name) {
+        reserved.set(name, true);
+    });
+    if (Array.isArray(options.reserved)) options.reserved.forEach(function(name) {
+        reserved.set(name, true);
+    });
 
     var cname = -1;
     var cache;
     if (options.cache) {
         cache = options.cache.props;
-        cache.each(function(mangled_name) {
-            push_uniq(reserved, mangled_name);
+        cache.each(function(name) {
+            reserved.set(name, true);
         });
     } else {
         cache = new Dictionary();
@@ -124,129 +188,141 @@ function mangle_properties(ast, options) {
     var regex = options.regex;
 
     // note debug is either false (disabled), or a string of the debug suffix to use (enabled).
-    // note debug may be enabled as an empty string, which is falsey. Also treat passing 'true'
+    // note debug may be enabled as an empty string, which is falsy. Also treat passing 'true'
     // the same as passing an empty string.
     var debug = options.debug !== false;
-    var debug_name_suffix;
-    if (debug) {
-        debug_name_suffix = (options.debug === true ? "" : options.debug);
-    }
+    var debug_suffix;
+    if (debug) debug_suffix = options.debug === true ? "" : options.debug;
 
-    var names_to_mangle = [];
-    var unmangleable = [];
+    var names_to_mangle = new Dictionary();
+    var unmangleable = reserved.clone();
 
     // step 1: find candidates to mangle
     ast.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_ObjectKeyVal) {
-            add(node.key);
-        }
-        else if (node instanceof AST_ObjectProperty) {
-            // setter or getter, since KeyVal is handled above
-            add(node.key.name);
-        }
-        else if (node instanceof AST_Dot) {
-            add(node.property);
-        }
-        else if (node instanceof AST_Sub) {
-            addStrings(node.property, add);
-        }
-        else if (node instanceof AST_Call
-            && node.expression.print_to_string() == "Object.defineProperty") {
-            addStrings(node.args[1], add);
+        if (node.TYPE == "Call") {
+            var exp = node.expression;
+            if (exp instanceof AST_Dot) switch (exp.property) {
+              case "defineProperty":
+              case "getOwnPropertyDescriptor":
+                if (node.args.length < 2) break;
+                exp = exp.expression;
+                if (!(exp instanceof AST_SymbolRef)) break;
+                if (exp.name != "Object") break;
+                if (!exp.definition().undeclared) break;
+                addStrings(node.args[1], add);
+                break;
+              case "hasOwnProperty":
+                if (node.args.length < 1) break;
+                addStrings(node.args[0], add);
+                break;
+            }
+        } else if (node instanceof AST_ClassProperty
+            || node instanceof AST_DestructuredKeyVal
+            || node instanceof AST_ObjectProperty) {
+            if (node.key instanceof AST_Node) {
+                addStrings(node.key, add);
+            } else {
+                add(node.key);
+            }
+        } else if (node instanceof AST_Dot) {
+            if (is_lhs(node, this.parent())) add(node.property);
+        } else if (node instanceof AST_Sub) {
+            if (is_lhs(node, this.parent())) addStrings(node.property, add);
         }
     }));
 
-    // step 2: transform the tree, renaming properties
-    return ast.transform(new TreeTransformer(function(node) {
-        if (node instanceof AST_ObjectKeyVal) {
-            node.key = mangle(node.key);
-        }
-        else if (node instanceof AST_ObjectProperty) {
-            // setter or getter
-            node.key.name = mangle(node.key.name);
-        }
-        else if (node instanceof AST_Dot) {
+    // step 2: renaming properties
+    ast.walk(new TreeWalker(function(node) {
+        if (node instanceof AST_Binary) {
+            if (node.operator == "in") mangleStrings(node.left);
+        } else if (node.TYPE == "Call") {
+            var exp = node.expression;
+            if (exp instanceof AST_Dot) switch (exp.property) {
+              case "defineProperty":
+              case "getOwnPropertyDescriptor":
+                if (node.args.length < 2) break;
+                exp = exp.expression;
+                if (!(exp instanceof AST_SymbolRef)) break;
+                if (exp.name != "Object") break;
+                if (!exp.definition().undeclared) break;
+                mangleStrings(node.args[1]);
+                break;
+              case "hasOwnProperty":
+                if (node.args.length < 1) break;
+                mangleStrings(node.args[0]);
+                break;
+            }
+        } else if (node instanceof AST_ClassProperty
+            || node instanceof AST_DestructuredKeyVal
+            || node instanceof AST_ObjectProperty) {
+            if (node.key instanceof AST_Node) {
+                mangleStrings(node.key);
+            } else {
+                node.key = mangle(node.key);
+            }
+        } else if (node instanceof AST_Dot) {
             node.property = mangle(node.property);
-        }
-        else if (!options.keep_quoted && node instanceof AST_Sub) {
-            node.property = mangleStrings(node.property);
-        }
-        else if (node instanceof AST_Call
-            && node.expression.print_to_string() == "Object.defineProperty") {
-            node.args[1] = mangleStrings(node.args[1]);
+        } else if (node instanceof AST_Sub) {
+            if (!options.keep_quoted) mangleStrings(node.property);
         }
     }));
 
     // only function declarations after this line
 
     function can_mangle(name) {
-        if (unmangleable.indexOf(name) >= 0) return false;
-        if (reserved.indexOf(name) >= 0) return false;
-        if (options.only_cache) {
-            return cache.has(name);
-        }
+        if (unmangleable.has(name)) return false;
         if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
         return true;
     }
 
     function should_mangle(name) {
-        if (regex && !regex.test(name)) return false;
-        if (reserved.indexOf(name) >= 0) return false;
-        return cache.has(name)
-            || names_to_mangle.indexOf(name) >= 0;
+        if (reserved.has(name)) {
+            AST_Node.info("Preserving reserved property {this}", name);
+            return false;
+        }
+        if (regex && !regex.test(name)) {
+            AST_Node.info("Preserving excluded property {this}", name);
+            return false;
+        }
+        return cache.has(name) || names_to_mangle.has(name);
     }
 
     function add(name) {
-        if (can_mangle(name))
-            push_uniq(names_to_mangle, name);
-
-        if (!should_mangle(name)) {
-            push_uniq(unmangleable, name);
-        }
+        if (can_mangle(name)) names_to_mangle.set(name, true);
+        if (!should_mangle(name)) unmangleable.set(name, true);
     }
 
     function mangle(name) {
-        if (!should_mangle(name)) {
-            return name;
-        }
-
+        if (!should_mangle(name)) return name;
         var mangled = cache.get(name);
         if (!mangled) {
             if (debug) {
-                // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo -> o._$foo$NNN_.
-                var debug_mangled = "_$" + name + "$" + debug_name_suffix + "_";
-
-                if (can_mangle(debug_mangled)) {
-                    mangled = debug_mangled;
-                }
+                // 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;
             }
-
             // either debug mode is off, or it is on and we could not use the mangled name
-            if (!mangled) {
-                do {
-                    mangled = base54(++cname);
-                } while (!can_mangle(mangled));
-            }
-
+            if (!mangled) do {
+                mangled = base54(++cname);
+            } while (!can_mangle(mangled));
+            if (/^#/.test(name)) mangled = "#" + mangled;
             cache.set(name, mangled);
         }
+        AST_Node.info("Mapping property {name} to {mangled}", {
+            mangled: mangled,
+            name: name,
+        });
         return mangled;
     }
 
     function mangleStrings(node) {
-        return node.transform(new TreeTransformer(function(node) {
-            if (node instanceof AST_Sequence) {
-                var last = node.expressions.length - 1;
-                node.expressions[last] = mangleStrings(node.expressions[last]);
-            }
-            else if (node instanceof AST_String) {
-                node.value = mangle(node.value);
-            }
-            else if (node instanceof AST_Conditional) {
-                node.consequent = mangleStrings(node.consequent);
-                node.alternative = mangleStrings(node.alternative);
-            }
-            return node;
-        }));
+        if (node instanceof AST_Sequence) {
+            mangleStrings(node.tail_node());
+        } else if (node instanceof AST_String) {
+            node.value = mangle(node.value);
+        } else if (node instanceof AST_Conditional) {
+            mangleStrings(node.consequent);
+            mangleStrings(node.alternative);
+        }
     }
 }

lib/sourcemap.js

@@ -1,7 +1,7 @@
 /***********************************************************************
 
   A JavaScript tokenizer / parser / beautifier / compressor.
-  https://github.com/mishoo/UglifyJS2
+  https://github.com/mishoo/UglifyJS
 
   -------------------------------- (C) ---------------------------------
 
@@ -43,62 +43,153 @@
 
 "use strict";
 
-// a small wrapper around fitzgen's source-map library
-function SourceMap(options) {
-    options = defaults(options, {
-        file: null,
-        root: null,
-        orig: null,
-        orig_line_diff: 0,
-        dest_line_diff: 0,
-    }, true);
-    var generator = new MOZ_SourceMap.SourceMapGenerator({
-        file: options.file,
-        sourceRoot: options.root
-    });
-    var maps = options.orig && Object.create(null);
-    if (maps) for (var source in options.orig) {
-        var map = new MOZ_SourceMap.SourceMapConsumer(options.orig[source]);
-        if (Array.isArray(options.orig[source].sources)) {
-            map._sources.toArray().forEach(function(source) {
-                var sourceContent = map.sourceContentFor(source, true);
-                if (sourceContent) generator.setSourceContent(source, sourceContent);
-            });
+var vlq_char = characters("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/");
+var vlq_bits = vlq_char.reduce(function(map, ch, bits) {
+    map[ch] = bits;
+    return map;
+}, Object.create(null));
+
+function vlq_decode(indices, str) {
+    var value = 0;
+    var shift = 0;
+    for (var i = 0, j = 0; i < str.length; i++) {
+        var bits = vlq_bits[str[i]];
+        value += (bits & 31) << shift;
+        if (bits & 32) {
+            shift += 5;
+        } else {
+            indices[j++] += value & 1 ? 0x80000000 | -(value >> 1) : value >> 1;
+            value = shift = 0;
         }
-        maps[source] = map;
     }
-    return {
-        add: function(source, gen_line, gen_col, orig_line, orig_col, name) {
-            var map = maps && maps[source];
-            if (map) {
-                var info = map.originalPositionFor({
-                    line: orig_line,
-                    column: orig_col
+    return j;
+}
+
+function vlq_encode(num) {
+    var result = "";
+    num = Math.abs(num) << 1 | num >>> 31;
+    do {
+        var bits = num & 31;
+        if (num >>>= 5) bits |= 32;
+        result += vlq_char[bits];
+    } while (num);
+    return result;
+}
+
+function create_array_map() {
+    var map = new Dictionary();
+    var array = [];
+    array.index = function(name) {
+        var index = map.get(name);
+        if (!(index >= 0)) {
+            index = array.length;
+            array.push(name);
+            map.set(name, index);
+        }
+        return index;
+    };
+    return array;
+}
+
+function SourceMap(options) {
+    var sources = create_array_map();
+    var sources_content = options.includeSources && new Dictionary();
+    var names = create_array_map();
+    var mappings = "";
+    if (options.orig) Object.keys(options.orig).forEach(function(name) {
+        var map = options.orig[name];
+        var indices = [ 0, 0, 1, 0, 0 ];
+        options.orig[name] = {
+            names: map.names,
+            mappings: map.mappings.split(/;/).map(function(line) {
+                indices[0] = 0;
+                return line.split(/,/).map(function(segment) {
+                    return indices.slice(0, vlq_decode(indices, segment));
                 });
-                if (info.source === null) return;
-                source = info.source;
-                orig_line = info.line;
-                orig_col = info.column;
-                name = info.name || name;
-            }
-            generator.addMapping({
-                name: name,
-                source: source,
-                generated: {
-                    line: gen_line + options.dest_line_diff,
-                    column: gen_col
-                },
-                original: {
-                    line: orig_line + options.orig_line_diff,
-                    column: orig_col
+            }),
+            sources: map.sources,
+        };
+        if (!sources_content || !map.sourcesContent) return;
+        for (var i = 0; i < map.sources.length; i++) {
+            var content = map.sourcesContent[i];
+            if (content) sources_content.set(map.sources[i], content);
+        }
+    });
+    var prev_source;
+    var generated_line = 1;
+    var generated_column = 0;
+    var source_index = 0;
+    var original_line = 1;
+    var original_column = 0;
+    var name_index = 0;
+    return {
+        add: options.orig ? function(source, gen_line, gen_col, orig_line, orig_col, name) {
+            var map = options.orig[source];
+            if (map) {
+                var segments = map.mappings[orig_line - 1];
+                if (!segments) return;
+                var indices;
+                for (var i = 0; i < segments.length; i++) {
+                    var col = segments[i][0];
+                    if (orig_col >= col) indices = segments[i];
+                    if (orig_col <= col) break;
                 }
-            });
-        },
-        get: function() {
-            return generator;
-        },
+                if (!indices || indices.length < 4) {
+                    source = null;
+                } else {
+                    source = map.sources[indices[1]];
+                    orig_line = indices[2];
+                    orig_col = indices[3];
+                    if (indices.length > 4) name = map.names[indices[4]];
+                }
+            }
+            add(source, gen_line, gen_col, orig_line, orig_col, name);
+        } : add,
+        setSourceContent: sources_content ? function(source, content) {
+            if (!sources_content.has(source)) {
+                sources_content.set(source, content);
+            }
+        } : noop,
         toString: function() {
-            return JSON.stringify(generator.toJSON());
+            return JSON.stringify({
+                version: 3,
+                file: options.filename || undefined,
+                sourceRoot: options.root || undefined,
+                sources: sources,
+                sourcesContent: sources_content ? sources.map(function(source) {
+                    return sources_content.get(source) || null;
+                }) : undefined,
+                names: names,
+                mappings: mappings,
+            });
         }
     };
+
+    function add(source, gen_line, gen_col, orig_line, orig_col, name) {
+        if (prev_source == null && source == null) return;
+        prev_source = source;
+        if (generated_line < gen_line) {
+            generated_column = 0;
+            do {
+                mappings += ";";
+            } while (++generated_line < gen_line);
+        } else if (mappings) {
+            mappings += ",";
+        }
+        mappings += vlq_encode(gen_col - generated_column);
+        generated_column = gen_col;
+        if (source == null) return;
+        var src_idx = sources.index(source);
+        mappings += vlq_encode(src_idx - source_index);
+        source_index = src_idx;
+        mappings += vlq_encode(orig_line - original_line);
+        original_line = orig_line;
+        mappings += vlq_encode(orig_col - original_column);
+        original_column = orig_col;
+        if (options.names && name != null) {
+            var name_idx = names.index(name);
+            mappings += vlq_encode(name_idx - name_index);
+            name_index = name_idx;
+        }
+    }
 }

lib/transform.js

@@ -1,7 +1,7 @@
 /***********************************************************************
 
   A JavaScript tokenizer / parser / beautifier / compressor.
-  https://github.com/mishoo/UglifyJS2
+  https://github.com/mishoo/UglifyJS
 
   -------------------------------- (C) ---------------------------------
 
@@ -52,7 +52,7 @@ TreeTransformer.prototype = new TreeWalker;
 
 (function(DEF) {
     function do_list(list, tw) {
-        return MAP(list, function(node) {
+        return List(list, function(node) {
             return node.transform(tw, true);
         });
     }
@@ -82,7 +82,7 @@ TreeTransformer.prototype = new TreeWalker;
         if (self.step) self.step = self.step.transform(tw);
         self.body = self.body.transform(tw);
     });
-    DEF(AST_ForIn, function(self, tw) {
+    DEF(AST_ForEnumeration, function(self, tw) {
         self.init = self.init.transform(tw);
         self.object = self.object.transform(tw);
         self.body = self.body.transform(tw);
@@ -116,7 +116,7 @@ TreeTransformer.prototype = new TreeWalker;
         if (self.bfinally) self.bfinally = self.bfinally.transform(tw);
     });
     DEF(AST_Catch, function(self, tw) {
-        self.argname = self.argname.transform(tw);
+        if (self.argname) self.argname = self.argname.transform(tw);
         self.body = do_list(self.body, tw);
     });
     DEF(AST_Definitions, function(self, tw) {
@@ -126,11 +126,36 @@ TreeTransformer.prototype = new TreeWalker;
         self.name = self.name.transform(tw);
         if (self.value) self.value = self.value.transform(tw);
     });
+    DEF(AST_DefaultValue, function(self, tw) {
+        self.name = self.name.transform(tw);
+        self.value = self.value.transform(tw);
+    });
     DEF(AST_Lambda, function(self, tw) {
         if (self.name) self.name = self.name.transform(tw);
         self.argnames = do_list(self.argnames, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
         self.body = do_list(self.body, tw);
     });
+    function transform_arrow(self, tw) {
+        self.argnames = do_list(self.argnames, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
+        if (self.value) {
+            self.value = self.value.transform(tw);
+        } else {
+            self.body = do_list(self.body, tw);
+        }
+    }
+    DEF(AST_Arrow, transform_arrow);
+    DEF(AST_AsyncArrow, transform_arrow);
+    DEF(AST_Class, function(self, tw) {
+        if (self.name) self.name = self.name.transform(tw);
+        if (self.extends) self.extends = self.extends.transform(tw);
+        self.properties = do_list(self.properties, tw);
+    });
+    DEF(AST_ClassProperty, function(self, tw) {
+        if (self.key instanceof AST_Node) self.key = self.key.transform(tw);
+        if (self.value) self.value = self.value.transform(tw);
+    });
     DEF(AST_Call, function(self, tw) {
         self.expression = self.expression.transform(tw);
         self.args = do_list(self.args, tw);
@@ -138,6 +163,12 @@ TreeTransformer.prototype = new TreeWalker;
     DEF(AST_Sequence, function(self, tw) {
         self.expressions = do_list(self.expressions, tw);
     });
+    DEF(AST_Await, function(self, tw) {
+        self.expression = self.expression.transform(tw);
+    });
+    DEF(AST_Yield, function(self, tw) {
+        if (self.expression) self.expression = self.expression.transform(tw);
+    });
     DEF(AST_Dot, function(self, tw) {
         self.expression = self.expression.transform(tw);
     });
@@ -145,6 +176,9 @@ TreeTransformer.prototype = new TreeWalker;
         self.expression = self.expression.transform(tw);
         self.property = self.property.transform(tw);
     });
+    DEF(AST_Spread, function(self, tw) {
+        self.expression = self.expression.transform(tw);
+    });
     DEF(AST_Unary, function(self, tw) {
         self.expression = self.expression.transform(tw);
     });
@@ -160,12 +194,43 @@ TreeTransformer.prototype = new TreeWalker;
     DEF(AST_Array, function(self, tw) {
         self.elements = do_list(self.elements, tw);
     });
+    DEF(AST_DestructuredArray, function(self, tw) {
+        self.elements = do_list(self.elements, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
+    });
+    DEF(AST_DestructuredKeyVal, function(self, tw) {
+        if (self.key instanceof AST_Node) self.key = self.key.transform(tw);
+        self.value = self.value.transform(tw);
+    });
+    DEF(AST_DestructuredObject, function(self, tw) {
+        self.properties = do_list(self.properties, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
+    });
     DEF(AST_Object, function(self, tw) {
         self.properties = do_list(self.properties, tw);
     });
     DEF(AST_ObjectProperty, function(self, tw) {
+        if (self.key instanceof AST_Node) self.key = self.key.transform(tw);
         self.value = self.value.transform(tw);
     });
+    DEF(AST_ExportDeclaration, function(self, tw) {
+        self.body = self.body.transform(tw);
+    });
+    DEF(AST_ExportDefault, function(self, tw) {
+        self.body = self.body.transform(tw);
+    });
+    DEF(AST_ExportReferences, function(self, tw) {
+        self.properties = do_list(self.properties, tw);
+    });
+    DEF(AST_Import, function(self, tw) {
+        if (self.all) self.all = self.all.transform(tw);
+        if (self.default) self.default = self.default.transform(tw);
+        if (self.properties) self.properties = do_list(self.properties, tw);
+    });
+    DEF(AST_Template, function(self, tw) {
+        if (self.tag) self.tag = self.tag.transform(tw);
+        self.expressions = do_list(self.expressions, tw);
+    });
 })(function(node, descend) {
     node.DEFMETHOD("transform", function(tw, in_list) {
         var x, y;

lib/utils.js

@@ -1,7 +1,7 @@
 /***********************************************************************
 
   A JavaScript tokenizer / parser / beautifier / compressor.
-  https://github.com/mishoo/UglifyJS2
+  https://github.com/mishoo/UglifyJS
 
   -------------------------------- (C) ---------------------------------
 
@@ -55,14 +55,6 @@ function find_if(func, array) {
     for (var i = array.length; --i >= 0;) if (func(array[i])) return array[i];
 }
 
-function repeat_string(str, i) {
-    if (i <= 0) return "";
-    if (i == 1) return str;
-    var d = repeat_string(str, i >> 1);
-    d += d;
-    return i & 1 ? d + str : d;
-}
-
 function configure_error_stack(fn) {
     Object.defineProperty(fn.prototype, "stack", {
         get: function() {
@@ -70,7 +62,7 @@ function configure_error_stack(fn) {
             err.name = this.name;
             try {
                 throw err;
-            } catch(e) {
+            } catch (e) {
                 return e.stack;
             }
         }
@@ -87,24 +79,13 @@ DefaultsError.prototype.name = "DefaultsError";
 configure_error_stack(DefaultsError);
 
 function defaults(args, defs, croak) {
-    if (args === true) args = {};
-    var ret = args || {};
-    if (croak) for (var i in ret) if (HOP(ret, i) && !HOP(defs, i)) {
-        throw new DefaultsError("`" + i + "` is not a supported option", defs);
+    if (croak) for (var i in args) {
+        if (HOP(args, i) && !HOP(defs, i)) throw new DefaultsError("`" + i + "` is not a supported option", defs);
     }
-    for (var i in defs) if (HOP(defs, i)) {
-        ret[i] = (args && HOP(args, i)) ? args[i] : defs[i];
+    for (var i in args) {
+        if (HOP(args, i)) defs[i] = args[i];
     }
-    return ret;
-}
-
-function merge(obj, ext) {
-    var count = 0;
-    for (var i in ext) if (HOP(ext, i)) {
-        obj[i] = ext[i];
-        count++;
-    }
-    return count;
+    return defs;
 }
 
 function noop() {}
@@ -113,69 +94,49 @@ function return_true() { return true; }
 function return_this() { return this; }
 function return_null() { return null; }
 
-var MAP = (function() {
-    function MAP(a, f, backwards) {
-        var ret = [], top = [], i;
-        function doit() {
+var List = (function() {
+    function List(a, f) {
+        var ret = [];
+        for (var i = 0; i < a.length; i++) {
             var val = f(a[i], i);
-            var is_last = val instanceof Last;
-            if (is_last) val = val.v;
-            if (val instanceof AtTop) {
-                val = val.v;
-                if (val instanceof Splice) {
-                    top.push.apply(top, backwards ? val.v.slice().reverse() : val.v);
-                } else {
-                    top.push(val);
-                }
-            }
-            else if (val !== skip) {
-                if (val instanceof Splice) {
-                    ret.push.apply(ret, backwards ? val.v.slice().reverse() : val.v);
-                } else {
-                    ret.push(val);
-                }
-            }
-            return is_last;
-        }
-        if (Array.isArray(a)) {
-            if (backwards) {
-                for (i = a.length; --i >= 0;) if (doit()) break;
-                ret.reverse();
-                top.reverse();
+            if (val === skip) continue;
+            if (val instanceof Splice) {
+                ret.push.apply(ret, val.v);
             } else {
-                for (i = 0; i < a.length; ++i) if (doit()) break;
+                ret.push(val);
             }
         }
-        else {
-            for (i in a) if (HOP(a, i)) if (doit()) break;
-        }
-        return top.concat(ret);
+        return ret;
     }
-    MAP.at_top = function(val) { return new AtTop(val) };
-    MAP.splice = function(val) { return new Splice(val) };
-    MAP.last = function(val) { return new Last(val) };
-    var skip = MAP.skip = {};
-    function AtTop(val) { this.v = val }
-    function Splice(val) { this.v = val }
-    function Last(val) { this.v = val }
-    return MAP;
+    List.is_op = function(val) {
+        return val === skip || val instanceof Splice;
+    };
+    List.splice = function(val) {
+        return new Splice(val);
+    };
+    var skip = List.skip = {};
+    function Splice(val) {
+        this.v = val;
+    }
+    return List;
 })();
 
 function push_uniq(array, el) {
-    if (array.indexOf(el) < 0)
-        array.push(el);
+    if (array.indexOf(el) < 0) return array.push(el);
 }
 
 function string_template(text, props) {
-    return text.replace(/\{(.+?)\}/g, function(str, p) {
-        return props && props[p];
+    return text.replace(/\{([^{}]+)\}/g, function(str, p) {
+        var value = p == "this" ? props : props[p];
+        if (value instanceof AST_Node) return value.print_to_string();
+        if (value instanceof AST_Token) return value.file + ":" + value.line + "," + value.col;
+        return value;
     });
 }
 
 function remove(array, el) {
-    for (var i = array.length; --i >= 0;) {
-        if (array[i] === el) array.splice(i, 1);
-    }
+    var index = array.indexOf(el);
+    if (index >= 0) array.splice(index, 1);
 }
 
 function makePredicate(words) {
@@ -189,63 +150,86 @@ function makePredicate(words) {
 
 function all(array, predicate) {
     for (var i = array.length; --i >= 0;)
-        if (!predicate(array[i]))
+        if (!predicate(array[i], i))
             return false;
     return true;
 }
 
 function Dictionary() {
-    this._values = Object.create(null);
-    this._size = 0;
+    this.values = Object.create(null);
 }
 Dictionary.prototype = {
     set: function(key, val) {
-        if (!this.has(key)) ++this._size;
-        this._values["$" + key] = val;
+        if (key == "__proto__") {
+            this.proto_value = val;
+        } else {
+            this.values[key] = val;
+        }
         return this;
     },
     add: function(key, val) {
-        if (this.has(key)) {
-            this.get(key).push(val);
+        var list = this.get(key);
+        if (list) {
+            list.push(val);
         } else {
             this.set(key, [ val ]);
         }
         return this;
     },
-    get: function(key) { return this._values["$" + key] },
+    get: function(key) {
+        return key == "__proto__" ? this.proto_value : this.values[key];
+    },
     del: function(key) {
-        if (this.has(key)) {
-            --this._size;
-            delete this._values["$" + key];
+        if (key == "__proto__") {
+            delete this.proto_value;
+        } else {
+            delete this.values[key];
         }
         return this;
     },
-    has: function(key) { return ("$" + key) in this._values },
+    has: function(key) {
+        return key == "__proto__" ? "proto_value" in this : key in this.values;
+    },
+    all: function(predicate) {
+        for (var i in this.values)
+            if (!predicate(this.values[i], i)) return false;
+        if ("proto_value" in this && !predicate(this.proto_value, "__proto__")) return false;
+        return true;
+    },
     each: function(f) {
-        for (var i in this._values)
-            f(this._values[i], i.substr(1));
+        for (var i in this.values)
+            f(this.values[i], i);
+        if ("proto_value" in this) f(this.proto_value, "__proto__");
     },
     size: function() {
-        return this._size;
+        return Object.keys(this.values).length + ("proto_value" in this);
     },
     map: function(f) {
         var ret = [];
-        for (var i in this._values)
-            ret.push(f(this._values[i], i.substr(1)));
+        for (var i in this.values)
+            ret.push(f(this.values[i], i));
+        if ("proto_value" in this) ret.push(f(this.proto_value, "__proto__"));
         return ret;
     },
     clone: function() {
         var ret = new Dictionary();
-        for (var i in this._values)
-            ret._values[i] = this._values[i];
-        ret._size = this._size;
+        this.each(function(value, i) {
+            ret.set(i, value);
+        });
         return ret;
     },
-    toObject: function() { return this._values }
+    toObject: function() {
+        var obj = {};
+        this.each(function(value, i) {
+            obj["$" + i] = value;
+        });
+        return obj;
+    },
 };
 Dictionary.fromObject = function(obj) {
     var dict = new Dictionary();
-    dict._size = merge(dict._values, obj);
+    for (var i in obj)
+        if (HOP(obj, i)) dict.set(i.slice(1), obj[i]);
     return dict;
 };
 
@@ -256,24 +240,48 @@ 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;
         }
         return false;
     }
 }
+
+function DEF_BITPROPS(ctor, props) {
+    if (props.length > 31) throw new Error("Too many properties: " + props.length + "\n" + props.join(", "));
+    props.forEach(function(name, pos) {
+        var mask = 1 << pos;
+        Object.defineProperty(ctor.prototype, name, {
+            get: function() {
+                return !!(this._bits & mask);
+            },
+            set: function(val) {
+                if (val)
+                    this._bits |= mask;
+                else
+                    this._bits &= ~mask;
+            },
+        });
+    });
+}

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": "3.4.4",
+  "version": "3.17.4",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -11,7 +11,7 @@
     "Alex Lam <alexlamsl@gmail.com>",
     "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)"
   ],
-  "repository": "mishoo/UglifyJS2",
+  "repository": "mishoo/UglifyJS",
   "main": "tools/node.js",
   "bin": {
     "uglifyjs": "bin/uglifyjs"
@@ -22,16 +22,12 @@
     "tools",
     "LICENSE"
   ],
-  "dependencies": {
-    "commander": "~2.16.0",
-    "source-map": "~0.6.1"
-  },
   "devDependencies": {
-    "acorn": "~5.7.1",
-    "semver": "~5.5.0"
+    "acorn": "~8.7.1",
+    "semver": "~6.3.0"
   },
   "scripts": {
-    "test": "node test/run-tests.js"
+    "test": "node test/compress.js && node test/mocha.js"
   },
   "keywords": [
     "cli",

test/benchmark.js

@@ -5,23 +5,23 @@
 
 var createHash = require("crypto").createHash;
 var fetch = require("./fetch");
-var fork = require("child_process").fork;
+var spawn = require("child_process").spawn;
 var zlib = require("zlib");
 var args = process.argv.slice(2);
-if (!args.length) {
-    args.push("-mc");
-}
+if (!args.length) args.push("-mc");
+args.unshift("bin/uglifyjs");
 args.push("--timings");
 var urls = [
-    "https://code.jquery.com/jquery-3.2.1.js",
-    "https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.6.4/angular.js",
-    "https://cdnjs.cloudflare.com/ajax/libs/mathjs/3.9.0/math.js",
-    "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.js",
+    "https://code.jquery.com/jquery-3.4.1.js",
+    "https://code.angularjs.org/1.7.8/angular.js",
+    "https://unpkg.com/mathjs@6.2.3/dist/math.js",
     "https://unpkg.com/react@15.3.2/dist/react.js",
-    "http://builds.emberjs.com/tags/v2.11.0/ember.prod.js",
-    "https://cdn.jsdelivr.net/lodash/4.17.4/lodash.js",
-    "https://cdnjs.cloudflare.com/ajax/libs/d3/4.5.0/d3.js",
-    "https://raw.githubusercontent.com/kangax/html-minifier/v3.5.7/dist/htmlminifier.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/d3/6.7.0/d3.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/antd/4.18.7/antd.js",
+    "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.12.2/ember.prod.js",
+    "https://raw.githubusercontent.com/kangax/html-minifier/v4.0.0/dist/htmlminifier.js",
 ];
 var results = {};
 var remaining = 2 * urls.length;
@@ -70,18 +70,20 @@ urls.forEach(function(url) {
     };
     fetch(url, function(err, res) {
         if (err) throw err;
-        var uglifyjs = fork("bin/uglifyjs", args, { silent: true });
+        var uglifyjs = spawn(process.argv[0], args, { silent: true });
         res.on("data", function(data) {
             results[url].input += data.length;
         }).pipe(uglifyjs.stdin);
+        var sha1 = createHash("sha1");
         uglifyjs.stdout.on("data", function(data) {
             results[url].output += data.length;
         }).pipe(zlib.createGzip({
             level: zlib.Z_BEST_COMPRESSION
         })).on("data", function(data) {
             results[url].gzip += data.length;
-        }).pipe(createHash("sha1")).on("data", function(data) {
-            results[url].sha1 = data.toString("hex");
+            sha1.update(data);
+        }).on("end", function() {
+            results[url].sha1 = sha1.digest("hex");
             done();
         });
         uglifyjs.stderr.setEncoding("utf8");

test/compress.js

@@ -0,0 +1,497 @@
+"use strict";
+
+require("../tools/tty");
+
+var assert = require("assert");
+var child_process = require("child_process");
+var fs = require("fs");
+var path = require("path");
+var sandbox = require("./sandbox");
+var semver = require("semver");
+var U = require("./node");
+
+var batch = 50;
+var dir = path.resolve(path.dirname(module.filename), "compress");
+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);
+    var tests = parse_test(path.resolve(dir, file));
+    process.exit(Object.keys(tests).slice(start, start + batch).filter(function(name) {
+        return !test_case(tests[name]);
+    }).length);
+} else {
+    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(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] = true;
+                }
+                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).");
+            console.error("!!! " + Object.keys(failed_files).join(", "));
+            process.exit(1);
+        }
+    })();
+}
+
+function evaluate(code) {
+    if (code instanceof U.AST_Node) code = make_code(code, { beautify: true });
+    return new Function("return(" + code + ")")();
+}
+
+function log() {
+    console.log("%s", tmpl.apply(null, arguments));
+}
+
+function make_code(ast, options, expression) {
+    var stream = U.OutputStream(options);
+    if (expression) ast = ast.clone(true).unwrap_expression();
+    ast.print(stream);
+    return stream.get();
+}
+
+function parse_test(file) {
+    var script = fs.readFileSync(file, "utf8");
+    try {
+        var ast = U.parse(script, { filename: file, module: "" });
+    } catch (e) {
+        console.error("Caught error while parsing tests in " + file);
+        console.error(e);
+        process.exit(1);
+    }
+    var tests = Object.create(null);
+    var tw = new U.TreeWalker(function(node, descend) {
+        if (node instanceof U.AST_LabeledStatement
+            && tw.parent() instanceof U.AST_Toplevel) {
+            var name = node.label.name;
+            if (name in tests) {
+                throw new Error('Duplicated test name "' + name + '" in ' + file);
+            }
+            tests[name] = get_one_test(name, node.body);
+            return true;
+        }
+        if (!(node instanceof U.AST_Toplevel)) croak(node);
+    });
+    ast.walk(tw);
+    return tests;
+
+    function croak(node) {
+        throw new Error(tmpl("Can't understand test file {file} [{line},{col}]\n{code}", {
+            file: file,
+            line: node.start.line,
+            col: node.start.col,
+            code: make_code(node, { beautify: false }),
+        }));
+    }
+
+    function read_string(stat) {
+        if (stat.TYPE == "SimpleStatement") {
+            var body = stat.body;
+            switch (body.TYPE) {
+              case "String":
+                return body.value;
+              case "Array":
+                return body.elements.map(function(element) {
+                    if (element.TYPE !== "String")
+                        throw new Error("Should be array of strings");
+                    return element.value;
+                }).join("\n");
+            }
+        }
+        throw new Error("Should be string or array of strings");
+    }
+
+    function get_one_test(name, block) {
+        var test = { name: name, options: {} };
+        var tw = new U.TreeWalker(function(node, descend) {
+            if (node instanceof U.AST_Assign) {
+                if (!(node.left instanceof U.AST_SymbolRef)) {
+                    croak(node);
+                }
+                var name = node.left.name;
+                assert.ok([
+                    "beautify",
+                    "expression",
+                    "mangle",
+                    "options",
+                    "rename",
+                ].indexOf(name) >= 0, tmpl("Unsupported setting {name} [{line},{col}]", {
+                    name: name,
+                    line: node.start.line,
+                    col: node.start.col,
+                }));
+                test[name] = evaluate(node.right);
+                return true;
+            }
+            if (node instanceof U.AST_LabeledStatement) {
+                var label = node.label;
+                assert.ok([
+                    "input",
+                    "expect",
+                    "expect_exact",
+                    "expect_warnings",
+                    "expect_stdout",
+                    "node_version",
+                ].indexOf(label.name) >= 0, tmpl("Unsupported label {name} [{line},{col}]", {
+                    name: label.name,
+                    line: label.start.line,
+                    col: label.start.col,
+                }));
+                var stat = node.body;
+                if (label.name == "expect_exact" || label.name == "node_version") {
+                    test[label.name] = read_string(stat);
+                } else if (label.name == "expect_stdout") {
+                    var body = stat.body;
+                    if (body instanceof U.AST_Boolean) {
+                        test[label.name] = body.value;
+                    } else if (body instanceof U.AST_Call) {
+                        var ctor = global[body.expression.name];
+                        assert.ok(ctor === Error || ctor.prototype instanceof Error, tmpl("Unsupported expect_stdout format [{line},{col}]", {
+                            line: label.start.line,
+                            col: label.start.col,
+                        }));
+                        test[label.name] = ctor.apply(null, body.args.map(function(node) {
+                            assert.ok(node instanceof U.AST_Constant, tmpl("Unsupported expect_stdout format [{line},{col}]", {
+                                line: label.start.line,
+                                col: label.start.col,
+                            }));
+                            return node.value;
+                        }));
+                    } else {
+                        test[label.name] = read_string(stat) + "\n";
+                    }
+                } else {
+                    test[label.name] = stat;
+                }
+                return true;
+            }
+        });
+        block.walk(tw);
+        return test;
+    }
+}
+
+// Try to reminify original input with standard options
+// to see if it matches expect_stdout.
+function reminify(expression, orig_options, input_code, input_formatted, stdout) {
+    for (var i = 0; i < minify_options.length; i++) {
+        var options = JSON.parse(minify_options[i]);
+        if (expression) {
+            if (!options.parse || typeof options.parse != "object") options.parse = {};
+            options.parse.expression = true;
+            if (options.compress == null) options.compress = {};
+            if (options.compress) {
+                if (typeof options.compress != "object") options.compress = {};
+                options.compress.expression = true;
+            }
+        }
+        [
+            "keep_fargs",
+            "keep_fnames",
+        ].forEach(function(name) {
+            if (name in orig_options) options[name] = orig_options[name];
+        });
+        var options_formatted = JSON.stringify(options, null, 4);
+        options.validate = true;
+        var result = U.minify(input_code, options);
+        if (result.error) {
+            log([
+                "!!! failed input reminify",
+                "---INPUT---",
+                "{input}",
+                "---OPTIONS---",
+                "{options}",
+                "--ERROR---",
+                "{error}",
+                "",
+                "",
+            ].join("\n"), {
+                input: input_formatted,
+                options: options_formatted,
+                error: result.error,
+            });
+            return false;
+        } else {
+            var toplevel = sandbox.has_toplevel(options);
+            var expected = stdout[toplevel ? 1 : 0];
+            var actual = run_code(expression, result.code, toplevel);
+            if (typeof expected != "string" && typeof actual != "string" && expected.name == actual.name) {
+                actual = expected;
+            }
+            if (!sandbox.same_stdout(expected, actual)) {
+                log([
+                    "!!! failed running reminified input",
+                    "---INPUT---",
+                    "{input}",
+                    "---OPTIONS---",
+                    "{options}",
+                    "---OUTPUT---",
+                    "{output}",
+                    "---EXPECTED {expected_type}---",
+                    "{expected}",
+                    "---ACTUAL {actual_type}---",
+                    "{actual}",
+                    "",
+                    "",
+                ].join("\n"), {
+                    input: input_formatted,
+                    options: options_formatted,
+                    output: result.code,
+                    expected_type: typeof expected == "string" ? "STDOUT" : "ERROR",
+                    expected: expected,
+                    actual_type: typeof actual == "string" ? "STDOUT" : "ERROR",
+                    actual: actual,
+                });
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+function run_code(expression, code, toplevel) {
+    return sandbox.run_code(expression ? "console.log(" + code + ");" : code, toplevel);
+}
+
+function test_case(test) {
+    log("    Running test [{name}]", { name: test.name });
+    U.AST_Node.enable_validation();
+    var output_options = test.beautify || {};
+    var expect;
+    if (test.expect) {
+        expect = to_toplevel(test.expect, test.mangle, test.expression);
+        expect = make_code(expect, output_options, test.expression);
+    } else {
+        expect = test.expect_exact;
+    }
+    var input = to_toplevel(test.input, test.mangle, test.expression);
+    var input_code = make_code(input, {
+        keep_quoted_props: true,
+    }, test.expression);
+    var input_formatted = make_code(test.input, {
+        annotations: true,
+        beautify: true,
+        comments: "all",
+        keep_quoted_props: true,
+        quote_style: 3,
+    });
+    try {
+        input.validate_ast();
+        U.parse(input_code, { expression: test.expression });
+    } catch (ex) {
+        log([
+            "!!! Cannot parse input",
+            "---INPUT---",
+            "{input}",
+            "--PARSE ERROR--",
+            "{error}",
+            "",
+            "",
+        ].join("\n"), {
+            input: input_formatted,
+            error: ex,
+        });
+        return false;
+    }
+    var warnings_emitted = [];
+    if (test.expect_warnings) {
+        var expected_warnings = make_code(test.expect_warnings, {
+            beautify: false,
+            quote_style: 2, // force double quote to match JSON
+        });
+        U.AST_Node.log_function(function(text) {
+            warnings_emitted.push(text);
+        }, /"INFO: /.test(expected_warnings));
+    }
+    var quoted_props;
+    if (test.mangle && test.mangle.properties && test.mangle.properties.keep_quoted) {
+        quoted_props = test.mangle.properties.reserved;
+        if (!Array.isArray(quoted_props)) quoted_props = [];
+        test.mangle.properties.reserved = quoted_props;
+        U.reserve_quoted_keys(input, quoted_props);
+    }
+    if (test.rename) {
+        input.figure_out_scope(test.mangle);
+        input.expand_names(test.mangle);
+    }
+    var cmp = new U.Compressor(test.options, true);
+    var output = cmp.compress(input);
+    output.figure_out_scope(test.mangle);
+    if (test.mangle) {
+        output.compute_char_frequency(test.mangle);
+        output.mangle_names(test.mangle);
+        if (quoted_props) U.reserve_quoted_keys(input, quoted_props);
+        if (test.mangle.properties) U.mangle_properties(output, test.mangle.properties);
+    }
+    var output_code = make_code(output, output_options, test.expression);
+    U.AST_Node.log_function();
+    if (expect != output_code) {
+        log([
+            "!!! failed",
+            "---INPUT---",
+            "{input}",
+            "---OUTPUT---",
+            "{output}",
+            "---EXPECTED---",
+            "{expected}",
+            "",
+            "",
+        ].join("\n"), {
+            input: input_formatted,
+            output: output_code,
+            expected: expect
+        });
+        return false;
+    }
+    // expect == output
+    try {
+        output.validate_ast();
+        U.parse(output_code, { expression: test.expression });
+    } catch (ex) {
+        log([
+            "!!! Test matched expected result but cannot parse output",
+            "---INPUT---",
+            "{input}",
+            "---OUTPUT---",
+            "{output}",
+            "--REPARSE ERROR--",
+            "{error}",
+            "",
+            "",
+        ].join("\n"), {
+            input: input_formatted,
+            output: output_code,
+            error: ex,
+        });
+        return false;
+    }
+    if (test.expect_warnings) {
+        warnings_emitted = warnings_emitted.map(function(input) {
+            return input.split(process.cwd() + path.sep).join("").split(path.sep).join("/");
+        });
+        var actual_warnings = JSON.stringify(warnings_emitted);
+        if (expected_warnings != actual_warnings) {
+            log([
+                "!!! failed",
+                "---INPUT---",
+                "{input}",
+                "---EXPECTED WARNINGS---",
+                "{expected_warnings}",
+                "---ACTUAL WARNINGS---",
+                "{actual_warnings}",
+                "",
+                "",
+            ].join("\n"), {
+                input: input_formatted,
+                expected_warnings: expected_warnings,
+                actual_warnings: actual_warnings,
+            });
+            return false;
+        }
+    }
+    if (test.expect_stdout && (!test.node_version || semver.satisfies(process.version, test.node_version))) {
+        var stdout = [ run_code(test.expression, input_code), run_code(test.expression, input_code, true) ];
+        var toplevel = sandbox.has_toplevel({
+            compress: test.options,
+            mangle: test.mangle
+        });
+        var actual = stdout[toplevel ? 1 : 0];
+        if (test.expect_stdout === true || test.expect_stdout instanceof Error && test.expect_stdout.name === actual.name) {
+            test.expect_stdout = actual;
+        }
+        if (!sandbox.same_stdout(test.expect_stdout, actual)) {
+            log([
+                "!!! Invalid input or expected stdout",
+                "---INPUT---",
+                "{input}",
+                "---EXPECTED {expected_type}---",
+                "{expected}",
+                "---ACTUAL {actual_type}---",
+                "{actual}",
+                "",
+                "",
+            ].join("\n"), {
+                input: input_formatted,
+                expected_type: typeof test.expect_stdout == "string" ? "STDOUT" : "ERROR",
+                expected: test.expect_stdout,
+                actual_type: typeof actual == "string" ? "STDOUT" : "ERROR",
+                actual: actual,
+            });
+            return false;
+        }
+        actual = run_code(test.expression, output_code, toplevel);
+        if (!sandbox.same_stdout(test.expect_stdout, actual)) {
+            log([
+                "!!! failed",
+                "---INPUT---",
+                "{input}",
+                "---EXPECTED {expected_type}---",
+                "{expected}",
+                "---ACTUAL {actual_type}---",
+                "{actual}",
+                "",
+                "",
+            ].join("\n"), {
+                input: input_formatted,
+                expected_type: typeof test.expect_stdout == "string" ? "STDOUT" : "ERROR",
+                expected: test.expect_stdout,
+                actual_type: typeof actual == "string" ? "STDOUT" : "ERROR",
+                actual: actual,
+            });
+            return false;
+        }
+        if (!reminify(test.expression, test.options, input_code, input_formatted, stdout)) {
+            return false;
+        }
+    }
+    return true;
+}
+
+function tmpl() {
+    return U.string_template.apply(null, arguments);
+}
+
+function to_toplevel(input, mangle_options, expression) {
+    if (!(input instanceof U.AST_BlockStatement)) throw new Error("Unsupported input syntax");
+    var offset = input.start.line;
+    var tokens = [];
+    input.walk(new U.TreeWalker(function(node) {
+        if (U.push_uniq(tokens, node.start)) node.start.line -= offset;
+        if (U.push_uniq(tokens, node.end)) node.end.line -= offset;
+    }));
+    var toplevel;
+    if (!expression) {
+        var directive = true;
+        toplevel = new U.AST_Toplevel(input.transform(new U.TreeTransformer(function(node) {
+            if (!directive) return node;
+            if (node === input) return;
+            if (node instanceof U.AST_SimpleStatement && node.body instanceof U.AST_String) {
+                return new U.AST_Directive(node.body);
+            }
+            directive = false;
+        })));
+    } else if (input.body.length == 1) {
+        toplevel = input.body[0].wrap_expression();
+    } else {
+        throw new Error("Invalid expression");
+    }
+    toplevel.figure_out_scope(mangle_options);
+    return toplevel;
+}

test/compress/annotations.js

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

test/compress/arguments.js

@@ -78,12 +78,13 @@ replace_index_strict: {
     ]
 }
 
-replace_index_keep_fargs: {
+replace_index_drop_fargs_1: {
     options = {
         arguments: true,
         evaluate: true,
         keep_fargs: false,
         properties: true,
+        reduce_vars: true,
     }
     input: {
         var arguments = [];
@@ -101,6 +102,13 @@ replace_index_keep_fargs: {
             var arguments;
             console.log(arguments[1], arguments["1"], arguments["foo"]);
         })("bar", 42);
+        (function() {
+            var arguments = {
+                1: "foo",
+                foo: "bar",
+            };
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
     }
     expect: {
         var arguments = [];
@@ -112,10 +120,17 @@ replace_index_keep_fargs: {
             console.log(b, b, arguments.foo);
         })("bar", 42);
         (function(arguments) {
-            console.log(arguments[1], arguments[1], arguments.foo);
+            console.log("bar"[1], "bar"[1], "bar".foo);
+        })("bar", 42);
+        (function(argument_0, argument_1) {
+            var arguments;
+            console.log(argument_1, argument_1, arguments.foo);
         })("bar", 42);
         (function() {
-            var arguments;
+            var arguments = {
+                1: "foo",
+                foo: "bar",
+            };
             console.log(arguments[1], arguments[1], arguments.foo);
         })("bar", 42);
     }
@@ -125,10 +140,11 @@ replace_index_keep_fargs: {
         "42 42 undefined",
         "a a undefined",
         "42 42 undefined",
+        "foo foo bar",
     ]
 }
 
-replace_index_keep_fargs_strict: {
+replace_index_drop_fargs_2: {
     options = {
         arguments: true,
         evaluate: true,
@@ -237,3 +253,802 @@ duplicate_argname: {
     }
     expect_stdout: "bar 42 foo 42 bar"
 }
+
+fraction: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            return arguments[0.3];
+        }("FAIL") || "PASS");
+    }
+    expect: {
+        console.log(function() {
+            return arguments[0.3];
+        }("FAIL") || "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3273: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        (function(a) {
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect: {
+        (function(a) {
+            console.log(a, a);
+            a++;
+            console.log(a, a);
+        })(0);
+    }
+    expect_stdout: [
+        "0 0",
+        "1 1",
+    ]
+}
+
+issue_3273_no_call_arg: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        (function(a) {
+            arguments[0] = "FAIL";
+            console.log(a);
+        })();
+    }
+    expect: {
+        (function(a) {
+            arguments[0] = "FAIL";
+            console.log(a);
+        })();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_3273_reduce_vars: {
+    options = {
+        arguments: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect: {
+        (function(a) {
+            console.log(a, a);
+            a++;
+            console.log(a, a);
+        })(0);
+    }
+    expect_stdout: [
+        "0 0",
+        "1 1",
+    ]
+}
+
+issue_3273_local_strict: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        (function(a) {
+            "use strict";
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect: {
+        (function(a) {
+            "use strict";
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect_stdout: [
+        "0 0",
+        "1 0",
+    ]
+}
+
+issue_3273_local_strict_reduce_vars: {
+    options = {
+        arguments: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            "use strict";
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect: {
+        (function(a) {
+            "use strict";
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect_stdout: [
+        "0 0",
+        "1 0",
+    ]
+}
+
+issue_3273_global_strict: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        "use strict";
+        (function(a) {
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect: {
+        "use strict";
+        (function(a) {
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect_stdout: [
+        "0 0",
+        "1 0",
+    ]
+}
+
+issue_3273_global_strict_reduce_vars: {
+    options = {
+        arguments: true,
+        reduce_vars: true,
+    }
+    input: {
+        "use strict";
+        (function(a) {
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect: {
+        "use strict";
+        (function(a) {
+            console.log(arguments[0], a);
+            arguments[0]++;
+            console.log(arguments[0], a);
+        })(0);
+    }
+    expect_stdout: [
+        "0 0",
+        "1 0",
+    ]
+}
+
+issue_3273_drop_fargs_1: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        (function() {
+            "use strict";
+            arguments[0]++;
+            console.log(arguments[0]);
+        })(0);
+    }
+    expect: {
+        (function(argument_0) {
+            "use strict";
+            argument_0++;
+            console.log(argument_0);
+        })(0);
+    }
+    expect_stdout: "1"
+}
+
+issue_3273_drop_fargs_2: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        (function() {
+            "use strict";
+            arguments[0]++;
+            console.log(arguments[0]);
+        })(0);
+    }
+    expect: {
+        (function(argument_0) {
+            "use strict";
+            argument_0++;
+            console.log(argument_0);
+        })(0);
+    }
+    expect_stdout: "1"
+}
+
+issue_3282_1: {
+    options = {
+        arguments: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        (function(t) {
+            return function() {
+                t();
+            };
+        })(function() {
+            'use strict';
+            function e() {
+                return arguments[0];
+            }
+            e();
+            e();
+        })();
+    }
+    expect: {
+        (function() {
+            return function() {
+                (function() {
+                    "use strict";
+                    function e() {
+                        return arguments[0];
+                    }
+                    e();
+                    e();
+                })();
+            };
+        })()();
+    }
+    expect_stdout: true
+}
+
+issue_3282_1_passes: {
+    options = {
+        arguments: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        (function(t) {
+            return function() {
+                t();
+            };
+        })(function() {
+            'use strict';
+            function e() {
+                return arguments[0];
+            }
+            e();
+            e();
+        })();
+    }
+    expect: {
+        (function() {
+            return function() {
+                (function() {
+                    "use strict";
+                    function e(argument_0) {
+                        return argument_0;
+                    }
+                    e();
+                    e();
+                })();
+            };
+        })()();
+    }
+    expect_stdout: true
+}
+
+issue_3282_2: {
+    options = {
+        arguments: true,
+        reduce_vars: true,
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        (function(f) {
+            f();
+        })(function() {
+            return (function(t) {
+                return function() {
+                    t();
+                };
+            })(function() {
+                'use strict';
+                function e() {
+                    return arguments[0];
+                }
+                e();
+                e();
+            })();
+        });
+    }
+    expect: {
+        (function() {
+            (function() {
+                return function(t) {
+                    return function() {
+                        t();
+                    };
+                }(function() {
+                    "use strict";
+                    function e() {
+                        return arguments[0];
+                    }
+                    e();
+                    e();
+                })();
+            })();
+        })();
+    }
+    expect_stdout: true
+}
+
+issue_3282_2_passes: {
+    options = {
+        arguments: true,
+        passes: 2,
+        reduce_vars: true,
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        (function(f) {
+            f();
+        })(function() {
+            return (function(t) {
+                return function() {
+                    t();
+                };
+            })(function() {
+                'use strict';
+                function e() {
+                    return arguments[0];
+                }
+                e();
+                e();
+            })();
+        });
+    }
+    expect: {
+        (function() {
+            (function() {
+                return function(t) {
+                    return function() {
+                        t();
+                    };
+                }(function() {
+                    "use strict";
+                    function e(argument_0) {
+                        return argument_0;
+                    }
+                    e();
+                    e();
+                })();
+            })();
+        })();
+    }
+    expect_stdout: true
+}
+
+issue_3420_1: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            return function() {
+                return arguments[0];
+            };
+        }().length);
+    }
+    expect: {
+        console.log(function() {
+            return function() {
+                return arguments[0];
+            };
+        }().length);
+    }
+    expect_stdout: "0"
+}
+
+issue_3420_2: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        var foo = function() {
+            delete arguments[0];
+        };
+        foo();
+    }
+    expect: {
+        var foo = function() {
+            delete arguments[0];
+        };
+        foo();
+    }
+    expect_stdout: true
+}
+
+issue_3420_3: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        "use strict";
+        var foo = function() {
+            delete arguments[0];
+        };
+        foo();
+    }
+    expect: {
+        "use strict";
+        var foo = function() {
+            delete arguments[0];
+        };
+        foo();
+    }
+    expect_stdout: true
+}
+
+issue_3420_4: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        !function() {
+            console.log(arguments[0]);
+            delete arguments[0];
+            console.log(arguments[0]);
+        }(42);
+    }
+    expect: {
+        !function(argument_0) {
+            console.log(argument_0);
+            delete arguments[0];
+            console.log(arguments[0]);
+        }(42);
+    }
+    expect_stdout: [
+        "42",
+        "undefined",
+    ]
+}
+
+issue_3420_5: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        "use strict";
+        !function() {
+            console.log(arguments[0]);
+            delete arguments[0];
+            console.log(arguments[0]);
+        }(42);
+    }
+    expect: {
+        "use strict";
+        !function(argument_0) {
+            console.log(argument_0);
+            delete arguments[0];
+            console.log(arguments[0]);
+        }(42);
+    }
+    expect_stdout: [
+        "42",
+        "undefined",
+    ]
+}
+
+issue_3420_6: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            return delete arguments[0];
+        }());
+    }
+    expect: {
+        console.log(function() {
+            return delete arguments[0];
+        }());
+    }
+    expect_stdout: "true"
+}
+
+issue_3420_7: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        "use strict";
+        console.log(function() {
+            return delete arguments[0];
+        }());
+    }
+    expect: {
+        "use strict";
+        console.log(function() {
+            return delete arguments[0];
+        }());
+    }
+    expect_stdout: "true"
+}
+
+issue_4200: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+    }
+    input: {
+        var o = {
+            get p() {
+                return arguments[0];
+            },
+        };
+        console.log(o.p);
+    }
+    expect: {
+        var o = {
+            get p() {
+                return arguments[0];
+            },
+        };
+        console.log(o.p);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4291_1: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            arguments[0] = "PASS";
+            return arguments;
+        }()[0]);
+    }
+    expect: {
+        console.log(function() {
+            arguments[0] = "PASS";
+            return arguments;
+        }()[0]);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4291_2: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        var a = function() {
+            if (arguments[0])
+                arguments[1] = "PASS";
+            return arguments;
+        }(42);
+        console.log(a[1], a[0], a.length);
+    }
+    expect: {
+        var a = function() {
+            if (arguments[0])
+                arguments[1] = "PASS";
+            return arguments;
+        }(42);
+        console.log(a[1], a[0], a.length);
+    }
+    expect_stdout: "PASS 42 1"
+}
+
+issue_4397: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(typeof function() {
+            arguments += 0;
+            return arguments[0];
+        }());
+    }
+    expect: {
+        console.log(typeof function() {
+            arguments += 0;
+            return arguments[0];
+        }());
+    }
+    expect_stdout: "string"
+}
+
+issue_4410_1: {
+    options = {
+        arguments: true,
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            console.log(arguments[0] === (a = 0) ? "FAIL" : "PASS");
+        })(1);
+    }
+    expect: {
+        (function(a) {
+            console.log(a === (a = 0) ? "FAIL" : "PASS");
+        })(1);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4410_2: {
+    options = {
+        arguments: true,
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function f(a) {
+            console.log(arguments[0] === (a = 0) ? "FAIL" : "PASS");
+        })(1);
+    }
+    expect: {
+        (function f(a) {
+            console.log(arguments[0] === (a = 0) ? "FAIL" : "PASS");
+        })(1);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4410_3: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        var a = 1;
+        (function f(b) {
+            a-- && f();
+            for (var c = 2; c--;)
+                switch (arguments[0]) {
+                  case b = 42:
+                  case 42:
+                    console.log("PASS");
+                }
+        })(null);
+    }
+    expect: {
+        var a = 1;
+        (function f(b) {
+            a-- && f();
+            for (var c = 2; c--;)
+                switch (arguments[0]) {
+                  case b = 42:
+                  case 42:
+                    console.log("PASS");
+                }
+        })(null);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4432: {
+    options = {
+        arguments: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            for (a in { FAIL: 42 });
+            return arguments[0];
+        }() || "PASS");
+    }
+    expect: {
+        console.log(function(a) {
+            for (a in { FAIL: 42 });
+            return arguments[0];
+        }() || "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4696: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+    }
+    input: {
+        console.log(function() {
+            for (arguments in [ 42 ]);
+            for (var a in arguments[0])
+                return "PASS";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            for (arguments in [ 42 ]);
+            for (var a in arguments[0])
+                return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4809: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+        reduce_vars: true,
+    }
+    input: {
+        A = 0;
+        (function() {
+            arguments[A] = "PASS";
+            console.log(arguments[0]);
+        })();
+    }
+    expect: {
+        A = 0;
+        (function() {
+            arguments[A] = "PASS";
+            console.log(arguments[0]);
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/arrays.js

@@ -13,9 +13,11 @@ holes_and_undefined: {
     }
 }
 
-constant_join: {
+constant_join_1: {
     options = {
         evaluate: true,
+        side_effects: true,
+        strings: true,
         unsafe: true,
     }
     input: {
@@ -56,7 +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 = "";
     }
@@ -65,6 +67,7 @@ constant_join: {
 constant_join_2: {
     options = {
         evaluate: true,
+        strings: true,
         unsafe: true,
     }
     input: {
@@ -94,9 +97,11 @@ constant_join_2: {
 constant_join_3: {
     options = {
         evaluate: true,
+        strings: true,
         unsafe: true,
     }
     input: {
+        var foo, bar, baz;
         var a = [ null ].join();
         var b = [ , ].join();
         var c = [ , 1, , 3 ].join();
@@ -111,6 +116,7 @@ constant_join_3: {
         var l = [ foo, bar + "baz" ].join("");
     }
     expect: {
+        var foo, bar, baz;
         var a = "";
         var b = "";
         var c = ",1,,3";
@@ -239,3 +245,182 @@ index_length: {
     }
     expect_stdout: "1 2"
 }
+
+constructor_bad: {
+    options = {
+        unsafe: true
+    }
+    input: {
+        try {
+            Array(NaN);
+            console.log("FAIL1");
+        } catch (ex) {
+            try {
+                new Array(NaN);
+                console.log("FAIL2");
+            } catch (ex) {
+                console.log("PASS");
+            }
+        }
+        try {
+            Array(3.14);
+            console.log("FAIL1");
+        } catch (ex) {
+            try {
+                new Array(3.14);
+                console.log("FAIL2");
+            } catch (ex) {
+                console.log("PASS");
+            }
+        }
+    }
+    expect: {
+        try {
+            Array(NaN);
+            console.log("FAIL1");
+        } catch (ex) {
+            try {
+                Array(NaN);
+                console.log("FAIL2");
+            } catch (ex) {
+                console.log("PASS");
+            }
+        }
+        try {
+            Array(3.14);
+            console.log("FAIL1");
+        } catch (ex) {
+            try {
+                Array(3.14);
+                console.log("FAIL2");
+            } catch (ex) {
+                console.log("PASS");
+            }
+        }
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+    ]
+    expect_warnings: [
+        "WARN: Invalid array length: 3.14 [test/compress/arrays.js:13,12]",
+        "WARN: Invalid array length: 3.14 [test/compress/arrays.js:17,16]",
+    ]
+}
+
+constructor_good: {
+    options = {
+        unsafe: true
+    }
+    input: {
+        console.log(Array());
+        console.log(Array(0));
+        console.log(Array(1));
+        console.log(Array(6));
+        console.log(Array(7));
+        console.log(Array(1, 2));
+        console.log(Array(false));
+        console.log(Array("foo"));
+        console.log(Array(Array));
+        console.log(new Array());
+        console.log(new Array(0));
+        console.log(new Array(1));
+        console.log(new Array(6));
+        console.log(new Array(7));
+        console.log(new Array(1, 2));
+        console.log(new Array(false));
+        console.log(new Array("foo"));
+        console.log(new Array(Array));
+    }
+    expect: {
+        console.log([]);
+        console.log([]);
+        console.log([,]);
+        console.log([,,,,,,]);
+        console.log(Array(7));
+        console.log([ 1, 2 ]);
+        console.log([ false ]);
+        console.log([ "foo" ]);
+        console.log(Array(Array));
+        console.log([]);
+        console.log([]);
+        console.log([,]);
+        console.log([,,,,,,]);
+        console.log(Array(7));
+        console.log([ 1, 2 ]);
+        console.log([ false ]);
+        console.log([ "foo" ]);
+        console.log(Array(Array));
+    }
+    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/ascii.js

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

test/compress/asm.js

@@ -1,5 +1,6 @@
 asm_mixed: {
     options = {
+        assignments: true,
         booleans: true,
         comparisons: true,
         conditionals: true,
@@ -75,9 +76,8 @@ asm_mixed: {
                 start = start | 0;
                 end = end | 0;
                 var sum = 0.0, p = 0, q = 0;
-                for (p = start << 3, q = end << 3; (p | 0) < (q | 0); p = p + 8 | 0) {
+                for (p = start << 3, q = end << 3; (p | 0) < (q | 0); p = p + 8 | 0)
                     sum = sum + +log(values[p >> 3]);
-                }
                 return +sum;
             }
             function geometricMean(start, end) {
@@ -90,12 +90,12 @@ asm_mixed: {
         function no_asm_GeometricMean(stdlib, foreign, buffer) {
             function logSum(start, end) {
                 start |= 0, end |= 0;
-                var sum = 0, p = 0, q = 0;
-                for (p = start << 3, q = end << 3; (0 | p) < (0 | q); p = p + 8 | 0) sum += +log(values[p >> 3]);
+                for (var sum = 0, p = 0, q = 0, p = start << 3, q = end << 3; (0 | p) < (0 | q); p = p + 8 | 0)
+                    sum += +log(values[p >> 3]);
                 return +sum;
             }
             function geometricMean(start, end) {
-                return start |= 0, end |= 0, +exp(+logSum(start, end) / +(end - start | 0));
+                return start |= 0, end |= 0, +exp(+logSum(start, end) / (end - start | 0));
             }
             var exp = stdlib.Math.exp, log = stdlib.Math.log, values = new stdlib.Float64Array(buffer);
             return { geometricMean: geometricMean };
@@ -165,3 +165,69 @@ asm_nested_functions: {
     }
     expect_exact: '0;function a(){"use asm";0.0}0;function b(){0;function c(){"use asm";0.0}0;function d(){0}0}0;'
 }
+
+issue_3636_1: {
+    mangle = {}
+    input: {
+        function n(stdlib, foreign, buffer) {
+            "use asm";
+            function add(x, y) {
+                x = x | 0;
+                y = y | 0;
+                return x + y | 0;
+            }
+            return {
+                add: add
+            };
+        }
+        console.log(new n().add("foo", 42));
+    }
+    expect: {
+        function n(o, e, u) {
+            "use asm";
+            function d(n, o) {
+                n = n | 0;
+                o = o | 0;
+                return n + o | 0;
+            }
+            return {
+                add: d
+            };
+        }
+        console.log(new n().add("foo", 42));
+    }
+    expect_stdout: "42"
+}
+
+issue_3636_2: {
+    mangle = {}
+    input: {
+        var n = function(stdlib, foreign, buffer) {
+            "use asm";
+            function add(x, y) {
+                x = x | 0;
+                y = y | 0;
+                return x + y | 0;
+            }
+            return {
+                add: add
+            };
+        };
+        console.log(new n().add("foo", 42));
+    }
+    expect: {
+        var n = function(n, o, e) {
+            "use asm";
+            function r(n, o) {
+                n = n | 0;
+                o = o | 0;
+                return n + o | 0;
+            }
+            return {
+                add: r
+            };
+        };
+        console.log(new n().add("foo", 42));
+    }
+    expect_stdout: "42"
+}

test/compress/assignment.js

@@ -1,238 +0,0 @@
-op_equals_left_local_var: {
-    options = {
-        evaluate: true,
-    }
-    input: {
-        var x;
-
-        x = x +   3;
-        x = x -   3;
-        x = x /   3;
-        x = x *   3;
-        x = x >>  3;
-        x = x <<  3;
-        x = x >>> 3;
-        x = x |   3;
-        x = x ^   3;
-        x = x %   3;
-        x = x &   3;
-
-        x = x +   g();
-        x = x -   g();
-        x = x /   g();
-        x = x *   g();
-        x = x >>  g();
-        x = x <<  g();
-        x = x >>> g();
-        x = x |   g();
-        x = x ^   g();
-        x = x %   g();
-        x = x &   g();
-    }
-    expect: {
-        var x;
-
-        x   += 3;
-        x   -= 3;
-        x   /= 3;
-        x   *= 3;
-        x  >>= 3;
-        x  <<= 3;
-        x >>>= 3;
-        x   |= 3;
-        x   ^= 3;
-        x   %= 3;
-        x   &= 3;
-
-        x   += g();
-        x   -= g();
-        x   /= g();
-        x   *= g();
-        x  >>= g();
-        x  <<= g();
-        x >>>= g();
-        x   |= g();
-        x   ^= g();
-        x   %= g();
-        x   &= g();
-    }
-}
-
-op_equals_right_local_var: {
-    options = {
-        evaluate: true,
-    }
-    input: {
-        var x;
-
-        x = (x -= 2) ^ x;
-
-        x = 3 +   x;
-        x = 3 -   x;
-        x = 3 /   x;
-        x = 3 *   x;
-        x = 3 >>  x;
-        x = 3 <<  x;
-        x = 3 >>> x;
-        x = 3 |   x;
-        x = 3 ^   x;
-        x = 3 %   x;
-        x = 3 &   x;
-
-        x = g() +   x;
-        x = g() -   x;
-        x = g() /   x;
-        x = g() *   x;
-        x = g() >>  x;
-        x = g() <<  x;
-        x = g() >>> x;
-        x = g() |   x;
-        x = g() ^   x;
-        x = g() %   x;
-        x = g() &   x;
-    }
-    expect: {
-        var x;
-
-        x = (x -= 2) ^ x;
-
-        x = 3 + x;
-        x = 3 - x;
-        x = 3 / x;
-        x *= 3;
-        x = 3 >> x;
-        x = 3 << x;
-        x = 3 >>> x;
-        x |= 3;
-        x ^= 3;
-        x = 3 % x;
-        x &= 3;
-
-        x = g() +   x;
-        x = g() -   x;
-        x = g() /   x;
-        x = g() *   x;
-        x = g() >>  x;
-        x = g() <<  x;
-        x = g() >>> x;
-        x = g() |   x;
-        x = g() ^   x;
-        x = g() %   x;
-        x = g() &   x;
-    }
-}
-op_equals_left_global_var: {
-    options = {
-        evaluate: true,
-    }
-    input: {
-        x = x +   3;
-        x = x -   3;
-        x = x /   3;
-        x = x *   3;
-        x = x >>  3;
-        x = x <<  3;
-        x = x >>> 3;
-        x = x |   3;
-        x = x ^   3;
-        x = x %   3;
-        x = x &   3;
-
-        x = x +   g();
-        x = x -   g();
-        x = x /   g();
-        x = x *   g();
-        x = x >>  g();
-        x = x <<  g();
-        x = x >>> g();
-        x = x |   g();
-        x = x ^   g();
-        x = x %   g();
-        x = x &   g();
-    }
-    expect: {
-        x   += 3;
-        x   -= 3;
-        x   /= 3;
-        x   *= 3;
-        x  >>= 3;
-        x  <<= 3;
-        x >>>= 3;
-        x   |= 3;
-        x   ^= 3;
-        x   %= 3;
-        x   &= 3;
-
-        x   += g();
-        x   -= g();
-        x   /= g();
-        x   *= g();
-        x  >>= g();
-        x  <<= g();
-        x >>>= g();
-        x   |= g();
-        x   ^= g();
-        x   %= g();
-        x   &= g();
-    }
-}
-
-op_equals_right_global_var: {
-    options = {
-        evaluate: true,
-    }
-    input: {
-        x = (x -= 2) ^ x;
-
-        x = 3 +   x;
-        x = 3 -   x;
-        x = 3 /   x;
-        x = 3 *   x;
-        x = 3 >>  x;
-        x = 3 <<  x;
-        x = 3 >>> x;
-        x = 3 |   x;
-        x = 3 ^   x;
-        x = 3 %   x;
-        x = 3 &   x;
-
-        x = g() +   x;
-        x = g() -   x;
-        x = g() /   x;
-        x = g() *   x;
-        x = g() >>  x;
-        x = g() <<  x;
-        x = g() >>> x;
-        x = g() |   x;
-        x = g() ^   x;
-        x = g() %   x;
-        x = g() &   x;
-    }
-    expect: {
-        x = (x -= 2) ^ x;
-
-        x = 3 +   x;
-        x = 3 -   x;
-        x = 3 /   x;
-        x *= 3;
-        x = 3 >>  x;
-        x = 3 <<  x;
-        x = 3 >>> x;
-        x |= 3;
-        x ^= 3;
-        x = 3 %   x;
-        x &= 3;
-
-        x = g() +   x;
-        x = g() -   x;
-        x = g() /   x;
-        x = g() *   x;
-        x = g() >>  x;
-        x = g() <<  x;
-        x = g() >>> x;
-        x = g() |   x;
-        x = g() ^   x;
-        x = g() %   x;
-        x = g() &   x;
-    }
-}

test/compress/assignments.js

@@ -0,0 +1,864 @@
+op_equals_left_local_var: {
+    options = {
+        assignments: true,
+        evaluate: true,
+    }
+    input: {
+        var x;
+
+        x = x +   3;
+        x = x -   3;
+        x = x /   3;
+        x = x *   3;
+        x = x >>  3;
+        x = x <<  3;
+        x = x >>> 3;
+        x = x |   3;
+        x = x ^   3;
+        x = x %   3;
+        x = x &   3;
+
+        x = x +   g();
+        x = x -   g();
+        x = x /   g();
+        x = x *   g();
+        x = x >>  g();
+        x = x <<  g();
+        x = x >>> g();
+        x = x |   g();
+        x = x ^   g();
+        x = x %   g();
+        x = x &   g();
+    }
+    expect: {
+        var x;
+
+        x   += 3;
+        x   -= 3;
+        x   /= 3;
+        x   *= 3;
+        x  >>= 3;
+        x  <<= 3;
+        x >>>= 3;
+        x   |= 3;
+        x   ^= 3;
+        x   %= 3;
+        x   &= 3;
+
+        x   += g();
+        x   -= g();
+        x   /= g();
+        x   *= g();
+        x  >>= g();
+        x  <<= g();
+        x >>>= g();
+        x   |= g();
+        x   ^= g();
+        x   %= g();
+        x   &= g();
+    }
+}
+
+op_equals_right_local_var: {
+    options = {
+        assignments: true,
+        evaluate: true,
+    }
+    input: {
+        var x;
+
+        x = (x -= 2) ^ x;
+
+        x = 3 +   x;
+        x = 3 -   x;
+        x = 3 /   x;
+        x = 3 *   x;
+        x = 3 >>  x;
+        x = 3 <<  x;
+        x = 3 >>> x;
+        x = 3 |   x;
+        x = 3 ^   x;
+        x = 3 %   x;
+        x = 3 &   x;
+
+        x = g() +   x;
+        x = g() -   x;
+        x = g() /   x;
+        x = g() *   x;
+        x = g() >>  x;
+        x = g() <<  x;
+        x = g() >>> x;
+        x = g() |   x;
+        x = g() ^   x;
+        x = g() %   x;
+        x = g() &   x;
+    }
+    expect: {
+        var x;
+
+        x = (x -= 2) ^ x;
+
+        x = 3 + x;
+        x = 3 - x;
+        x = 3 / x;
+        x *= 3;
+        x = 3 >> x;
+        x = 3 << x;
+        x = 3 >>> x;
+        x |= 3;
+        x ^= 3;
+        x = 3 % x;
+        x &= 3;
+
+        x = g() +   x;
+        x = g() -   x;
+        x = g() /   x;
+        x = g() *   x;
+        x = g() >>  x;
+        x = g() <<  x;
+        x = g() >>> x;
+        x = g() |   x;
+        x = g() ^   x;
+        x = g() %   x;
+        x = g() &   x;
+    }
+}
+op_equals_left_global_var: {
+    options = {
+        assignments: true,
+        evaluate: true,
+    }
+    input: {
+        x = x +   3;
+        x = x -   3;
+        x = x /   3;
+        x = x *   3;
+        x = x >>  3;
+        x = x <<  3;
+        x = x >>> 3;
+        x = x |   3;
+        x = x ^   3;
+        x = x %   3;
+        x = x &   3;
+
+        x = x +   g();
+        x = x -   g();
+        x = x /   g();
+        x = x *   g();
+        x = x >>  g();
+        x = x <<  g();
+        x = x >>> g();
+        x = x |   g();
+        x = x ^   g();
+        x = x %   g();
+        x = x &   g();
+    }
+    expect: {
+        x   += 3;
+        x   -= 3;
+        x   /= 3;
+        x   *= 3;
+        x  >>= 3;
+        x  <<= 3;
+        x >>>= 3;
+        x   |= 3;
+        x   ^= 3;
+        x   %= 3;
+        x   &= 3;
+
+        x   += g();
+        x   -= g();
+        x   /= g();
+        x   *= g();
+        x  >>= g();
+        x  <<= g();
+        x >>>= g();
+        x   |= g();
+        x   ^= g();
+        x   %= g();
+        x   &= g();
+    }
+}
+
+op_equals_right_global_var: {
+    options = {
+        assignments: true,
+        evaluate: true,
+    }
+    input: {
+        x = (x -= 2) ^ x;
+
+        x = 3 +   x;
+        x = 3 -   x;
+        x = 3 /   x;
+        x = 3 *   x;
+        x = 3 >>  x;
+        x = 3 <<  x;
+        x = 3 >>> x;
+        x = 3 |   x;
+        x = 3 ^   x;
+        x = 3 %   x;
+        x = 3 &   x;
+
+        x = g() +   x;
+        x = g() -   x;
+        x = g() /   x;
+        x = g() *   x;
+        x = g() >>  x;
+        x = g() <<  x;
+        x = g() >>> x;
+        x = g() |   x;
+        x = g() ^   x;
+        x = g() %   x;
+        x = g() &   x;
+    }
+    expect: {
+        x = (x -= 2) ^ x;
+
+        x = 3 +   x;
+        x = 3 -   x;
+        x = 3 /   x;
+        x *= 3;
+        x = 3 >>  x;
+        x = 3 <<  x;
+        x = 3 >>> x;
+        x |= 3;
+        x ^= 3;
+        x = 3 %   x;
+        x &= 3;
+
+        x = g() +   x;
+        x = g() -   x;
+        x = g() /   x;
+        x = g() *   x;
+        x = g() >>  x;
+        x = g() <<  x;
+        x = g() >>> x;
+        x = g() |   x;
+        x = g() ^   x;
+        x = g() %   x;
+        x = g() &   x;
+    }
+}
+
+increment_decrement_1: {
+    options = {
+        assignments: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            a += 1;
+            a -= 1;
+            return a;
+        }(42));
+    }
+    expect: {
+        console.log(function(a){
+            ++a;
+            --a;
+            return a;
+        }(42));
+    }
+    expect_stdout: "42"
+}
+
+increment_decrement_2: {
+    options = {
+        assignments: true,
+        passes: 2,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            a = a + 1;
+            a = a - 1;
+            a += 1;
+            a -= 1;
+            return a;
+        }(42));
+    }
+    expect: {
+        console.log(function(a){
+            ++a;
+            --a;
+            ++a;
+            --a;
+            return a;
+        }(42));
+    }
+    expect_stdout: "42"
+}
+
+lazily_chained_assignments: {
+    options = {
+        assignments: true,
+        collapse_vars: true,
+        conditionals: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            if (a = console.log("foo"))
+                a = console.log("bar");
+            return a;
+        }
+        function g(b) {
+            if (b = console.log("baz"))
+                ;
+            else
+                b = console.log("moo");
+            return b;
+        }
+        console.log(f(), g());
+    }
+    expect: {
+        function f(a) {
+            return console.log("foo") && console.log("bar");
+        }
+        function g(b) {
+            return console.log("baz") || console.log("moo");
+        }
+        console.log(f(), g());
+    }
+    expect_stdout: [
+        "foo",
+        "baz",
+        "moo",
+        "undefined undefined",
+    ]
+}
+
+issue_3375_1: {
+    options = {
+        assignments: true,
+        reduce_vars: true,
+    }
+    input: {
+        function p(o) {
+            console.log(typeof o, o);
+        }
+        p(function(b) {
+            var a = b += 1;
+            --b;
+            return a;
+        }("object"));
+    }
+    expect: {
+        function p(o) {
+            console.log(typeof o, o);
+        }
+        p(function(b) {
+            var a = b += 1;
+            --b;
+            return a;
+        }("object"));
+    }
+    expect_stdout: "string object1"
+}
+
+issue_3375_2: {
+    options = {
+        assignments: true,
+        reduce_vars: true,
+    }
+    input: {
+        function p(o) {
+            console.log(typeof o, o);
+        }
+        p(function(b) {
+            var a = b -= 1;
+            --b;
+            return a;
+        }("object"));
+    }
+    expect: {
+        function p(o) {
+            console.log(typeof o, o);
+        }
+        p(function(b) {
+            var a = --b;
+            --b;
+            return a;
+        }("object"));
+    }
+    expect_stdout: "number NaN"
+}
+
+issue_3427: {
+    options = {
+        assignments: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a;
+            a || (a = {});
+        })();
+    }
+    expect: {}
+}
+
+issue_3429_1: {
+    options = {
+        assignments: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        (function(b) {
+            b && (b = a = "FAIL");
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        (function(b) {
+            b = b && (a = "FAIL");
+        })();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3429_2: {
+    options = {
+        assignments: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        (function(b) {
+            b || (b = a = "FAIL");
+        })(42);
+        console.log(a);
+    }
+    expect: {
+        var a;
+        (function(b) {
+            b = b || (a = "FAIL");
+        })(42);
+        console.log(a);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_3949_1: {
+    options = {
+        assignments: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        var a = 42;
+        function f() {
+            var b = a;
+            b = b >> 2;
+            return 100 + b;
+        }
+        console.log(f());
+    }
+    expect: {
+        var a = 42;
+        function f() {
+            var b = a;
+            b >>= 2;
+            return 100 + b;
+        }
+        console.log(f());
+    }
+    expect_stdout: "110"
+}
+
+issue_3949_2: {
+    options = {
+        assignments: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        var a = 42;
+        function f() {
+            var b = a;
+            b = 5 & b;
+            return 100 + b;
+        }
+        console.log(f());
+    }
+    expect: {
+        var a = 42;
+        function f() {
+            var b = a;
+            b &= 5;
+            return 100 + b;
+        }
+        console.log(f());
+    }
+    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_1: {
+    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_collapse_vars_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "PASS";
+        (function(b) {
+            b ||= (a = "FAIL", {});
+            return b;
+        })(console).log(a);
+    }
+    expect: {
+        var a = "PASS";
+        (function(b) {
+            return b ||= (a = "FAIL", {});
+        })(console).log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+logical_collapse_vars_3: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 6;
+        a *= 7;
+        a ??= "FAIL";
+        console.log(a);
+    }
+    expect: {
+        var a = 6;
+        a = a * 7 ?? "FAIL";
+        console.log(a);
+    }
+    expect_stdout: "42"
+    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"
+}
+
+evaluate_lazy_assignment: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 42;
+        console.log(a &&= "PASS");
+    }
+    expect: {
+        console.log("PASS");
+    }
+    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: {
+        var a = A = "FAIL", b = "PASS", c;
+        c &&= b = a, console.log(b);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4827_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0, b = "PASS";
+        function f(c) {
+            a++,
+            c &&= b = a;
+        }
+        f();
+        console.log(b);
+    }
+    expect: {
+        var a = 0, b = "PASS";
+        a++,
+        c &&= b = a;
+        var c;
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4827_3: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 0, b, c;
+        a++;
+        c &&= b = a;
+        console.log(b);
+    }
+    expect: {
+        var a = 0, b, c;
+        a++;
+        c &&= b = a;
+        console.log(b);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=15"
+}
+
+issue_4876: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        try {
+            var a = null;
+            var b = a &&= 42;
+            b.p;
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            var a = null;
+            var b = a &&= 42;
+            b.p;
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4924_1: {
+    options = {
+        collapse_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, b;
+        console.log("PASS");
+        a = function() {};
+        b = function() {}(b ||= a);
+    }
+    expect: {
+        var b;
+        console.log("PASS");
+        b = void (b ||= function() {});
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_4924_2: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        passes: 2,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, b;
+        console.log("PASS");
+        a = function() {};
+        b = function() {}(b ||= a);
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=15"
+}
+
+issue_5670: {
+    options = {
+        assignments: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a, b) {
+            a && a && (a = b += "") || console.log("PASS");
+        })();
+    }
+    expect: {
+        (function(a, b) {
+            a = a,
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}

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: ">=10.4.0"
+}
+
+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: ">=10.4.0"
+}
+
+evaluate: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log((0xDEAD_BEEFn).toString(16));
+    }
+    expect: {
+        console.log(0xdeadbeefn.toString(16));
+    }
+    expect_stdout: "deadbeef"
+    node_version: ">=10.4.0"
+}
+
+Number: {
+    options = {
+        unsafe: true,
+    }
+    input: {
+        console.log(Number(-0xfeed_dead_beef_badn));
+    }
+    expect: {
+        console.log(+("" + -0xfeed_dead_beef_badn));
+    }
+    expect_stdout: "-1148098955808013200"
+    node_version: ">=10.4.0"
+}
+
+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: ">=10.4.0"
+}
+
+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: ">=10.4.0"
+}

test/compress/booleans.js

@@ -0,0 +1,866 @@
+iife_boolean_context: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        console.log(function() {
+            return Object(1) || false;
+        }() ? "PASS" : "FAIL");
+        console.log(function() {
+            return [].length || true;
+        }() ? "PASS" : "FAIL");
+    }
+    expect: {
+        console.log(function() {
+            return Object(1);
+        }() ? "PASS" : "FAIL");
+        console.log(function() {
+            return [].length, 1;
+        }() ? "PASS" : "FAIL");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+    ]
+    expect_warnings: [
+        "WARN: Dropping side-effect-free || [test/compress/booleans.js:2,19]",
+        "WARN: Boolean || always true [test/compress/booleans.js:5,19]",
+    ]
+}
+
+de_morgan_1a: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        function f(a) {
+            return a || a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect: {
+        function f(a) {
+            return a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect_stdout: "null 42"
+}
+
+de_morgan_1b: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        function f(a) {
+            return a && a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect: {
+        function f(a) {
+            return a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect_stdout: "null 42"
+}
+
+de_morgan_1c: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        console.log(delete (NaN && NaN));
+    }
+    expect: {
+        console.log(delete (0, NaN));
+    }
+    expect_stdout: "true"
+}
+
+de_morgan_1d: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        function f(a) {
+            return (a = false) || a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect: {
+        function f(a) {
+            return a = !1;
+        }
+        console.log(f(null), f(42));
+    }
+    expect_stdout: "false false"
+}
+
+de_morgan_2a: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b) {
+            return a || (a || b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a || b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "undefined {}",
+        "42 42",
+    ]
+}
+
+de_morgan_2b: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a || (a && b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "42 42",
+    ]
+}
+
+de_morgan_2c: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a && (a || b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "42 42",
+    ]
+}
+
+de_morgan_2d: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            return a && (a && b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a && b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "undefined {}",
+    ]
+}
+
+de_morgan_2e: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b) {
+            return (a && b) && b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a && b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "undefined {}",
+    ]
+}
+
+de_morgan_3a: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a || b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || b || c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "undefined {} true true",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3b: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a || b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || b && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "false false undefined {}",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3c: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a && b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "undefined {} undefined {}",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3d: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a && b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3e: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a || b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3f: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a || b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "undefined {} undefined {}",
+    ]
+}
+
+de_morgan_3g: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a && b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && (b || c);
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "undefined {} true true",
+    ]
+}
+
+de_morgan_3h: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a && b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && b && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "false false undefined {}",
+    ]
+}
+
+conditional_chain: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a ? a : b ? b : 42;
+        }
+        console.log(f("PASS", "FAIL"));
+    }
+    expect: {
+        function f(a, b) {
+            return a || b || 42;
+        }
+        console.log(f("PASS", "FAIL"));
+    }
+    expect_stdout: "PASS"
+}
+
+negated_if: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(function(a) {
+            if (!a)
+                return a ? "FAIL" : "PASS";
+        }(!console));
+    }
+    expect: {
+        console.log(function(a) {
+            if (!a)
+                return "PASS";
+        }(!console));
+    }
+    expect_stdout: "PASS"
+}
+
+concat_truthy: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        console.log("foo") + (console.log("bar"), "baz") || console.log("moo");
+    }
+    expect: {
+        console.log("foo") + (console.log("bar"), "baz");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    expect_warnings: [
+        "WARN: + in boolean context always true [test/compress/booleans.js:1,8]",
+        "WARN: Condition left of || always true [test/compress/booleans.js:1,8]",
+    ]
+}
+
+process_returns: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        (function() {
+            return 42;
+        })() && console.log("PASS");
+    }
+    expect: {
+        (function() {
+            return 42;
+        })() && console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3465_1: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        console.log(function(a) {
+            return typeof a;
+        }() ? "PASS" : "FAIL");
+    }
+    expect: {
+        console.log(function(a) {
+            return 1;
+        }() ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3465_2: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        console.log(function f(a) {
+            if (!a) console.log(f(42));
+            return typeof a;
+        }() ? "PASS" : "FAIL");
+    }
+    expect: {
+        console.log(function f(a) {
+            if (!a) console.log(f(42));
+            return typeof a;
+        }() ? "PASS" : "FAIL");
+    }
+    expect_stdout: [
+        "number",
+        "PASS",
+    ]
+}
+
+issue_3465_3: {
+    options = {
+        booleans: true,
+        passes: 2,
+        unused: true,
+    }
+    input: {
+        console.log(function f(a) {
+            return typeof a;
+        }() ? "PASS" : "FAIL");
+    }
+    expect: {
+        console.log(function(a) {
+            return 1;
+        }() ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2737_2: {
+    options = {
+        booleans: true,
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(bar) {
+            for (;bar();) break;
+        })(function qux() {
+            return console.log("PASS"), qux;
+        });
+    }
+    expect: {
+        (function(bar) {
+            for (;bar();) break;
+        })(function() {
+            return console.log("PASS"), 1;
+        });
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3658: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function f() {
+            console || f();
+            return "PASS";
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            console || f();
+            return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3690: {
+    options = {
+        booleans: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            return function() {
+                return a = [ this ];
+            }() ? "PASS" : "FAIL";
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            return function() {
+                return 1;
+            }() ? "PASS" : "FAIL";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4374: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        if_return: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            console.log(f());
+            function f(a) {
+                if (null) return 0;
+                if (a) return 1;
+                return 0;
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            console.log(function(a) {
+                return !null && a ? 1 : 0;
+            }());
+        })();
+    }
+    expect_stdout: "0"
+}
+
+issue_5028_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var a = 1;
+        console.log(function() {
+            return a-- ? a-- ? "FAIL 1" : "PASS" : "FAIL 2";
+        }());
+    }
+    expect: {
+        var a = 1;
+        console.log(function() {
+            return a-- ? a-- ? "FAIL 1" : "PASS" : "FAIL 2";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5028_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        dead_code: true,
+        if_return: true,
+    }
+    input: {
+        var a = 1;
+        (function() {
+            if (a--)
+                if (a--)
+                    a = "FAIL";
+                else
+                    return;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        (function() {
+            a-- && a-- && (a = "FAIL");
+        })();
+        console.log(a);
+    }
+    expect_stdout: "-1"
+}
+
+issue_5028_3: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        if_return: true,
+    }
+    input: {
+        var a = 1;
+        (function() {
+            if (a--)
+                if (a--)
+                    a = "FAIL";
+                else
+                    return;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        (function() {
+            a-- && a-- && (a = "FAIL");
+        })();
+        console.log(a);
+    }
+    expect_stdout: "-1"
+}
+
+issue_5041_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var a = 42;
+        if (a)
+            if ([ a = null ])
+                if (a)
+                    console.log("FAIL");
+                else
+                    console.log("PASS");
+    }
+    expect: {
+        var a = 42;
+        a && [ a = null ] && (a ? console.log("FAIL") : console.log("PASS"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5041_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var a;
+        if (!a)
+            if (a = 42)
+                if (a)
+                    console.log("PASS");
+                else
+                    console.log("FAIL");
+    }
+    expect: {
+        var a;
+        a || (a = 42) && (a ? console.log("PASS") : console.log("FAIL"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5228: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+    }
+    input: {
+        console.log(function() {
+            return !function() {
+                do {
+                    return null;
+                } while (console);
+            }();
+        }());
+    }
+    expect: {
+        console.log(function() {
+            do {
+                return !0;
+            } while (console);
+            return !0;
+        }());
+    }
+    expect_stdout: "true"
+}
+
+issue_5469: {
+    options = {
+        assignments: true,
+        booleans: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        console.log(function f(a) {
+            a && 42[a = A && null];
+        }());
+    }
+    expect: {
+        console.log(function f(a) {
+            a && A,
+            0;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5694_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var Infinity;
+        // Node.js v0.12~6 (vm): 42
+        console.log((Infinity = 42) && Infinity);
+    }
+    expect: {
+        var Infinity;
+        console.log((Infinity = 42) && Infinity);
+    }
+    expect_stdout: true
+}
+
+issue_5694_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var undefined;
+        // Node.js v0.12~6 (vm): NaN
+        console.log(("foo", ++undefined) || undefined);
+    }
+    expect: {
+        var undefined;
+        console.log(("foo", ++undefined) || undefined);
+    }
+    expect_stdout: true
+}

test/compress/comparisons.js

@@ -33,10 +33,26 @@ unsafe_comps: {
     }
     expect: {
         var obj1, obj2;
-        obj2 <  obj1 ? g1() : f1();
-        obj1 <  obj2 ? f2() : g2();
-        obj1 <  obj2 ? g3() : f3();
-        obj2 <  obj1 ? f4() : g4();
+        (obj2 <  obj1 ? g1 : f1)();
+        (obj1 <  obj2 ? f2 : g2)();
+        (obj1 <  obj2 ? g3 : f3)();
+        (obj2 <  obj1 ? f4 : g4)();
+    }
+}
+
+unsafe_in_instanceof: {
+    options = {
+        side_effects: true,
+        unsafe_comps: true,
+    }
+    input: {
+        var a;
+        42 in a;
+        f() instanceof "foo";
+    }
+    expect: {
+        var a;
+        f();
     }
 }
 
@@ -93,6 +109,59 @@ self_comparison_2: {
     expect_stdout: "false true"
 }
 
+self_comparison_3: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        var a;
+        function f() {
+            var b = a;
+            a = null;
+            return b;
+        }
+        for (var i = 0; i < 2; i++)
+            console.log(f() === f());
+    }
+    expect: {
+        var a;
+        function f() {
+            var b = a;
+            a = null;
+            return b;
+        }
+        for (var i = 0; i < 2; i++)
+            console.log(f() === f());
+    }
+    expect_stdout: [
+        "false",
+        "true",
+    ]
+}
+
+self_comparison_4: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {};
+        console.log(o == o, o != o);
+        console.log(o === o, o !== o);
+    }
+    expect: {
+        console.log(!0, !1);
+        console.log(!0, !1);
+    }
+    expect_stdout: [
+        "true false",
+        "true false",
+    ]
+}
+
 issue_2857_1: {
     options = {
         comparisons: true,
@@ -206,6 +275,7 @@ issue_2857_3: {
 issue_2857_4: {
     options = {
         comparisons: true,
+        conditionals: true,
     }
     input: {
         function f(a, p) {
@@ -236,6 +306,7 @@ issue_2857_4: {
 issue_2857_5: {
     options = {
         comparisons: true,
+        conditionals: true,
     }
     input: {
         function f(a, p) {
@@ -323,3 +394,150 @@ is_number_unsafe: {
     }
     expect_stdout: "true"
 }
+
+is_boolean_var: {
+    options = {
+        comparisons: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a, b) {
+            for (var i = 0, c = !b; i < a.length; i++)
+                if (!a[i] === c)
+                    return i;
+        }([ false, true ], 42));
+    }
+    expect: {
+        console.log(function(a, b) {
+            for (var i = 0, c = !b; i < a.length; i++)
+                if (!a[i] == c)
+                    return i;
+        }([ false, true ], 42));
+    }
+    expect_stdout: "1"
+}
+
+is_defined: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        console.log(function a() {
+            return void 0 === a;
+        }());
+    }
+    expect: {
+        console.log(function a() {
+            return a, false;
+        }());
+    }
+    expect_stdout: "false"
+    expect_warnings: [
+        "WARN: Expression always defined [test/compress/comparisons.js:2,19]",
+    ]
+}
+
+unsafe_indexOf: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        unsafe: true,
+    }
+    input: {
+        var a = Object.keys({ foo: 42 });
+        if (a.indexOf("bar") < 0) console.log("PASS");
+        if (0 > a.indexOf("bar")) console.log("PASS");
+        if (a.indexOf("foo") >= 0) console.log("PASS");
+        if (0 <= a.indexOf("foo")) console.log("PASS");
+        if (a.indexOf("foo") > -1) console.log("PASS");
+        if (-1 < a.indexOf("foo")) console.log("PASS");
+        if (a.indexOf("bar") == -1) console.log("PASS");
+        if (-1 == a.indexOf("bar")) console.log("PASS");
+        if (a.indexOf("bar") === -1) console.log("PASS");
+        if (-1 === a.indexOf("bar")) console.log("PASS");
+        if (a.indexOf("foo") != -1) console.log("PASS");
+        if (-1 != a.indexOf("foo")) console.log("PASS");
+        if (a.indexOf("foo") !== -1) console.log("PASS");
+        if (-1 !== a.indexOf("foo")) console.log("PASS");
+    }
+    expect: {
+        var a = Object.keys({ foo: 42 });
+        if (!~a.indexOf("bar")) console.log("PASS");
+        if (!~a.indexOf("bar")) console.log("PASS");
+        if (~a.indexOf("foo")) console.log("PASS");
+        if (~a.indexOf("foo")) console.log("PASS");
+        if (~a.indexOf("foo")) console.log("PASS");
+        if (~a.indexOf("foo")) console.log("PASS");
+        if (!~a.indexOf("bar")) console.log("PASS");
+        if (!~a.indexOf("bar")) console.log("PASS");
+        if (!~a.indexOf("bar")) console.log("PASS");
+        if (!~a.indexOf("bar")) console.log("PASS");
+        if (~a.indexOf("foo")) console.log("PASS");
+        if (~a.indexOf("foo")) console.log("PASS");
+        if (~a.indexOf("foo")) console.log("PASS");
+        if (~a.indexOf("foo")) console.log("PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+}
+
+issue_3413: {
+    options = {
+        comparisons: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        var b;
+        void 0 !== ("" < b || void 0) || console.log("PASS");
+    }
+    expect: {
+        var b;
+        void 0 === ("" < b || void 0) && console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+nullish_assign: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        var a;
+        void 0 !== (a = "PASS".split("")) && null !== a && console.log(a.join("-"));
+    }
+    expect: {
+        var a;
+        null != (a = "PASS".split("")) && console.log(a.join("-"));
+    }
+    expect_stdout: "P-A-S-S"
+}
+
+nullish_chain: {
+    options = {
+        comparisons: true,
+        conditionals: true,
+    }
+    input: {
+        var a;
+        A || B || void 0 === a || null === a || C;
+    }
+    expect: {
+        var a;
+        A || B || null == a || C;
+    }
+}

test/compress/concat-strings.js

@@ -12,7 +12,7 @@ concat_1: {
 
         var e = 1 + x() + 2 + "X" + 3 + "boo";
 
-        // be careful with concatentation with "\0" with octal-looking strings.
+        // be careful with concatenation with "\0" with octal-looking strings.
         var f = "\0" + 360 + "\0" + 8 + "\0";
     }
     expect: {
@@ -26,7 +26,9 @@ concat_1: {
 }
 
 concat_2: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             1 + (2 + 3),
@@ -55,7 +57,9 @@ concat_2: {
 }
 
 concat_3: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             1 + 2 + (3 + 4 + 5),
@@ -84,7 +88,9 @@ concat_3: {
 }
 
 concat_4: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             1 + "2" + (3 + 4 + 5),
@@ -113,7 +119,9 @@ concat_4: {
 }
 
 concat_5: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             "1" + 2 + (3 + 4 + 5),
@@ -142,7 +150,9 @@ concat_5: {
 }
 
 concat_6: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             "1" + "2" + (3 + 4 + 5),
@@ -171,6 +181,9 @@ concat_6: {
 }
 
 concat_7: {
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             "" + 1,
@@ -197,6 +210,9 @@ concat_7: {
 }
 
 concat_8: {
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             1 + "",
@@ -221,3 +237,87 @@ concat_8: {
     }
     expect_stdout: true
 }
+
+concat_9: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        reduce_vars: true,
+        strings: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "foo";
+        console.log(
+            12 + (34 + a),
+            null + (34 + a),
+            12 + (null + a),
+            false + (34 + a),
+            12 + (false + a),
+            "bar" + (34 + a),
+            12 + ("bar" + a)
+        );
+    }
+    expect: {
+        var a = "foo";
+        console.log(
+            "1234" + a,
+            "null34" + a,
+            "12null" + a,
+            !1 + (34 + a),
+            12 + (!1 + a),
+            "bar34" + a,
+            "12bar" + a
+        );
+    }
+    expect_stdout: true
+}
+
+concat_sequence: {
+    options = {
+        collapse_vars: true,
+        strings: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        console.log(12 + (a = null, "34" + a));
+    }
+    expect: {
+        console.log(12 + "34" + null);
+    }
+    expect_stdout: "1234null"
+}
+
+issue_3689: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a + ("" + (a[0] = 0));
+        }([]));
+    }
+    expect: {
+        console.log(function(a) {
+            return a + ("" + (a[0] = 0));
+        }([]));
+    }
+    expect_stdout: "00"
+}
+
+issue_5145: {
+    options = {
+        strings: true,
+    }
+    input: {
+        var a = [];
+        console.log("" + a + ((a[0] = 4) + "2"));
+    }
+    expect: {
+        var a = [];
+        console.log("" + a + (a[0] = 4) + "2");
+    }
+    expect_stdout: "42"
+}

test/compress/directives.js

@@ -0,0 +1,175 @@
+simple_statement_is_not_a_directive: {
+    input: {
+        "use strict"
+            .split(" ")
+            .forEach(function(s) {
+                console.log(s);
+            });
+        console.log(!this); // is strict mode?
+        (function() {
+            "directive"
+            ""
+            "use strict"
+            "hello world"
+                .split(" ")
+                .forEach(function(s) {
+                    console.log(s);
+                });
+            console.log(!this); // is strict mode?
+        })();
+    }
+    expect: {
+        "use strict".split(" ").forEach(function(s) {
+            console.log(s);
+        });
+        console.log(!this);
+        (function() {
+            "directive";
+            "";
+            "use strict";
+            "hello world".split(" ").forEach(function(s) {
+                console.log(s);
+            });
+            console.log(!this);
+        })();
+    }
+    expect_stdout: [
+        "use",
+        "strict",
+        "false",
+        "hello",
+        "world",
+        "true",
+    ]
+}
+
+drop_lone_use_strict: {
+    options = {
+        directives: true,
+        unused: true,
+    }
+    input: {
+        function f1() {
+            "use strict";
+        }
+        function f2() {
+            "use strict";
+            function f3() {
+                "use strict";
+            }
+        }
+        (function f4() {
+            "use strict";
+        })();
+    }
+    expect: {
+        function f1() {
+        }
+        function f2() {
+        }
+        (function() {})();
+    }
+}
+
+issue_3166: {
+    options = {
+        directives: true,
+    }
+    input: {
+        "foo";
+        "use strict";
+        function f() {
+            "use strict";
+            "bar";
+            "use asm";
+        }
+    }
+    expect: {
+        "use strict";
+        function f() {
+            "use asm";
+        }
+    }
+}
+
+valid_after_invalid_1: {
+    input: {
+        console.log(typeof function() {
+            "use\x20strict";
+            "use strict";
+            return this;
+        }());
+    }
+    expect: {
+        console.log(typeof function() {
+            "use\x20strict";
+            "use strict";
+            return this;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+valid_after_invalid_2: {
+    options = {
+        directives: true,
+    }
+    input: {
+        console.log(typeof function() {
+            "use\x20strict";
+            "use strict";
+            return this;
+        }());
+    }
+    expect: {
+        console.log(typeof function() {
+            "use strict";
+            return this;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5368_1: {
+    expression = true
+    options = {
+        directives: true,
+        expression: true,
+    }
+    input: {
+        "foo"
+    }
+    expect_exact: '"foo"'
+    expect_stdout: "foo"
+}
+
+issue_5368_2: {
+    expression = true
+    options = {
+        directives: true,
+        expression: true,
+    }
+    input: {
+        (function() {
+            "foo";
+        })()
+    }
+    expect_exact: "function(){}()"
+    expect_stdout: "undefined"
+}
+
+issue_5368_3: {
+    options = {
+        directives: true,
+        expression: true,
+    }
+    input: {
+        "foo";
+        (function() {
+            "bar";
+        })();
+    }
+    expect: {
+        (function() {})();
+    }
+}

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: ">=10.4.0"
+}
+
+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, 2 ** 30, 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 +1,582 @@
+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";'
+}
+
+non_identifiers: {
+    beautify = {
+        quote_style: 3,
+    }
+    input: {
+        export * as "42" from 'foo';
+        export { '42', "delete" as 'foo' } from "bar";
+    }
+    expect_exact: "export*as\"42\"from'foo';export{'42',delete as foo}from\"bar\";"
+}
+
+same_quotes: {
+    beautify = {
+        beautify: true,
+        quote_style: 3,
+    }
+    input: {
+        export * from 'foo';
+        export {} from "bar";
+    }
+    expect_exact: [
+        "export * from 'foo';",
+        "",
+        'export {} from "bar";',
+    ]
+}
+
+drop_unused: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default 42;
+        export default (x, y) => x * x;
+        export default class A extends B { get p() { h() } }
+        export default function*(a, b) {}
+        export default async function f({ c }, ...[ d ]) {}
+        export var e;
+        export function g(x, [ y ], ...z) {}
+        function h() {}
+    }
+    expect: {
+        export default 42;
+        export default (x, y) => x * x;
+        export default class extends B { get p() { h() } }
+        export default function*(a, b) {}
+        export default async function({}) {}
+        export var e;
+        export function g(x, []) {}
+        function h() {}
+    }
+}
+
+mangle: {
+    rename = false
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        const a = 42;
+        export let b, { foo: c } = a;
+        export function f(d, { [b]: e }) {
+            d(e, f);
+        }
+        export default a;
+        export default async function g(x, ...{ [c]: y }) {
+            (await x)(g, y);
+        }
+    }
+    expect: {
+        const t = 42;
+        export let b, { foo: c } = t;
+        export function f(t, { [b]: o }) {
+            t(o, f);
+        }
+        export default t;
+        export default async function e(t, ...{ [c]: o}) {
+            (await t)(e, o);
+        }
+    }
+}
+
+mangle_rename: {
+    rename = true
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        const a = 42;
+        export let b, { foo: c } = a;
+        export function f(d, { [b]: e }) {
+            d(e, f);
+        }
+        export default a;
+        export default async function g(x, ...{ [c]: y }) {
+            (await x)(g, y);
+        }
+    }
+    expect: {
+        const t = 42;
+        export let b, { foo: c } = t;
+        export function f(t, { [b]: o }) {
+            t(o, f);
+        }
+        export default t;
+        export default async function e(t, ...{ [c]: o}) {
+            (await t)(e, o);
+        }
+    }
+}
+
+hoist_exports_1: {
+    options = {
+        hoist_exports: true,
+    }
+    input: {
+        export { a };
+        export var b;
+        export function f() {}
+    }
+    expect: {
+        var b;
+        function f() {}
+        export { a, b, f };
+    }
+}
+
+hoist_exports_2: {
+    options = {
+        evaluate: true,
+        hoist_exports: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        const a = 42;
+        export let bbb, { foo: ccc } = a;
+        export function fff(d, { [bbb]: e }) {
+            d(e, fff);
+        }
+        export default a;
+        export default async function g(x, ...{ [ccc]: y }) {
+            (await x)(g, y);
+        }
+    }
+    expect: {
+        let e, a = 42["foo"];
+        function f(t, { [e]: o }) {
+            t(o, f);
+        }
+        export default 42;
+        export default async function n(t, ...{ [a]: o }) {
+            (await t)(n, o);
+        };
+        export { e as bbb, a as ccc, f as fff };
+    }
+}
+
+hoist_vars: {
+    options = {
+        hoist_vars: true,
+    }
+    input: {
+        var a;
+        export var b = 42;
+    }
+    expect: {
+        var a;
+        export var b = 42;
+    }
+}
+
+keep_return_values: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        export default function() {
+            return [];
+        }
+        export default function f() {
+            return null;
+        }
+    }
+    expect: {
+        export default function() {
+            return [];
+        }
+        export default function f() {
+            return null;
+        }
+    }
+}
+
+in_use: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f() {}
+        f.prototype.p = 42;
+    }
+    expect: {
+        export function f() {}
+        f.prototype.p = 42;
+    }
+}
+
+in_use_default: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f() {}
+        f.prototype.p = 42;
+    }
+    expect: {
+        export default function f() {}
+        f.prototype.p = 42;
+    }
+}
+
+single_use: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f() {
+            console.log("PASS");
+        }
+        f();
+    }
+    expect: {
+        export function f() {
+            console.log("PASS");
+        }
+        f();
+    }
+}
+
+single_use_default: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f() {
+            console.log("PASS");
+        }
+        f();
+    }
+    expect: {
+        export default function f() {
+            console.log("PASS");
+        }
+        f();
+    }
+}
+
+single_use_class: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export class A {}
+        A.prototype.p = "PASS";
+    }
+    expect: {
+        export class A {}
+        A.prototype.p = "PASS";
+    }
+}
+
+single_use_class_default: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class A {}
+        A.prototype.p = "PASS";
+    }
+    expect: {
+        export default class A {}
+        A.prototype.p = "PASS";
+    }
+}
+
+hoist_funs: {
+    options = {
+        hoist_funs: true,
+    }
+    input: {
+        export function f() {}
+        export default async function* g() {}
+    }
+    expect_exact: "export function f(){}export default async function*g(){}"
+}
+
+instanceof_default_class: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class A {
+            f(a) {
+                return a instanceof A;
+            }
+        }
+    }
+    expect: {
+        export default class A {
+            f(a) {
+                return a instanceof A;
+            }
+        }
+    }
+}
+
+instanceof_default_function: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f() {
+            if (!(this instanceof f))
+                throw new Error("must instantiate");
+        }
+    }
+    expect: {
+        export default function f() {
+            if (!(this instanceof f))
+                throw new Error("must instantiate");
+        }
+    }
+}
+
+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";
+    }
+}
+
+issue_5444: {
+    options = {
+        unused: true,
+    }
+    input: {
+        export var a = (console, console);
+    }
+    expect: {
+        console;
+        export var a = console;
+    }
+}
+
+issue_5628: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a;
+        export default function f() {
+            for (a in 42);
+        }
+        console.log(a);
+    }
+    expect: {
+        var a;
+        export default function f() {
+            for (a in 42);
+        }
+        console.log(a);
+    }
+}

test/compress/global_defs.js

@@ -12,6 +12,20 @@ must_replace: {
     }
 }
 
+repeated_nodes: {
+    options = {
+        global_defs: {
+            "@N": "rand()",
+        },
+    }
+    input: {
+        console.log(N, N);
+    }
+    expect: {
+        console.log(rand(), rand());
+    }
+}
+
 keyword: {
     options = {
         global_defs: {
@@ -141,9 +155,8 @@ mixed: {
         console.log(CONFIG);
     }
     expect_warnings: [
-        "WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:127,22]",
-        "WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:128,22]",
-        "WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:130,8]",
+        "WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:4,22]",
+        "WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:7,8]",
     ]
 }
 
@@ -197,3 +210,23 @@ issue_2167: {
         doWork();
     }
 }
+
+issue_3217: {
+    options = {
+        collapse_vars: true,
+        global_defs: {
+            "@o": "{fn:function(){var a=42;console.log(a)}}",
+        },
+        inline: true,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        o.fn();
+    }
+    expect: {
+        console.log(42);
+    }
+}

test/compress/hoist_props.js

@@ -217,7 +217,8 @@ name_collision_1: {
         var obj_foo = 1;
         var obj_bar = 2;
         function f() {
-            var obj_foo$0 = 3,
+            var obj,
+                obj_foo$0 = 3,
                 obj_bar = 4,
                 obj_b_r = 5,
                 obj_b_r$0 = 6,
@@ -249,7 +250,8 @@ name_collision_2: {
         console.log(o.p === o.p, o["+"](4), o["-"](5), o__$0, o__$1);
     }
     expect: {
-        var o_p = 1,
+        var o,
+            o_p = 1,
             o__ = function(x) {
                 return x;
             },
@@ -283,7 +285,8 @@ name_collision_3: {
         console.log(o.p === o.p, o["+"](4), o["-"](5));
     }
     expect: {
-        var o_p = 1,
+        var o,
+            o_p = 1,
             o__ = function(x) {
                 return x;
             },
@@ -297,6 +300,33 @@ name_collision_3: {
     expect_stdout: "true 4 6"
 }
 
+name_collision_4: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 0,
+                q: "PASS",
+            };
+            return function(o_p) {
+                if (!o.p) return o_p;
+            }(o.q);
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o, o_p$0 = 0, o_q = "PASS";
+            return function(o_p) {
+                if (!o_p$0) return o_p;
+            }(o_q);
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
 contains_this_1: {
     options = {
         evaluate: true,
@@ -432,6 +462,11 @@ issue_2473_1: {
         var x = {};
         var y = [];
     }
+    expect_warnings: [
+        "INFO: Retaining variable x",
+        "INFO: Retaining variable y",
+        "WARN: Dropping unused variable z [test/compress/hoist_props.js:3,12]",
+    ]
 }
 
 issue_2473_2: {
@@ -454,6 +489,11 @@ issue_2473_2: {
         var x = {};
         var y = [];
     }
+    expect_warnings: [
+        "INFO: Retaining variable x",
+        "INFO: Retaining variable y",
+        "WARN: Dropping unused variable z [test/compress/hoist_props.js:3,12]",
+    ]
 }
 
 issue_2473_3: {
@@ -479,6 +519,9 @@ issue_2473_3: {
         console.log(o.a, o.b);
     }
     expect_stdout: "1 2"
+    expect_warnings: [
+        "INFO: Retaining variable o",
+    ]
 }
 
 issue_2473_4: {
@@ -505,6 +548,9 @@ issue_2473_4: {
         })();
     }
     expect_stdout: "1 2"
+    expect_warnings: [
+        "INFO: Dropping unused variable o [test/compress/hoist_props.js:2,16]",
+    ]
 }
 
 issue_2508_1: {
@@ -664,7 +710,7 @@ issue_2519: {
     }
     expect: {
         function testFunc() {
-            return 1 * ((6 + 5) / 2);
+            return +((6 + 5) / 2);
         }
         console.log(testFunc());
     }
@@ -741,7 +787,7 @@ issue_3046: {
     expect: {
         console.log(function(a) {
             do {
-                var b_c = a++;
+                var b, b_c = a++;
             } while (b_c && a);
             return a;
         }(0));
@@ -750,6 +796,32 @@ issue_3046: {
 }
 
 issue_3071_1: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        join_vars: true,
+        passes: 3,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var obj = {};
+            obj.one = 1;
+            obj.two = 2;
+            console.log(obj.one, obj.two);
+        })();
+    }
+    expect: {
+        console.log(1, 2);
+    }
+    expect_stdout: "1 2"
+}
+
+issue_3071_1_toplevel: {
     options = {
         evaluate: true,
         hoist_props: true,
@@ -767,18 +839,17 @@ issue_3071_1: {
             var obj = {};
             obj.one = 1;
             obj.two = 2;
-            console.log(obj.one);
+            console.log(obj.one, obj.two);
         })();
     }
     expect: {
-        console.log(1);
+        console.log(1, 2);
     }
-    expect_stdout: "1"
+    expect_stdout: "1 2"
 }
 
 issue_3071_2: {
     options = {
-        evaluate: true,
         hoist_props: true,
         inline: true,
         join_vars: true,
@@ -793,19 +864,18 @@ issue_3071_2: {
             obj = {};
             obj.one = 1;
             obj.two = 2;
-            console.log(obj.one);
+            console.log(obj.one, obj.two);
             var obj;
         })();
     }
     expect: {
-        console.log(1);
+        console.log(1, 2);
     }
-    expect_stdout: "1"
+    expect_stdout: "1 2"
 }
 
 issue_3071_2_toplevel: {
     options = {
-        evaluate: true,
         hoist_props: true,
         inline: true,
         join_vars: true,
@@ -821,14 +891,14 @@ issue_3071_2_toplevel: {
             obj = {};
             obj.one = 1;
             obj.two = 2;
-            console.log(obj.one);
+            console.log(obj.one, obj.two);
             var obj;
         })();
     }
     expect: {
-        console.log(1);
+        console.log(1, 2);
     }
-    expect_stdout: "1"
+    expect_stdout: "1 2"
 }
 
 issue_3071_3: {
@@ -862,3 +932,311 @@ issue_3071_3: {
     }
     expect_stdout: "2"
 }
+
+issue_3411: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+    }
+    input: {
+        var c = 1;
+        !function f() {
+            var o = {
+                p: --c && f()
+            };
+            +o || console.log("PASS");
+        }();
+    }
+    expect: {
+        var c = 1;
+        !function f() {
+            var o, o_p = --c && f();
+            +{} || console.log("PASS");
+        }();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3440: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            function f() {
+                console.log(o.p);
+            }
+            var o = {
+                p: "PASS",
+            };
+            return f;
+        })()();
+    }
+    expect: {
+        (function() {
+            var o_p = "PASS";
+            return function() {
+                console.log(o_p);
+            };
+        })()();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3868: {
+    options = {
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+    }
+    input: {
+        (function(t) {
+            t = {};
+            ({
+                get p() {},
+                q: (console.log("PASS"), +t),
+            }).r;
+        })();
+    }
+    expect: {
+        (function(t) {
+            t = {};
+            ({
+                get p() {},
+                q: (console.log("PASS"), +t),
+            }).r;
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3871: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function() {
+            do {
+                var b = {
+                    get null() {
+                        c;
+                    }
+                };
+            } while (!b);
+            return "PASS";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            do {
+                var b = {
+                    get null() {
+                        c;
+                    }
+                };
+            } while (!b);
+            return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3945_1: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+    }
+    input: {
+        function f() {
+            o.p;
+            var o = {
+                q: 0,
+            };
+        }
+    }
+    expect: {
+        function f() {
+            o.p;
+            var o, o_q = 0;
+        }
+    }
+}
+
+issue_3945_2: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        console.log(typeof o);
+        var o = {
+            p: 0,
+        };
+    }
+    expect: {
+        console.log(typeof o);
+        var o, o_p = 0;
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4023: {
+    options = {
+        comparisons: true,
+        hoist_props: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        typeofs: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a = function() {
+                return { p: 0 };
+            }();
+            return console.log("undefined" != typeof a);
+        }
+        f();
+    }
+    expect: {
+        console.log(void 0 !== {});
+    }
+    expect_stdout: "true"
+}
+
+object_super: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            f(a) {
+                return a ? console.log("PASS") : super.log("PASS");
+            },
+        };
+        o.f(42);
+    }
+    expect: {
+        var o = {
+            f(a) {
+                return a ? console.log("PASS") : super.log("PASS");
+            },
+        };
+        o.f(42);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4985: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = { p: 42 };
+        console.log(function() {
+            a;
+        }());
+    }
+    expect: {
+        var a, a_p = 42;
+        console.log(function() {
+            ({});
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5182: {
+    options = {
+        hoist_props: true,
+        merge_vars: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = console;
+        log = o.log;
+        o = {
+            p: function(a) {
+                console.log(a ? "PASS" : "FAIL");
+                return a;
+            },
+        };
+        log(o.p(42));
+    }
+    expect: {
+        var o = console;
+        log = o.log;
+        o = function(a) {
+            console.log(a ? "PASS" : "FAIL");
+            return a;
+        };
+        log(o(42));
+    }
+    expect_stdout: [
+        "PASS",
+        "42",
+    ]
+}
+
+issue_5441: {
+    options = {
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(function(a) {
+            (function() {
+                a = { p: this };
+            })();
+            return typeof a;
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            (function() {
+                a_p = this;
+            })();
+            var a_p;
+            return typeof {};
+        }());
+    }
+    expect_stdout: "object"
+}
+
+issue_5498: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            __proto__: 42,
+        };
+        while (console.log(typeof o.__proto__));
+    }
+    expect: {
+        var o = {
+            __proto__: 42,
+        };
+        while (console.log(typeof o.__proto__));
+    }
+    expect_stdout: "object"
+}

test/compress/hoist_vars.js

@@ -2,6 +2,8 @@ statements: {
     options = {
         hoist_funs: false,
         hoist_vars: true,
+        join_vars: true,
+        unused: true,
     }
     input: {
         function f() {
@@ -25,6 +27,8 @@ statements_funs: {
     options = {
         hoist_funs: true,
         hoist_vars: true,
+        join_vars: true,
+        unused: true,
     }
     input: {
         function f() {
@@ -48,6 +52,8 @@ sequences: {
     options = {
         hoist_funs: false,
         hoist_vars: true,
+        join_vars: true,
+        unused: true,
     }
     input: {
         function f() {
@@ -71,6 +77,8 @@ sequences_funs: {
     options = {
         hoist_funs: true,
         hoist_vars: true,
+        join_vars: true,
+        unused: true,
     }
     input: {
         function f() {
@@ -89,10 +97,38 @@ 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: {
+        a = "PASS";
+        var a;
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
 issue_2295: {
     options = {
         collapse_vars: true,
         hoist_vars: true,
+        join_vars: true,
+        unused: true,
     }
     input: {
         function foo(o) {
@@ -109,3 +145,659 @@ issue_2295: {
         }
     }
 }
+
+issue_4487_1: {
+    options = {
+        functions: true,
+        hoist_vars: true,
+        join_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: {
+        var a = function f() {
+            var f = console.log(typeof f);
+        };
+        a();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4487_2: {
+    options = {
+        functions: true,
+        hoist_vars: true,
+        join_vars: true,
+        keep_fnames: true,
+        passes: 2,
+        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_4487_3: {
+    options = {
+        functions: true,
+        hoist_vars: true,
+        join_vars: true,
+        keep_fnames: true,
+        passes: 3,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function f() {
+            var f = console.log(typeof f);
+        };
+        var b = a();
+    }
+    expect: {
+        (function a() {
+            console.log(typeof void 0);
+        })();
+    }
+    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: {
+        for (var k in !(A = 0));
+        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() {
+            return (A = 2) + typeof !1;
+        }());
+    }
+    expect_stdout: "2boolean"
+}
+
+issue_4736: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        join_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(1 << 30);
+            })();
+        })();
+    }
+    expect_stdout: "1073741824"
+}
+
+issue_4839: {
+    options = {
+        evaluate: true,
+        hoist_vars: true,
+        join_vars: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var log = console.log, o = function(a, b) {
+            return b && b;
+        }("foo");
+        for (var k in o)
+            throw "FAIL";
+        log("PASS");
+    }
+    expect: {
+        var k, log = console.log;
+        for (k in void 0)
+            throw "FAIL";
+        log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4859: {
+    options = {
+        evaluate: true,
+        hoist_vars: true,
+        join_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) {
+            console.log(2 + 1 / 0);
+            return f;
+        })();
+    }
+    expect_stdout: "Infinity"
+}
+
+issue_4893_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            var a = null;
+            var b = null;
+            var c = null;
+            b.p += a = 42;
+            f;
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try{
+            (function f() {
+                null.p += 42;
+                f;
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4893_2: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            var a = null;
+            var b = null;
+            var c = null;
+            b.p += a = 42;
+            f;
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try{
+            (function() {
+                var a;
+                a = null;
+                a.p += 42;
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4898: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        loops: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        do {
+            var b = [ console.log("PASS") ];
+            var c = b;
+        } while (c.p = 0);
+    }
+    expect: {
+        var b;
+        b = [ console.log("PASS") ];
+        b.p = 0;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5187_1: {
+    options = {
+        hoist_props: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a = 42;
+            do {
+                var b = { 0: a++ };
+            } while (console.log(b[b ^= 0]));
+        }
+        f();
+    }
+    expect: {
+        (function() {
+            var a, b;
+            a = 42;
+            do {
+                b = { 0: a++ };
+            } while (console.log(b[b ^= 0]));
+        })();
+    }
+    expect_stdout: "42"
+}
+
+issue_5187_2: {
+    options = {
+        hoist_props: true,
+        hoist_vars: true,
+        join_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a = 42;
+            do {
+                var b = { 0: a++ };
+            } while (console.log(b[b ^= 0]));
+        }
+        f();
+    }
+    expect: {
+        (function() {
+            var b, a = 42;
+            do {
+                b = { 0: a++ };
+            } while (console.log(b[b ^= 0]));
+        })();
+    }
+    expect_stdout: "42"
+}
+
+issue_5195: {
+    options = {
+        hoist_props: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a;
+            do {
+                var b = { p: a };
+            } while (console.log(b += ""));
+        }
+        f();
+    }
+    expect: {
+        (function() {
+            var a, b;
+            do {
+                b = { p: a };
+            } while (console.log(b += ""));
+        })();
+    }
+    expect_stdout: "[object Object]"
+}
+
+issue_5378: {
+    options = {
+        hoist_vars: true,
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 2;
+        while (a--)
+            (function() {
+                var b;
+                var c;
+                while (console.log(b));
+                --b;
+            })();
+    }
+    expect: {
+        var a = 2;
+        while (a--) {
+            b = void 0;
+            var b, c;
+            while (console.log(b));
+            --b;
+        }
+    }
+    expect_stdout: [
+        "undefined",
+        "undefined",
+    ]
+}
+
+issue_5411_1: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        b++;
+        b = a;
+        var b = b, c = c && c[b];
+        console.log(b);
+    }
+    expect: {
+        var a, b, c;
+        b++;
+        b = a = "PASS";
+        c = c && c[b];
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5411_2: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        b++;
+        b = a;
+        var b = b, c = c && c[b];
+        console.log(b);
+    }
+    expect: {
+        var b, c;
+        b++;
+        b = "PASS",
+        c;
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5411_3: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = console;
+        a++;
+        var a = A = a;
+        console.log(A);
+    }
+    expect: {
+        var a;
+        a = console;
+        a = A = ++a;
+        console.log(A);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_5411_4: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        join_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = console;
+        a++;
+        var a = A = a;
+        console.log(A);
+    }
+    expect: {
+        var a = console;
+        a = A = ++a;
+        console.log(A);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_5626: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function() {
+            return console.log(arguments[0]), 42;
+        }("PASS") ? null : "foo";
+        for (var b in a)
+            FAIL;
+    }
+    expect: {
+        (function() {
+            console.log(arguments[0]);
+        }("PASS"));
+        for (var b in null)
+            FAIL;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5638_1: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        var a = [ 42 ];
+        console || FAIL(a);
+        console.log(a++);
+    }
+    expect: {
+        var a;
+        a = "FAIL";
+        a = [ 42 ];
+        console || FAIL(a);
+        console.log(a++);
+    }
+    expect_stdout: "42"
+}
+
+issue_5638_2: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        var a = [ 6 ];
+        console || FAIL(a);
+        console.log(a *= 7);
+    }
+    expect: {
+        var a;
+        a = "FAIL";
+        a = [ 6 ];
+        console || FAIL(a);
+        console.log(a *= 7);
+    }
+    expect_stdout: "42"
+}
+
+issue_5638_3: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var log = console.log;
+        var o = { foo: 42 };
+        for (var k in o) {
+            var v = o[k];
+            log(k || v, v++);
+        }
+    }
+    expect: {
+        var log, o, k, v;
+        log = console.log;
+        for (k in o = { foo: 42 }) {
+            v = o[k];
+            log(k || v, v++);
+        }
+    }
+    expect_stdout: "foo 42"
+}
+
+issue_5638_4: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var log = console.log;
+        var o = { foo: 6 };
+        for (var k in o) {
+            var v = o[k];
+            log(k || v, v *= 7);
+        }
+    }
+    expect: {
+        var log, o, k, v;
+        log = console.log;
+        for (k in o = { foo: 6 }) {
+            v = o[k];
+            log(k || v, v *= 7);
+        }
+    }
+    expect_stdout: "foo 42"
+}

test/compress/html_comments.js

@@ -1,55 +1,107 @@
 html_comment_in_expression: {
     input: {
-        function f(a, b, x, y) { return a < !--b && x-- > y; }
+        (function(a, b) {
+            console.log(a < !--b && a-- > b, a, b);
+        })(1, 2);
     }
-    expect_exact: "function f(a,b,x,y){return a< !--b&&x-- >y}";
+    expect_exact: "(function(a,b){console.log(a<! --b&&a-- >b,a,b)})(1,2);"
+    expect_stdout: "false 1 1"
 }
 
 html_comment_in_less_than: {
     input: {
-        function f(a, b) { return a < !--b; }
+        (function(a, b, c) {
+            console.log(
+                a < !--b,
+                a < !--b + c,
+                a + b < !--c,
+                a, b, c
+            );
+        })(1, 2, 3);
     }
-    expect_exact: "function f(a,b){return a< !--b}";
+    expect_exact: "(function(a,b,c){console.log(a<! --b,a<! --b+c,a+b<! --c,a,b,c)})(1,2,3);"
+    expect_stdout: "false true false 1 0 2"
 }
 
 html_comment_in_left_shift: {
     input: {
-        function f(a, b) { return a << !--b; }
+        (function(a, b, c) {
+            console.log(
+                a << !--b,
+                a << !--b + c,
+                a + b << !--c,
+                a, b, c
+            );
+        })(1, 2, 3);
     }
-    expect_exact: "function f(a,b){return a<< !--b}";
-}
-
-html_comment_in_right_shift: {
-    input: {
-        function f(a, b) { return a-- >> b; }
-    }
-    expect_exact: "function f(a,b){return a-- >>b}";
-}
-
-html_comment_in_zero_fill_right_shift: {
-    input: {
-        function f(a, b) { return a-- >>> b; }
-    }
-    expect_exact: "function f(a,b){return a-- >>>b}";
+    expect_exact: "(function(a,b,c){console.log(a<<! --b,a<<! --b+c,a+b<<! --c,a,b,c)})(1,2,3);"
+    expect_stdout: "1 16 1 1 0 2"
 }
 
 html_comment_in_greater_than: {
     input: {
-        function f(a, b) { return a-- > b; }
+        (function(a, b, c) {
+            console.log(
+                a-- > b,
+                a-- > b + c,
+                a + b-- > c,
+                a, b, c
+            );
+        })(1, 2, 3);
     }
-    expect_exact: "function f(a,b){return a-- >b}";
+    expect_exact: "(function(a,b,c){console.log(a-- >b,a-- >b+c,a+b-- >c,a,b,c)})(1,2,3);"
+    expect_stdout: "false false false -1 1 3"
 }
 
 html_comment_in_greater_than_or_equal: {
     input: {
-        function f(a, b) { return a-- >= b; }
+        (function(a, b, c) {
+            console.log(
+                a-- >= b,
+                a-- >= b + c,
+                a + b-- >= c,
+                a, b, c
+            );
+        })(1, 2, 3);
     }
-    expect_exact: "function f(a,b){return a-- >=b}";
+    expect_exact: "(function(a,b,c){console.log(a-- >=b,a-- >=b+c,a+b-- >=c,a,b,c)})(1,2,3);"
+    expect_stdout: "false false false -1 1 3"
+}
+
+html_comment_in_right_shift: {
+    input: {
+        (function(a, b, c) {
+            console.log(
+                a-- >> b,
+                a-- >> b + c,
+                a + b-- >> c,
+                a, b, c
+            );
+        })(1, 2, 3);
+    }
+    expect_exact: "(function(a,b,c){console.log(a-- >>b,a-- >>b+c,a+b-- >>c,a,b,c)})(1,2,3);"
+    expect_stdout: "0 0 0 -1 1 3"
+}
+
+html_comment_in_zero_fill_right_shift: {
+    input: {
+        (function(a, b, c) {
+            console.log(
+                a-- >>> b,
+                a-- >>> b + c,
+                a + b-- >>> c,
+                a, b, c
+            );
+        })(1, 2, 3);
+    }
+    expect_exact: "(function(a,b,c){console.log(a-- >>>b,a-- >>>b+c,a+b-- >>>c,a,b,c)})(1,2,3);"
+    expect_stdout: "0 0 0 -1 1 3"
 }
 
 html_comment_in_string_literal: {
     input: {
-        function f() { return "<!--HTML-->comment in<!--string literal-->"; }
+        console.log("<!--HTML-->comment in<!--string literal-->".length);
     }
-    expect_exact: 'function f(){return"\\x3c!--HTML--\\x3ecomment in\\x3c!--string literal--\\x3e"}';
+    expect_exact: 'console.log("\\x3c!--HTML--\\x3ecomment in\\x3c!--string literal--\\x3e".length);'
+    expect_stdout: "42"
 }

test/compress/ie8.js

@@ -1,713 +0,0 @@
-do_screw: {
-    options = {
-        ie8: false,
-    }
-    beautify = {
-        ie8: false,
-        ascii_only: true,
-    }
-    input: {
-        f("\v");
-    }
-    expect_exact: 'f("\\v");'
-}
-
-dont_screw: {
-    options = {
-        ie8: true,
-    }
-    beautify = {
-        ie8: true,
-        ascii_only: true,
-    }
-    input: {
-        f("\v");
-    }
-    expect_exact: 'f("\\x0B");'
-}
-
-do_screw_constants: {
-    options = {
-        ie8: false,
-    }
-    input: {
-        f(undefined, Infinity);
-    }
-    expect_exact: "f(void 0,1/0);"
-}
-
-dont_screw_constants: {
-    options = {
-        ie8: true,
-    }
-    input: {
-        f(undefined, Infinity);
-    }
-    expect_exact: "f(undefined,Infinity);"
-}
-
-do_screw_try_catch: {
-    options = {
-        ie8: false,
-    }
-    mangle = {
-        ie8: false,
-    }
-    beautify = {
-        ie8: false,
-    }
-    input: {
-        good = function(e){
-            return function(error){
-                try{
-                    e()
-                } catch(e) {
-                    error(e)
-                }
-            }
-        };
-    }
-    expect: {
-        good = function(n){
-            return function(t){
-                try{
-                    n()
-                } catch(n) {
-                    t(n)
-                }
-            }
-        };
-    }
-}
-
-dont_screw_try_catch: {
-    options = {
-        ie8: true,
-    }
-    mangle = {
-        ie8: true,
-    }
-    beautify = {
-        ie8: true,
-    }
-    input: {
-        bad = function(e){
-            return function(error){
-                try{
-                    e()
-                } catch(e) {
-                    error(e)
-                }
-            }
-        };
-    }
-    expect: {
-        bad = function(t){
-            return function(n){
-                try{
-                    t()
-                } catch(t) {
-                    n(t)
-                }
-            }
-        };
-    }
-}
-
-do_screw_try_catch_undefined: {
-    options = {
-        ie8: false,
-    }
-    mangle = {
-        ie8: false,
-    }
-    beautify = {
-        ie8: false,
-    }
-    input: {
-        function a(b){
-            try {
-                throw 'Stuff';
-            } catch (undefined) {
-                console.log('caught: ' + undefined);
-            }
-            console.log('undefined is ' + undefined);
-            return b === undefined;
-        };
-    }
-    expect: {
-        function a(o){
-            try{
-                throw "Stuff"
-            } catch (o) {
-                console.log("caught: "+o)
-            }
-            console.log("undefined is " + void 0);
-            return void 0===o
-        }
-    }
-    expect_stdout: true
-}
-
-dont_screw_try_catch_undefined: {
-    options = {
-        ie8: true,
-    }
-    mangle = {
-        ie8: true,
-    }
-    beautify = {
-        ie8: true,
-    }
-    input: {
-        function a(b){
-            try {
-                throw 'Stuff';
-            } catch (undefined) {
-                console.log('caught: ' + undefined);
-            }
-            console.log('undefined is ' + undefined);
-            return b === undefined;
-        };
-    }
-    expect: {
-        function a(n){
-            try{
-                throw "Stuff"
-            } catch (undefined) {
-                console.log("caught: " + undefined)
-            }
-            console.log("undefined is " + undefined);
-            return n === undefined
-        }
-    }
-    expect_stdout: true
-}
-
-reduce_vars: {
-    options = {
-        evaluate: true,
-        ie8: true,
-        reduce_funcs: true,
-        reduce_vars: true,
-        unused: true,
-    }
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        function f() {
-            var a;
-            try {
-                x();
-            } catch (a) {
-                y();
-            }
-            alert(a);
-        }
-    }
-    expect: {
-        function f() {
-            var t;
-            try {
-                x();
-            } catch (t) {
-                y();
-            }
-            alert(t);
-        }
-    }
-}
-
-issue_1586_1: {
-    options = {
-        ie8: true,
-    }
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        function f() {
-            try {
-                x();
-            } catch (err) {
-                console.log(err.message);
-            }
-        }
-    }
-    expect_exact: "function f(){try{x()}catch(c){console.log(c.message)}}"
-}
-
-issue_1586_2: {
-    options = {
-        ie8: false,
-    }
-    mangle = {
-        ie8: false,
-    }
-    input: {
-        function f() {
-            try {
-                x();
-            } catch (err) {
-                console.log(err.message);
-            }
-        }
-    }
-    expect_exact: "function f(){try{x()}catch(c){console.log(c.message)}}"
-}
-
-issue_2120_1: {
-    mangle = {
-        ie8: false,
-    }
-    input: {
-        "aaaaaaaa";
-        var a = 1, b = "FAIL";
-        try {
-            throw 1;
-        } catch (c) {
-            try {
-                throw 0;
-            } catch (a) {
-                if (c) b = "PASS";
-            }
-        }
-        console.log(b);
-    }
-    expect: {
-        "aaaaaaaa";
-        var a = 1, b = "FAIL";
-        try {
-            throw 1;
-        } catch (t) {
-            try {
-                throw 0;
-            } catch (a) {
-                if (t) b = "PASS";
-            }
-        }
-        console.log(b);
-    }
-    expect_stdout: "PASS"
-}
-
-issue_2120_2: {
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        "aaaaaaaa";
-        var a = 1, b = "FAIL";
-        try {
-            throw 1;
-        } catch (c) {
-            try {
-                throw 0;
-            } catch (a) {
-                if (c) b = "PASS";
-            }
-        }
-        console.log(b);
-    }
-    expect: {
-        "aaaaaaaa";
-        var a = 1, b = "FAIL";
-        try {
-            throw 1;
-        } catch (c) {
-            try {
-                throw 0;
-            } catch (a) {
-                if (c) b = "PASS";
-            }
-        }
-        console.log(b);
-    }
-    expect_stdout: "PASS"
-}
-
-issue_2254_1: {
-    mangle = {
-        ie8: false,
-    }
-    input: {
-        "eeeeee";
-        try {
-            console.log(f("PASS"));
-        } catch (e) {}
-        function f(s) {
-            try {
-                throw "FAIL";
-            } catch (e) {
-                return s;
-            }
-        }
-    }
-    expect: {
-        "eeeeee";
-        try {
-            console.log(f("PASS"));
-        } catch (e) {}
-        function f(t) {
-            try {
-                throw "FAIL";
-            } catch (e) {
-                return t;
-            }
-        }
-    }
-    expect_stdout: "PASS"
-}
-
-issue_2254_2: {
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        "eeeeee";
-        try {
-            console.log(f("PASS"));
-        } catch (e) {}
-        function f(s) {
-            try {
-                throw "FAIL";
-            } catch (e) {
-                return s;
-            }
-        }
-    }
-    expect: {
-        "eeeeee";
-        try {
-            console.log(f("PASS"));
-        } catch (e) {}
-        function f(t) {
-            try {
-                throw "FAIL";
-            } catch (e) {
-                return t;
-            }
-        }
-    }
-    expect_stdout: "PASS"
-}
-
-issue_24_1: {
-    mangle = {
-        ie8: false,
-    }
-    input: {
-        (function(a) {
-            console.log(typeof function f(){} === typeof a ? "FAIL" : "PASS");
-        })();
-    }
-    expect: {
-        (function(o) {
-            console.log(typeof function o(){} === typeof o ? "FAIL" : "PASS");
-        })();
-    }
-    expect_stdout: "PASS"
-}
-
-issue_24_2: {
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        (function(a) {
-            console.log(typeof function f(){} === typeof a ? "FAIL" : "PASS");
-        })();
-    }
-    expect: {
-        (function(o) {
-            console.log(typeof function n(){} === typeof o ? "FAIL" : "PASS");
-        })();
-    }
-    expect_stdout: "PASS"
-}
-
-issue_2976_1: {
-    mangle = {
-        ie8: false,
-    }
-    input: {
-        console.log(function f() {
-            var a;
-            return a === f ? "FAIL" : "PASS";
-        }());
-    }
-    expect: {
-        console.log(function n() {
-            var o;
-            return o === n ? "FAIL" : "PASS";
-        }());
-    }
-    expect_stdout: "PASS"
-}
-
-issue_2976_2: {
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        console.log(function f() {
-            var a;
-            return a === f ? "FAIL" : "PASS";
-        }());
-    }
-    expect: {
-        console.log(function f() {
-            var n;
-            return n === f ? "FAIL" : "PASS";
-        }());
-    }
-    expect_stdout: "PASS"
-}
-
-issue_2976_3: {
-    mangle = {
-        ie8: true,
-        toplevel: true,
-    }
-    input: {
-        console.log(function f() {
-            var a;
-            return a === f ? "FAIL" : "PASS";
-        }());
-    }
-    expect: {
-        console.log(function o() {
-            var n;
-            return n === o ? "FAIL" : "PASS";
-        }());
-    }
-    expect_stdout: "PASS"
-}
-
-issue_3035: {
-    mangle = {
-        ie8: false,
-    }
-    input: {
-        var c = "FAIL";
-        (function(a) {
-            try {
-                throw 1;
-            } catch (b) {
-                try {
-                    throw 0;
-                } catch (a) {
-                    b && (c = "PASS");
-                }
-            }
-        })();
-        console.log(c);
-    }
-    expect: {
-        var c = "FAIL";
-        (function(o) {
-            try {
-                throw 1;
-            } catch (t) {
-                try {
-                    throw 0;
-                } catch (o) {
-                    t && (c = "PASS");
-                }
-            }
-        })();
-        console.log(c);
-    }
-    expect_stdout: "PASS"
-}
-
-issue_3035_ie8: {
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        var c = "FAIL";
-        (function(a) {
-            try {
-                throw 1;
-            } catch (b) {
-                try {
-                    throw 0;
-                } catch (a) {
-                    b && (c = "PASS");
-                }
-            }
-        })();
-        console.log(c);
-    }
-    expect: {
-        var c = "FAIL";
-        (function(t) {
-            try {
-                throw 1;
-            } catch (o) {
-                try {
-                    throw 0;
-                } catch (t) {
-                    o && (c = "PASS");
-                }
-            }
-        })();
-        console.log(c);
-    }
-    expect_stdout: "PASS"
-}
-
-issue_3197_1: {
-    options = {
-        ie8: false,
-        inline: true,
-        reduce_vars: true,
-        side_effects: true,
-        unused: true,
-    }
-    mangle = {
-        ie8: false,
-    }
-    input: {
-        var window = {};
-        !function() {
-            function Foo() {
-                console.log(this instanceof Foo);
-            }
-            window.Foo = Foo;
-        }();
-        new window.Foo();
-    }
-    expect: {
-        var window = {};
-        window.Foo = function o() {
-            console.log(this instanceof o);
-        };
-        new window.Foo();
-    }
-    expect_stdout: "true"
-}
-
-issue_3197_1_ie8: {
-    options = {
-        ie8: true,
-        inline: true,
-        reduce_vars: true,
-        side_effects: true,
-        unused: true,
-    }
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        var window = {};
-        !function() {
-            function Foo() {
-                console.log(this instanceof Foo);
-            }
-            window.Foo = Foo;
-        }();
-        new window.Foo();
-    }
-    expect: {
-        var window = {};
-        window.Foo = function Foo() {
-            console.log(this instanceof Foo);
-        };
-        new window.Foo();
-    }
-    expect_stdout: "true"
-}
-
-issue_3197_2: {
-    mangle = {
-        ie8: false,
-    }
-    input: {
-        (function(a) {
-            var f = function f() {
-                console.log(this instanceof f);
-            };
-            new f(a);
-        })();
-    }
-    expect: {
-        (function(n) {
-            var o = function n() {
-                console.log(this instanceof n);
-            };
-            new o(n);
-        })();
-    }
-    expect_stdout: "true"
-}
-
-issue_3197_2_ie8: {
-    mangle = {
-        ie8: true,
-    }
-    input: {
-        (function(a) {
-            var f = function f() {
-                console.log(this instanceof f);
-            };
-            new f(a);
-        })();
-    }
-    expect: {
-        (function(n) {
-            var o = function o() {
-                console.log(this instanceof o);
-            };
-            new o(n);
-        })();
-    }
-    expect_stdout: "true"
-}
-
-issue_3206_1: {
-    options = {
-        evaluate: true,
-        ie8: false,
-        reduce_vars: true,
-        typeofs: true,
-        unused: true,
-    }
-    input: {
-        console.log(function() {
-            var foo = function bar() {};
-            return "function" == typeof bar;
-        }());
-    }
-    expect: {
-        console.log(function() {
-            return "function" == typeof bar;
-        }());
-    }
-    expect_stdout: "false"
-}
-
-issue_3206_2: {
-    options = {
-        evaluate: true,
-        ie8: true,
-        reduce_vars: true,
-        typeofs: true,
-        unused: true,
-    }
-    input: {
-        console.log(function() {
-            var foo = function bar() {};
-            return "function" == typeof bar;
-        }());
-    }
-    expect: {
-        console.log(function() {
-            (function bar() {});
-            return "function" == typeof bar;
-        }());
-    }
-    expect_stdout: "false"
-}

test/compress/imports.js

@@ -0,0 +1,270 @@
+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";'
+}
+
+non_identifiers: {
+    beautify = {
+        quote_style: 3,
+    }
+    input: {
+        import { '42' as foo } from "bar";
+        import { "foo" as bar } from 'baz';
+    }
+    expect_exact: "import{'42'as foo}from\"bar\";import{foo as bar}from'baz';"
+}
+
+dynamic: {
+    input: {
+        (async a => await import(a))("foo").then(bar);
+    }
+    expect_exact: '(async a=>await import(a))("foo").then(bar);'
+}
+
+dynamic_nought: {
+    input: {
+        import(foo);
+    }
+    expect_exact: "import(foo);"
+}
+
+import_meta_1: {
+    input: {
+        console.log(import.meta, import.meta.url);
+    }
+    expect_exact: "console.log(import.meta,import.meta.url);"
+}
+
+import_meta_2: {
+    input: {
+        import.meta.url.split("/").forEach(function(part, index) {
+            console.log(index, part);
+        });
+    }
+    expect_exact: 'import.meta.url.split("/").forEach(function(part,index){console.log(index,part)});'
+}
+
+same_quotes: {
+    beautify = {
+        beautify: true,
+        quote_style: 3,
+    }
+    input: {
+        import 'foo';
+        import "bar";
+    }
+    expect_exact: [
+        "import 'foo';",
+        "",
+        'import "bar";',
+    ]
+}
+
+drop_unused: {
+    options = {
+        imports: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        import a, * as b from "foo";
+        import { c } from "bar";
+        import { d, _ as e } from "baz";
+        console.log(d);
+    }
+    expect: {
+        import "foo";
+        import "bar";
+        import { d as d } from "baz";
+        console.log(d);
+    }
+}
+
+drop_side_effect_free: {
+    options = {
+        imports: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        import foo from "bar";
+        var a = foo;
+    }
+    expect: {
+        import "bar";
+    }
+}
+
+mangle: {
+    rename = false
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        import foo, { bar } from "baz";
+        console.log(moo);
+        import * as moo from "moz";
+    }
+    expect: {
+        import o, { bar as m } from "baz";
+        console.log(r);
+        import * as r from "moz";
+    }
+}
+
+rename_mangle: {
+    rename = true
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        import foo, { bar } from "baz";
+        console.log(moo);
+        import * as moo from "moz";
+    }
+    expect: {
+        import o, { bar as m } from "baz";
+        console.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";
+    }
+}
+
+pr_5550_1: {
+    input: {
+        if (console)
+            import("foo");
+        else
+            import.meta.url.replace(/bar/g, console.log);
+    }
+    expect: {
+        if (console)
+            import("foo");
+        else
+            import.meta.url.replace(/bar/g, console.log);
+    }
+}
+
+pr_5550_2: {
+    input: {
+        L: {
+            import("foo");
+            import.meta.url.replace(/bar/g, console.log);
+        }
+    }
+    expect: {
+        L: {
+            import("foo");
+            import.meta.url.replace(/bar/g, console.log);
+        }
+    }
+}

test/compress/indentation.js

@@ -0,0 +1,100 @@
+numeric: {
+    beautify = {
+        beautify: true,
+        indent_start: 1,
+        indent_level: 3,
+    }
+    input: {
+        switch (42) {
+          case null:
+            console.log("FAIL");
+        }
+        console.log("PASS");
+    }
+    expect_exact: [
+        " switch (42) {",
+        "  case null:",
+        '    console.log("FAIL");',
+        " }",
+        "",
+        ' console.log("PASS");',
+    ]
+    expect_stdout: "PASS"
+}
+
+spaces: {
+    beautify = {
+        beautify: true,
+        indent_start: " ",
+        indent_level: "   ",
+    }
+    input: {
+        switch (42) {
+          case null:
+            console.log("FAIL");
+        }
+        console.log("PASS");
+    }
+    expect_exact: [
+        " switch (42) {",
+        "  case null:",
+        '    console.log("FAIL");',
+        " }",
+        "",
+        ' console.log("PASS");',
+    ]
+    expect_stdout: "PASS"
+}
+
+tabs: {
+    beautify = {
+        beautify: true,
+        indent_start: "\t",
+        indent_level: "\t",
+    }
+    input: {
+        switch (42) {
+          case null:
+            console.log("FAIL");
+        }
+        console.log("PASS");
+    }
+    expect_exact: [
+        "\tswitch (42) {",
+        "\tcase null:",
+        '\t\tconsole.log("FAIL");',
+        "\t}",
+        "",
+        '\tconsole.log("PASS");',
+    ]
+    expect_stdout: "PASS"
+}
+
+mixed: {
+    beautify = {
+        beautify: true,
+        indent_start: "\n",
+        indent_level: "       \t",
+    }
+    input: {
+        switch (42) {
+          case null:
+            console.log("FAIL");
+        }
+        console.log("PASS");
+    }
+    expect_exact: [
+        "",
+        "switch (42) {",
+        "",
+        "    case null:",
+        "",
+        '       \tconsole.log("FAIL");',
+        "",
+        "}",
+        "",
+        "",
+        'console.log("PASS");',
+    ]
+    expect_stdout: "PASS"
+}

test/compress/issue-1034.js

@@ -30,16 +30,16 @@ non_hoisted_function_after_return: {
     }
     expect: {
         function foo(x) {
-            return x ? bar() : baz();
+            return (x ? bar : baz)();
             function bar() { return 7 }
             function baz() { return 8 }
         }
     }
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:20,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:23,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:26,12]",
-        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:27,21]"
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:4,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:10,12]",
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:11,21]",
     ]
 }
 
@@ -59,7 +59,6 @@ non_hoisted_function_after_return_2a: {
         passes: 2,
         side_effects: true,
         unused: true,
-        warnings: "verbose",
     }
     input: {
         function foo(x) {
@@ -85,19 +84,16 @@ non_hoisted_function_after_return_2a: {
         }
     }
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:68,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:68,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:71,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:71,16]",
-        "WARN: Dropping unused variable a [test/compress/issue-1034.js:68,20]",
-        "WARN: Dropping unused function nope [test/compress/issue-1034.js:75,21]",
-        "WARN: pass 0: last_count: Infinity, count: 37",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:73,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:73,12]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:76,12]",
-        "WARN: Dropping unused variable b [test/compress/issue-1034.js:71,20]",
-        "WARN: Dropping unused variable c [test/compress/issue-1034.js:73,16]",
-        "WARN: pass 1: last_count: 37, count: 18",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:4,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:7,16]",
+        "WARN: Dropping unused variable a [test/compress/issue-1034.js:4,20]",
+        "WARN: Dropping unused function nope [test/compress/issue-1034.js:11,21]",
+        "INFO: pass 0: last_count: Infinity, count: 35",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:9,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
+        "INFO: Dropping unused variable b [test/compress/issue-1034.js:7,20]",
+        "INFO: Dropping unused variable c [test/compress/issue-1034.js:9,16]",
+        "INFO: pass 1: last_count: 35, count: 18",
     ]
 }
 
@@ -139,12 +135,8 @@ non_hoisted_function_after_return_2b: {
         }
     }
     expect_warnings: [
-        // duplicate warnings no longer emitted
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:126,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:126,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:128,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:128,12]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:132,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
     ]
 }
 
@@ -183,7 +175,7 @@ non_hoisted_function_after_return_strict: {
     expect: {
         "use strict";
         function foo(x) {
-            return x ? bar() : baz();
+            return (x ? bar : baz)();
             function bar() { return 7 }
             function baz() { return 8 }
         }
@@ -191,10 +183,10 @@ non_hoisted_function_after_return_strict: {
     }
     expect_stdout: "8 7"
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:171,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:174,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:177,12]",
-        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:178,21]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:5,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:8,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:11,12]",
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:12,21]",
     ]
 }
 
@@ -214,7 +206,6 @@ non_hoisted_function_after_return_2a_strict: {
         passes: 2,
         side_effects: true,
         unused: true,
-        warnings: "verbose",
     }
     input: {
         "use strict";
@@ -245,19 +236,16 @@ non_hoisted_function_after_return_2a_strict: {
     }
     expect_stdout: "5 6"
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:224,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:224,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:227,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:227,16]",
-        "WARN: Dropping unused variable a [test/compress/issue-1034.js:224,20]",
-        "WARN: Dropping unused function nope [test/compress/issue-1034.js:231,21]",
-        "WARN: pass 0: last_count: Infinity, count: 48",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:229,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:229,12]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:232,12]",
-        "WARN: Dropping unused variable b [test/compress/issue-1034.js:227,20]",
-        "WARN: Dropping unused variable c [test/compress/issue-1034.js:229,16]",
-        "WARN: pass 1: last_count: 48, count: 29",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:5,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,16]",
+        "WARN: Dropping unused variable a [test/compress/issue-1034.js:5,20]",
+        "WARN: Dropping unused function nope [test/compress/issue-1034.js:12,21]",
+        "INFO: pass 0: last_count: Infinity, count: 46",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:10,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:13,12]",
+        "INFO: Dropping unused variable b [test/compress/issue-1034.js:8,20]",
+        "INFO: Dropping unused variable c [test/compress/issue-1034.js:10,16]",
+        "INFO: pass 1: last_count: 46, count: 29",
     ]
 }
 
@@ -304,11 +292,7 @@ non_hoisted_function_after_return_2b_strict: {
     }
     expect_stdout: "5 6"
     expect_warnings: [
-        // duplicate warnings no longer emitted
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:287,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:287,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:289,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:289,12]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:293,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:9,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:13,12]",
     ]
 }

test/compress/issue-1052.js

@@ -4,22 +4,21 @@ multiple_functions: {
         if_return: true,
     }
     input: {
-        ( function() {
-            if ( !window ) {
+        (function() {
+            if (!window)
                 return;
-            }
             function f() {}
             function g() {}
-        } )();
+        })();
     }
     expect: {
-        ( function() {
+        (function() {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
-            if ( window );
+            if (!window);
             function f() {}
             function g() {}
-        } )();
+        })();
     }
 }
 
@@ -29,18 +28,17 @@ single_function: {
         if_return: true,
     }
     input: {
-        ( function() {
-            if ( !window ) {
+        (function() {
+            if (!window)
                 return;
-            }
             function f() {}
-        } )();
+        })();
     }
     expect: {
-        ( function() {
-            if ( window );
+        (function() {
+            if (!window);
             function f() {}
-        } )();
+        })();
     }
 }
 
@@ -50,28 +48,26 @@ deeply_nested: {
         if_return: true,
     }
     input: {
-        ( function() {
-            if ( !window ) {
+        (function() {
+            if (!window)
                 return;
-            }
             function f() {}
             function g() {}
-            if ( !document ) {
+            if (!document)
                 return;
-            }
             function h() {}
-        } )();
+        })();
     }
     expect: {
-        ( function() {
+        (function() {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
-            if ( window )
-                if (document);
+            if (!window);
+            else if (!document);
             function f() {}
             function g() {}
             function h() {}
-        } )();
+        })();
     }
 }
 
@@ -81,18 +77,18 @@ not_hoisted_when_already_nested: {
         if_return: true,
     }
     input: {
-        ( function() {
-            if ( !window ) {
+        (function() {
+            if (!window)
                 return;
-            }
-            if ( foo ) function f() {}
-        } )();
+            if (foo) function f() {}
+        })();
     }
     expect: {
-        ( function() {
-            if ( window )
-                if ( foo ) function f() {}
-        } )();
+        (function() {
+            if (!window);
+            else if (foo)
+                function f() {}
+        })();
     }
 }
 
@@ -104,15 +100,19 @@ defun_if_return: {
     input: {
         function e() {
             function f() {}
-            if (!window) return;
-            else function g() {}
+            if (!window)
+                return;
+            else
+                function g() {}
             function h() {}
         }
     }
     expect: {
         function e() {
             function f() {}
-            if (window) function g() {}
+            if (!window);
+            else
+                function g() {}
             function h() {}
         }
     }
@@ -126,8 +126,10 @@ defun_hoist_funs: {
     input: {
         function e() {
             function f() {}
-            if (!window) return;
-            else function g() {}
+            if (!window)
+                return;
+            else
+                function g() {}
             function h() {}
         }
     }
@@ -136,7 +138,7 @@ defun_hoist_funs: {
             function f() {}
             function g() {}
             function h() {}
-            if (window);
+            if (!window);
         }
     }
 }
@@ -149,15 +151,18 @@ defun_else_if_return: {
     input: {
         function e() {
             function f() {}
-            if (window) function g() {}
-            else return;
+            if (window)
+                function g() {}
+            else
+                return;
             function h() {}
         }
     }
     expect: {
         function e() {
             function f() {}
-            if (window) function g() {}
+            if (window)
+                function g() {}
             function h() {}
         }
     }

test/compress/issue-1105.js

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

test/compress/issue-12.js

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

test/compress/issue-1202.js

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

test/compress/issue-1261.js

@@ -1,5 +1,6 @@
 pure_function_calls: {
     options = {
+        annotations: true,
         booleans: true,
         comparisons: true,
         conditionals: true,
@@ -48,18 +49,19 @@ pure_function_calls: {
         a.b(), f.g();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:16,8]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:16,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:29,37]",
-        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:29,16]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:27,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:37,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:38,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:3,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:3,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:16,37]",
+        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:16,16]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:14,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:24,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:25,31]",
     ]
 }
 
 pure_function_calls_toplevel: {
     options = {
+        annotations: true,
         booleans: true,
         comparisons: true,
         conditionals: true,
@@ -110,22 +112,23 @@ pure_function_calls_toplevel: {
         a.b(), f.g();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:77,8]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:77,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:90,37]",
-        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:90,16]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:88,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:105,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:106,31]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:82,33]",
-        "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:82,12]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:98,45]",
-        "WARN: Dropping unused variable MyClass [test/compress/issue-1261.js:98,12]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:3,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:3,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:16,37]",
+        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:16,16]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:14,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:31,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:32,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:8,33]",
+        "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:8,12]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:24,45]",
+        "WARN: Dropping unused variable MyClass [test/compress/issue-1261.js:24,12]",
     ]
 }
 
 should_warn: {
     options = {
+        annotations: true,
         booleans: true,
         conditionals: true,
         evaluate: true,
@@ -155,29 +158,29 @@ should_warn: {
         baz();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,61]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,23]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:135,23]",
-        "WARN: Boolean || always true [test/compress/issue-1261.js:136,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:136,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:136,23]",
-        "WARN: Condition left of || always true [test/compress/issue-1261.js:137,8]",
-        "WARN: Condition always true [test/compress/issue-1261.js:137,8]",
-        "WARN: Boolean && always false [test/compress/issue-1261.js:138,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:138,23]",
-        "WARN: Condition always false [test/compress/issue-1261.js:138,23]",
-        "WARN: Condition left of && always false [test/compress/issue-1261.js:139,8]",
-        "WARN: Condition always false [test/compress/issue-1261.js:139,8]",
-        "WARN: + in boolean context always true [test/compress/issue-1261.js:140,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:140,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:140,23]",
-        "WARN: + in boolean context always true [test/compress/issue-1261.js:141,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:141,31]",
-        "WARN: Condition always true [test/compress/issue-1261.js:141,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:142,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:143,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:143,24]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:144,31]",
-        "WARN: Condition always false [test/compress/issue-1261.js:144,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:1,61]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:1,23]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:1,23]",
+        "WARN: Boolean || always true [test/compress/issue-1261.js:2,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:2,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:2,23]",
+        "WARN: Condition left of || always true [test/compress/issue-1261.js:3,8]",
+        "WARN: Condition always true [test/compress/issue-1261.js:3,8]",
+        "WARN: Boolean && always false [test/compress/issue-1261.js:4,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:4,23]",
+        "WARN: Condition always false [test/compress/issue-1261.js:4,23]",
+        "WARN: Condition left of && always false [test/compress/issue-1261.js:5,8]",
+        "WARN: Condition always false [test/compress/issue-1261.js:5,8]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:6,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:6,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:6,23]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:7,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:7,31]",
+        "WARN: Condition always true [test/compress/issue-1261.js:7,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:8,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:9,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:9,24]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:10,31]",
+        "WARN: Condition always false [test/compress/issue-1261.js:10,8]",
     ]
 }

test/compress/issue-1321.js

@@ -1,6 +1,7 @@
 issue_1321_no_debug: {
     mangle = {
         properties: {
+            domprops: true,
             keep_quoted: true,
         },
     }
@@ -23,6 +24,7 @@ issue_1321_debug: {
     mangle = {
         properties: {
             debug: "",
+            domprops: true,
             keep_quoted: true,
         },
     }
@@ -44,6 +46,7 @@ issue_1321_debug: {
 issue_1321_with_quoted: {
     mangle = {
         properties: {
+            domprops: true,
             keep_quoted: false,
         },
     }

test/compress/issue-143.js

@@ -1,5 +1,5 @@
 /**
- * There was an incorrect sort behaviour documented in issue #143:
+ * There was an incorrect sort behavior documented in issue #143:
  * (x = f(…)) <= x → x >= (x = f(…))
  *
  * For example, let the equation be:
@@ -12,37 +12,54 @@
  * a >= (a = parseInt('100')) → 99 >= 100 → false
  */
 
-tranformation_sort_order_equal: {
+transformation_sort_order_equal: {
     options = {
         comparisons: true,
     }
-
-    input: { (a = parseInt('100')) == a }
-    expect: { (a = parseInt('100')) == a }
+    input: {
+        console.log((a = parseInt("100")) == a);
+    }
+    expect: {
+        console.log((a = parseInt("100")) == a);
+    }
+    expect_stdout: "true"
 }
 
-tranformation_sort_order_unequal: {
+transformation_sort_order_unequal: {
     options = {
         comparisons: true,
     }
-
-    input: { (a = parseInt('100')) != a }
-    expect: { (a = parseInt('100')) != a }
+    input: {
+        console.log((a = parseInt("100")) != a);
+    }
+    expect: {
+        console.log((a = parseInt("100")) != a);
+    }
+    expect_stdout: "false"
 }
 
-tranformation_sort_order_lesser_or_equal: {
+transformation_sort_order_lesser_or_equal: {
     options = {
         comparisons: true,
     }
-
-    input: { (a = parseInt('100')) <= a }
-    expect: { (a = parseInt('100')) <= a }
+    input: {
+        console.log((a = parseInt("100")) <= a);
+    }
+    expect: {
+        console.log((a = parseInt("100")) <= a);
+    }
+    expect_stdout: "true"
 }
-tranformation_sort_order_greater_or_equal: {
+
+transformation_sort_order_greater_or_equal: {
     options = {
         comparisons: true,
     }
-
-    input: { (a = parseInt('100')) >= a }
-    expect: { (a = parseInt('100')) >= a }
-}
+    input: {
+        console.log((a = parseInt("100")) >= a);
+    }
+    expect: {
+        console.log((a = parseInt("100")) >= a);
+    }
+    expect_stdout: "true"
+}

test/compress/issue-1446.js

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

test/compress/issue-1447.js

@@ -40,6 +40,9 @@ conditional_false_stray_else_in_loop: {
             console.log(i);
         }
     }
-    expect_exact: "for(var i=1;i<=4;++i)if(!(i<=2))console.log(i);"
-    expect_stdout: true
+    expect_exact: "for(var i=1;i<=4;++i)if(i<=2);else console.log(i);"
+    expect_stdout: [
+        "3",
+        "4",
+    ]
 }

test/compress/issue-1588.js

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

test/compress/issue-1609.js

@@ -52,3 +52,30 @@ chained_evaluation_2: {
         })();
     }
 }
+
+chained_evaluation_3: {
+    options = {
+        collapse_vars: true,
+        evaluate: 10,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = "long piece of string";
+            (function() {
+                var b = a, c;
+                c = f(b);
+                c.bar = b;
+            })();
+        })();
+    }
+    expect: {
+        (function() {
+            (function() {
+                f("long piece of string").bar = "long piece of string";
+            })();
+        })();
+    }
+}

test/compress/issue-1639.js

@@ -1,4 +1,3 @@
-
 issue_1639_1: {
     options = {
         booleans: true,
@@ -12,7 +11,6 @@ issue_1639_1: {
     }
     input: {
         var a = 100, b = 10;
-
         var L1 = 5;
         while (--L1 > 0) {
             if ((--b), false) {
@@ -21,15 +19,15 @@ issue_1639_1: {
                 }
             }
         }
-
         console.log(a, b);
     }
     expect: {
-        for (var a = 100, b = 10, L1 = 5; --L1 > 0;)
-            if (--b, 0) var ignore = 0;
+        for (var a = 100, b = 10, L1 = 5, ignore; --L1 > 0;) {
+            --b;
+        }
         console.log(a, b);
     }
-    expect_stdout: true
+    expect_stdout: "100 6"
 }
 
 issue_1639_2: {
@@ -44,25 +42,23 @@ issue_1639_2: {
     }
     input: {
         var a = 100, b = 10;
-
         function f19() {
             if (++a, false)
                 if (a)
                     if (++a);
         }
         f19();
-
         console.log(a, b);
     }
     expect: {
         var a = 100, b = 10;
         function f19() {
-            ++a, 0;
+            ++a, 1;
         }
         f19(),
         console.log(a, b);
     }
-    expect_stdout: true
+    expect_stdout: "101 10"
 }
 
 issue_1639_3: {
@@ -84,5 +80,5 @@ issue_1639_3: {
         a++,
         console.log(a, b);
     }
-    expect_stdout: true
+    expect_stdout: "101 10"
 }

test/compress/issue-1656.js

@@ -35,11 +35,7 @@ f7: {
         console.log(a, b);
     }
     expect_exact: [
-        "var b = 10;",
-        "",
-        "!function() {",
-        "    b = 100;",
-        "}(), console.log(100, b);",
+        "console.log(100, 100);",
     ]
-    expect_stdout: true
+    expect_stdout: "100 100"
 }

test/compress/issue-1704.js

@@ -1,10 +1,10 @@
 mangle_catch: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -22,11 +22,11 @@ mangle_catch: {
 
 mangle_catch_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -44,11 +44,11 @@ mangle_catch_ie8: {
 
 mangle_catch_var: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -66,11 +66,11 @@ mangle_catch_var: {
 
 mangle_catch_var_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -88,11 +88,11 @@ mangle_catch_var_ie8: {
 
 mangle_catch_toplevel: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -110,11 +110,11 @@ mangle_catch_toplevel: {
 
 mangle_catch_ie8_toplevel: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -132,11 +132,11 @@ mangle_catch_ie8_toplevel: {
 
 mangle_catch_var_toplevel: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -154,11 +154,11 @@ mangle_catch_var_toplevel: {
 
 mangle_catch_var_ie8_toplevel: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -176,11 +176,11 @@ mangle_catch_var_ie8_toplevel: {
 
 mangle_catch_redef_1: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -198,11 +198,11 @@ mangle_catch_redef_1: {
 
 mangle_catch_redef_1_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -220,11 +220,11 @@ mangle_catch_redef_1_ie8: {
 
 mangle_catch_redef_1_toplevel: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -242,11 +242,11 @@ mangle_catch_redef_1_toplevel: {
 
 mangle_catch_redef_1_ie8_toplevel: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -264,11 +264,11 @@ mangle_catch_redef_1_ie8_toplevel: {
 
 mangle_catch_redef_2: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -285,11 +285,11 @@ mangle_catch_redef_2: {
 
 mangle_catch_redef_2_ie8: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -306,11 +306,11 @@ mangle_catch_redef_2_ie8: {
 
 mangle_catch_redef_2_toplevel: {
     options = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -327,11 +327,11 @@ mangle_catch_redef_2_toplevel: {
 
 mangle_catch_redef_2_ie8_toplevel: {
     options = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -348,7 +348,7 @@ mangle_catch_redef_2_ie8_toplevel: {
 
 mangle_catch_redef_3: {
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: false,
     }
     input: {
@@ -356,6 +356,7 @@ mangle_catch_redef_3: {
         try {
             throw 0;
         } catch (o) {
+            // prints "FAIL" if inlined on Node.js v4-
             (function() {
                 function f() {
                     o = "FAIL";
@@ -367,11 +368,12 @@ mangle_catch_redef_3: {
     }
     expect_exact: 'var o="PASS";try{throw 0}catch(o){(function(){function c(){o="FAIL"}c(),c()})()}console.log(o);'
     expect_stdout: "PASS"
+    node_version: ">=6"
 }
 
 mangle_catch_redef_3_toplevel: {
     mangle = {
-        ie8: false,
+        ie: false,
         toplevel: true,
     }
     input: {
@@ -379,6 +381,7 @@ mangle_catch_redef_3_toplevel: {
         try {
             throw 0;
         } catch (o) {
+            // prints "FAIL" if inlined on Node.js v4-
             (function() {
                 function f() {
                     o = "FAIL";
@@ -390,11 +393,12 @@ mangle_catch_redef_3_toplevel: {
     }
     expect_exact: 'var c="PASS";try{throw 0}catch(c){(function(){function o(){c="FAIL"}o(),o()})()}console.log(c);'
     expect_stdout: "PASS"
+    node_version: ">=6"
 }
 
-mangle_catch_redef_ie8_3: {
+mangle_catch_redef_3_ie8: {
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: false,
     }
     input: {
@@ -402,6 +406,7 @@ mangle_catch_redef_ie8_3: {
         try {
             throw 0;
         } catch (o) {
+            // prints "FAIL" if inlined on Node.js v4-
             (function() {
                 function f() {
                     o = "FAIL";
@@ -413,11 +418,12 @@ mangle_catch_redef_ie8_3: {
     }
     expect_exact: 'var o="PASS";try{throw 0}catch(o){(function(){function c(){o="FAIL"}c(),c()})()}console.log(o);'
     expect_stdout: "PASS"
+    node_version: ">=6"
 }
 
 mangle_catch_redef_3_ie8_toplevel: {
     mangle = {
-        ie8: true,
+        ie: true,
         toplevel: true,
     }
     input: {
@@ -425,6 +431,7 @@ mangle_catch_redef_3_ie8_toplevel: {
         try {
             throw 0;
         } catch (o) {
+            // prints "FAIL" if inlined on Node.js v4-
             (function() {
                 function f() {
                     o = "FAIL";
@@ -436,4 +443,5 @@ mangle_catch_redef_3_ie8_toplevel: {
     }
     expect_exact: 'var c="PASS";try{throw 0}catch(c){(function(){function o(){c="FAIL"}o(),o()})()}console.log(c);'
     expect_stdout: "PASS"
+    node_version: ">=6"
 }

test/compress/issue-1733.js

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

test/compress/issue-1770.js

@@ -46,18 +46,28 @@ mangle_props: {
             obj[1/0],
             obj["Infinity"],
             obj[-1/0],
-            obj[-1/0],
+            obj[-(1/0)],
             obj["-Infinity"],
             obj[null],
             obj["null"]
         );
     }
     expect_stdout: "1 1 1 2 2 2 3 3 3 4 4 4 5 5"
+    expect_warnings: [
+        "INFO: Preserving reserved property undefined",
+        "INFO: Preserving reserved property NaN",
+        "INFO: Preserving reserved property Infinity",
+        "INFO: Preserving reserved property -Infinity",
+        "INFO: Preserving reserved property null",
+        "INFO: Preserving reserved property log",
+    ]
 }
 
 numeric_literal: {
     mangle = {
-        properties: true,
+        properties: {
+            domprops: true,
+        },
     }
     beautify = {
         beautify: true,
@@ -106,11 +116,19 @@ numeric_literal: {
         "4 5 4 4",
         "8 7 8",
     ]
+    expect_warnings: [
+        "INFO: Mapping property 0x25 to o",
+        "INFO: Mapping property 1E42 to b",
+        "INFO: Preserving reserved property log",
+    ]
 }
 
 identifier: {
     mangle = {
-        properties: true,
+        properties: {
+            builtins: true,
+            domprops: true,
+        },
     }
     input: {
         var obj = {
@@ -209,37 +227,37 @@ identifier: {
             B: 28,
             C: 29,
             D: 30,
-            F: 31,
-            G: 32,
-            false: 33,
-            null: 34,
-            true: 35,
-            H: 36,
-            I: 37,
-            J: 38,
-            K: 39,
-            L: 40,
-            M: 41,
-            N: 42,
-            O: 43,
-            P: 44,
-            Q: 45,
-            R: 46,
-            S: 47,
-            T: 48,
-            U: 49,
-            V: 50,
-            W: 51,
-            X: 52,
-            Y: 53,
-            Z: 54,
-            $: 55,
-            _: 56,
-            ee: 57,
-            te: 58,
-            ne: 59,
-            ae: 60,
-            ie: 61,
+            E: 31,
+            F: 32,
+            G: 33,
+            H: 34,
+            I: 35,
+            J: 36,
+            K: 37,
+            L: 38,
+            M: 39,
+            N: 40,
+            O: 41,
+            P: 42,
+            Q: 43,
+            R: 44,
+            S: 45,
+            T: 46,
+            U: 47,
+            V: 48,
+            W: 49,
+            X: 50,
+            Y: 51,
+            Z: 52,
+            $: 53,
+            _: 54,
+            ee: 55,
+            te: 56,
+            ne: 57,
+            ae: 58,
+            ie: 59,
+            oe: 60,
+            re: 61,
         };
     }
 }

test/compress/issue-208.js

@@ -64,11 +64,11 @@ mixed: {
         x = 0;
     }
     expect_warnings: [
-        "WARN: global_defs ENV redefined [test/compress/issue-208.js:45,12]",
-        "WARN: global_defs FOO redefined [test/compress/issue-208.js:46,12]",
-        "WARN: global_defs FOO redefined [test/compress/issue-208.js:48,10]",
-        "WARN: global_defs DEBUG redefined [test/compress/issue-208.js:49,8]",
-        "WARN: global_defs DEBUG redefined [test/compress/issue-208.js:50,8]",
-        "WARN: global_defs DEBUG redefined [test/compress/issue-208.js:51,8]",
+        "WARN: global_defs ENV redefined [test/compress/issue-208.js:1,12]",
+        "WARN: global_defs FOO redefined [test/compress/issue-208.js:2,12]",
+        "WARN: global_defs FOO redefined [test/compress/issue-208.js:4,10]",
+        "WARN: global_defs DEBUG redefined [test/compress/issue-208.js:5,8]",
+        "WARN: global_defs DEBUG redefined [test/compress/issue-208.js:6,8]",
+        "WARN: global_defs DEBUG redefined [test/compress/issue-208.js:7,8]",
     ]
 }

test/compress/issue-269.js

@@ -1,98 +1,111 @@
 issue_269_1: {
-	options = {
+    options = {
         unsafe: true,
     }
-	input: {
-		f(
-			String(x),
-			Number(x),
-			Boolean(x),
+    input: {
+        var x = {};
+        console.log(
+            String(x),
+            Number(x),
+            Boolean(x),
 
-			String(),
-			Number(),
-			Boolean()
-		);
-	}
-	expect: {
-		f(
-			x + '', +x, !!x,
-			'', 0, false
-		);
-	}
+            String(),
+            Number(),
+            Boolean()
+        );
+    }
+    expect: {
+        var x = {};
+        console.log(
+            "" + x, +("" + x), !!x,
+            "", 0, false
+        );
+    }
+    expect_stdout: true
 }
 
 issue_269_dangers: {
-	options = {
+    options = {
         unsafe: true,
     }
-	input: {
-		f(
-			String(x, x),
-			Number(x, x),
-			Boolean(x, x)
-		);
-	}
-	expect: {
-		f(String(x, x), Number(x, x), Boolean(x, x));
-	}
+    input: {
+        var x = {};
+        console.log(
+            String(x, x),
+            Number(x, x),
+            Boolean(x, x)
+        );
+    }
+    expect: {
+        var x = {};
+        console.log(String(x, x), Number(x, x), Boolean(x, x));
+    }
+    expect_stdout: true
 }
 
 issue_269_in_scope: {
-	options = {
+    options = {
         unsafe: true,
     }
-	input: {
-		var String, Number, Boolean;
-		f(
-			String(x),
-			Number(x, x),
-			Boolean(x)
-		);
-	}
-	expect: {
-		var String, Number, Boolean;
-		f(String(x), Number(x, x), Boolean(x));
-	}
+    input: {
+        var String, Number, Boolean;
+        var x = {};
+        console.log(
+            String(x),
+            Number(x, x),
+            Boolean(x)
+        );
+    }
+    expect: {
+        var String, Number, Boolean;
+        var x = {};
+        console.log(String(x), Number(x, x), Boolean(x));
+    }
+    expect_stdout: true
 }
 
 strings_concat: {
-	options = {
+    options = {
+        strings: true,
         unsafe: true,
     }
-	input: {
-		f(
-			String(x + 'str'),
-			String('str' + x)
-		);
-	}
-	expect: {
-		f(
-			x + 'str',
-			'str' + x
-		);
-	}
+    input: {
+        var x = {};
+        console.log(
+            String(x + "str"),
+            String("str" + x)
+        );
+    }
+    expect: {
+        var x = {};
+        console.log(
+            x + "str",
+            "str" + x
+        );
+    }
+    expect_stdout: true
 }
 
 regexp: {
-	options = {
+    options = {
         evaluate: true,
         unsafe: true,
     }
-	input: {
-		RegExp("foo");
-		RegExp("bar", "ig");
-		RegExp(foo);
-		RegExp("bar", ig);
-		RegExp("should", "fail");
-	}
-	expect: {
-		/foo/;
-		/bar/ig;
-		RegExp(foo);
-		RegExp("bar", ig);
-		RegExp("should", "fail");
-	}
-	expect_warnings: [
-		'WARN: Error converting RegExp("should","fail") [test/compress/issue-269.js:86,2]',
-	]
+    input: {
+        RegExp("foo");
+        RegExp("bar", "ig");
+        RegExp(foo);
+        RegExp("bar", ig);
+        RegExp("should", "fail");
+    }
+    expect: {
+        /foo/;
+        /bar/ig;
+        RegExp(foo);
+        RegExp("bar", ig);
+        RegExp("should", "fail");
+    }
+    expect_warnings: [
+        'WARN: Error converting RegExp("should","fail") [test/compress/issue-269.js:5,8]',
+    ]
 }

test/compress/issue-2719.js

@@ -26,7 +26,7 @@ warn: {
         }().length);
     }
     expect_warnings: [
-        "WARN: Function.protoype.caller not supported [test/compress/issue-2719.js:17,19]",
-        "WARN: Function.protoype.arguments not supported [test/compress/issue-2719.js:17,19]",
+        "WARN: Function.prototype.arguments not supported [test/compress/issue-2719.js:5,19]",
+        "WARN: Function.prototype.caller not supported [test/compress/issue-2719.js:5,19]",
     ]
 }

test/compress/issue-281.js

@@ -108,6 +108,7 @@ safe_undefined: {
 }
 
 negate_iife_3: {
+    expression = true
     options = {
         conditionals: true,
         expression: true,
@@ -123,6 +124,7 @@ negate_iife_3: {
 }
 
 negate_iife_3_off: {
+    expression = true
     options = {
         conditionals: true,
         expression: true,
@@ -203,6 +205,7 @@ negate_iife_5_off: {
 }
 
 issue_1254_negate_iife_true: {
+    expression = true
     options = {
         expression: true,
         inline: true,
@@ -215,11 +218,12 @@ issue_1254_negate_iife_true: {
             };
         })()();
     }
-    expect_exact: 'void console.log("test");'
+    expect_exact: 'void console.log("test")'
     expect_stdout: true
 }
 
 issue_1254_negate_iife_nested: {
+    expression = true
     options = {
         expression: true,
         inline: true,
@@ -232,7 +236,7 @@ issue_1254_negate_iife_nested: {
             };
         })()()()()();
     }
-    expect_exact: '(void console.log("test"))()()();'
+    expect_exact: '(void console.log("test"))()()()'
 }
 
 negate_iife_issue_1073: {
@@ -426,6 +430,7 @@ wrap_iife_in_return_call: {
 
 pure_annotation_1: {
     options = {
+        annotations: true,
         inline: true,
         side_effects: true,
     }
@@ -439,6 +444,7 @@ pure_annotation_1: {
 
 pure_annotation_2: {
     options = {
+        annotations: true,
         collapse_vars: true,
         inline: true,
         side_effects: true,
@@ -463,15 +469,19 @@ 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 +496,17 @@ 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-368.js

@@ -15,7 +15,7 @@ collapse: {
             var a;
             b = c();
             a = typeof b === 'function' ? b() : b;
-            return 'stirng' == typeof a && d();
+            return 'string' == typeof a && d();
         }
         function f3(c) {
             var a;
@@ -41,7 +41,7 @@ collapse: {
             return void 0 !== ('function' === typeof b ? b() : b) && c();
         }
         function f2(b) {
-            return 'stirng' == typeof ('function' === typeof (b = c()) ? b() : b) && d();
+            return 'string' == typeof ('function' === typeof (b = c()) ? b() : b) && d();
         }
         function f3(c) {
             var a;

test/compress/issue-3768.js

@@ -0,0 +1,128 @@
+mangle: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var e = eval, x = 42;
+        (function() {
+            console.log(e("typeof x"));
+        })();
+    }
+    expect: {
+        var e = eval, x = 42;
+        (function() {
+            console.log(e("typeof x"));
+        })();
+    }
+    expect_stdout: true
+}
+
+compress: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var a = 42;
+            return eval("typeof a");
+        }(), function(e) {
+            var a = null;
+            return e("typeof a");
+        }(eval), function(eval) {
+            var a = false;
+            return eval("typeof a");
+        }(eval), function(f) {
+            var a = "STRING";
+            var eval = f;
+            return eval("typeof a");
+        }(eval), function(g) {
+            var a = eval;
+            function eval() {
+                return g;
+            }
+            return eval()("typeof a");
+        }(eval));
+    }
+    expect: {
+        console.log(function() {
+            var a = 42;
+            return eval("typeof a");
+        }(), (0, eval)("typeof a"), function(eval) {
+            var a = false;
+            return eval("typeof a");
+        }(eval), function(f) {
+            var a = "STRING";
+            var eval = f;
+            return eval("typeof a");
+        }(eval), function(g) {
+            var a = eval;
+            function eval() {
+                return g;
+            }
+            return eval()("typeof a");
+        }(eval));
+    }
+    expect_stdout: "number undefined boolean string undefined"
+}
+
+call_arg_1: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var z = "foo";
+        (function() {
+            var z = false;
+            (function(e) {
+                var z = 42;
+                e("console.log(typeof z)");
+            })(eval);
+        })();
+    }
+    expect: {
+        var z = "foo";
+        (function() {
+            var o = false;
+            (function(o) {
+                var a = 42;
+                o("console.log(typeof z)");
+            })(eval);
+        })();
+    }
+    expect_stdout: true
+}
+
+call_arg_2: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        function eval() {
+            console.log("PASS");
+        }
+        var z = "foo";
+        (function() {
+            var z = false;
+            (function(e) {
+                var z = 42;
+                e("console.log(typeof z)");
+            })(eval);
+        })();
+    }
+    expect: {
+        function n() {
+            console.log("PASS");
+        }
+        var o = "foo";
+        (function() {
+            var o = false;
+            (function(o) {
+                var n = 42;
+                o("console.log(typeof z)");
+            })(n);
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/issue-5614.js

@@ -0,0 +1,195 @@
+record_update: {
+    options = {
+        loops: true,
+        passes: 3,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var value = { a: 42, b: "PASS" };
+        var unused = _Utils_update(value, { b: "FAIL" });
+        function _Utils_update(oldRecord, updatedFields) {
+            var newRecord = {};
+            for (var key in oldRecord)
+                newRecord[key] = oldRecord[key];
+            for (var key in updatedFields)
+                newRecord[key] = updatedFields[key];
+            return newRecord;
+        }
+    }
+    expect: {}
+}
+
+currying: {
+    options = {
+        inline: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function F(arity, fun, wrapper) {
+            wrapper.a = arity;
+            wrapper.f = fun;
+            return wrapper;
+        }
+        function F2(fun) {
+            return F(2, fun, function(a) {
+                return function(b) {
+                    return fun(a, b);
+                };
+            });
+        }
+        function _Utils_eq(x, y) {
+            var pair, stack = [], isEqual = _Utils_eqHelp(x, y, 0, stack);
+            while (isEqual && (pair = stack.pop()))
+                isEqual = _Utils_eqHelp(pair.a, pair.b, 0, stack);
+            return isEqual;
+        }
+        var _Utils_equal = F2(_Utils_eq);
+    }
+    expect: {}
+}
+
+conditional_property_write: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var o = {};
+            if (a)
+                o.p = console.log("foo");
+            else
+                o.q = console.log("bar");
+            o.r = console.log("baz");
+        }
+        f(42);
+        f(null);
+    }
+    expect: {
+        function f(a) {
+            if (a)
+                console.log("foo");
+            else
+                console.log("bar");
+            console.log("baz");
+        }
+        f(42);
+        f(null);
+    }
+    expect_stdout: [
+        "foo",
+        "baz",
+        "bar",
+        "baz",
+    ]
+}
+
+reassign_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS", b = "FAIL";
+        (b = a).toString();
+        console.log(b);
+    }
+    expect: {
+        var b = "FAIL";
+        (b = "PASS").toString();
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+reassign_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        if (false) {
+            a = null + 0;
+            a();
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        if (false) {
+            a = 0;
+            a();
+        }
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+reassign_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 0;
+        (a = a || "PASS").toString();
+        console.log(a);
+    }
+    expect: {
+        var a = 0;
+        (a = (0, "PASS")).toString();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+retain_instance_write: {
+    options = {
+        pure_getters: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            return a;
+        }
+        function g() {
+            var o = {};
+            var b = new f(o);
+            if (console)
+                b.p = "PASS";
+            return o;
+        }
+        console.log(g().p);
+    }
+    expect: {
+        function f(a) {
+            return a;
+        }
+        function g() {
+            var o = {};
+            var b = new f(o);
+            if (console)
+                b.p = "PASS";
+            return o;
+        }
+        console.log(g().p);
+    }
+    expect_stdout: "PASS"
+}

test/compress/issue-637.js

@@ -16,7 +16,6 @@ wrongly_optimized: {
         function func() {
             foo();
         }
-        // TODO: optimize to `func(), bar()`
-        (func(), 1) && bar();
+        func(), 1, bar();
     }
 }

test/compress/issue-640.js

@@ -21,7 +21,7 @@ cond_5: {
         }
     }
     expect: {
-        some_condition() && some_other_condition() ? do_something() : alternate();
+        (some_condition() && some_other_condition() ? do_something : alternate)();
         if (some_condition() && some_other_condition()) do_something();
     }
 }
@@ -68,6 +68,7 @@ drop_console_2: {
 }
 
 drop_value: {
+    expression = true
     options = {
         expression: true,
         side_effects: true,
@@ -84,6 +85,7 @@ wrongly_optimized: {
     options = {
         booleans: true,
         conditionals: true,
+        dead_code: true,
         evaluate: true,
         expression: true,
     }
@@ -99,12 +101,13 @@ wrongly_optimized: {
         function func() {
             foo();
         }
-        // TODO: optimize to `func(), bar()`
-        if (func(), 1) bar();
+        func(), 1;
+        bar();
     }
 }
 
 negate_iife_1: {
+    expression = true
     options = {
         expression: true,
         negate_iife: true,
@@ -118,6 +121,7 @@ negate_iife_1: {
 }
 
 negate_iife_3: {
+    expression = true
     options = {
         conditionals: true,
         expression: true,
@@ -132,6 +136,7 @@ negate_iife_3: {
 }
 
 negate_iife_3_off: {
+    expression = true
     options = {
         conditionals: true,
         expression: true,
@@ -214,6 +219,7 @@ negate_iife_5_off: {
 }
 
 issue_1254_negate_iife_true: {
+    expression = true
     options = {
         expression: true,
         negate_iife: true,
@@ -225,11 +231,12 @@ issue_1254_negate_iife_true: {
             };
         })()();
     }
-    expect_exact: '(function(){return function(){console.log("test")}})()();'
+    expect_exact: 'function(){return function(){console.log("test")}}()()'
     expect_stdout: true
 }
 
 issue_1254_negate_iife_nested: {
+    expression = true
     options = {
         expression: true,
         negate_iife: true,
@@ -241,7 +248,7 @@ issue_1254_negate_iife_nested: {
             };
         })()()()()();
     }
-    expect_exact: '(function(){return function(){console.log("test")}})()()()()();'
+    expect_exact: 'function(){return function(){console.log("test")}}()()()()()'
     expect_stdout: true
 }
 
@@ -316,7 +323,35 @@ iife: {
         typeof function g() {}();
     }
     expect: {
-        x = 42, function a() {}(), function b() {}(), function c() {}(),
-        function d() {}(), function e() {}(), function f() {}(), typeof function g() {}();
+        x = 42,
+        function a() {}(),
+        !function b() {}(),
+        ~function c() {}(),
+        +function d() {}(),
+        -function e() {}(),
+        void function f() {}(),
+        typeof function g() {}();
+    }
+}
+
+iife_drop_side_effect_free: {
+    options = {
+        expression: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        x = 42;
+        (function a() {})();
+        !function b() {}();
+        ~function c() {}();
+        +function d() {}();
+        -function e() {}();
+        void function f() {}();
+        typeof function g() {}();
+    }
+    expect: {
+        x = 42,
+        typeof void 0;
     }
 }

test/compress/issue-747.js

@@ -1,6 +1,7 @@
 dont_reuse_prop: {
     mangle = {
         properties: {
+            domprops: true,
             regex: /asd/,
         },
     }
@@ -19,11 +20,17 @@ dont_reuse_prop: {
         console.log(obj.a);
     }
     expect_stdout: "123"
+    expect_warnings: [
+        "INFO: Preserving excluded property a",
+        "INFO: Mapping property asd to b",
+        "INFO: Preserving reserved property log",
+    ]
 }
 
 unmangleable_props_should_always_be_reserved: {
     mangle = {
         properties: {
+            domprops: true,
             regex: /asd/,
         },
     }
@@ -42,4 +49,9 @@ unmangleable_props_should_always_be_reserved: {
         console.log(obj.a);
     }
     expect_stdout: "123"
+    expect_warnings: [
+        "INFO: Preserving excluded property a",
+        "INFO: Mapping property asd to b",
+        "INFO: Preserving reserved property log",
+    ]
 }

test/compress/issue-782.js

@@ -8,7 +8,7 @@ remove_sequence: {
         (0, 1, _decorators.logThis)();
     }
     expect: {
-        eval();
+        (0, eval)();
         logThis();
         (0, _decorators.logThis)();
     }

test/compress/issue-892.js

@@ -1,6 +1,4 @@
 dont_mangle_arguments: {
-    mangle = {
-    };
     options = {
         booleans: true,
         comparisons: true,
@@ -21,12 +19,13 @@ dont_mangle_arguments: {
         side_effects: true,
         unused: true,
     }
+    mangle = {}
     input: {
         (function(){
             var arguments = arguments, not_arguments = 9;
             console.log(not_arguments, arguments);
-        })(5,6,7);
+        })(5, 6, 7);
     }
-    expect_exact: "(function(){var arguments=arguments,o=9;console.log(o,arguments)})(5,6,7);"
+    expect_exact: "(function(){var arguments,o=9;console.log(o,arguments)})(5,6,7);"
     expect_stdout: true
 }

test/compress/issue-913.js

@@ -1,17 +1,18 @@
 keep_var_for_in: {
     options = {
         hoist_vars: true,
+        join_vars: true,
         unused: true,
     }
     input: {
-        (function(obj){
+        (function(obj) {
             var foo = 5;
             for (var i in obj)
                 return foo;
         })();
     }
     expect: {
-        (function(obj){
+        (function(obj) {
             var i, foo = 5;
             for (i in obj)
                 return foo;

test/compress/issue-973.js

@@ -53,20 +53,23 @@ this_binding_conditionals: {
 this_binding_collapse_vars: {
     options = {
         collapse_vars: true,
-        toplevel: true,
         unused: true,
     }
     input: {
-        "use strict";
-        var c = a; c();
-        var d = a.b; d();
-        var e = eval; e();
+        function f() {
+            "use strict";
+            var c = a; c();
+            var d = a.b; d();
+            var e = eval; e();
+        }
     }
     expect: {
-        "use strict";
-        a();
-        (0, a.b)();
-        (0, eval)();
+        function f() {
+            "use strict";
+            a();
+            (0, a.b)();
+            (0, eval)();
+        }
     }
 }
 
@@ -97,7 +100,7 @@ this_binding_side_effects: {
         (function(foo) {
             foo();
             (0, foo.bar)();
-            eval("console.log(foo);");
+            (0, eval)("console.log(foo);");
         }());
         (function(foo) {
             "use strict";
@@ -144,7 +147,7 @@ this_binding_sequences: {
             return eval("this");
         }()),
         console.log(typeof function() {
-            return eval("this");
+            return (0, eval)("this");
         }()),
         console.log(typeof function() {
             "use strict";

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/issue-979.js

@@ -1,4 +1,4 @@
-issue979_reported: {
+reported: {
     options = {
         booleans: true,
         comparisons: true,
@@ -17,29 +17,26 @@ issue979_reported: {
     }
     input: {
         function f1() {
-            if (a == 1 || b == 2) {
+            if (a == 1 || b == 2)
                 foo();
-            }
         }
         function f2() {
-            if (!(a == 1 || b == 2)) {
-            }
-            else {
+            if (!(a == 1 || b == 2));
+            else
                 foo();
-            }
         }
     }
     expect: {
         function f1() {
-            1!=a&&2!=b||foo();
+            1 != a && 2 != b || foo();
         }
         function f2() {
-            1!=a&&2!=b||foo();
+            1 != a && 2 != b || foo();
         }
     }
 }
 
-issue979_test_negated_is_best: {
+test_negated_is_best: {
     options = {
         booleans: true,
         comparisons: true,
@@ -58,53 +55,47 @@ issue979_test_negated_is_best: {
     }
     input: {
         function f3() {
-            if (a == 1 | b == 2) {
+            if (a == 1 | b == 2)
                 foo();
-            }
         }
         function f4() {
-            if (!(a == 1 | b == 2)) {
-            }
-            else {
+            if (!(a == 1 | b == 2));
+            else
                 foo();
-            }
         }
         function f5() {
-            if (a == 1 && b == 2) {
+            if (a == 1 && b == 2)
                 foo();
-            }
         }
         function f6() {
-            if (!(a == 1 && b == 2)) {
-            }
-            else {
+            if (!(a == 1 && b == 2));
+            else
                 foo();
-            }
         }
         function f7() {
-            if (a == 1 || b == 2) {
+            if (a == 1 || b == 2)
                 foo();
-            }
-            else {
+            else
                 return bar();
-            }
         }
     }
     expect: {
         function f3() {
-            1==a|2==b&&foo();
+            1 == a | 2 == b && foo();
         }
         function f4() {
-            1==a|2==b&&foo();
+            1 == a | 2 == b && foo();
         }
         function f5() {
-            1==a&&2==b&&foo();
+            1 == a && 2 == b && foo();
         }
         function f6() {
-            1!=a||2!=b||foo();
+            1 == a && 2 == b && foo();
         }
         function f7() {
-            if(1!=a&&2!=b)return bar();foo()
+            if (1 != a && 2 != b)
+                return bar();
+            foo();
         }
     }
 }

test/compress/labels.js

@@ -3,6 +3,7 @@ labels_1: {
         conditionals: true,
         dead_code: true,
         if_return: true,
+        unused: true,
     }
     input: {
         out: {
@@ -21,6 +22,7 @@ labels_2: {
         conditionals: true,
         dead_code: true,
         if_return: true,
+        unused: true,
     }
     input: {
         out: {
@@ -61,6 +63,7 @@ labels_4: {
         conditionals: true,
         dead_code: true,
         if_return: true,
+        unused: true,
     }
     input: {
         out: for (var i = 0; i < 5; ++i) {
@@ -80,8 +83,9 @@ labels_5: {
         conditionals: true,
         dead_code: true,
         if_return: true,
+        unused: true,
     }
-    // should keep the break-s in the following
+    // should keep `break`s below
     input: {
         while (foo) {
             if (bar) break;
@@ -97,14 +101,18 @@ labels_5: {
             if (bar) break;
             console.log("foo");
         }
-        out: while (foo) {
-            if (bar) break out;
+        while (foo) {
+            if (bar) break;
             console.log("foo");
         }
     }
 }
 
 labels_6: {
+    options = {
+        dead_code: true,
+        unused: true,
+    }
     input: {
         out: break out;
     };
@@ -159,6 +167,7 @@ labels_9: {
         conditionals: true,
         dead_code: true,
         if_return: true,
+        unused: true,
     }
     input: {
         out: while (foo) {
@@ -182,21 +191,243 @@ labels_10: {
         conditionals: true,
         dead_code: true,
         if_return: true,
+        unused: true,
     }
     input: {
-        out: while (foo) {
-            x();
-            y();
+        out: while (42) {
+            console.log("PASS");
             break out;
-            z();
-            k();
+            console.log("FAIL");
         }
     };
     expect: {
-        out: while (foo) {
-            x();
-            y();
-            break out;
+        while (42) {
+            console.log("PASS");
+            break;
         }
     }
+    expect_stdout: "PASS"
+}
+
+labels_11: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unused: true,
+    }
+    input: {
+        L: if (console.log("PASS"))
+            break L;
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+labels_12: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        if_return: true,
+    }
+    input: {
+        L: try {
+            if (console.log("foo"))
+                break L;
+            throw "bar";
+        } catch (e) {
+            console.log(e);
+            break L;
+        } finally {
+            if (console.log("baz"))
+                break L;
+        }
+    }
+    expect: {
+        L: try {
+            if (!console.log("foo"))
+                throw "bar";
+        } catch (e) {
+            console.log(e);
+        } finally {
+            if (console.log("baz"))
+                break L;
+        }
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
+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"
+}
+
+issue_5522: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        console.log(function() {
+            L: try {
+                return "FAIL";
+            } finally {
+                break L;
+            }
+            return "PASS";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            L: try {
+                return "FAIL";
+            } finally {
+                break L;
+            }
+            return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5524: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        L: try {
+            FAIL;
+        } finally {
+            break L;
+        }
+        console.log("PASS");
+    }
+    expect: {
+        L: try {
+            FAIL;
+        } finally {
+            break L;
+        }
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
 }

test/compress/loops.js

@@ -6,7 +6,7 @@ while_becomes_for: {
         while (foo()) bar();
     }
     expect: {
-        for (; foo(); ) bar();
+        for (;foo();) bar();
     }
 }
 
@@ -19,7 +19,7 @@ drop_if_break_1: {
             if (foo()) break;
     }
     expect: {
-        for (; !foo(););
+        for (;!foo(););
     }
 }
 
@@ -32,7 +32,7 @@ drop_if_break_2: {
             if (foo()) break;
     }
     expect: {
-        for (; bar() && !foo(););
+        for (;bar() && !foo(););
     }
 }
 
@@ -70,7 +70,7 @@ drop_if_break_4: {
         }
     }
     expect: {
-        for (; bar() && (x(), y(), !foo());) z(), k();
+        for (;bar() && (x(), y(), !foo());) z(), k();
     }
 }
 
@@ -82,7 +82,7 @@ drop_if_else_break_1: {
         for (;;) if (foo()) bar(); else break;
     }
     expect: {
-        for (; foo(); ) bar();
+        for (;foo();) bar();
     }
 }
 
@@ -97,7 +97,7 @@ drop_if_else_break_2: {
         }
     }
     expect: {
-        for (; bar() && foo();) baz();
+        for (;bar() && foo();) baz();
     }
 }
 
@@ -114,7 +114,7 @@ drop_if_else_break_3: {
         }
     }
     expect: {
-        for (; bar() && foo();) {
+        for (;bar() && foo();) {
             baz();
             stuff1();
             stuff2();
@@ -138,7 +138,7 @@ drop_if_else_break_4: {
         }
     }
     expect: {
-        for (; bar() && (x(), y(), foo());) baz(), z(), k();
+        for (;bar() && (x(), y(), foo());) baz(), z(), k();
     }
 }
 
@@ -193,15 +193,15 @@ evaluate: {
         } while (false);
     }
     expect: {
-        for(;;)
+        for (;;)
             a();
-        for(;;)
+        for (;;)
             c();
         d();
     }
 }
 
-issue_1532: {
+issue_1532_1: {
     options = {
         evaluate: true,
         loops: true,
@@ -210,24 +210,62 @@ issue_1532: {
         function f(x, y) {
             do {
                 if (x) break;
-                foo();
+                console.log(y);
             } while (false);
         }
+        f(null, "PASS");
+        f(42, "FAIL");
+    }
+    expect: {
+        function f(x, y) {
+            for (; !x && (console.log(y), false););
+        }
+        f(null, "PASS");
+        f(42, "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_1532_2: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        function f(x, y) {
+            do {
+                if (x) {
+                    console.log(x);
+                    break;
+                }
+                console.log(y);
+            } while (false);
+        }
+        f(null, "PASS");
+        f(42, "FAIL");
     }
     expect: {
         function f(x, y) {
             do {
-                if (x) break;
-                foo();
-            } while (false);
+                if (x) {
+                    console.log(x);
+                    break;
+                }
+            } while (console.log(y), false);
         }
+        f(null, "PASS");
+        f(42, "FAIL");
     }
+    expect_stdout: [
+        "PASS",
+        "42",
+    ]
 }
 
 issue_186: {
     beautify = {
         beautify: false,
-        ie8: false,
+        ie: false,
     }
     input: {
         var x = 3;
@@ -246,7 +284,7 @@ issue_186: {
 issue_186_ie8: {
     beautify = {
         beautify: false,
-        ie8: true,
+        ie: true,
     }
     input: {
         var x = 3;
@@ -265,7 +303,7 @@ issue_186_ie8: {
 issue_186_beautify: {
     beautify = {
         beautify: true,
-        ie8: false,
+        ie: false,
     }
     input: {
         var x = 3;
@@ -292,7 +330,7 @@ issue_186_beautify: {
 issue_186_beautify_ie8: {
     beautify = {
         beautify: true,
-        ie8: true,
+        ie: true,
     }
     input: {
         var x = 3;
@@ -322,7 +360,7 @@ issue_186_braces: {
     beautify = {
         beautify: false,
         braces: true,
-        ie8: false,
+        ie: false,
     }
     input: {
         var x = 3;
@@ -342,7 +380,7 @@ issue_186_braces_ie8: {
     beautify = {
         beautify: false,
         braces: true,
-        ie8: true,
+        ie: true,
     }
     input: {
         var x = 3;
@@ -362,7 +400,7 @@ issue_186_beautify_braces: {
     beautify = {
         beautify: true,
         braces: true,
-        ie8: false,
+        ie: false,
     }
     input: {
         var x = 3;
@@ -394,7 +432,7 @@ issue_186_beautify_braces_ie8: {
     beautify = {
         beautify: true,
         braces: true,
-        ie8: true,
+        ie: true,
     }
     input: {
         var x = 3;
@@ -463,14 +501,14 @@ do_switch: {
     }
 }
 
-in_parenthesis_1: {
+in_parentheses_1: {
     input: {
         for (("foo" in {});0;);
     }
     expect_exact: 'for(("foo"in{});0;);'
 }
 
-in_parenthesis_2: {
+in_parentheses_2: {
     input: {
         for ((function(){ "foo" in {}; });0;);
     }
@@ -509,8 +547,8 @@ dead_code_condition: {
         console.log(a);
     }
     expect: {
-        var c;
         var a = 0, b = 5;
+        var c;
         a += 1, 0,
         console.log(a);
     }
@@ -523,13 +561,13 @@ issue_2740_1: {
         loops: true,
     }
     input: {
-        for (; ; ) break;
-        for (a(); ; ) break;
-        for (; b(); ) break;
-        for (c(); d(); ) break;
-        for (; ; e()) break;
-        for (f(); ; g()) break;
-        for (; h(); i()) break;
+        for (;;) break;
+        for (a();;) break;
+        for (;b();) break;
+        for (c(); d();) break;
+        for (;;e()) break;
+        for (f();; g()) break;
+        for (;h(); i()) break;
         for (j(); k(); l()) break;
     }
     expect: {
@@ -549,6 +587,7 @@ issue_2740_2: {
         dead_code: true,
         loops: true,
         passes: 2,
+        unused: true,
     }
     input: {
         L1: while (x()) {
@@ -564,6 +603,7 @@ issue_2740_3: {
     options = {
         dead_code: true,
         loops: true,
+        unused: true,
     }
     input: {
         L1: for (var x = 0; x < 3; x++) {
@@ -574,9 +614,11 @@ issue_2740_3: {
         console.log(x, y);
     }
     expect: {
-        L1: for (var x = 0; x < 3; x++)
-            for (var y = 0; y < 2; y++)
+        L1: for (var x = 0; x < 3; x++) {
+            var y = 0;
+            if (y < 2)
                 break L1;
+        }
         console.log(x, y);
     }
     expect_stdout: "0 0"
@@ -587,6 +629,7 @@ issue_2740_4: {
         dead_code: true,
         loops: true,
         passes: 2,
+        unused: true,
     }
     input: {
         L1: for (var x = 0; x < 3; x++) {
@@ -611,6 +654,7 @@ issue_2740_5: {
         dead_code: true,
         loops: true,
         passes: 2,
+        unused: true,
     }
     input: {
         L1: for (var x = 0; x < 3; x++) {
@@ -646,3 +690,661 @@ issue_2904: {
     }
     expect_stdout: "1"
 }
+
+issue_3371: {
+    options = {
+        functions: true,
+        join_vars: true,
+        loops: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = function() {
+                console.log("PASS");
+            };
+            while (a());
+        })();
+    }
+    expect: {
+        (function() {
+            function a() {
+                console.log("PASS");
+            }
+            for (;a(););
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+step: {
+    options = {
+        loops: true,
+        side_effects: true,
+    }
+    input: {
+        for (var i = 0; i < 42; "foo", i++, "bar");
+        console.log(i);
+    }
+    expect: {
+        for (var i = 0; i < 42; i++);
+        console.log(i);
+    }
+    expect_stdout: "42"
+}
+
+empty_for_in: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        for (var a in [ 1, 2, 3 ]) {
+            var b = a + 1;
+        }
+    }
+    expect: {}
+    expect_warnings: [
+        "WARN: Dropping unused variable b [test/compress/loops.js:2,16]",
+        "INFO: Dropping unused loop variable a [test/compress/loops.js:1,17]",
+    ]
+}
+
+empty_for_in_used: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        for (var a in [ 1, 2, 3 ]) {
+            var b = a + 1;
+        }
+        console.log(a);
+    }
+    expect: {
+        for (var a in [ 1, 2, 3 ]);
+        console.log(a);
+    }
+    expect_stdout: "2"
+    expect_warnings: [
+        "WARN: Dropping unused variable b [test/compress/loops.js:2,16]",
+    ]
+}
+
+empty_for_in_side_effects: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        for (var a in {
+            foo: console.log("PASS")
+        }) {
+            var b = a + "bar";
+        }
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    expect_warnings: [
+        "WARN: Dropping unused variable b [test/compress/loops.js:4,16]",
+        "INFO: Dropping unused loop variable a [test/compress/loops.js:1,17]",
+        "WARN: Side effects in object of for-in loop [test/compress/loops.js:2,17]",
+    ]
+}
+
+empty_for_in_prop_init: {
+    options = {
+        loops: true,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        console.log(function f() {
+            var a = "bar";
+            for ((a, f)[a] in console.log("foo"));
+            return a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var a = "bar";
+            console.log("foo");
+            return a;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    expect_warnings: [
+        "INFO: Dropping unused loop variable f [test/compress/loops.js:3,21]",
+        "WARN: Side effects in object of for-in loop [test/compress/loops.js:3,30]",
+    ]
+}
+
+for_of: {
+    input: {
+        var a = [ "PASS", 42 ];
+        a.p = "FAIL";
+        for (a of (null, a))
+            console.log(a);
+    }
+    expect_exact: 'var a=["PASS",42];a.p="FAIL";for(a of(null,a))console.log(a);'
+    expect_stdout: true
+    node_version: ">=0.12"
+}
+
+for_async_of: {
+    input: {
+        var async = [ "PASS", 42 ];
+        async.p = "FAIL";
+        for (async of (null, async))
+            console.log(async);
+    }
+    expect_exact: 'var async=["PASS",42];async.p="FAIL";for(async of(null,async))console.log(async);'
+    expect_stdout: true
+    node_version: ">=0.12 <16"
+}
+
+for_of_regexp: {
+    input: {
+        for (var a of /foo/);
+    }
+    expect_exact: "for(var a of/foo/);"
+}
+
+for_await_of_regexp: {
+    input: {
+        for await (var a of /foo/);
+    }
+    expect_exact: "for await(var a of/foo/);"
+}
+
+issue_3631_1: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        loops: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        L: do {
+            for (;;) continue L;
+            var b = 1;
+        } while (b && c++);
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        do {
+            var b;
+        } while (b && c++);
+        console.log(c);
+    }
+    expect_stdout: "0"
+}
+
+issue_3631_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        loops: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        L: for (var a = 1; a--; console.log(b)) {
+            for (;;) continue L;
+            var b = "FAIL";
+        }
+    }
+    expect: {
+        for (var a = 1; a--; console.log(b))
+            var b;
+    }
+    expect_stdout: "undefined"
+}
+
+loop_if_break: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        function f(a, b) {
+            try {
+                while (a) {
+                    if (b) {
+                        break;
+                        var c = 42;
+                        console.log(c);
+                    } else {
+                        var d = false;
+                        throw d;
+                    }
+                }
+            } catch (e) {
+                console.log("E:", e);
+            }
+            console.log(a, b, c, d);
+        }
+        f(0, 0);
+        f(0, 1);
+        f(1, 0);
+        f(1, 1);
+    }
+    expect: {
+        function f(a, b) {
+            try {
+                for (;a && !b;) {
+                    var d = false;
+                    throw d;
+                    var c;
+                }
+            } catch (e) {
+                console.log("E:", e);
+            }
+            console.log(a, b, c, d);
+        }
+        f(0, 0);
+        f(0, 1);
+        f(1, 0);
+        f(1, 1);
+    }
+    expect_stdout: [
+        "0 0 undefined undefined",
+        "0 1 undefined undefined",
+        "E: false",
+        "1 0 undefined false",
+        "1 1 undefined undefined",
+    ]
+}
+
+loop_return: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        function f(a) {
+            while (a) return 42;
+            return "foo";
+        }
+        console.log(f(0), f(1));
+    }
+    expect: {
+        function f(a) {
+            if (a) return 42;
+            return "foo";
+        }
+        console.log(f(0), f(1));
+    }
+    expect_stdout: "foo 42"
+}
+
+issue_3634_1: {
+    options = {
+        loops: true,
+    }
+    input: {
+        var b = 0;
+        L: while (++b < 2)
+            while (1)
+                if (b) break L;
+        console.log(b);
+    }
+    expect: {
+        var b = 0;
+        L: for (;++b < 2;)
+            for (;1;)
+                if (b) break L;
+        console.log(b);
+    }
+    expect_stdout: "1"
+}
+
+issue_3634_2: {
+    options = {
+        loops: true,
+    }
+    input: {
+        var b = 0;
+        L: while (++b < 2)
+            while (1)
+                if (!b)
+                    continue L;
+                else
+                    break L;
+        console.log(b);
+    }
+    expect: {
+        var b = 0;
+        L: for (;++b < 2;)
+            for (;1;)
+                if (!b)
+                    continue L;
+                else
+                    break L;
+        console.log(b);
+    }
+    expect_stdout: "1"
+}
+
+issue_4075: {
+    options = {
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL";
+        (function() {
+            for (a in { PASS: 0 });
+        })()
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        (function() {
+            for (a in { PASS: 0 });
+        })()
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4082: {
+    options = {
+        keep_fargs: false,
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        (function(a) {
+            for (a in "foo")
+                var b;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        (function(a) {
+            for (a in "foo");
+        })();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4084: {
+    options = {
+        keep_fargs: false,
+        loops: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            function f(a) {
+                var b = a++;
+                for (a in "foo");
+            }
+            f();
+            return typeof a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            (function() {
+                0;
+            })();
+            return typeof a;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4091_1: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            for (var e in 42);
+        }
+        console.log(e && e);
+    }
+    expect: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4091_2: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            for (e in 42);
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4182_1: {
+    options = {
+        loops: true,
+    }
+    input: {
+        (function() {
+            do {
+                try {
+                    return;
+                } finally {
+                    continue;
+                }
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect: {
+        (function() {
+            do {
+                try {
+                    return;
+                } finally {
+                    continue;
+                }
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4182_2: {
+    options = {
+        loops: true,
+    }
+    input: {
+        (function() {
+            L: do {
+                do {
+                    try {
+                        return;
+                    } finally {
+                        continue L;
+                    }
+                    console.log("FAIL");
+                } while (0);
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect: {
+        (function() {
+            L: do {
+                do {
+                    try {
+                        return;
+                    } finally {
+                        continue L;
+                    }
+                } while (console.log("FAIL"), 0);
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+do_continue: {
+    options = {
+        loops: true,
+    }
+    input: {
+        try {
+            do {
+                continue;
+            } while ([ A ]);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            do {
+                continue;
+            } while ([ A ]);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4240: {
+    options = {
+        loops: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            function f() {
+                var o = { PASS: 42 };
+                for (a in o);
+            }
+            (function() {
+                if (f());
+            })();
+            console.log(a);
+        })();
+    }
+    expect: {
+        (function(a) {
+            (function() {
+                if (function() {
+                    for (a in { PASS: 42 });
+                }());
+            })();
+            console.log(a);
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4355: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        loops: true,
+        passes: 2,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        while (function() {
+            var a;
+            for (a in console.log("PASS"))
+                var b = 0;
+        }())
+            var c;
+    }
+    expect: {
+        (function() {
+            console.log("PASS");
+        })();
+        var c;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4564: {
+    options = {
+        loops: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw null;
+        } catch (a) {
+            var a;
+            (function() {
+                for (a in "foo");
+            })();
+            console.log(a);
+        }
+    }
+    expect: {
+        try {
+            throw null;
+        } catch (a) {
+            var a;
+            (function() {
+                for (a in "foo");
+            })();
+            console.log(a);
+        }
+    }
+    expect_stdout: "2"
+}

test/compress/max_line_len.js

@@ -37,6 +37,51 @@ just_enough: {
     expect_warnings: []
 }
 
+drop_semicolon: {
+    beautify = {
+        max_line_len: 5,
+        semicolons: true,
+    }
+    input: {
+        var a;
+        console.log(a || 42);
+    }
+    expect_exact: [
+        "var a",
+        "console.log(",
+        "a||42",
+        ");",
+    ]
+    expect_stdout: "42"
+    expect_warnings: [
+        "WARN: Output exceeds 5 characters",
+    ]
+}
+
+template_newline: {
+    beautify = {
+        max_line_len: 2,
+    }
+    input: {
+        console.log(`foo
+bar`);
+    }
+    expect_exact: [
+        "console.log(",
+        "`foo",
+        "bar`",
+        ");",
+    ]
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    expect_warnings: [
+        "WARN: Output exceeds 2 characters",
+    ]
+    node_version: ">=4"
+}
+
 issue_304: {
     beautify = {
         max_line_len: 10,