v3.17.0

fixes #5602

.gitattributes

@@ -0,0 +1 @@
+*.js    text eol=lf

.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

.gitignore

@@ -1,2 +1,3 @@
+/node_modules/
+/npm-debug.log
 tmp/
-node_modules/

.travis.yml

@@ -1,6 +0,0 @@
-language: node_js
-before_install: "npm install -g npm"
-node_js:
-    - "0.8"
-    - "0.10"
-    - "0.11"

CONTRIBUTING.md

@@ -0,0 +1,61 @@
+Contributing
+============
+
+## Documentation
+
+Every new feature and API change should be accompanied by a README additon.
+
+## Testing
+
+All features and bugs should have tests that verify the fix. You can run all
+tests using `npm test`.
+
+The most common type of test are tests that verify input and output of the
+Uglify transforms. These tests exist in `test/compress`. New tests can be added
+either to an existing file or in a new file `issue-xxx.js`.
+
+Tests that cannot be expressed as a simple AST can be found in `test/mocha`.
+
+## Code style
+
+- File encoding must be `UTF-8`.
+- `LF` is always used as a line ending.
+- Statements end with semicolons.
+- Indentation uses 4 spaces, switch `case` 2 spaces.
+- Identifiers use `snake_case`.
+- Strings use double quotes (`"`).
+- Use a trailing comma for multiline array and object literals to minimize diffs.
+- The Uglify code only uses ES5, even in the `harmony` branch.
+- Line length should be at most 80 cols, except when it is easier to read a
+  longer line.
+- If both sides of a comparison are of the same type, `==` and `!=` are used.
+- Multiline conditions place `&&` and `||` first on the line.
+
+**Example feature**
+
+```js
+OPT(AST_Debugger, function(self, compressor) {
+    if (compressor.option("drop_debugger"))
+        return make_node(AST_EmptyStatement, self);
+    return self;
+});
+```
+
+**Example test case**
+
+```js
+drop_debugger: {
+    options = {
+        drop_debugger: true,
+    }
+    input: {
+        debugger;
+        if (foo) debugger;
+    }
+    expect: {
+        if (foo);
+    }
+}
+```
+
+

LICENSE

@@ -1,6 +1,6 @@
 UglifyJS is released under the BSD license:
 
-Copyright 2012-2013 (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

lib/minify.js

@@ -0,0 +1,275 @@
+"use strict";
+
+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, 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]);
+        }
+    }
+    AST_Node.warn("inline source map not found: {name}", {
+        name: name,
+    });
+}
+
+function parse_source_map(content) {
+    try {
+        return JSON.parse(content);
+    } catch (ex) {
+        throw new Error("invalid input source map: " + content);
+    }
+}
+
+function set_shorthand(name, options, keys) {
+    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) {
+    if (!cache) return;
+    if (!("props" in cache)) {
+        cache.props = new Dictionary();
+    } else if (!(cache.props instanceof Dictionary)) {
+        cache.props = Dictionary.fromObject(cache.props);
+    }
+}
+
+function to_json(cache) {
+    return {
+        props: cache.props.toObject()
+    };
+}
+
+function minify(files, options) {
+    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: !!(options && options["module"]),
+            v8: false,
+            validate: false,
+            warnings: false,
+            webkit: false,
+            wrap: false,
+        }, true);
+        if (options.validate) AST_Node.enable_validation();
+        var timings = options.timings && { start: Date.now() };
+        if (options.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,
+                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") {
+                    options.mangle.properties = {};
+                }
+                if (options.mangle.properties.keep_quoted) {
+                    quoted_props = options.mangle.properties.reserved;
+                    if (!Array.isArray(quoted_props)) quoted_props = [];
+                    options.mangle.properties.reserved = quoted_props;
+                }
+                if (options.nameCache && !("cache" in options.mangle.properties)) {
+                    options.mangle.properties.cache = options.nameCache.props || {};
+                }
+            }
+            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.log_function(function(warning) {
+            warnings.push(warning);
+        }, options.warnings == "verbose");
+        if (timings) timings.parse = Date.now();
+        var toplevel;
+        options.parse = options.parse || {};
+        if (files instanceof AST_Node) {
+            toplevel = files;
+        } else {
+            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);
+            }
+            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 = 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;
+                }
+            }
+        }
+        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.rename);
+            toplevel.expand_names(options.rename);
+        }
+        if (timings) timings.compress = Date.now();
+        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();
+        if (options.mangle) {
+            toplevel.compute_char_frequency(options.mangle);
+            toplevel.mangle_names(options.mangle);
+        }
+        if (timings) timings.properties = Date.now();
+        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 = {};
+        var output = defaults(options.output, {
+            ast: false,
+            code: true,
+        });
+        if (output.ast) result.ast = toplevel;
+        if (output.code) {
+            if (options.sourceMap) {
+                output.source_map = SourceMap(options.sourceMap);
+                if (options.sourceMap.includeSources) {
+                    if (files instanceof AST_Toplevel) {
+                        throw new Error("original source content unavailable");
+                    } else for (var name in files) if (HOP(files, name)) {
+                        output.source_map.setSourceContent(name, files[name]);
+                    }
+                }
+            }
+            delete output.ast;
+            delete output.code;
+            var stream = OutputStream(output);
+            toplevel.print(stream);
+            result.code = stream.get();
+            if (options.sourceMap) {
+                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;
+                    }
+                }
+            }
+        }
+        if (options.nameCache && options.mangle) {
+            if (options.mangle.cache) options.nameCache.vars = to_json(options.mangle.cache);
+            if (options.mangle.properties && options.mangle.properties.cache) {
+                options.nameCache.props = to_json(options.mangle.properties.cache);
+            }
+        }
+        if (timings) {
+            timings.end = Date.now();
+            result.timings = {
+                parse: 1e-3 * (timings.rename - timings.parse),
+                rename: 1e-3 * (timings.compress - timings.rename),
+                compress: 1e-3 * (timings.scope - timings.compress),
+                scope: 1e-3 * (timings.mangle - timings.scope),
+                mangle: 1e-3 * (timings.properties - timings.mangle),
+                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;
+        }
+        return result;
+    } catch (ex) {
+        return { error: ex };
+    } finally {
+        AST_Node.log_function();
+        AST_Node.disable_validation();
+    }
+}

lib/propmangle.js

@@ -0,0 +1,302 @@
+/***********************************************************************
+
+  A JavaScript tokenizer / parser / beautifier / compressor.
+  https://github.com/mishoo/UglifyJS
+
+  -------------------------------- (C) ---------------------------------
+
+                           Author: Mihai Bazon
+                         <mihai.bazon@gmail.com>
+                       http://mihai.bazon.net/blog
+
+  Distributed under the BSD license:
+
+    Copyright 2012 (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
+    are met:
+
+        * Redistributions of source code must retain the above
+          copyright notice, this list of conditions and the following
+          disclaimer.
+
+        * Redistributions in binary form must reproduce the above
+          copyright notice, this list of conditions and the following
+          disclaimer in the documentation and/or other materials
+          provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
+    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+    TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+    THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+ ***********************************************************************/
+
+"use strict";
+
+function get_builtins() {
+    var names = new Dictionary();
+    // constants
+    [
+        "NaN",
+        "null",
+        "true",
+        "false",
+        "Infinity",
+        "-Infinity",
+        "undefined",
+    ].forEach(add);
+    // 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 (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) {
+        names.set(name, true);
+    }
+}
+
+function reserve_quoted_keys(ast, reserved) {
+    ast.walk(new TreeWalker(function(node) {
+        if (node instanceof AST_ClassProperty) {
+            if (node.start && node.start.quote) add(node.key);
+        } else if (node instanceof AST_ObjectProperty) {
+            if (node.start && node.start.quote) add(node.key);
+        } else if (node instanceof AST_Sub) {
+            addStrings(node.property, add);
+        }
+    }));
+
+    function add(name) {
+        push_uniq(reserved, name);
+    }
+}
+
+function addStrings(node, add) {
+    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) {
+    options = defaults(options, {
+        builtins: false,
+        cache: null,
+        debug: false,
+        keep_quoted: false,
+        regex: null,
+        reserved: null,
+    }, true);
+
+    var reserved = options.builtins ? new Dictionary() : get_builtins();
+    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(name) {
+            reserved.set(name, true);
+        });
+    } else {
+        cache = new Dictionary();
+    }
+
+    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'
+    // the same as passing an empty string.
+    var debug = options.debug !== false;
+    var debug_suffix;
+    if (debug) debug_suffix = options.debug === true ? "" : options.debug;
+
+    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_Binary) {
+            if (node.operator == "in") addStrings(node.left, add);
+        } else if (node.TYPE == "Call") {
+            var exp = node.expression;
+            if (exp instanceof AST_Dot) switch (exp.property) {
+              case "defineProperty":
+              case "getOwnPropertyDescriptor":
+                if (node.args.length < 2) break;
+                exp = exp.expression;
+                if (!(exp instanceof AST_SymbolRef)) break;
+                if (exp.name != "Object") break;
+                if (!exp.definition().undeclared) break;
+                addStrings(node.args[1], add);
+                break;
+              case "hasOwnProperty":
+                if (node.args.length < 1) break;
+                addStrings(node.args[0], add);
+                break;
+            }
+        } else if (node instanceof AST_ClassProperty) {
+            if (typeof node.key == "string") add(node.key);
+        } else if (node instanceof AST_Dot) {
+            add(node.property);
+        } else if (node instanceof AST_ObjectProperty) {
+            if (typeof node.key == "string") add(node.key);
+        } else if (node instanceof AST_Sub) {
+            addStrings(node.property, add);
+        }
+    }));
+
+    // step 2: renaming properties
+    ast.walk(new TreeWalker(function(node) {
+        if (node instanceof AST_Binary) {
+            if (node.operator == "in") mangleStrings(node.left);
+        } else if (node.TYPE == "Call") {
+            var exp = node.expression;
+            if (exp instanceof AST_Dot) switch (exp.property) {
+              case "defineProperty":
+              case "getOwnPropertyDescriptor":
+                if (node.args.length < 2) break;
+                exp = exp.expression;
+                if (!(exp instanceof AST_SymbolRef)) break;
+                if (exp.name != "Object") break;
+                if (!exp.definition().undeclared) break;
+                mangleStrings(node.args[1]);
+                break;
+              case "hasOwnProperty":
+                if (node.args.length < 1) break;
+                mangleStrings(node.args[0]);
+                break;
+            }
+        } else if (node instanceof AST_ClassProperty) {
+            if (typeof node.key == "string") node.key = mangle(node.key);
+        } else if (node instanceof AST_Dot) {
+            node.property = mangle(node.property);
+        } else if (node instanceof AST_ObjectProperty) {
+            if (typeof node.key == "string") node.key = mangle(node.key);
+        } else if (node instanceof AST_Sub) {
+            if (!options.keep_quoted) mangleStrings(node.property);
+        }
+    }));
+
+    // only function declarations after this line
+
+    function can_mangle(name) {
+        if (unmangleable.has(name)) return false;
+        if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
+        return true;
+    }
+
+    function should_mangle(name) {
+        if (reserved.has(name)) return false;
+        if (regex && !regex.test(name)) return false;
+        return cache.has(name) || names_to_mangle.has(name);
+    }
+
+    function add(name) {
+        if (can_mangle(name)) names_to_mangle.set(name, true);
+        if (!should_mangle(name)) unmangleable.set(name, true);
+    }
+
+    function mangle(name) {
+        if (!should_mangle(name)) return name;
+        var mangled = cache.get(name);
+        if (!mangled) {
+            if (debug) {
+                // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo ---> o._$foo$NNN_.
+                var debug_mangled = "_$" + name + "$" + debug_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 (/^#/.test(name)) mangled = "#" + mangled;
+            cache.set(name, mangled);
+        }
+        return mangled;
+    }
+
+    function mangleStrings(node) {
+        if (node instanceof AST_Sequence) {
+            mangleStrings(node.expressions.tail_node());
+        } else if (node instanceof AST_String) {
+            node.value = mangle(node.value);
+        } else if (node instanceof AST_Conditional) {
+            mangleStrings(node.consequent);
+            mangleStrings(node.alternative);
+        }
+    }
+}

lib/sourcemap.js

@@ -1,7 +1,7 @@
 /***********************************************************************
 
   A JavaScript tokenizer / parser / beautifier / compressor.
-  https://github.com/mishoo/UglifyJS2
+  https://github.com/mishoo/UglifyJS
 
   -------------------------------- (C) ---------------------------------
 
@@ -43,45 +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,
+var vlq_char = characters("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/");
+var vlq_bits = vlq_char.reduce(function(map, ch, bits) {
+    map[ch] = bits;
+    return map;
+}, Object.create(null));
 
-        orig_line_diff : 0,
-        dest_line_diff : 0,
-    });
-    var generator = new MOZ_SourceMap.SourceMapGenerator({
-        file       : options.file,
-        sourceRoot : options.root
-    });
-    var orig_map = options.orig && new MOZ_SourceMap.SourceMapConsumer(options.orig);
-    function add(source, gen_line, gen_col, orig_line, orig_col, name) {
-        if (orig_map) {
-            var info = orig_map.originalPositionFor({
-                line: orig_line,
-                column: orig_col
-            });
-            if (info.source === null) {
-                return;
-            }
-            source = info.source;
-            orig_line = info.line;
-            orig_col = info.column;
-            name = info.name || name;
+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;
         }
-        generator.addMapping({
-            generated : { line: gen_line + options.dest_line_diff, column: gen_col },
-            original  : { line: orig_line + options.orig_line_diff, column: orig_col },
-            source    : source,
-            name      : name
-        });
+    }
+    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));
+                });
+            }),
+            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        : add,
-        get        : function() { return generator },
-        toString   : function() { return generator.toString() }
+        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;
+                }
+                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({
+                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) ---------------------------------
 
@@ -43,8 +43,6 @@
 
 "use strict";
 
-// Tree transformer helpers.
-
 function TreeTransformer(before, after) {
     TreeWalker.call(this);
     this.before = before;
@@ -52,167 +50,201 @@ function TreeTransformer(before, after) {
 }
 TreeTransformer.prototype = new TreeWalker;
 
-(function(undefined){
-
-    function _(node, descend) {
-        node.DEFMETHOD("transform", function(tw, in_list){
-            var x, y;
-            tw.push(this);
-            if (tw.before) x = tw.before(this, descend, in_list);
-            if (x === undefined) {
-                if (!tw.after) {
-                    x = this;
-                    descend(x, tw);
-                } else {
-                    tw.stack[tw.stack.length - 1] = x = this.clone();
-                    descend(x, tw);
-                    y = tw.after(x, in_list);
-                    if (y !== undefined) x = y;
-                }
-            }
-            tw.pop();
-            return x;
-        });
-    };
-
+(function(DEF) {
     function do_list(list, tw) {
-        return MAP(list, function(node){
+        return List(list, function(node) {
             return node.transform(tw, true);
         });
-    };
+    }
 
-    _(AST_Node, noop);
-
-    _(AST_LabeledStatement, function(self, tw){
+    DEF(AST_Node, noop);
+    DEF(AST_LabeledStatement, function(self, tw) {
         self.label = self.label.transform(tw);
         self.body = self.body.transform(tw);
     });
-
-    _(AST_SimpleStatement, function(self, tw){
+    DEF(AST_SimpleStatement, function(self, tw) {
         self.body = self.body.transform(tw);
     });
-
-    _(AST_Block, function(self, tw){
+    DEF(AST_Block, function(self, tw) {
         self.body = do_list(self.body, tw);
     });
-
-    _(AST_DWLoop, function(self, tw){
+    DEF(AST_Do, function(self, tw) {
+        self.body = self.body.transform(tw);
+        self.condition = self.condition.transform(tw);
+    });
+    DEF(AST_While, function(self, tw) {
         self.condition = self.condition.transform(tw);
         self.body = self.body.transform(tw);
     });
-
-    _(AST_For, function(self, tw){
+    DEF(AST_For, function(self, tw) {
         if (self.init) self.init = self.init.transform(tw);
         if (self.condition) self.condition = self.condition.transform(tw);
         if (self.step) self.step = self.step.transform(tw);
         self.body = self.body.transform(tw);
     });
-
-    _(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);
     });
-
-    _(AST_With, function(self, tw){
+    DEF(AST_With, function(self, tw) {
         self.expression = self.expression.transform(tw);
         self.body = self.body.transform(tw);
     });
-
-    _(AST_Exit, function(self, tw){
+    DEF(AST_Exit, function(self, tw) {
         if (self.value) self.value = self.value.transform(tw);
     });
-
-    _(AST_LoopControl, function(self, tw){
+    DEF(AST_LoopControl, function(self, tw) {
         if (self.label) self.label = self.label.transform(tw);
     });
-
-    _(AST_If, function(self, tw){
+    DEF(AST_If, function(self, tw) {
         self.condition = self.condition.transform(tw);
         self.body = self.body.transform(tw);
         if (self.alternative) self.alternative = self.alternative.transform(tw);
     });
-
-    _(AST_Switch, function(self, tw){
+    DEF(AST_Switch, function(self, tw) {
         self.expression = self.expression.transform(tw);
         self.body = do_list(self.body, tw);
     });
-
-    _(AST_Case, function(self, tw){
+    DEF(AST_Case, function(self, tw) {
         self.expression = self.expression.transform(tw);
         self.body = do_list(self.body, tw);
     });
-
-    _(AST_Try, function(self, tw){
+    DEF(AST_Try, function(self, tw) {
         self.body = do_list(self.body, tw);
         if (self.bcatch) self.bcatch = self.bcatch.transform(tw);
         if (self.bfinally) self.bfinally = self.bfinally.transform(tw);
     });
-
-    _(AST_Catch, function(self, tw){
-        self.argname = self.argname.transform(tw);
+    DEF(AST_Catch, function(self, tw) {
+        if (self.argname) self.argname = self.argname.transform(tw);
         self.body = do_list(self.body, tw);
     });
-
-    _(AST_Definitions, function(self, tw){
+    DEF(AST_Definitions, function(self, tw) {
         self.definitions = do_list(self.definitions, tw);
     });
-
-    _(AST_VarDef, function(self, tw){
+    DEF(AST_VarDef, function(self, tw) {
         self.name = self.name.transform(tw);
         if (self.value) self.value = self.value.transform(tw);
     });
-
-    _(AST_Lambda, function(self, 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);
     });
-
-    _(AST_Call, function(self, 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);
     });
-
-    _(AST_Seq, function(self, tw){
-        self.car = self.car.transform(tw);
-        self.cdr = self.cdr.transform(tw);
+    DEF(AST_Sequence, function(self, tw) {
+        self.expressions = do_list(self.expressions, tw);
     });
-
-    _(AST_Dot, function(self, tw){
+    DEF(AST_Await, function(self, tw) {
         self.expression = self.expression.transform(tw);
     });
-
-    _(AST_Sub, function(self, 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);
+    });
+    DEF(AST_Sub, function(self, tw) {
         self.expression = self.expression.transform(tw);
         self.property = self.property.transform(tw);
     });
-
-    _(AST_Unary, function(self, tw){
+    DEF(AST_Spread, function(self, tw) {
         self.expression = self.expression.transform(tw);
     });
-
-    _(AST_Binary, function(self, tw){
+    DEF(AST_Unary, function(self, tw) {
+        self.expression = self.expression.transform(tw);
+    });
+    DEF(AST_Binary, function(self, tw) {
         self.left = self.left.transform(tw);
         self.right = self.right.transform(tw);
     });
-
-    _(AST_Conditional, function(self, tw){
+    DEF(AST_Conditional, function(self, tw) {
         self.condition = self.condition.transform(tw);
         self.consequent = self.consequent.transform(tw);
         self.alternative = self.alternative.transform(tw);
     });
-
-    _(AST_Array, function(self, tw){
+    DEF(AST_Array, function(self, tw) {
         self.elements = do_list(self.elements, tw);
     });
-
-    _(AST_Object, function(self, tw){
-        self.properties = do_list(self.properties, tw);
+    DEF(AST_DestructuredArray, function(self, tw) {
+        self.elements = do_list(self.elements, tw);
+        if (self.rest) self.rest = self.rest.transform(tw);
     });
-
-    _(AST_ObjectProperty, function(self, 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;
+        tw.push(this);
+        if (tw.before) x = tw.before(this, descend, in_list);
+        if (typeof x === "undefined") {
+            x = this;
+            descend(x, tw);
+            if (tw.after) {
+                y = tw.after(x, in_list);
+                if (typeof y !== "undefined") x = y;
+            }
+        }
+        tw.pop();
+        return x;
+    });
+});

lib/utils.js

@@ -1,7 +1,7 @@
 /***********************************************************************
 
   A JavaScript tokenizer / parser / beautifier / compressor.
-  https://github.com/mishoo/UglifyJS2
+  https://github.com/mishoo/UglifyJS
 
   -------------------------------- (C) ---------------------------------
 
@@ -43,260 +43,245 @@
 
 "use strict";
 
-function array_to_hash(a) {
-    var ret = Object.create(null);
-    for (var i = 0; i < a.length; ++i)
-        ret[a[i]] = true;
-    return ret;
-};
-
-function slice(a, start) {
-    return Array.prototype.slice.call(a, start || 0);
-};
-
 function characters(str) {
     return str.split("");
-};
+}
 
 function member(name, array) {
-    for (var i = array.length; --i >= 0;)
-        if (array[i] == name)
-            return true;
-    return false;
-};
+    return array.indexOf(name) >= 0;
+}
 
 function find_if(func, array) {
-    for (var i = 0, n = array.length; i < n; ++i) {
-        if (func(array[i]))
-            return array[i];
-    }
-};
+    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;
-    if (i & 1) d += str;
-    return d;
-};
+function configure_error_stack(fn) {
+    Object.defineProperty(fn.prototype, "stack", {
+        get: function() {
+            var err = new Error(this.message);
+            err.name = this.name;
+            try {
+                throw err;
+            } catch (e) {
+                return e.stack;
+            }
+        }
+    });
+}
 
 function DefaultsError(msg, defs) {
-    Error.call(this, msg);
-    this.msg = msg;
+    this.message = msg;
     this.defs = defs;
-};
+}
 DefaultsError.prototype = Object.create(Error.prototype);
 DefaultsError.prototype.constructor = DefaultsError;
-
-DefaultsError.croak = function(msg, defs) {
-    throw new DefaultsError(msg, defs);
-};
+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 (ret.hasOwnProperty(i) && !defs.hasOwnProperty(i))
-        DefaultsError.croak("`" + i + "` is not a supported option", defs);
-    for (var i in defs) if (defs.hasOwnProperty(i)) {
-        ret[i] = (args && args.hasOwnProperty(i)) ? args[i] : defs[i];
+    if (croak) for (var i in args) {
+        if (HOP(args, i) && !HOP(defs, i)) throw new DefaultsError("`" + i + "` is not a supported option", defs);
     }
-    return ret;
-};
-
-function merge(obj, ext) {
-    for (var i in ext) if (ext.hasOwnProperty(i)) {
-        obj[i] = ext[i];
+    for (var i in args) {
+        if (HOP(args, i)) defs[i] = args[i];
     }
-    return obj;
-};
+    return defs;
+}
 
-function noop() {};
+function noop() {}
+function return_false() { return false; }
+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 (a instanceof Array) {
-            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 (a.hasOwnProperty(i)) if (doit()) break;
-        }
-        return top.concat(ret);
+        return ret;
+    }
+    List.is_op = function(val) {
+        return val === skip || val instanceof Splice;
     };
-    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.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[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 mergeSort(array, cmp) {
-    if (array.length < 2) return array.slice();
-    function merge(a, b) {
-        var r = [], ai = 0, bi = 0, i = 0;
-        while (ai < a.length && bi < b.length) {
-            cmp(a[ai], b[bi]) <= 0
-                ? r[i++] = a[ai++]
-                : r[i++] = b[bi++];
-        }
-        if (ai < a.length) r.push.apply(r, a.slice(ai));
-        if (bi < b.length) r.push.apply(r, b.slice(bi));
-        return r;
-    };
-    function _ms(a) {
-        if (a.length <= 1)
-            return a;
-        var m = Math.floor(a.length / 2), left = a.slice(0, m), right = a.slice(m);
-        left = _ms(left);
-        right = _ms(right);
-        return merge(left, right);
-    };
-    return _ms(array);
-};
-
-function set_difference(a, b) {
-    return a.filter(function(el){
-        return b.indexOf(el) < 0;
-    });
-};
-
-function set_intersection(a, b) {
-    return a.filter(function(el){
-        return b.indexOf(el) >= 0;
-    });
-};
-
-// this function is taken from Acorn [1], written by Marijn Haverbeke
-// [1] https://github.com/marijnh/acorn
 function makePredicate(words) {
-    if (!(words instanceof Array)) words = words.split(" ");
-    var f = "", cats = [];
-    out: for (var i = 0; i < words.length; ++i) {
-        for (var j = 0; j < cats.length; ++j)
-            if (cats[j][0].length == words[i].length) {
-                cats[j].push(words[i]);
-                continue out;
-            }
-        cats.push([words[i]]);
-    }
-    function compareTo(arr) {
-        if (arr.length == 1) return f += "return str === " + JSON.stringify(arr[0]) + ";";
-        f += "switch(str){";
-        for (var i = 0; i < arr.length; ++i) f += "case " + JSON.stringify(arr[i]) + ":";
-        f += "return true}return false;";
-    }
-    // When there are more than three length categories, an outer
-    // switch first dispatches on the lengths, to save on comparisons.
-    if (cats.length > 3) {
-        cats.sort(function(a, b) {return b.length - a.length;});
-        f += "switch(str.length){";
-        for (var i = 0; i < cats.length; ++i) {
-            var cat = cats[i];
-            f += "case " + cat[0].length + ":";
-            compareTo(cat);
-        }
-        f += "}";
-        // Otherwise, simply generate a flat `switch` statement.
-    } else {
-        compareTo(words);
-    }
-    return new Function("str", f);
-};
+    if (!Array.isArray(words)) words = words.split(" ");
+    var map = Object.create(null);
+    words.forEach(function(word) {
+        map[word] = true;
+    });
+    return map;
+}
 
 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();
+        this.each(function(value, i) {
+            ret.set(i, value);
+        });
+        return ret;
+    },
+    toObject: function() {
+        var obj = {};
+        this.each(function(value, i) {
+            obj["$" + i] = value;
+        });
+        return obj;
+    },
 };
+Dictionary.fromObject = function(obj) {
+    var dict = new Dictionary();
+    for (var i in obj)
+        if (HOP(obj, i)) dict.set(i.slice(1), obj[i]);
+    return dict;
+};
+
+function HOP(obj, prop) {
+    return Object.prototype.hasOwnProperty.call(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, arrow, export_default) {
+    var node = stack.parent(-1);
+    for (var i = 0, p; p = stack.parent(i++); node = p) {
+        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_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

@@ -1,37 +1,56 @@
 {
   "name": "uglify-js",
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
-    "homepage": "http://lisperator.net/uglifyjs",
-    "main": "tools/node.js",
-    "version": "2.4.16",
-    "engines": { "node" : ">=0.4.0" },
-    "maintainers": [{
-        "name": "Mihai Bazon",
-        "email": "mihai.bazon@gmail.com",
-        "web": "http://lisperator.net/"
-    }],
-    "repository": {
-        "type": "git",
-        "url": "https://github.com/mishoo/UglifyJS2.git"
-    },
-    "dependencies": {
-        "async"      : "~0.2.6",
-        "source-map" : "0.1.34",
-        "optimist": "~0.3.5",
-        "uglify-to-browserify": "~1.0.0"
-    },
-    "devDependencies": {
-        "acorn": "~0.6.0",
-        "escodegen": "~1.3.3",
-        "esfuzz": "~0.3.1",
-        "estraverse": "~1.5.1"
-    },
-    "browserify": {
-        "transform": [ "uglify-to-browserify" ]
-    },
-    "bin": {
-        "uglifyjs" : "bin/uglifyjs"
-    },
-    "license": "BSD",
-    "scripts": {"test": "node test/run-tests.js"}
+  "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
+  "license": "BSD-2-Clause",
+  "version": "3.17.0",
+  "engines": {
+    "node": ">=0.8.0"
+  },
+  "maintainers": [
+    "Alex Lam <alexlamsl@gmail.com>",
+    "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)"
+  ],
+  "repository": "mishoo/UglifyJS",
+  "main": "tools/node.js",
+  "bin": {
+    "uglifyjs": "bin/uglifyjs"
+  },
+  "files": [
+    "bin",
+    "lib",
+    "tools",
+    "LICENSE"
+  ],
+  "devDependencies": {
+    "acorn": "~8.7.1",
+    "semver": "~6.3.0"
+  },
+  "scripts": {
+    "test": "node test/compress.js && node test/mocha.js"
+  },
+  "keywords": [
+    "cli",
+    "compress",
+    "compressor",
+    "ecma",
+    "ecmascript",
+    "es",
+    "es5",
+    "javascript",
+    "js",
+    "jsmin",
+    "min",
+    "minification",
+    "minifier",
+    "minify",
+    "optimize",
+    "optimizer",
+    "pack",
+    "packer",
+    "parse",
+    "parser",
+    "uglifier",
+    "uglify"
+  ]
 }

test/benchmark.js

@@ -0,0 +1,98 @@
+#! /usr/bin/env node
+// -*- js -*-
+
+"use strict";
+
+var createHash = require("crypto").createHash;
+var fetch = require("./fetch");
+var spawn = require("child_process").spawn;
+var zlib = require("zlib");
+var args = process.argv.slice(2);
+if (!args.length) args.push("-mc");
+args.unshift("bin/uglifyjs");
+args.push("--timings");
+var urls = [
+    "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",
+    "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;
+function done() {
+    if (!--remaining) {
+        var failures = [];
+        var sum = { input: 0, output: 0, gzip: 0 };
+        urls.forEach(function(url) {
+            var info = results[url];
+            console.log();
+            console.log(url);
+            console.log(info.log);
+            console.log("Original:", info.input, "bytes");
+            console.log("Uglified:", info.output, "bytes");
+            console.log("GZipped: ", info.gzip, "bytes");
+            console.log("SHA1 sum:", info.sha1);
+            if (info.code) {
+                failures.push(url);
+            }
+            sum.input += info.input;
+            sum.output += info.output;
+            sum.gzip += info.gzip;
+        });
+        if (failures.length) {
+            console.error("Benchmark failed:");
+            failures.forEach(function(url) {
+                console.error(url);
+            });
+            process.exit(1);
+        } else {
+            console.log();
+            console.log("Subtotal");
+            console.log();
+            console.log("Original:", sum.input, "bytes");
+            console.log("Uglified:", sum.output, "bytes");
+            console.log("GZipped: ", sum.gzip, "bytes");
+        }
+    }
+}
+urls.forEach(function(url) {
+    results[url] = {
+        input: 0,
+        output: 0,
+        gzip: 0,
+        log: ""
+    };
+    fetch(url, function(err, res) {
+        if (err) throw err;
+        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;
+            sha1.update(data);
+        }).on("end", function() {
+            results[url].sha1 = sha1.digest("hex");
+            done();
+        });
+        uglifyjs.stderr.setEncoding("utf8");
+        uglifyjs.stderr.on("data", function(data) {
+            results[url].log += data;
+        });
+        uglifyjs.on("exit", function(code) {
+            results[url].code = code;
+            done();
+        });
+    });
+});

test/compress.js

@@ -0,0 +1,481 @@
+"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;
+                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, {}, 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));
+    }
+    if (test.mangle && test.mangle.properties && test.mangle.properties.keep_quoted) {
+        var 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 (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;
+    }));
+    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/arrays.js

@@ -13,18 +13,29 @@ holes_and_undefined: {
     }
 }
 
-constant_join: {
+constant_join_1: {
     options = {
-        unsafe   : true,
-        evaluate : true
-    };
+        evaluate: true,
+        side_effects: true,
+        strings: true,
+        unsafe: true,
+    }
     input: {
         var a = [ "foo", "bar", "baz" ].join("");
         var a1 = [ "foo", "bar", "baz" ].join();
+        var a2 = [ "foo", "bar", "baz" ].join(null);
+        var a3 = [ "foo", "bar", "baz" ].join(void 0);
+        var a4 = [ "foo", , "baz" ].join();
+        var a5 = [ "foo", null, "baz" ].join();
+        var a6 = [ "foo", void 0, "baz" ].join();
         var b = [ "foo", 1, 2, 3, "bar" ].join("");
         var c = [ boo(), "foo", 1, 2, 3, "bar", bar() ].join("");
         var c1 = [ boo(), bar(), "foo", 1, 2, 3, "bar", bar() ].join("");
         var c2 = [ 1, 2, "foo", "bar", baz() ].join("");
+        var c3 = [ boo() + bar() + "foo", 1, 2, 3, "bar", bar() + "foo" ].join("");
+        var c4 = [ 1, 2, null, undefined, "foo", "bar", baz() ].join("");
+        var c5 = [ boo() + bar() + "foo", 1, 2, 3, "bar", bar() + "foo" ].join();
+        var c6 = [ 1, 2, null, undefined, "foo", "bar", baz() ].join();
         var d = [ "foo", 1 + 2 + "bar", "baz" ].join("-");
         var e = [].join(foo + bar);
         var f = [].join("");
@@ -33,12 +44,21 @@ constant_join: {
     expect: {
         var a = "foobarbaz";
         var a1 = "foo,bar,baz";
+        var a2 = "foonullbarnullbaz";
+        var a3 = "foo,bar,baz";
+        var a4 = "foo,,baz";
+        var a5 = "foo,,baz";
+        var a6 = "foo,,baz";
         var b = "foo123bar";
         var c = boo() + "foo123bar" + bar();
         var c1 = "" + boo() + bar() + "foo123bar" + bar();
         var c2 = "12foobar" + baz();
+        var c3 = boo() + bar() + "foo123bar" + bar() + "foo";
+        var c4 = "12foobar" + baz();
+        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 = "";
     }
@@ -46,9 +66,10 @@ constant_join: {
 
 constant_join_2: {
     options = {
-        unsafe   : true,
-        evaluate : true
-    };
+        evaluate: true,
+        strings: true,
+        unsafe: true,
+    }
     input: {
         var a = [ "foo", "bar", boo(), "baz", "x", "y" ].join("");
         var b = [ "foo", "bar", boo(), "baz", "x", "y" ].join("-");
@@ -72,3 +93,334 @@ constant_join_2: {
         var f = "strstr" + variable + "foobarmoo" + foo;
     }
 }
+
+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();
+        var d = [ foo ].join();
+        var e = [ foo, null, undefined, bar ].join("-");
+        var f = [ foo, bar ].join("");
+        var g = [ null, "foo", null, bar + "baz" ].join("");
+        var h = [ null, "foo", null, bar + "baz" ].join("-");
+        var i = [ "foo" + bar, null, baz + "moo" ].join("");
+        var j = [ foo + "bar", baz ].join("");
+        var k = [ foo, "bar" + baz ].join("");
+        var l = [ foo, bar + "baz" ].join("");
+    }
+    expect: {
+        var foo, bar, baz;
+        var a = "";
+        var b = "";
+        var c = ",1,,3";
+        var d = "" + foo;
+        var e = [ foo, "-", bar ].join("-");
+        var f = "" + foo + bar;
+        var g = "foo" + bar + "baz";
+        var h = [ "-foo-", bar + "baz" ].join("-");
+        var i = "foo" + bar + baz + "moo";
+        var j = foo + "bar" + baz;
+        var k = foo + "bar" + baz;
+        var l = foo + (bar + "baz");
+    }
+}
+
+for_loop: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        function f0() {
+            var a = [1, 2, 3];
+            var b = 0;
+            for (var i = 0; i < a.length; i++)
+                b += a[i];
+            return b;
+        }
+        function f1() {
+            var a = [1, 2, 3];
+            var b = 0;
+            for (var i = 0, len = a.length; i < len; i++)
+                b += a[i];
+            return b;
+        }
+        function f2() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < a.length; i++)
+                a[i]++;
+            return a[2];
+        }
+        console.log(f0(), f1(), f2());
+    }
+    expect: {
+        function f0() {
+            var a = [1, 2, 3];
+            var b = 0;
+            for (var i = 0; i < 3; i++)
+                b += a[i];
+            return b;
+        }
+        function f1() {
+            var a = [1, 2, 3];
+            var b = 0;
+            for (var i = 0; i < 3; i++)
+                b += a[i];
+            return b;
+        }
+        function f2() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < a.length; i++)
+                a[i]++;
+            return a[2];
+        }
+        console.log(f0(), f1(), f2());
+    }
+    expect_stdout: "6 6 4"
+}
+
+index: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a[0], a[1]);
+    }
+    expect: {
+        console.log(1, 2);
+    }
+    expect_stdout: "1 2"
+}
+
+length: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a.length);
+    }
+    expect: {
+        console.log(2);
+    }
+    expect_stdout: "2"
+}
+
+index_length: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a[0], a.length);
+    }
+    expect: {
+        console.log(1, 2);
+    }
+    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/asm.js

@@ -0,0 +1,233 @@
+asm_mixed: {
+    options = {
+        assignments: true,
+        booleans: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        drop_debugger: true,
+        evaluate: true,
+        hoist_funs: true,
+        hoist_vars: true,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        keep_fnames: false,
+        loops: true,
+        negate_iife: true,
+        properties: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        // adapted from http://asmjs.org/spec/latest/
+        function asm_GeometricMean(stdlib, foreign, buffer) {
+          "use asm";
+          var exp = stdlib.Math.exp;
+          var log = stdlib.Math.log;
+          var values = new stdlib.Float64Array(buffer);
+          function logSum(start, end) {
+            start = start|0;
+            end = end|0;
+            var sum = 0.0, p = 0, q = 0;
+            // asm.js forces byte addressing of the heap by requiring shifting by 3
+            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) {
+            start = start|0;
+            end = end|0;
+            return +exp(+logSum(start, end) / +((end - start)|0));
+          }
+          return { geometricMean: geometricMean };
+        }
+        function no_asm_GeometricMean(stdlib, foreign, buffer) {
+          var exp = stdlib.Math.exp;
+          var log = stdlib.Math.log;
+          var values = new stdlib.Float64Array(buffer);
+          function logSum(start, end) {
+            start = start|0;
+            end = end|0;
+            var sum = 0.0, p = 0, q = 0;
+            // asm.js forces byte addressing of the heap by requiring shifting by 3
+            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) {
+            start = start|0;
+            end = end|0;
+            return +exp(+logSum(start, end) / +((end - start)|0));
+          }
+          return { geometricMean: geometricMean };
+        }
+    }
+    expect: {
+        function asm_GeometricMean(stdlib, foreign, buffer) {
+            "use asm";
+            var exp = stdlib.Math.exp;
+            var log = stdlib.Math.log;
+            var values = new stdlib.Float64Array(buffer);
+            function logSum(start, end) {
+                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)
+                    sum = sum + +log(values[p >> 3]);
+                return +sum;
+            }
+            function geometricMean(start, end) {
+                start = start | 0;
+                end = end | 0;
+                return +exp(+logSum(start, end) / +(end - start | 0));
+            }
+            return { geometricMean: geometricMean };
+        }
+        function no_asm_GeometricMean(stdlib, foreign, buffer) {
+            function logSum(start, end) {
+                start |= 0, end |= 0;
+                for (var sum = 0, p = 0, q = 0, p = start << 3, q = end << 3; (0 | p) < (0 | q); p = p + 8 | 0)
+                    sum += +log(values[p >> 3]);
+                return +sum;
+            }
+            function geometricMean(start, end) {
+                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 };
+        }
+    }
+}
+
+asm_toplevel: {
+    options = {}
+    input: {
+        "use asm";
+        0.0;
+        function f() {
+            0.0;
+            (function(){
+                0.0;
+            });
+        }
+        0.0;
+    }
+    expect_exact: '"use asm";0.0;function f(){0.0;(function(){0.0})}0.0;'
+}
+
+asm_function_expression: {
+    options = {}
+    input: {
+        0.0;
+        var a = function() {
+            "use asm";
+            0.0;
+        }
+        function f() {
+            0.0;
+            return function(){
+                "use asm";
+                0.0;
+            }
+            0.0;
+        }
+        0.0;
+    }
+    expect_exact: '0;var a=function(){"use asm";0.0};function f(){0;return function(){"use asm";0.0};0}0;'
+}
+
+asm_nested_functions: {
+    options = {}
+    input: {
+        0.0;
+        function a() {
+            "use asm";
+            0.0;
+        }
+        0.0;
+        function b() {
+            0.0;
+            function c(){
+                "use asm";
+                0.0;
+            }
+            0.0;
+            function d(){
+                0.0;
+            }
+            0.0;
+        }
+        0.0;
+    }
+    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/assignments.js

@@ -0,0 +1,805 @@
+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"
+}
+
+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"
+}

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 +1,788 @@
+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_2a: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b) {
+            return a || (a || b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a || b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "undefined {}",
+        "42 42",
+    ]
+}
+
+de_morgan_2b: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a || (a && b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "42 42",
+    ]
+}
+
+de_morgan_2c: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a && (a || b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "42 42",
+    ]
+}
+
+de_morgan_2d: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            return a && (a && b);
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a && b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "undefined {}",
+    ]
+}
+
+de_morgan_3a: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a || b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || b || c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "undefined {} true true",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3b: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a || b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || b && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "false false undefined {}",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3c: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a && b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a || c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "undefined {} undefined {}",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3d: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a || ((a && b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3e: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a || b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "42 42 42 42",
+    ]
+}
+
+de_morgan_3f: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a || b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "undefined {} undefined {}",
+    ]
+}
+
+de_morgan_3g: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a && b) || c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && (b || c);
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "undefined {} true true",
+    ]
+}
+
+de_morgan_3h: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b, c) {
+            return a && ((a && b) && c);
+        }
+        console.log(f(null, false), f(null, false, {}), f(null, true), f(null, true, {}));
+        console.log(f(42, false), f(42, false, {}), f(42, true), f(42, true, {}));
+    }
+    expect: {
+        function f(a, b, c) {
+            return a && b && c;
+        }
+        console.log(f(null, !1), f(null, !1, {}), f(null, !0), f(null, !0, {}));
+        console.log(f(42, !1), f(42, !1, {}), f(42, !0), f(42, !0, {}));
+    }
+    expect_stdout: [
+        "null null null null",
+        "false false undefined {}",
+    ]
+}
+
+conditional_chain: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+    }
+    input: {
+        function f(a, b) {
+            return a ? a : b ? b : 42;
+        }
+        console.log(f("PASS", "FAIL"));
+    }
+    expect: {
+        function f(a, b) {
+            return a || b || 42;
+        }
+        console.log(f("PASS", "FAIL"));
+    }
+    expect_stdout: "PASS"
+}
+
+negated_if: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(function(a) {
+            if (!a)
+                return a ? "FAIL" : "PASS";
+        }(!console));
+    }
+    expect: {
+        console.log(function(a) {
+            if (!a)
+                return "PASS";
+        }(!console));
+    }
+    expect_stdout: "PASS"
+}
+
+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"
+}

test/compress/comparisons.js

@@ -0,0 +1,540 @@
+comparisons: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        var obj1, obj2;
+        var result1 = obj1 <= obj2;
+        var result2 = obj1 <  obj2;
+        var result3 = obj1 >= obj2;
+        var result4 = obj1 >  obj2;
+    }
+    expect: {
+        var obj1, obj2;
+        var result1 = obj1 <= obj2;
+        var result2 = obj1 <  obj2;
+        var result3 = obj2 <= obj1;
+        var result4 = obj2 <  obj1;
+    }
+}
+
+unsafe_comps: {
+    options = {
+        comparisons: true,
+        conditionals: true,
+        unsafe_comps: true,
+    }
+    input: {
+        var obj1, obj2;
+        obj1 <= obj2 ? f1() : g1();
+        obj1 <  obj2 ? f2() : g2();
+        obj1 >= obj2 ? f3() : g3();
+        obj1 >  obj2 ? f4() : g4();
+    }
+    expect: {
+        var obj1, obj2;
+        (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();
+    }
+}
+
+dont_change_in_or_instanceof_expressions: {
+    input: {
+        1 in 1;
+        null in null;
+        1 instanceof 1;
+        null instanceof null;
+    }
+    expect: {
+        1 in 1;
+        null in null;
+        1 instanceof 1;
+        null instanceof null;
+    }
+}
+
+self_comparison_1: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        a === a;
+        a !== b;
+        b.c === a.c;
+        b.c !== b.c;
+    }
+    expect: {
+        a == a;
+        a !== b;
+        b.c === a.c;
+        b.c != b.c;
+    }
+}
+
+self_comparison_2: {
+    options = {
+        comparisons: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        function f() {}
+        var o = {};
+        console.log(f != f, o === o);
+    }
+    expect: {
+        function f() {}
+        var o = {};
+        console.log(false, true);
+    }
+    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,
+    }
+    input: {
+        function f1(a) {
+            a === undefined || a === null;
+            a === undefined || a !== null;
+            a !== undefined || a === null;
+            a !== undefined || a !== null;
+            a === undefined && a === null;
+            a === undefined && a !== null;
+            a !== undefined && a === null;
+            a !== undefined && a !== null;
+        }
+        function f2(a) {
+            a === null || a === undefined;
+            a === null || a !== undefined;
+            a !== null || a === undefined;
+            a !== null || a !== undefined;
+            a === null && a === undefined;
+            a === null && a !== undefined;
+            a !== null && a === undefined;
+            a !== null && a !== undefined;
+        }
+    }
+    expect: {
+        function f1(a) {
+            null == a;
+            void 0 === a || null !== a;
+            void 0 !== a || null === a;
+            void 0 !== a || null !== a;
+            void 0 === a && null === a;
+            void 0 === a && null !== a;
+            void 0 !== a && null === a;
+            null != a;
+        }
+        function f2(a) {
+            null == a;
+            null === a || void 0 !== a;
+            null !== a || void 0 === a;
+            null !== a || void 0 !== a;
+            null === a && void 0 === a;
+            null === a && void 0 !== a;
+            null !== a && void 0 === a;
+            null != a;
+        }
+    }
+}
+
+issue_2857_2: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            a === undefined || a === null || p;
+            a === undefined || a !== null || p;
+            a !== undefined || a === null || p;
+            a !== undefined || a !== null || p;
+            a === undefined && a === null || p;
+            a === undefined && a !== null || p;
+            a !== undefined && a === null || p;
+            a !== undefined && a !== null || p;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            null == a || p;
+            void 0 === a || null !== a || p;
+            void 0 !== a || null === a || p;
+            void 0 !== a || null !== a || p;
+            void 0 === a && null === a || p;
+            void 0 === a && null !== a || p;
+            void 0 !== a && null === a || p;
+            null != a || p;
+        }
+    }
+}
+
+issue_2857_3: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            a === undefined || a === null && p;
+            a === undefined || a !== null && p;
+            a !== undefined || a === null && p;
+            a !== undefined || a !== null && p;
+            a === undefined && a === null && p;
+            a === undefined && a !== null && p;
+            a !== undefined && a === null && p;
+            a !== undefined && a !== null && p;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            void 0 === a || null === a && p;
+            void 0 === a || null !== a && p;
+            void 0 !== a || null === a && p;
+            void 0 !== a || null !== a && p;
+            void 0 === a && null === a && p;
+            void 0 === a && null !== a && p;
+            void 0 !== a && null === a && p;
+            null != a && p;
+        }
+    }
+}
+
+issue_2857_4: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            p || a === undefined || a === null;
+            p || a === undefined || a !== null;
+            p || a !== undefined || a === null;
+            p || a !== undefined || a !== null;
+            p || a === undefined && a === null;
+            p || a === undefined && a !== null;
+            p || a !== undefined && a === null;
+            p || a !== undefined && a !== null;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            p || null == a;
+            p || void 0 === a || null !== a;
+            p || void 0 !== a || null === a;
+            p || void 0 !== a || null !== a;
+            p || void 0 === a && null === a;
+            p || void 0 === a && null !== a;
+            p || void 0 !== a && null === a;
+            p || null != a;
+        }
+    }
+}
+
+issue_2857_5: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            p && a === undefined || a === null;
+            p && a === undefined || a !== null;
+            p && a !== undefined || a === null;
+            p && a !== undefined || a !== null;
+            p && a === undefined && a === null;
+            p && a === undefined && a !== null;
+            p && a !== undefined && a === null;
+            p && a !== undefined && a !== null;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            p && void 0 === a || null === a;
+            p && void 0 === a || null !== a;
+            p && void 0 !== a || null === a;
+            p && void 0 !== a || null !== a;
+            p && void 0 === a && null === a;
+            p && void 0 === a && null !== a;
+            p && void 0 !== a && null === a;
+            p && null != a;
+        }
+    }
+}
+
+issue_2857_6: {
+    options = {
+        comparisons: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+    }
+    input: {
+        function f(a) {
+            if (({}).b === undefined || {}.b === null)
+                return a.b !== undefined && a.b !== null;
+        }
+        console.log(f({
+            a: [ null ],
+            get b() {
+                return this.a.shift();
+            }
+        }));
+    }
+    expect: {
+        function f(a) {
+            if (null == {}.b)
+                return void 0 !== a.b && null !== a.b;
+        }
+        console.log(f({
+            a: [ null ],
+            get b() {
+                return this.a.shift();
+            }
+        }));
+    }
+    expect_stdout: "true"
+}
+
+is_boolean_unsafe: {
+    options = {
+        comparisons: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(/foo/.test("bar") === [].isPrototypeOf({}));
+    }
+    expect: {
+        console.log(/foo/.test("bar") == [].isPrototypeOf({}));
+    }
+    expect_stdout: "true"
+}
+
+is_number_unsafe: {
+    options = {
+        comparisons: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(Math.acos(42) !== "foo".charCodeAt(4));
+    }
+    expect: {
+        console.log(Math.acos(42) != "foo".charCodeAt(4));
+    }
+    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,
+    }
+    input: {
+        var a;
+        A || B || void 0 === a || null === a || C;
+    }
+    expect: {
+        var a;
+        A || B || null == a || C;
+    }
+}

test/compress/concat-strings.js

@@ -1,7 +1,7 @@
 concat_1: {
     options = {
-        evaluate: true
-    };
+        evaluate: true,
+    }
     input: {
         var a = "foo" + "bar" + x() + "moo" + "foo" + y() + "x" + "y" + "z" + q();
         var b = "foo" + 1 + x() + 2 + "boo";
@@ -11,6 +11,9 @@ concat_1: {
         var d = 1 + x() + 2 + 3 + "boo";
 
         var e = 1 + x() + 2 + "X" + 3 + "boo";
+
+        // be careful with concatentation with "\0" with octal-looking strings.
+        var f = "\0" + 360 + "\0" + 8 + "\0";
     }
     expect: {
         var a = "foobar" + x() + "moofoo" + y() + "xyz" + q();
@@ -18,5 +21,286 @@ concat_1: {
         var c = 1 + x() + 2 + "boo";
         var d = 1 + x() + 2 + 3 + "boo";
         var e = 1 + x() + 2 + "X3boo";
+        var f = "\x00360\x008\0";
     }
 }
+
+concat_2: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(
+            1 + (2 + 3),
+            1 + (2 + "3"),
+            1 + ("2" + 3),
+            1 + ("2" + "3"),
+            "1" + (2 + 3),
+            "1" + (2 + "3"),
+            "1" + ("2" + 3),
+            "1" + ("2" + "3")
+        );
+    }
+    expect: {
+        console.log(
+            1 + (2 + 3),
+            1 + (2 + "3"),
+            1 + "2" + 3,
+            1 + "2" + "3",
+            "1" + (2 + 3),
+            "1" + 2 + "3",
+            "1" + "2" + 3,
+            "1" + "2" + "3"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_3: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(
+            1 + 2 + (3 + 4 + 5),
+            1 + 2 + (3 + 4 + "5"),
+            1 + 2 + (3 + "4" + 5),
+            1 + 2 + (3 + "4" + "5"),
+            1 + 2 + ("3" + 4 + 5),
+            1 + 2 + ("3" + 4 + "5"),
+            1 + 2 + ("3" + "4" + 5),
+            1 + 2 + ("3" + "4" + "5")
+        );
+    }
+    expect: {
+        console.log(
+            1 + 2 + (3 + 4 + 5),
+            1 + 2 + (3 + 4 + "5"),
+            1 + 2 + (3 + "4") + 5,
+            1 + 2 + (3 + "4") + "5",
+            1 + 2 + "3" + 4 + 5,
+            1 + 2 + "3" + 4 + "5",
+            1 + 2 + "3" + "4" + 5,
+            1 + 2 + "3" + "4" + "5"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_4: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(
+            1 + "2" + (3 + 4 + 5),
+            1 + "2" + (3 + 4 + "5"),
+            1 + "2" + (3 + "4" + 5),
+            1 + "2" + (3 + "4" + "5"),
+            1 + "2" + ("3" + 4 + 5),
+            1 + "2" + ("3" + 4 + "5"),
+            1 + "2" + ("3" + "4" + 5),
+            1 + "2" + ("3" + "4" + "5")
+        );
+    }
+    expect: {
+        console.log(
+            1 + "2" + (3 + 4 + 5),
+            1 + "2" + (3 + 4) + "5",
+            1 + "2" + 3 + "4" + 5,
+            1 + "2" + 3 + "4" + "5",
+            1 + "2" + "3" + 4 + 5,
+            1 + "2" + "3" + 4 + "5",
+            1 + "2" + "3" + "4" + 5,
+            1 + "2" + "3" + "4" + "5"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_5: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(
+            "1" + 2 + (3 + 4 + 5),
+            "1" + 2 + (3 + 4 + "5"),
+            "1" + 2 + (3 + "4" + 5),
+            "1" + 2 + (3 + "4" + "5"),
+            "1" + 2 + ("3" + 4 + 5),
+            "1" + 2 + ("3" + 4 + "5"),
+            "1" + 2 + ("3" + "4" + 5),
+            "1" + 2 + ("3" + "4" + "5")
+        );
+    }
+    expect: {
+        console.log(
+            "1" + 2 + (3 + 4 + 5),
+            "1" + 2 + (3 + 4) + "5",
+            "1" + 2 + 3 + "4" + 5,
+            "1" + 2 + 3 + "4" + "5",
+            "1" + 2 + "3" + 4 + 5,
+            "1" + 2 + "3" + 4 + "5",
+            "1" + 2 + "3" + "4" + 5,
+            "1" + 2 + "3" + "4" + "5"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_6: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(
+            "1" + "2" + (3 + 4 + 5),
+            "1" + "2" + (3 + 4 + "5"),
+            "1" + "2" + (3 + "4" + 5),
+            "1" + "2" + (3 + "4" + "5"),
+            "1" + "2" + ("3" + 4 + 5),
+            "1" + "2" + ("3" + 4 + "5"),
+            "1" + "2" + ("3" + "4" + 5),
+            "1" + "2" + ("3" + "4" + "5")
+        );
+    }
+    expect: {
+        console.log(
+            "1" + "2" + (3 + 4 + 5),
+            "1" + "2" + (3 + 4) + "5",
+            "1" + "2" + 3 + "4" + 5,
+            "1" + "2" + 3 + "4" + "5",
+            "1" + "2" + "3" + 4 + 5,
+            "1" + "2" + "3" + 4 + "5",
+            "1" + "2" + "3" + "4" + 5,
+            "1" + "2" + "3" + "4" + "5"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_7: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(
+            "" + 1,
+            "" + "1",
+            "" + 1 + 2,
+            "" + 1 + "2",
+            "" + "1" + 2,
+            "" + "1" + "2",
+            "" + (x += "foo")
+        );
+    }
+    expect: {
+        console.log(
+            "" + 1,
+            "1",
+            "" + 1 + 2,
+            1 + "2",
+            "1" + 2,
+            "1" + "2",
+            x += "foo"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_8: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(
+            1 + "",
+            "1" + "",
+            1 + 2 + "",
+            1 + "2" + "",
+            "1" + 2 + "",
+            "1" + "2" + "",
+            (x += "foo") + ""
+        );
+    }
+    expect: {
+        console.log(
+            1 + "",
+            "1",
+            1 + 2 + "",
+            1 + "2",
+            "1" + 2,
+            "1" + "2",
+            x += "foo"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_9: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        reduce_vars: true,
+        strings: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "foo";
+        console.log(
+            12 + (34 + a),
+            null + (34 + a),
+            12 + (null + a),
+            false + (34 + a),
+            12 + (false + a),
+            "bar" + (34 + a),
+            12 + ("bar" + a)
+        );
+    }
+    expect: {
+        var a = "foo";
+        console.log(
+            "1234" + a,
+            "null34" + a,
+            "12null" + a,
+            !1 + (34 + a),
+            12 + (!1 + a),
+            "bar34" + a,
+            "12bar" + a
+        );
+    }
+    expect_stdout: true
+}
+
+issue_3689: {
+    options = {
+        strings: true,
+    }
+    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/debugger.js

@@ -1,7 +1,7 @@
 keep_debugger: {
     options = {
-        drop_debugger: false
-    };
+        drop_debugger: false,
+    }
     input: {
         debugger;
     }
@@ -12,8 +12,8 @@ keep_debugger: {
 
 drop_debugger: {
     options = {
-        drop_debugger: true
-    };
+        drop_debugger: true,
+    }
     input: {
         debugger;
         if (foo) debugger;

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/drop-console.js

@@ -0,0 +1,26 @@
+drop_console_1: {
+    options = {}
+    input: {
+        console.log('foo');
+        console.log.apply(console, arguments);
+    }
+    expect: {
+        console.log('foo');
+        console.log.apply(console, arguments);
+    }
+}
+
+drop_console_2: {
+    options = {
+        drop_console: true,
+    }
+    input: {
+        console.log('foo');
+        console.log.apply(console, arguments);
+    }
+    expect: {
+        // with regular compression these will be stripped out as well
+        void 0;
+        void 0;
+    }
+}

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 +1,562 @@
+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;
+    }
+}

test/compress/global_defs.js

@@ -0,0 +1,232 @@
+must_replace: {
+    options = {
+        global_defs: {
+            D: "foo bar",
+        },
+    }
+    input: {
+        console.log(D);
+    }
+    expect: {
+        console.log("foo bar");
+    }
+}
+
+repeated_nodes: {
+    options = {
+        global_defs: {
+            "@N": "rand()",
+        },
+    }
+    input: {
+        console.log(N, N);
+    }
+    expect: {
+        console.log(rand(), rand());
+    }
+}
+
+keyword: {
+    options = {
+        global_defs: {
+            undefined: 0,
+            NaN: 1,
+            Infinity: 2,
+        },
+    }
+    input: {
+        console.log(undefined, NaN, Infinity);
+    }
+    expect: {
+        console.log(0, 1, 2);
+    }
+}
+
+object: {
+    options = {
+        evaluate: true,
+        global_defs: {
+            CONFIG: {
+                DEBUG: [ 0 ],
+                VALUE: 42,
+            },
+        },
+        side_effects: true,
+        unsafe: true,
+    }
+    input: {
+        function f(CONFIG) {
+            // CONFIG not global - do not replace
+            return CONFIG.VALUE;
+        }
+        function g() {
+            var CONFIG = { VALUE: 1 };
+            // CONFIG not global - do not replace
+            return CONFIG.VALUE;
+        }
+        function h() {
+            return CONFIG.VALUE;
+        }
+        if (CONFIG.DEBUG[0])
+            console.debug("foo");
+    }
+    expect: {
+        function f(CONFIG) {
+            return CONFIG.VALUE;
+        }
+        function g() {
+            var CONFIG = { VALUE: 1 };
+            return CONFIG.VALUE;
+        }
+        function h() {
+            return 42;
+        }
+        if (0)
+            console.debug("foo");
+    }
+}
+
+expanded: {
+    options = {
+        global_defs: {
+            "CONFIG.DEBUG": [ 0 ],
+            "CONFIG.VALUE": 42,
+        },
+    }
+    input: {
+        function f(CONFIG) {
+            // CONFIG not global - do not replace
+            return CONFIG.VALUE;
+        }
+        function g() {
+            var CONFIG = { VALUE: 1 };
+            // CONFIG not global - do not replace
+            return CONFIG.VALUE;
+        }
+        function h() {
+            return CONFIG.VALUE;
+        }
+        if (CONFIG.DEBUG[0])
+            console.debug("foo");
+    }
+    expect: {
+        function f(CONFIG) {
+            return CONFIG.VALUE;
+        }
+        function g() {
+            var CONFIG = { VALUE: 1 };
+            return CONFIG.VALUE;
+        }
+        function h() {
+            return 42;
+        }
+        if ([0][0])
+            console.debug("foo");
+    }
+}
+
+mixed: {
+    options = {
+        evaluate: true,
+        global_defs: {
+            "CONFIG.VALUE": 42,
+            "FOO.BAR": "moo",
+        },
+        properties: true,
+    }
+    input: {
+        var FOO = { BAR: 0 };
+        console.log(FOO.BAR);
+        console.log(++CONFIG.DEBUG);
+        console.log(++CONFIG.VALUE);
+        console.log(++CONFIG["VAL" + "UE"]);
+        console.log(++DEBUG[CONFIG.VALUE]);
+        CONFIG.VALUE.FOO = "bar";
+        console.log(CONFIG);
+    }
+    expect: {
+        var FOO = { BAR: 0 };
+        console.log("moo");
+        console.log(++CONFIG.DEBUG);
+        console.log(++CONFIG.VALUE);
+        console.log(++CONFIG.VALUE);
+        console.log(++DEBUG[42]);
+        CONFIG.VALUE.FOO = "bar";
+        console.log(CONFIG);
+    }
+    expect_warnings: [
+        "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]",
+    ]
+}
+
+issue_1801: {
+    options = {
+        booleans: true,
+        global_defs: {
+            "CONFIG.FOO.BAR": true,
+        },
+    }
+    input: {
+        console.log(CONFIG.FOO.BAR);
+    }
+    expect: {
+        console.log(!0);
+    }
+}
+
+issue_1986: {
+    options = {
+        global_defs: {
+            "@alert": "console.log",
+        },
+    }
+    input: {
+        alert(42);
+    }
+    expect: {
+        console.log(42);
+    }
+}
+
+issue_2167: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        global_defs: {
+            "@isDevMode": "function(){}",
+        },
+        passes: 2,
+        side_effects: true,
+    }
+    input: {
+        if (isDevMode()) {
+            greetOverlord();
+        }
+        doWork();
+    }
+    expect: {
+        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_vars.js

@@ -0,0 +1,605 @@
+statements: {
+    options = {
+        hoist_funs: false,
+        hoist_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1;
+            var b = 2;
+            var c = 3;
+            function g() {}
+            return g(a, b, c);
+        }
+    }
+    expect: {
+        function f() {
+            var a = 1, b = 2, c = 3;
+            function g() {}
+            return g(a, b, c);
+        }
+    }
+}
+
+statements_funs: {
+    options = {
+        hoist_funs: true,
+        hoist_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1;
+            var b = 2;
+            var c = 3;
+            function g() {}
+            return g(a, b, c);
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            var a = 1, b = 2, c = 3;
+            return g(a, b, c);
+        }
+    }
+}
+
+sequences: {
+    options = {
+        hoist_funs: false,
+        hoist_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1, b = 2;
+            function g() {}
+            var c = 3;
+            return g(a, b, c);
+        }
+    }
+    expect: {
+        function f() {
+            var c, a = 1, b = 2;
+            function g() {}
+            c = 3;
+            return g(a, b, c);
+        }
+    }
+}
+
+sequences_funs: {
+    options = {
+        hoist_funs: true,
+        hoist_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1, b = 2;
+            function g() {}
+            var c = 3;
+            return g(a, b, c);
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            var a = 1, b = 2, c = 3;
+            return g(a, b, c);
+        }
+    }
+}
+
+catch_var: {
+    options = {
+        dead_code: true,
+        hoist_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            a;
+        } catch (a) {
+            var a = 0;
+            a;
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2295: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+    }
+    input: {
+        function foo(o) {
+            var a = o.a;
+            if (a) return a;
+            var a = 1;
+        }
+    }
+    expect: {
+        function foo(o) {
+            var a = o.a;
+            if (a) return a;
+            a = 1;
+        }
+    }
+}
+
+issue_4487_1: {
+    options = {
+        functions: true,
+        hoist_vars: true,
+        keep_fnames: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function f() {
+            var f = console.log(typeof f);
+        };
+        var b = a();
+    }
+    expect: {
+        var a = function f() {
+            var f = console.log(typeof f);
+        };
+        a();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4487_2: {
+    options = {
+        functions: true,
+        hoist_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,
+        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() {
+            var a = 2;
+            return (A = a) + typeof !1;
+        }());
+    }
+    expect_stdout: "2boolean"
+}
+
+issue_4736: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        function f() {
+            (function g() {
+                var b = (a = 0, 1 << 30);
+                var c = (a = 0, console.log(b));
+                var d = c;
+            })(f);
+        }
+        f();
+    }
+    expect: {
+        (function() {
+            (function() {
+                0,
+                console.log(1 << 30);
+            })();
+        })();
+    }
+    expect_stdout: "1073741824"
+}
+
+issue_4839: {
+    options = {
+        evaluate: true,
+        hoist_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,
+        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: {
+    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 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 b, c, a = "PASS";
+        b++;
+        b = a;
+        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 = c && c[b];
+        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 = console;
+        a = A = ++a;
+        console.log(A);
+    }
+    expect_stdout: "NaN"
+}

test/compress/html_comments.js

@@ -0,0 +1,107 @@
+html_comment_in_expression: {
+    input: {
+        (function(a, b) {
+            console.log(a < !--b && a-- > b, a, b);
+        })(1, 2);
+    }
+    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(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: "false true false 1 0 2"
+}
+
+html_comment_in_left_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: "1 16 1 1 0 2"
+}
+
+html_comment_in_greater_than: {
+    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: "false false false -1 1 3"
+}
+
+html_comment_in_greater_than_or_equal: {
+    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: "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: {
+        console.log("<!--HTML-->comment in<!--string literal-->".length);
+    }
+    expect_exact: 'console.log("\\x3c!--HTML--\\x3ecomment in\\x3c!--string literal--\\x3e".length);'
+    expect_stdout: "42"
+}

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";
+        consoe.log(moo);
+        import * as moo from "moz";
+    }
+    expect: {
+        import o, { bar as m } from "baz";
+        consoe.log(r);
+        import * as r from "moz";
+    }
+}
+
+rename_mangle: {
+    rename = true
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        import foo, { bar } from "baz";
+        consoe.log(moo);
+        import * as moo from "moz";
+    }
+    expect: {
+        import o, { bar as m } from "baz";
+        consoe.log(r);
+        import * as r from "moz";
+    }
+}
+
+keep_ref: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        import foo from "bar";
+        foo();
+    }
+    expect: {
+        import foo from "bar";
+        foo();
+    }
+}
+
+forbid_merge: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        import A from "foo";
+        export default class extends A {}
+        var f = () => () => {};
+        f();
+        f();
+    }
+    expect: {
+        import A from "foo";
+        export default class extends A {}
+        var f = () => () => {};
+        f();
+        f();
+    }
+}
+
+issue_4708_1: {
+    options = {
+        imports: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        import a from "foo";
+    }
+    expect: {
+        var a;
+        import a from "foo";
+    }
+}
+
+issue_4708_2: {
+    options = {
+        imports: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        console.log(a);
+        import a from "foo";
+    }
+    expect: {
+        var a;
+        console.log(a);
+        import a from "foo";
+    }
+}
+
+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

@@ -0,0 +1,298 @@
+non_hoisted_function_after_return: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: false,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function foo(x) {
+            if (x) {
+                return bar();
+                not_called1();
+            } else {
+                return baz();
+                not_called2();
+            }
+            function bar() { return 7; }
+            return not_reached;
+            function UnusedFunction() {}
+            function baz() { return 8; }
+        }
+    }
+    expect: {
+        function foo(x) {
+            return (x ? bar : baz)();
+            function bar() { return 7 }
+            function baz() { return 8 }
+        }
+    }
+    expect_warnings: [
+        "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]",
+    ]
+}
+
+non_hoisted_function_after_return_2a: {
+    options = {
+        booleans: true,
+        collapse_vars: false,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: false,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        passes: 2,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function foo(x) {
+            if (x) {
+                return bar(1);
+                var a = not_called(1);
+            } else {
+                return bar(2);
+                var b = not_called(2);
+            }
+            var c = bar(3);
+            function bar(x) { return 7 - x; }
+            function nope() {}
+            return b || c;
+        }
+    }
+    expect: {
+        function foo(x) {
+            return bar(x ? 1 : 2);
+            function bar(x) {
+                return 7 - x;
+            }
+        }
+    }
+    expect_warnings: [
+        "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",
+    ]
+}
+
+non_hoisted_function_after_return_2b: {
+    options = {
+        booleans: true,
+        collapse_vars: false,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: false,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function foo(x) {
+            if (x) {
+                return bar(1);
+            } else {
+                return bar(2);
+                var b;
+            }
+            var c = bar(3);
+            function bar(x) {
+                return 7 - x;
+            }
+            return b || c;
+        }
+    }
+    expect: {
+        function foo(x) {
+            return bar(x ? 1 : 2);
+            function bar(x) { return 7 - x; }
+        }
+    }
+    expect_warnings: [
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
+    ]
+}
+
+non_hoisted_function_after_return_strict: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: false,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function foo(x) {
+            if (x) {
+                return bar();
+                not_called1();
+            } else {
+                return baz();
+                not_called2();
+            }
+            function bar() { return 7; }
+            return not_reached;
+            function UnusedFunction() {}
+            function baz() { return 8; }
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect: {
+        "use strict";
+        function foo(x) {
+            return (x ? bar : baz)();
+            function bar() { return 7 }
+            function baz() { return 8 }
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect_stdout: "8 7"
+    expect_warnings: [
+        "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]",
+    ]
+}
+
+non_hoisted_function_after_return_2a_strict: {
+    options = {
+        booleans: true,
+        collapse_vars: false,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: false,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        passes: 2,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function foo(x) {
+            if (x) {
+                return bar(1);
+                var a = not_called(1);
+            } else {
+                return bar(2);
+                var b = not_called(2);
+            }
+            var c = bar(3);
+            function bar(x) { return 7 - x; }
+            function nope() {}
+            return b || c;
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect: {
+        "use strict";
+        function foo(x) {
+            return bar(x ? 1 : 2);
+            function bar(x) {
+                return 7 - x;
+            }
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect_stdout: "5 6"
+    expect_warnings: [
+        "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",
+    ]
+}
+
+non_hoisted_function_after_return_2b_strict: {
+    options = {
+        booleans: true,
+        collapse_vars: false,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: false,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function foo(x) {
+            if (x) {
+                return bar(1);
+            } else {
+                return bar(2);
+                var b;
+            }
+            var c = bar(3);
+            function bar(x) {
+                return 7 - x;
+            }
+            return b || c;
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect: {
+        "use strict";
+        function foo(x) {
+            return bar(x ? 1 : 2);
+            function bar(x) { return 7 - x; }
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect_stdout: "5 6"
+    expect_warnings: [
+        "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-1041.js

@@ -0,0 +1,30 @@
+const_pragma: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+    }
+
+    input: {
+        /** @const */ var goog = goog || {};
+    }
+    expect: {
+        var goog = goog || {};
+    }
+}
+
+// for completeness' sake
+not_const: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+    }
+
+    input: {
+        var goog = goog || {};
+    }
+    expect: {
+        var goog = goog || {};
+    }
+}

test/compress/issue-105.js

@@ -1,25 +0,0 @@
-typeof_eq_undefined: {
-    options = {
-        comparisons: true
-    };
-    input: { a = typeof b.c != "undefined" }
-    expect: { a = "undefined" != typeof b.c }
-}
-
-typeof_eq_undefined_unsafe: {
-    options = {
-        comparisons: true,
-        unsafe: true
-    };
-    input: { a = typeof b.c != "undefined" }
-    expect: { a = void 0 !== b.c }
-}
-
-typeof_eq_undefined_unsafe2: {
-    options = {
-        comparisons: true,
-        unsafe: true
-    };
-    input: { a = "undefined" != typeof b.c }
-    expect: { a = void 0 !== b.c }
-}

test/compress/issue-1052.js

@@ -0,0 +1,169 @@
+multiple_functions: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        (function() {
+            if (!window)
+                return;
+            function f() {}
+            function g() {}
+        })();
+    }
+    expect: {
+        (function() {
+            // NOTE: other compression steps will reduce this
+            // down to just `window`.
+            if (!window);
+            function f() {}
+            function g() {}
+        })();
+    }
+}
+
+single_function: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        (function() {
+            if (!window)
+                return;
+            function f() {}
+        })();
+    }
+    expect: {
+        (function() {
+            if (!window);
+            function f() {}
+        })();
+    }
+}
+
+deeply_nested: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        (function() {
+            if (!window)
+                return;
+            function f() {}
+            function g() {}
+            if (!document)
+                return;
+            function h() {}
+        })();
+    }
+    expect: {
+        (function() {
+            // NOTE: other compression steps will reduce this
+            // down to just `window`.
+            if (!window);
+            else if (!document);
+            function f() {}
+            function g() {}
+            function h() {}
+        })();
+    }
+}
+
+not_hoisted_when_already_nested: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        (function() {
+            if (!window)
+                return;
+            if (foo) function f() {}
+        })();
+    }
+    expect: {
+        (function() {
+            if (!window);
+            else if (foo)
+                function f() {}
+        })();
+    }
+}
+
+defun_if_return: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        function e() {
+            function f() {}
+            if (!window)
+                return;
+            else
+                function g() {}
+            function h() {}
+        }
+    }
+    expect: {
+        function e() {
+            function f() {}
+            if (!window);
+            else
+                function g() {}
+            function h() {}
+        }
+    }
+}
+
+defun_hoist_funs: {
+    options = {
+        hoist_funs: true,
+        if_return: true,
+    }
+    input: {
+        function e() {
+            function f() {}
+            if (!window)
+                return;
+            else
+                function g() {}
+            function h() {}
+        }
+    }
+    expect: {
+        function e() {
+            function f() {}
+            function g() {}
+            function h() {}
+            if (!window);
+        }
+    }
+}
+
+defun_else_if_return: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        function e() {
+            function f() {}
+            if (window)
+                function g() {}
+            else
+                return;
+            function h() {}
+        }
+    }
+    expect: {
+        function e() {
+            function f() {}
+            if (window)
+                function g() {}
+            function h() {}
+        }
+    }
+}

test/compress/issue-1105.js

@@ -0,0 +1,309 @@
+with_in_global_scope: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var o = 42;
+        with(o) {
+            var foo = 'something'
+        }
+        doSomething(o);
+    }
+    expect: {
+        var o=42;
+        with(o)
+            var foo = "something";
+        doSomething(o);
+    }
+}
+with_in_function_scope: {
+    options = {
+        unused: true,
+    }
+    input: {
+        function foo() {
+            var o = 42;
+            with(o) {
+                var foo = "something"
+            }
+            doSomething(o);
+        }
+    }
+    expect: {
+        function foo() {
+            var o=42;
+            with(o)
+                var foo = "something";
+            doSomething(o)
+        }
+    }
+}
+compress_with_with_in_other_scope: {
+    options = {
+        unused: true,
+    }
+    input: {
+        function foo() {
+            var o = 42;
+            with(o) {
+                var foo = "something"
+            }
+            doSomething(o);
+        }
+        function bar() {
+            var unused = 42;
+            return something();
+        }
+    }
+    expect: {
+        function foo() {
+            var o = 42;
+            with(o)
+                var foo = "something";
+            doSomething(o)
+        }
+        function bar() {
+            return something()
+        }
+    }
+}
+with_using_existing_variable_outside_scope: {
+    options = {
+        unused: true,
+    }
+    input: {
+        function f() {
+            var o = {};
+            var unused = {}; // Doesn't get removed because upper scope uses with
+            function foo() {
+                with(o) {
+                    var foo = "something"
+                }
+                doSomething(o);
+            }
+            foo()
+        }
+    }
+    expect: {
+        function f() {
+            var o = {};
+            var unused = {};
+            function foo() {
+                with(o)
+                    var foo = "something";
+                doSomething(o)
+            }
+            foo()
+        }
+    }
+}
+check_drop_unused_in_peer_function: {
+    options = {
+        unused: true,
+    }
+    input: {
+        function outer() {
+            var o = {};
+            var unused = {};     // should be kept
+            function foo() {     // should be kept
+                function not_in_use() {
+                    var nested_unused = "foo"; // should be dropped
+                    return 24;
+                }
+                var unused = {}; // should be kept
+                with (o) {
+                    var foo = "something";
+                }
+                doSomething(o);
+            }
+            function bar() {
+                var unused = {}; // should be dropped
+                doSomethingElse();
+            }
+            foo();
+            bar();
+        }
+    }
+    expect: {
+        function outer() {
+            var o = {};
+            var unused = {};     // should be kept
+            function foo() {     // should be kept
+                function not_in_use() {
+                    return 24;
+                }
+                var unused = {}; // should be kept
+                with (o)
+                    var foo = "something";
+                doSomething(o);
+            }
+            function bar() {
+                doSomethingElse();
+            }
+            foo();
+            bar();
+        }
+    }
+}
+
+Infinity_not_in_with_scope: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var o = { Infinity: "FAIL" };
+        var vInfinity = "Infinity";
+        vInfinity = Infinity;
+        console.log(vInfinity);
+    }
+    expect: {
+        var o = { Infinity: "FAIL" };
+        var vInfinity = "Infinity";
+        vInfinity = 1/0;
+        console.log(vInfinity);
+    }
+    expect_stdout: "Infinity"
+}
+
+Infinity_in_with_scope: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var o = { Infinity: "PASS" };
+        var vInfinity = "Infinity";
+        with (o) { vInfinity = Infinity; }
+        console.log(vInfinity);
+    }
+    expect: {
+        var o = { Infinity: "PASS" };
+        var vInfinity = "Infinity";
+        with (o) vInfinity = Infinity;
+        console.log(vInfinity);
+    }
+    expect_stdout: "PASS"
+}
+
+assorted_Infinity_NaN_undefined_in_with_scope: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: true,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        keep_infinity: false,
+        sequences: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var f = console.log;
+        var o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5,
+        };
+        if (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(2 + 7 + undefined, 2 + 7 + void 0);
+        }
+        with (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(2 + 7 + undefined, 2 + 7 + void 0);
+        }
+    }
+    expect: {
+        var f = console.log, o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5
+        };
+        if (o) {
+            f(void 0, void 0);
+            f(NaN, NaN);
+            f(1/0, 1/0);
+            f(-1/0, -1/0);
+            f(NaN, NaN);
+        }
+        with (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -1/0);
+            f(9 + undefined, 9 + void 0);
+        }
+    }
+    expect_stdout: true
+}
+
+assorted_Infinity_NaN_undefined_in_with_scope_keep_infinity: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: true,
+        if_return: true,
+        join_vars: true,
+        keep_fargs: true,
+        keep_infinity: true,
+        sequences: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var f = console.log;
+        var o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5,
+        };
+        if (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(2 + 7 + undefined, 2 + 7 + void 0);
+        }
+        with (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(2 + 7 + undefined, 2 + 7 + void 0);
+        }
+    }
+    expect: {
+        var f = console.log, o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5
+        };
+        if (o) {
+            f(void 0, void 0);
+            f(NaN, NaN);
+            f(Infinity, 1/0);
+            f(-Infinity, -1/0);
+            f(NaN, NaN);
+        }
+        with (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -1/0);
+            f(9 + undefined, 9 + void 0);
+        }
+    }
+    expect_stdout: true
+}

test/compress/issue-12.js

@@ -1,11 +1,78 @@
 keep_name_of_getter: {
-    options = { unused: true };
-    input: { a = { get foo () {} } }
-    expect: { a = { get foo () {} } }
+    options = {
+        unused: true,
+    }
+    input: {
+        a = {
+            get foo() {},
+        };
+    }
+    expect: {
+        a = {
+            get foo() {},
+        };
+    }
 }
 
 keep_name_of_setter: {
-    options = { unused: true };
-    input: { a = { set foo () {} } }
-    expect: { a = { set foo () {} } }
+    options = {
+        unused: true,
+    }
+    input: {
+        a = {
+            set foo(v) {},
+        };
+    }
+    expect: {
+        a = {
+            set foo(v) {},
+        };
+    }
+}
+
+setter_with_operator_keys: {
+    input: {
+        var tokenCodes = {
+            get instanceof() {
+                return test0;
+            },
+            set instanceof(value) {
+                test0 = value;
+            },
+            set typeof(value) {
+                test1 = value;
+            },
+            get typeof() {
+                return test1;
+            },
+            set else(value) {
+                test2 = value;
+            },
+            get else() {
+                return test2;
+            },
+        };
+    }
+    expect: {
+        var tokenCodes = {
+            get instanceof() {
+                return test0;
+            },
+            set instanceof(value) {
+                test0 = value;
+            },
+            set typeof(value) {
+                test1 = value;
+            },
+            get typeof() {
+                return test1;
+            },
+            set else(value) {
+                test2 = value;
+            },
+            get else() {
+                return test2;
+            },
+        };
+    }
 }

test/compress/issue-1202.js

@@ -0,0 +1,51 @@
+mangle_keep_fnames_false: {
+    options = {
+        keep_fargs: true,
+        keep_fnames: true,
+    }
+    mangle = {
+        keep_fnames: false,
+    }
+    input: {
+        "use strict";
+        function total() {
+            return function n(a, b, c) {
+                return a + b + c;
+            };
+        }
+    }
+    expect: {
+        "use strict";
+        function total() {
+            return function t(n, r, u) {
+                return n + r + u;
+            };
+        }
+    }
+}
+
+mangle_keep_fnames_true: {
+    options = {
+        keep_fargs: true,
+        keep_fnames: true,
+    }
+    mangle = {
+        keep_fnames: true,
+    }
+    input: {
+        "use strict";
+        function total() {
+            return function n(a, b, c) {
+                return a + b + c;
+            };
+        }
+    }
+    expect: {
+        "use strict";
+        function total() {
+            return function n(t, r, u) {
+                return t + r + u;
+            };
+        }
+    }
+}

test/compress/issue-1261.js

@@ -0,0 +1,186 @@
+pure_function_calls: {
+    options = {
+        annotations: true,
+        booleans: true,
+        comparisons: true,
+        conditionals: true,
+        evaluate: true,
+        if_return: true,
+        join_vars: true,
+        negate_iife: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        // pure top-level IIFE will be dropped
+        // @__PURE__ - comment
+        (function() {
+            console.log("iife0");
+        })();
+
+        // pure top-level IIFE assigned to unreferenced var will not be dropped
+        var iife1 = /*@__PURE__*/(function() {
+            console.log("iife1");
+            function iife1() {}
+            return iife1;
+        })();
+
+        (function(){
+            // pure IIFE in function scope assigned to unreferenced var will be dropped
+            var iife2 = /*#__PURE__*/(function() {
+                console.log("iife2");
+                function iife2() {}
+                return iife2;
+            })();
+        })();
+
+        // comment #__PURE__ comment
+        bar(), baz(), quux();
+        a.b(), /* @__PURE__ */ c.d.e(), f.g();
+    }
+    expect: {
+        var iife1 = function() {
+            console.log("iife1");
+            function iife1() {}
+            return iife1;
+        }();
+
+        baz(), quux();
+        a.b(), f.g();
+    }
+    expect_warnings: [
+        "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,
+        evaluate: true,
+        if_return: true,
+        join_vars: true,
+        negate_iife: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        // pure top-level IIFE will be dropped
+        // @__PURE__ - comment
+        (function() {
+            console.log("iife0");
+        })();
+
+        // pure top-level IIFE assigned to unreferenced var will be dropped
+        var iife1 = /*@__PURE__*/(function() {
+            console.log("iife1");
+            function iife1() {}
+            return iife1;
+        })();
+
+        (function(){
+            // pure IIFE in function scope assigned to unreferenced var will be dropped
+            var iife2 = /*#__PURE__*/(function() {
+                console.log("iife2");
+                function iife2() {}
+                return iife2;
+            })();
+        })();
+
+        // pure top-level calls will be dropped regardless of the leading comments position
+        var MyClass = /*#__PURE__*//*@class*/(function(){
+            function MyClass() {}
+            MyClass.prototype.method = function() {};
+            return MyClass;
+        })();
+
+        // comment #__PURE__ comment
+        bar(), baz(), quux();
+        a.b(), /* @__PURE__ */ c.d.e(), f.g();
+    }
+    expect: {
+        baz(), quux();
+        a.b(), f.g();
+    }
+    expect_warnings: [
+        "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,
+        side_effects: true,
+    }
+    input: {
+        /* @__PURE__ */(function(){x})(), void/* @__PURE__ */(function(){y})();
+        /* @__PURE__ */(function(){x})() || true ? foo() : bar();
+        true || /* @__PURE__ */(function(){y})() ? foo() : bar();
+        /* @__PURE__ */(function(){x})() && false ? foo() : bar();
+        false && /* @__PURE__ */(function(){y})() ? foo() : bar();
+        /* @__PURE__ */(function(){x})() + "foo" ? bar() : baz();
+        "foo" + /* @__PURE__ */(function(){y})() ? bar() : baz();
+        /* @__PURE__ */(function(){x})() ? foo() : foo();
+        [/* @__PURE__ */(function(){x})()] ? foo() : bar();
+        !{ foo: /* @__PURE__ */(function(){x})() } ? bar() : baz();
+    }
+    expect: {
+        foo();
+        foo();
+        bar();
+        bar();
+        bar();
+        bar();
+        foo();
+        foo();
+        baz();
+    }
+    expect_warnings: [
+        "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-1275.js

@@ -0,0 +1,49 @@
+string_plus_optimization: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_funs: true,
+        if_return: true,
+        join_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function foo(anything) {
+            function throwing_function() {
+                throw "nope";
+            }
+            try {
+                console.log('0' + throwing_function() ? "yes" : "no");
+            } catch (ex) {
+                console.log(ex);
+            }
+            console.log('0' + anything ? "yes" : "no");
+            console.log(anything + '0' ? "Yes" : "No");
+            console.log('' + anything);
+            console.log(anything + '');
+        }
+        foo();
+    }
+    expect: {
+        function foo(anything) {
+            function throwing_function() {
+                throw "nope";
+            }
+            try {
+                console.log((throwing_function(), "yes"));
+            } catch (ex) {
+                console.log(ex);
+            }
+            console.log("yes");
+            console.log("Yes");
+            console.log('' + anything);
+            console.log(anything + '');
+        }
+        foo();
+    }
+    expect_stdout: true
+}

test/compress/issue-1321.js

@@ -0,0 +1,63 @@
+issue_1321_no_debug: {
+    mangle = {
+        properties: {
+            keep_quoted: true,
+        },
+    }
+    input: {
+        var x = {};
+        x.foo = 1;
+        x["a"] = 2 * x.foo;
+        console.log(x.foo, x["a"]);
+    }
+    expect: {
+        var x = {};
+        x.x = 1;
+        x["a"] = 2 * x.x;
+        console.log(x.x, x["a"]);
+    }
+    expect_stdout: true
+}
+
+issue_1321_debug: {
+    mangle = {
+        properties: {
+            debug: "",
+            keep_quoted: true,
+        },
+    }
+    input: {
+        var x = {};
+        x.foo = 1;
+        x["_$foo$_"] = 2 * x.foo;
+        console.log(x.foo, x["_$foo$_"]);
+    }
+    expect: {
+        var x = {};
+        x.x = 1;
+        x["_$foo$_"] = 2 * x.x;
+        console.log(x.x, x["_$foo$_"]);
+    }
+    expect_stdout: true
+}
+
+issue_1321_with_quoted: {
+    mangle = {
+        properties: {
+            keep_quoted: false,
+        },
+    }
+    input: {
+        var x = {};
+        x.foo = 1;
+        x["a"] = 2 * x.foo;
+        console.log(x.foo, x["a"]);
+    }
+    expect: {
+        var x = {};
+        x.x = 1;
+        x["o"] = 2 * x.x;
+        console.log(x.x, x["o"]);
+    }
+    expect_stdout: true
+}

test/compress/issue-143.js

@@ -15,7 +15,7 @@
 tranformation_sort_order_equal: {
     options = {
         comparisons: true,
-    };
+    }
 
     input: { (a = parseInt('100')) == a }
     expect: { (a = parseInt('100')) == a }
@@ -24,7 +24,7 @@ tranformation_sort_order_equal: {
 tranformation_sort_order_unequal: {
     options = {
         comparisons: true,
-    };
+    }
 
     input: { (a = parseInt('100')) != a }
     expect: { (a = parseInt('100')) != a }
@@ -33,7 +33,7 @@ tranformation_sort_order_unequal: {
 tranformation_sort_order_lesser_or_equal: {
     options = {
         comparisons: true,
-    };
+    }
 
     input: { (a = parseInt('100')) <= a }
     expect: { (a = parseInt('100')) <= a }
@@ -41,7 +41,7 @@ tranformation_sort_order_lesser_or_equal: {
 tranformation_sort_order_greater_or_equal: {
     options = {
         comparisons: true,
-    };
+    }
 
     input: { (a = parseInt('100')) >= a }
     expect: { (a = parseInt('100')) >= a }

test/compress/issue-1431.js

@@ -0,0 +1,151 @@
+level_zero: {
+    options = {
+        keep_fnames: true,
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            function n(a) {
+                return a * a;
+            }
+            return function() {
+                return x;
+            };
+        }
+    }
+    expect: {
+        function f(r) {
+            function n(n) {
+                return n * n;
+            }
+            return function() {
+                return r;
+            };
+        }
+    }
+}
+
+level_one: {
+    options = {
+        keep_fnames: true,
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function n(a) {
+                    return a * a;
+                }
+                return x(n);
+            };
+        }
+    }
+    expect: {
+        function f(r) {
+            return function() {
+                function n(n) {
+                    return n * n;
+                }
+                return r(n);
+            };
+        }
+    }
+}
+
+level_two: {
+    options = {
+        keep_fnames: true,
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function r(a) {
+                    return a * a;
+                }
+                return function() {
+                    function n(a) {
+                        return a * a;
+                    }
+                    return x(n);
+                };
+            };
+        }
+    }
+    expect: {
+        function f(t) {
+            return function() {
+                function r(n) {
+                    return n * n;
+                }
+                return function() {
+                    function n(n) {
+                        return n * n;
+                    }
+                    return t(n);
+                };
+            };
+        }
+    }
+}
+
+level_three: {
+    options = {
+        keep_fnames: true,
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function r(a) {
+                    return a * a;
+                }
+                return [
+                    function() {
+                        function t(a) {
+                            return a * a;
+                        }
+                        return t;
+                    },
+                    function() {
+                        function n(a) {
+                            return a * a;
+                        }
+                        return x(n);
+                    }
+                ];
+            };
+        }
+    }
+    expect: {
+        function f(t) {
+            return function() {
+                function r(n) {
+                    return n * n;
+                }
+                return [
+                    function() {
+                        function t(n) {
+                            return n * n;
+                        }
+                        return t;
+                    },
+                    function() {
+                        function n(n) {
+                            return n * n;
+                        }
+                        return t(n);
+                    }
+                ];
+            };
+        }
+    }
+}

test/compress/issue-1443.js

@@ -0,0 +1,61 @@
+// tests assume that variable `undefined` not redefined and has `void 0` as value
+
+unsafe_undefined: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unsafe_undefined: true,
+    }
+    mangle = {}
+    input: {
+        function f(undefined) {
+            return function() {
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }
+    }
+    expect: {
+        function f(n) {
+            return function() {
+                return a ? b : c ? d : n;
+            };
+        }
+    }
+}
+
+keep_fnames: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unsafe_undefined: true,
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(undefined) {
+            return function() {
+                function n(a) {
+                    return a * a;
+                }
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }
+    }
+    expect: {
+        function f(r) {
+            return function() {
+                function n(n) {
+                    return n * n;
+                }
+                return a ? b : c ? d : r;
+            };
+        }
+    }
+}

test/compress/issue-1446.js

@@ -0,0 +1,75 @@
+typeof_eq_undefined: {
+    options = {
+        comparisons: true,
+        typeofs: true,
+    }
+    input: {
+        var a = typeof b != "undefined";
+        b = typeof a != "undefined";
+        var c = typeof d.e !== "undefined";
+        var f = "undefined" === typeof g;
+        g = "undefined" === typeof f;
+        var h = "undefined" == typeof i.j;
+    }
+    expect: {
+        var a = "undefined" != typeof b;
+        b = void 0 !== a;
+        var c = void 0 !== d.e;
+        var f = "undefined" == typeof g;
+        g = void 0 === f;
+        var h = void 0 === i.j;
+    }
+}
+
+typeof_eq_undefined_ie8: {
+    options = {
+        comparisons: true,
+        ie: true,
+        typeofs: true,
+    }
+    input: {
+        var a = typeof b != "undefined";
+        b = typeof a != "undefined";
+        var c = typeof d.e !== "undefined";
+        var f = "undefined" === typeof g;
+        g = "undefined" === typeof f;
+        var h = "undefined" == typeof i.j;
+    }
+    expect: {
+        var a = "undefined" != typeof b;
+        b = void 0 !== a;
+        var c = "undefined" != typeof d.e;
+        var f = "undefined" == typeof g;
+        g = void 0 === f;
+        var h = "undefined" == typeof i.j;
+    }
+}
+
+undefined_redefined: {
+    options = {
+        comparisons: true,
+        typeofs: true,
+    }
+    input: {
+        function f(undefined) {
+            var n = 1;
+            return typeof n == "undefined";
+        }
+    }
+    expect_exact: "function f(undefined){var n=1;return void 0===n}"
+}
+
+undefined_redefined_mangle: {
+    options = {
+        comparisons: true,
+        typeofs: true,
+    }
+    mangle = {}
+    input: {
+        function f(undefined) {
+            var n = 1;
+            return typeof n == "undefined";
+        }
+    }
+    expect_exact: "function f(n){var r=1;return void 0===r}"
+}

test/compress/issue-1447.js

@@ -0,0 +1,48 @@
+else_with_empty_block: {
+    options = {}
+    input: {
+        if (x)
+            yes();
+        else {
+        }
+    }
+    expect_exact: "if(x)yes();"
+}
+
+else_with_empty_statement: {
+    options = {}
+    input: {
+        if (x)
+            yes();
+        else
+            ;
+    }
+    expect_exact: "if(x)yes();"
+}
+
+conditional_false_stray_else_in_loop: {
+    options = {
+        booleans: true,
+        comparisons: true,
+        conditionals: false,
+        dead_code: true,
+        evaluate: true,
+        hoist_vars: true,
+        if_return: true,
+        join_vars: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        for (var i = 1; i <= 4; ++i) {
+            if (i <= 2) continue;
+            console.log(i);
+        }
+    }
+    expect_exact: "for(var i=1;i<=4;++i)if(i<=2);else console.log(i);"
+    expect_stdout: [
+        "3",
+        "4",
+    ]
+}

test/compress/issue-1569.js

@@ -0,0 +1,19 @@
+inner_reference: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        !function f(a) {
+            return a && f(a - 1) + a;
+        }(42);
+        !function g(a) {
+            return a;
+        }(42);
+    }
+    expect: {
+        !function f(a) {
+            return a && f(a - 1) + a;
+        }(42);
+        !void 0;
+    }
+}

test/compress/issue-1588.js

@@ -0,0 +1,87 @@
+screw_ie8: {
+    options = {
+        ie: false,
+    }
+    mangle = {
+        ie: false,
+    }
+    input: {
+        try { throw "foo"; } catch (x) { console.log(x); }
+    }
+    expect_exact: 'try{throw"foo"}catch(o){console.log(o)}'
+    expect_stdout: [
+        "foo"
+    ]
+}
+
+support_ie8: {
+    options = {
+        ie: true,
+    }
+    mangle = {
+        ie: true,
+    }
+    input: {
+        try { throw "foo"; } catch (x) { console.log(x); }
+    }
+    expect_exact: 'try{throw"foo"}catch(x){console.log(x)}'
+    expect_stdout: "foo"
+}
+
+safe_undefined: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unsafe: false,
+    }
+    mangle = {}
+    input: {
+        var a, c;
+        console.log(function(undefined) {
+            return function() {
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }(1)());
+    }
+    expect: {
+        var a, c;
+        console.log(function(n) {
+            return function() {
+                return a ? b : c ? d : void 0;
+            };
+        }(1)());
+    }
+    expect_stdout: true
+}
+
+unsafe_undefined: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unsafe_undefined: true,
+    }
+    mangle = {}
+    input: {
+        var a, c;
+        console.log(function(undefined) {
+            return function() {
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }()());
+    }
+    expect: {
+        var a, c;
+        console.log(function(n) {
+            return function() {
+                return a ? b : c ? d : n;
+            };
+        }()());
+    }
+    expect_stdout: true
+}

test/compress/issue-1609.js

@@ -0,0 +1,81 @@
+chained_evaluation_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = 1;
+            (function() {
+                var b = a, c;
+                c = f(b);
+                c.bar = b;
+            })();
+        })();
+    }
+    expect: {
+        (function() {
+            (function() {
+                f(1).bar = 1;
+            })();
+        })();
+    }
+}
+
+chained_evaluation_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        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() {
+                var b = "long piece of string";
+                f(b).bar = b;
+            })();
+        })();
+    }
+}
+
+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

@@ -0,0 +1,84 @@
+issue_1639_1: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        join_vars: true,
+        loops: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        var L1 = 5;
+        while (--L1 > 0) {
+            if ((--b), false) {
+                if (b) {
+                    var ignore = 0;
+                }
+            }
+        }
+        console.log(a, b);
+    }
+    expect: {
+        for (var a = 100, b = 10, L1 = 5, ignore; --L1 > 0;) {
+            --b;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "100 6"
+}
+
+issue_1639_2: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+    }
+    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, 1;
+        }
+        f19(),
+        console.log(a, b);
+    }
+    expect_stdout: "101 10"
+}
+
+issue_1639_3: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        a++ && false && a ? 0 : 0;
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        a++,
+        console.log(a, b);
+    }
+    expect_stdout: "101 10"
+}

test/compress/issue-1656.js

@@ -0,0 +1,41 @@
+f7: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        drop_debugger: true,
+        evaluate: true,
+        hoist_funs: true,
+        if_return: true,
+        join_vars: true,
+        loops: true,
+        negate_iife: true,
+        passes: 3,
+        properties: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        function f22464() {
+            var brake146670 = 5;
+            while (((b = a) ? !a : ~a ? null : b += a) && --brake146670 > 0) {
+            }
+        }
+        f22464();
+        console.log(a, b);
+    }
+    expect_exact: [
+        "console.log(100, 100);",
+    ]
+    expect_stdout: "100 100"
+}

test/compress/issue-1673.js

@@ -0,0 +1,166 @@
+side_effects_catch: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                try {
+                    throw 0;
+                } catch (e) {
+                    console.log("PASS");
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                try {
+                    throw 0;
+                } catch (e) {
+                    console.log("PASS");
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_else: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            function g() {
+                if (x);
+                else console.log("PASS");
+            }
+            g();
+        }
+        f(0);
+    }
+    expect: {
+        function f(x) {
+            (function() {
+                if (x);
+                else console.log("PASS");
+            })();
+        }
+        f(0);
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_finally: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                try {
+                    x();
+                } catch (e) {
+                } finally {
+                    console.log("PASS");
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                try {
+                    x();
+                } catch (e) {
+                } finally {
+                    console.log("PASS");
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_label: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            function g() {
+                L: {
+                    console.log("PASS");
+                    break L;
+                }
+            }
+            g();
+        }
+        f(0);
+    }
+    expect: {
+        function f(x) {
+            (function() {
+                L: {
+                    console.log("PASS");
+                    break L;
+                }
+            })();
+        }
+        f(0);
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_switch: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                switch (0) {
+                  default:
+                  case console.log("PASS"):
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                switch (0) {
+                  default:
+                  case console.log("PASS"):
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}

test/compress/issue-1704.js

@@ -0,0 +1,447 @@
+mangle_catch: {
+    options = {
+        ie: false,
+        toplevel: false,
+    }
+    mangle = {
+        ie: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(o){a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_ie8: {
+    options = {
+        ie: true,
+        toplevel: false,
+    }
+    mangle = {
+        ie: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(args){a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var: {
+    options = {
+        ie: false,
+        toplevel: false,
+    }
+    mangle = {
+        ie: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(o){var a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_ie8: {
+    options = {
+        ie: true,
+        toplevel: false,
+    }
+    mangle = {
+        ie: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(args){var a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_toplevel: {
+    options = {
+        ie: false,
+        toplevel: true,
+    }
+    mangle = {
+        ie: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var c="FAIL";try{throw 1}catch(o){c="PASS"}console.log(c);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_ie8_toplevel: {
+    options = {
+        ie: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_toplevel: {
+    options = {
+        ie: false,
+        toplevel: true,
+    }
+    mangle = {
+        ie: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var r="FAIL";try{throw 1}catch(o){var r="PASS"}console.log(r);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_ie8_toplevel: {
+    options = {
+        ie: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1: {
+    options = {
+        ie: false,
+        toplevel: false,
+    }
+    mangle = {
+        ie: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="PASS";try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_ie8: {
+    options = {
+        ie: true,
+        toplevel: false,
+    }
+    mangle = {
+        ie: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="PASS";try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_toplevel: {
+    options = {
+        ie: false,
+        toplevel: true,
+    }
+    mangle = {
+        ie: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="PASS";try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_ie8_toplevel: {
+    options = {
+        ie: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="PASS";try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_2: {
+    options = {
+        ie: false,
+        toplevel: false,
+    }
+    mangle = {
+        ie: false,
+        toplevel: false,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_ie8: {
+    options = {
+        ie: true,
+        toplevel: false,
+    }
+    mangle = {
+        ie: true,
+        toplevel: false,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_toplevel: {
+    options = {
+        ie: false,
+        toplevel: true,
+    }
+    mangle = {
+        ie: false,
+        toplevel: true,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_ie8_toplevel: {
+    options = {
+        ie: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie: true,
+        toplevel: true,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_3: {
+    mangle = {
+        ie: false,
+        toplevel: false,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            // prints "FAIL" if inlined on Node.js v4-
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    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 = {
+        ie: false,
+        toplevel: true,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            // prints "FAIL" if inlined on Node.js v4-
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    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_3_ie8: {
+    mangle = {
+        ie: true,
+        toplevel: false,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            // prints "FAIL" if inlined on Node.js v4-
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    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 = {
+        ie: true,
+        toplevel: true,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            // prints "FAIL" if inlined on Node.js v4-
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    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

@@ -0,0 +1,97 @@
+function_iife_catch: {
+    mangle = {
+        ie: false,
+    }
+    input: {
+        function f(n) {
+            !function() {
+                try {
+                    throw 0;
+                } catch (n) {
+                    var a = 1;
+                    console.log(n, a);
+                }
+            }();
+        }
+        f();
+    }
+    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
+    expect_stdout: "0 1"
+}
+
+function_iife_catch_ie8: {
+    mangle = {
+        ie: true,
+    }
+    input: {
+        function f(n) {
+            !function() {
+                try {
+                    throw 0;
+                } catch (n) {
+                    var a = 1;
+                    console.log(n, a);
+                }
+            }();
+        }
+        f();
+    }
+    expect_exact: "function f(c){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
+    expect_stdout: "0 1"
+}
+
+function_catch_catch: {
+    mangle = {
+        ie: false,
+    }
+    input: {
+        var o = 0;
+        function f() {
+            try {
+                throw 1;
+            } catch (c) {
+                try {
+                    throw 2;
+                } catch (o) {
+                    var o = 3;
+                    console.log(o);
+                }
+            }
+            console.log(o);
+        }
+        f();
+    }
+    expect_exact: "var o=0;function f(){try{throw 1}catch(o){try{throw 2}catch(c){var c=3;console.log(c)}}console.log(c)}f();"
+    expect_stdout: [
+        "3",
+        "undefined",
+    ]
+}
+
+function_catch_catch_ie8: {
+    mangle = {
+        ie: true,
+    }
+    input: {
+        var o = 0;
+        function f() {
+            try {
+                throw 1;
+            } catch (c) {
+                try {
+                    throw 2;
+                } catch (o) {
+                    var o = 3;
+                    console.log(o);
+                }
+            }
+            console.log(o);
+        }
+        f();
+    }
+    expect_exact: "var o=0;function f(){try{throw 1}catch(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_stdout: [
+        "3",
+        "undefined",
+    ]
+}

test/compress/issue-1750.js

@@ -0,0 +1,54 @@
+case_1: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a = 0, b = 1;
+        switch (true) {
+          case a || true:
+          default:
+            b = 2;
+          case true:
+        }
+        console.log(a, b);
+    }
+    expect: {
+        var a = 0, b = 1;
+        switch (true) {
+          case a || true:
+            b = 2;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "0 2"
+}
+
+case_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a = 0, b = 1;
+        switch (0) {
+          default:
+            b = 2;
+          case a:
+            a = 3;
+          case 0:
+        }
+        console.log(a, b);
+    }
+    expect: {
+        var a = 0, b = 1;
+        switch (0) {
+          case a:
+            a = 3;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "3 1"
+}

test/compress/issue-1770.js

@@ -0,0 +1,247 @@
+mangle_props: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        var obj = {
+            undefined: 1,
+            NaN: 2,
+            Infinity: 3,
+            "-Infinity": 4,
+            null: 5,
+        };
+        console.log(
+            obj[void 0],
+            obj[undefined],
+            obj["undefined"],
+            obj[0/0],
+            obj[NaN],
+            obj["NaN"],
+            obj[1/0],
+            obj[Infinity],
+            obj["Infinity"],
+            obj[-1/0],
+            obj[-Infinity],
+            obj["-Infinity"],
+            obj[null],
+            obj["null"]
+        );
+    }
+    expect: {
+        var obj = {
+            undefined: 1,
+            NaN: 2,
+            Infinity: 3,
+            "-Infinity": 4,
+            null: 5,
+        };
+        console.log(
+            obj[void 0],
+            obj[void 0],
+            obj["undefined"],
+            obj[0/0],
+            obj[NaN],
+            obj["NaN"],
+            obj[1/0],
+            obj[1/0],
+            obj["Infinity"],
+            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"
+}
+
+numeric_literal: {
+    mangle = {
+        properties: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        var obj = {
+            0: 0,
+            "-0": 1,
+            42: 2,
+            "42": 3,
+            0x25: 4,
+            "0x25": 5,
+            1E42: 6,
+            "1E42": 7,
+            "1e+42": 8,
+        };
+        console.log(obj[-0], obj[-""], obj["-0"]);
+        console.log(obj[42], obj["42"]);
+        console.log(obj[0x25], obj["0x25"], obj[37], obj["37"]);
+        console.log(obj[1E42], obj["1E42"], obj["1e+42"]);
+    }
+    expect_exact: [
+        'var obj = {',
+        '    0: 0,',
+        '    "-0": 1,',
+        '    42: 2,',
+        '    42: 3,',
+        '    37: 4,',
+        '    o: 5,',
+        '    1e42: 6,',
+        '    b: 7,',
+        '    1e42: 8',
+        '};',
+        '',
+        'console.log(obj[-0], obj[-""], obj["-0"]);',
+        '',
+        'console.log(obj[42], obj["42"]);',
+        '',
+        'console.log(obj[37], obj["o"], obj[37], obj["37"]);',
+        '',
+        'console.log(obj[1e42], obj["b"], obj["1e+42"]);',
+    ]
+    expect_stdout: [
+        "0 0 1",
+        "3 3",
+        "4 5 4 4",
+        "8 7 8",
+    ]
+}
+
+identifier: {
+    mangle = {
+        properties: {
+            builtins: true,
+        },
+    }
+    input: {
+        var obj = {
+            abstract: 1,
+            boolean: 2,
+            byte: 3,
+            char: 4,
+            class: 5,
+            double: 6,
+            enum: 7,
+            export: 8,
+            extends: 9,
+            final: 10,
+            float: 11,
+            goto: 12,
+            implements: 13,
+            import: 14,
+            int: 15,
+            interface: 16,
+            let: 17,
+            long: 18,
+            native: 19,
+            package: 20,
+            private: 21,
+            protected: 22,
+            public: 23,
+            short: 24,
+            static: 25,
+            super: 26,
+            synchronized: 27,
+            this: 28,
+            throws: 29,
+            transient: 30,
+            volatile: 31,
+            yield: 32,
+            false: 33,
+            null: 34,
+            true: 35,
+            break: 36,
+            case: 37,
+            catch: 38,
+            const: 39,
+            continue: 40,
+            debugger: 41,
+            default: 42,
+            delete: 43,
+            do: 44,
+            else: 45,
+            finally: 46,
+            for: 47,
+            function: 48,
+            if: 49,
+            in: 50,
+            instanceof: 51,
+            new: 52,
+            return: 53,
+            switch: 54,
+            throw: 55,
+            try: 56,
+            typeof: 57,
+            var: 58,
+            void: 59,
+            while: 60,
+            with: 61,
+        };
+    }
+    expect: {
+        var obj = {
+            e: 1,
+            t: 2,
+            n: 3,
+            a: 4,
+            i: 5,
+            o: 6,
+            r: 7,
+            l: 8,
+            s: 9,
+            c: 10,
+            f: 11,
+            u: 12,
+            d: 13,
+            h: 14,
+            p: 15,
+            b: 16,
+            v: 17,
+            w: 18,
+            y: 19,
+            g: 20,
+            m: 21,
+            k: 22,
+            x: 23,
+            j: 24,
+            z: 25,
+            q: 26,
+            A: 27,
+            B: 28,
+            C: 29,
+            D: 30,
+            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-1787.js

@@ -0,0 +1,17 @@
+unary_prefix: {
+    options = {
+        evaluate: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var x = -(2 / 3);
+            return x;
+        }());
+    }
+    expect_exact: "console.log(-2/3);"
+    expect_stdout: true
+}

test/compress/issue-1833.js

@@ -0,0 +1,138 @@
+iife_for: {
+    options = {
+        negate_iife: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: for (;;) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: for (;;) break L;
+            }();
+        }();
+    }
+}
+
+iife_for_in: {
+    options = {
+        negate_iife: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: for (var a in x) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: for (var a in x) break L;
+            }();
+        }();
+    }
+}
+
+iife_do: {
+    options = {
+        negate_iife: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: do {
+                    break L;
+                } while (1);
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: do {
+                    break L;
+                } while (1);
+            }();
+        }();
+    }
+}
+
+iife_while: {
+    options = {
+        negate_iife: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: while (1) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: while (1) break L;
+            }();
+        }();
+    }
+}
+
+label_do: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        L: do {
+            continue L;
+        } while (0);
+    }
+    expect: {
+        L: do {
+            continue L;
+        } while (0);
+    }
+}
+
+label_while: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        function f() {
+            L: while (0) continue L;
+        }
+    }
+    expect_exact: "function f(){L:0}"
+}

test/compress/issue-1943.js

@@ -0,0 +1,31 @@
+operator: {
+    input: {
+        a. //comment
+        typeof
+    }
+    expect_exact: "a.typeof;"
+}
+
+name: {
+    input: {
+        a. //comment
+        b
+    }
+    expect_exact: "a.b;"
+}
+
+keyword: {
+    input: {
+        a. //comment
+        default
+    }
+    expect_exact: "a.default;"
+}
+
+atom: {
+    input: {
+        a. //comment
+        true
+    }
+    expect_exact: "a.true;"
+}

test/compress/issue-208.js

@@ -0,0 +1,74 @@
+do_not_update_lhs: {
+    options = {
+        global_defs: {
+            DEBUG: 0,
+        },
+    }
+    input: {
+        DEBUG++;
+        DEBUG += 1;
+        DEBUG = 1;
+    }
+    expect: {
+        DEBUG++;
+        DEBUG += 1;
+        DEBUG = 1;
+    }
+}
+
+do_update_rhs: {
+    options = {
+        global_defs: {
+            DEBUG: 0,
+        },
+    }
+    input: {
+        MY_DEBUG = DEBUG;
+        MY_DEBUG += DEBUG;
+    }
+    expect: {
+        MY_DEBUG = 0;
+        MY_DEBUG += 0;
+    }
+}
+
+mixed: {
+    options = {
+        evaluate: true,
+        global_defs: {
+            DEBUG: 0,
+            ENV: 1,
+            FOO: 2,
+        },
+    }
+    input: {
+        var ENV = 3;
+        var FOO = 4;
+        f(ENV * 10);
+        --FOO;
+        DEBUG = 1;
+        DEBUG++;
+        DEBUG += 1;
+        f(DEBUG);
+        x = DEBUG;
+    }
+    expect: {
+        var ENV = 3;
+        var FOO = 4;
+        f(10);
+        --FOO;
+        DEBUG = 1;
+        DEBUG++;
+        DEBUG += 1;
+        f(0);
+        x = 0;
+    }
+    expect_warnings: [
+        "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-22.js

@@ -1,5 +1,7 @@
 return_with_no_value_in_if_body: {
-    options = { conditionals: true };
+    options = {
+        conditionals: true,
+    }
     input: {
         function foo(bar) {
             if (bar) {

test/compress/issue-2652.js

@@ -0,0 +1,33 @@
+insert_semicolon: {
+    beautify = {
+        beautify: true,
+        comments: "all",
+    }
+    input: {
+        var a
+        /* foo */ var b
+    }
+    expect_exact: [
+        "var a",
+        "/* foo */;",
+        "",
+        "var b;",
+    ]
+}
+
+unary_postfix: {
+    beautify = {
+        beautify: true,
+        comments: "all",
+    }
+    input: {
+        a
+        /* foo */++b
+    }
+    expect_exact: [
+        "a",
+        "/* foo */;",
+        "",
+        "++b;",
+    ]
+}

test/compress/issue-267.js

@@ -1,5 +1,7 @@
 issue_267: {
-    options = { comparisons: true };
+    options = {
+        comparisons: true,
+    }
     input: {
         x = a % b / b * c * 2;
         x = a % b * 2

test/compress/issue-269.js

@@ -1,66 +1,111 @@
 issue_269_1: {
-	options = {unsafe: true};
-	input: {
-		f(
-			String(x),
-			Number(x),
-			Boolean(x),
+    options = {
+        unsafe: true,
+    }
+    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 = {unsafe: true};
-	input: {
-		f(
-			String(x, x),
-			Number(x, x),
-			Boolean(x, x)
-		);
-	}
-	expect: {
-		f(String(x, x), Number(x, x), Boolean(x, x));
-	}
+    options = {
+        unsafe: true,
+    }
+    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 = {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));
-	}
+    options = {
+        unsafe: true,
+    }
+    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 = {unsafe: true};
-	input: {
-		f(
-			String(x + 'str'),
-			String('str' + x)
-		);
-	}
-	expect: {
-		f(
-			x + 'str',
-			'str' + x
-		);
-	}
+    options = {
+        strings: true,
+        unsafe: true,
+    }
+    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 = {
+        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:5,8]',
+    ]
 }

test/compress/issue-2719.js

@@ -0,0 +1,32 @@
+warn: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return g();
+        }
+        function g() {
+            return g["call" + "er"].arguments;
+        }
+        // 3
+        console.log(f(1, 2, 3).length);
+    }
+    expect: {
+        // TypeError: Cannot read property 'arguments' of null
+        console.log(function g() {
+            return g.caller.arguments;
+        }().length);
+    }
+    expect_warnings: [
+        "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

@@ -0,0 +1,512 @@
+collapse_vars_constants: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f1(x) {
+            var a = 4, b = x.prop, c = 5, d = sideeffect1(), e = sideeffect2();
+            return b + (function() { return d - a * e - c; })();
+        }
+        function f2(x) {
+            var a = 4, b = x.prop, c = 5, not_used = sideeffect1(), e = sideeffect2();
+            return b + (function() { return -a * e - c; })();
+        }
+    }
+    expect: {
+        function f1(x) {
+            var b = x.prop, d = sideeffect1(), e = sideeffect2();
+            return b + (d - 4 * e - 5);
+        }
+        function f2(x) {
+            var b = x.prop;
+            sideeffect1();
+            return b + (-4 * sideeffect2() - 5);
+        }
+    }
+}
+
+modified: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        unused: true,
+    }
+    input: {
+        function f5(b) {
+            var a = function() {
+                return b;
+            }();
+            return b++ + a;
+        }
+        console.log(f5(1));
+    }
+    expect: {
+        function f5(b) {
+            var a = b;
+            return b++ + a;
+        }
+        console.log(f5(1));
+    }
+    expect_stdout: "2"
+}
+
+ref_scope: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var a = 1, b = 2, c = 3;
+            var a = c++, b = b /= a;
+            return function() {
+                return a;
+            }() + b;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var a = 1, b = 2, c = 3;
+            b = b /= a = c++;
+            return a + b;
+        }());
+    }
+    expect_stdout: true
+}
+
+safe_undefined: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        inline: true,
+        unsafe: false,
+        unused: true,
+    }
+    mangle = {}
+    input: {
+        var a, c;
+        console.log(function(undefined) {
+            return function() {
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }(1)());
+    }
+    expect: {
+        var a, c;
+        console.log(a ? b : c ? d : void 0);
+    }
+    expect_stdout: true
+}
+
+negate_iife_3: {
+    expression = true
+    options = {
+        conditionals: true,
+        expression: true,
+        inline: true,
+        negate_iife: true,
+    }
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        t ? console.log(true) : console.log(false);
+    }
+}
+
+negate_iife_3_off: {
+    expression = true
+    options = {
+        conditionals: true,
+        expression: true,
+        inline: true,
+        negate_iife: false,
+    }
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        t ? console.log(true) : console.log(false);
+    }
+}
+
+negate_iife_4: {
+    options = {
+        conditionals: true,
+        expression: true,
+        inline: true,
+        negate_iife: true,
+        sequences: true,
+    }
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        t ? console.log(true) : console.log(false), void console.log("something");
+    }
+}
+
+negate_iife_5: {
+    options = {
+        conditionals: true,
+        expression: true,
+        inline: true,
+        negate_iife: true,
+        sequences: true,
+    }
+    input: {
+        if ((function(){ return t })()) {
+            foo(true);
+        } else {
+            bar(false);
+        }
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        t ? foo(true) : bar(false), void console.log("something");
+    }
+}
+
+negate_iife_5_off: {
+    options = {
+        conditionals: true,
+        expression: true,
+        inline: true,
+        negate_iife: false,
+        sequences: true,
+    }
+    input: {
+        if ((function(){ return t })()) {
+            foo(true);
+        } else {
+            bar(false);
+        }
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        t ? foo(true) : bar(false), void console.log("something");
+    }
+}
+
+issue_1254_negate_iife_true: {
+    expression = true
+    options = {
+        expression: true,
+        inline: true,
+        negate_iife: true,
+    }
+    input: {
+        (function() {
+            return function() {
+                console.log('test')
+            };
+        })()();
+    }
+    expect_exact: 'void console.log("test")'
+    expect_stdout: true
+}
+
+issue_1254_negate_iife_nested: {
+    expression = true
+    options = {
+        expression: true,
+        inline: true,
+        negate_iife: true,
+    }
+    input: {
+        (function() {
+            return function() {
+                console.log('test')
+            };
+        })()()()()();
+    }
+    expect_exact: '(void console.log("test"))()()()'
+}
+
+negate_iife_issue_1073: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        inline: true,
+        negate_iife: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        new (function(a) {
+            return function Foo() {
+                this.x = a;
+                console.log(this);
+            };
+        }(7))();
+    }
+    expect: {
+        new function() {
+            this.x = 7,
+            console.log(this);
+        }();
+    }
+    expect_stdout: true
+}
+
+issue_1288_side_effects: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        inline: true,
+        negate_iife: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        if (w) ;
+        else {
+            (function f() {})();
+        }
+        if (!x) {
+            (function() {
+                x = {};
+            })();
+        }
+        if (y)
+            (function() {})();
+        else
+            (function(z) {
+                return z;
+            })(0);
+    }
+    expect: {
+        w;
+        x || (x = {});
+        y;
+    }
+}
+
+inner_var_for_in_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1, b = 2;
+            for (b in (function() {
+                return x(a, b, c);
+            })()) {
+                var c = 3, d = 4;
+                x(a, b, c, d);
+            }
+            x(a, b, c, d);
+        }
+    }
+    expect: {
+        function f() {
+            var a = 1, b = 2;
+            for (b in x(1, b, c)) {
+                var c = 3, d = 4;
+                x(1, b, c, d);
+            }
+            x(1, b, c, d);
+        }
+    }
+}
+
+issue_1595_3: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function f(a) {
+            return g(a + 1);
+        })(2);
+    }
+    expect: {
+        g(3);
+    }
+}
+
+issue_1758: {
+    options = {
+        inline: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(function(c) {
+            var undefined = 42;
+            return function() {
+                c--;
+                c--, c.toString();
+                return;
+            }();
+        }());
+    }
+    expect: {
+        console.log(function(c) {
+            var undefined = 42;
+            return c--, c--, void c.toString();
+        }());
+    }
+    expect_stdout: "undefined"
+}
+wrap_iife: {
+    options = {
+        inline: true,
+        negate_iife: false,
+    }
+    beautify = {
+        wrap_iife: true,
+    }
+    input: {
+        (function() {
+            return function() {
+                console.log('test')
+            };
+        })()();
+    }
+    expect_exact: 'void console.log("test");'
+}
+
+wrap_iife_in_expression: {
+    options = {
+        inline: true,
+        negate_iife: false,
+    }
+    beautify = {
+        wrap_iife: true,
+    }
+    input: {
+        foo = (function() {
+            return bar();
+        })();
+    }
+    expect_exact: 'foo=bar();'
+}
+
+wrap_iife_in_return_call: {
+    options = {
+        inline: true,
+        negate_iife: false,
+    }
+    beautify = {
+        wrap_iife: true,
+    }
+    input: {
+        (function() {
+            return (function() {
+                console.log('test')
+            })();
+        })()();
+    }
+    expect_exact: '(void console.log("test"))();'
+}
+
+pure_annotation_1: {
+    options = {
+        annotations: true,
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        /*@__PURE__*/(function() {
+            console.log("hello");
+        }());
+    }
+    expect_exact: ""
+}
+
+pure_annotation_2: {
+    options = {
+        annotations: true,
+        collapse_vars: true,
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        /*@__PURE__*/(function(n) {
+            console.log("hello", n);
+        }(42));
+    }
+    expect_exact: ""
+}
+
+drop_fargs: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        keep_fargs: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        !function(a_1) {
+            a++;
+        }(a++ + (a && console.log(a)));
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        ++a && console.log(a),
+        a++;
+        console.log(a);
+    }
+    expect_stdout: [
+        "2",
+        "3",
+    ]
+}
+
+keep_fargs: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        keep_fargs: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        !function(a_1) {
+            a++;
+        }(a++ + (a && console.log(a)));
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        ++a && console.log(a),
+        a++;
+        console.log(a);
+    }
+    expect_stdout: [
+        "2",
+        "3",
+    ]
+}

test/compress/issue-2871.js

@@ -0,0 +1,37 @@
+comparison_with_undefined: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        a == undefined;
+        a != undefined;
+        a === undefined;
+        a !== undefined;
+
+        undefined == a;
+        undefined != a;
+        undefined === a;
+        undefined !== a;
+
+        void 0 == a;
+        void 0 != a;
+        void 0 === a;
+        void 0 !== a;
+    }
+    expect: {
+        null == a;
+        null != a;
+        void 0 === a;
+        void 0 !== a;
+
+        null == a;
+        null != a;
+        void 0 === a;
+        void 0 !== a;
+
+        null == a;
+        null != a;
+        void 0 === a;
+        void 0 !== a;
+    }
+}

test/compress/issue-2989.js

@@ -0,0 +1,21 @@
+inline_script_off: {
+    beautify = {
+        inline_script: false,
+    }
+    input: {
+        console.log("</sCrIpT>");
+    }
+    expect_exact: 'console.log("</sCrIpT>");'
+    expect_stdout: "</sCrIpT>"
+}
+
+inline_script_on: {
+    beautify = {
+        inline_script: true,
+    }
+    input: {
+        console.log("</sCrIpT>");
+    }
+    expect_exact: 'console.log("<\\/sCrIpT>");'
+    expect_stdout: "</sCrIpT>"
+}

test/compress/issue-368.js

@@ -0,0 +1,55 @@
+collapse: {
+    options = {
+        collapse_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f1() {
+            var a;
+            a = typeof b === 'function' ? b() : b;
+            return a !== undefined && c();
+        }
+        function f2(b) {
+            var a;
+            b = c();
+            a = typeof b === 'function' ? b() : b;
+            return 'stirng' == typeof a && d();
+        }
+        function f3(c) {
+            var a;
+            a = b(a / 2);
+            if (a < 0) {
+                a++;
+                ++c;
+                return c / 2;
+            }
+        }
+        function f4(c) {
+            var a;
+            a = b(a / 2);
+            if (a < 0) {
+                a++;
+                c++;
+                return c / 2;
+            }
+        }
+    }
+    expect: {
+        function f1() {
+            return void 0 !== ('function' === typeof b ? b() : b) && c();
+        }
+        function f2(b) {
+            return 'stirng' == typeof ('function' === typeof (b = c()) ? b() : b) && d();
+        }
+        function f3(c) {
+            var a;
+            if ((a = b(a / 2)) < 0) return a++, ++c / 2;
+        }
+        function f4(c) {
+            var a;
+            if ((a = b(a / 2)) < 0) return a++, ++c / 2;
+        }
+    }
+}

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-44.js

@@ -1,5 +1,7 @@
 issue_44_valid_ast_1: {
-    options = { unused: true };
+    options = {
+        unused: true,
+    }
     input: {
         function a(b) {
             for (var i = 0, e = b.qoo(); ; i++) {}
@@ -14,7 +16,9 @@ issue_44_valid_ast_1: {
 }
 
 issue_44_valid_ast_2: {
-    options = { unused: true };
+    options = {
+        unused: true,
+    }
     input: {
         function a(b) {
             if (foo) for (var i = 0, e = b.qoo(); ; i++) {}

test/compress/issue-59.js

@@ -1,8 +1,8 @@
 keep_continue: {
     options = {
         dead_code: true,
-        evaluate: true
-    };
+        evaluate: true,
+    }
     input: {
         while (a) {
             if (b) {