fix collapse_vars regression in destructuring (#2897)

fixes #2896

.github/ISSUE_TEMPLATE.md

@@ -8,7 +8,16 @@
 
 **Uglify version (`uglifyjs -V`)**
 
-**JavaScript input**  <!-- ideally as small as possible -->
+**JavaScript input**
+
+<!--
+    A complete parsable JS program exhibiting the issue with
+    UglifyJS alone - without third party tools or libraries.
+    Ideally the input should be as small as possible.
+    Post a link to a gist if necessary.
+
+    Issues without a reproducible test case will be closed.
+-->
 
 **The `uglifyjs` CLI command executed or `minify()` options used.**
 

.travis.yml

@@ -1,12 +1,14 @@
 language: node_js
-before_install: "npm install -g npm"
 node_js:
     - "0.10"
     - "0.12"
     - "4"
     - "6"
+    - "8"
 env:
     - UGLIFYJS_TEST_ALL=1
 matrix:
   fast_finish: true
 sudo: false
+cache:
+  directories: tmp

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 2012-2018 (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

appveyor.yml

@@ -1,24 +1,20 @@
 environment:
   matrix:
-  - nodejs_version: "0.10"
-  - nodejs_version: "0.12"
-  - nodejs_version: "4.0"
-  - nodejs_version: "6.0"
-
+    - nodejs_version: "0.10"
+    - nodejs_version: "0.12"
+    - nodejs_version: "4"
+    - nodejs_version: "6"
+    - nodejs_version: "8"
+install:
+  - ps: Install-Product node $env:nodejs_version
+  - set UGLIFYJS_TEST_ALL=1
+  - npm install
+build: off
+cache:
+  - tmp
 matrix:
   fast_finish: true
-
-platform:
-  - x86
-  - x64
-
-install:
-  - ps: Install-Product node $env:nodejs_version $env:platform
-  - npm install
-
 test_script:
   - node --version
   - npm --version
   - npm test
-
-build: off

bin/uglifyjs

@@ -3,11 +3,7 @@
 
 "use strict";
 
-// workaround for tty output truncation upon process.exit()
-[process.stdout, process.stderr].forEach(function(stream){
-    if (stream._handle && stream._handle.setBlocking)
-        stream._handle.setBlocking(true);
-});
+require("../tools/exit");
 
 var fs = require("fs");
 var info = require("../package.json");
@@ -15,31 +11,46 @@ var path = require("path");
 var program = require("commander");
 var UglifyJS = require("../tools/node");
 
-var skip_keys = [ "cname", "enclosed", "parent_scope", "scope", "thedef", "uses_eval", "uses_with" ];
+var skip_keys = [ "cname", "inlined", "parent_scope", "scope", "uses_eval", "uses_with" ];
 var files = {};
 var options = {
     compress: false,
     mangle: false
 };
-program._name = info.name;
-program.version(info.version);
+program.version(info.name + " " + info.version);
 program.parseArgv = program.parse;
 program.parse = undefined;
-program.option("-p, --parse <options>", "Specify parser options.", parse_js("parse", true));
-program.option("-c, --compress [options]", "Enable compressor/specify compressor options.", parse_js("compress", true));
-program.option("-m, --mangle [options]", "Mangle names/specify mangler options.", parse_js("mangle", true));
-program.option("--mangle-props [options]", "Mangle properties/specify mangler options.", parse_js("mangle-props", true));
-program.option("-b, --beautify [options]", "Beautify output/specify output options.", parse_js("beautify", true));
+if (process.argv.indexOf("ast") >= 0) program.helpInformation = UglifyJS.describe_ast;
+else if (process.argv.indexOf("options") >= 0) program.helpInformation = function() {
+    var text = [];
+    var options = UglifyJS.default_options();
+    for (var option in options) {
+        text.push("--" + (option == "output" ? "beautify" : option == "sourceMap" ? "source-map" : option) + " options:");
+        text.push(format_object(options[option]));
+        text.push("");
+    }
+    return text.join("\n");
+};
+program.option("-p, --parse <options>", "Specify parser options.", parse_js());
+program.option("-c, --compress [options]", "Enable compressor/specify compressor options.", parse_js());
+program.option("-m, --mangle [options]", "Mangle names/specify mangler options.", parse_js());
+program.option("--mangle-props [options]", "Mangle properties/specify mangler options.", parse_js());
+program.option("-b, --beautify [options]", "Beautify output/specify output options.", parse_js());
 program.option("-o, --output <file>", "Output file (default STDOUT).");
 program.option("--comments [filter]", "Preserve copyright comments in the output.");
 program.option("--config-file <file>", "Read minify() options from JSON file.");
 program.option("-d, --define <expr>[=value]", "Global definitions.", parse_js("define"));
+program.option("--ecma <version>", "Specify ECMAScript release: 5, 6, 7 or 8.");
 program.option("--ie8", "Support non-standard Internet Explorer 8.");
+program.option("--keep-classnames", "Do not mangle/drop class names.");
 program.option("--keep-fnames", "Do not mangle/drop function names. Useful for code relying on Function.prototype.name.");
 program.option("--name-cache <file>", "File to hold mangled name mappings.");
+program.option("--rename", "Force symbol expansion.");
+program.option("--no-rename", "Disable symbol expansion.");
+program.option("--safari10", "Support non-standard Safari 10.");
 program.option("--self", "Build UglifyJS as a library (implies --wrap UglifyJS)");
 program.option("--source-map [options]", "Enable source map/specify source map options.", parse_source_map());
-program.option("--stats", "Display operations run time on STDERR.")
+program.option("--timings", "Display operations run time on STDERR.")
 program.option("--toplevel", "Compress and/or mangle variables in toplevel scope.");
 program.option("--verbose", "Print diagnostic messages.");
 program.option("--warn", "Print warning messages.");
@@ -55,6 +66,7 @@ if (!program.output && program.sourceMap && program.sourceMap.url != "inline") {
     "compress",
     "ie8",
     "mangle",
+    "safari10",
     "sourceMap",
     "toplevel",
     "wrap"
@@ -63,6 +75,10 @@ if (!program.output && program.sourceMap && program.sourceMap.url != "inline") {
         options[name] = program[name];
     }
 });
+if ("ecma" in program) {
+    if (program.ecma != (program.ecma | 0)) fatal("ERROR: ecma must be an integer");
+    options.ecma = program.ecma | 0;
+}
 if (program.beautify) {
     options.output = typeof program.beautify == "object" ? program.beautify : {};
     if (!("beautify" in options.output)) {
@@ -80,6 +96,9 @@ if (program.define) {
         options.compress.global_defs[expr] = program.define[expr];
     }
 }
+if (program.keepClassnames) {
+    options.keep_classnames = true;
+}
 if (program.keepFnames) {
     options.keep_fnames = true;
 }
@@ -96,17 +115,8 @@ if (program.mangleProps) {
     if (typeof options.mangle != "object") options.mangle = {};
     options.mangle.properties = program.mangleProps;
 }
-var cache;
 if (program.nameCache) {
-    cache = JSON.parse(read_file(program.nameCache, "{}"));
-    if (options.mangle) {
-        if (typeof options.mangle != "object") options.mangle = {};
-        options.mangle.cache = to_cache("vars");
-        if (options.mangle.properties) {
-            if (typeof options.mangle.properties != "object") options.mangle.properties = {};
-            options.mangle.properties.cache = to_cache("props");
-        }
-    }
+    options.nameCache = JSON.parse(read_file(program.nameCache, "{}"));
 }
 if (program.output == "ast") {
     options.output = {
@@ -115,12 +125,17 @@ if (program.output == "ast") {
     };
 }
 if (program.parse) {
-    if (program.parse.acorn || program.parse.spidermonkey) {
-        if (program.sourceMap) fatal("ERROR: inline source map only works with built-in parser");
-    } else {
+    if (!program.parse.acorn && !program.parse.spidermonkey) {
         options.parse = program.parse;
+    } else if (program.sourceMap && program.sourceMap.content == "inline") {
+        fatal("ERROR: inline source map only works with built-in parser");
     }
 }
+if (~program.rawArgs.indexOf("--rename")) {
+    options.rename = true;
+} else if (!program.rename) {
+    options.rename = false;
+}
 var convert_path = function(name) {
     return name;
 };
@@ -140,7 +155,7 @@ if (program.verbose) {
 }
 if (program.self) {
     if (program.args.length) {
-        console.error("WARN: Ignoring input files since --self was passed");
+        print_error("WARN: Ignoring input files since --self was passed");
     }
     if (!options.wrap) options.wrap = "UglifyJS";
     simple_glob(UglifyJS.FILES).forEach(function(name) {
@@ -170,9 +185,9 @@ function convert_ast(fn) {
 
 function run() {
     UglifyJS.AST_Node.warn_function = function(msg) {
-        console.error("WARN:", msg);
+        print_error("WARN: " + msg);
     };
-    if (program.stats) program.stats = Date.now();
+    if (program.timings) options.timings = true;
     try {
         if (program.parse) {
             if (program.parse.acorn) {
@@ -199,7 +214,7 @@ function run() {
     if (result.error) {
         var ex = result.error;
         if (ex.name == "SyntaxError") {
-            console.error("Parse error at " + ex.filename + ":" + ex.line + "," + ex.col);
+            print_error("Parse error at " + ex.filename + ":" + ex.line + "," + ex.col);
             var col = ex.col;
             var lines = files[ex.filename].split(/\r?\n/);
             var line = lines[ex.line - 1];
@@ -208,21 +223,35 @@ function run() {
                 col = line.length;
             }
             if (line) {
-                if (col > 40) {
-                    line = line.slice(col - 40);
-                    col = 40;
+                var limit = 70;
+                if (col > limit) {
+                    line = line.slice(col - limit);
+                    col = limit;
                 }
-                console.error(line.slice(0, 80));
-                console.error(line.slice(0, col).replace(/\S/g, " ") + "^");
+                print_error(line.slice(0, 80));
+                print_error(line.slice(0, col).replace(/\S/g, " ") + "^");
             }
         }
         if (ex.defs) {
-            console.error("Supported options:");
-            console.error(ex.defs);
+            print_error("Supported options:");
+            print_error(format_object(ex.defs));
         }
         fatal(ex);
     } else if (program.output == "ast") {
-        console.log(JSON.stringify(result.ast, function(key, value) {
+        if (!options.compress && !options.mangle) {
+            result.ast.figure_out_scope({});
+        }
+        print(JSON.stringify(result.ast, function(key, value) {
+            if (value) switch (key) {
+              case "thedef":
+                return symdef(value);
+              case "enclosed":
+                return value.length ? value.map(symdef) : undefined;
+              case "variables":
+              case "functions":
+              case "globals":
+                return value.size() ? value.map(symdef) : undefined;
+            }
             if (skip_key(key)) return;
             if (value instanceof UglifyJS.AST_Token) return;
             if (value instanceof UglifyJS.Dictionary) return;
@@ -230,6 +259,11 @@ function run() {
                 var result = {
                     _class: "AST_" + value.TYPE
                 };
+                if (value.block_scope) {
+                    result.variables = value.block_scope.variables;
+                    result.functions = value.block_scope.functions;
+                    result.enclosed = value.block_scope.enclosed;
+                }
                 value.CTOR.PROPS.forEach(function(prop) {
                     result[prop] = value[prop];
                 });
@@ -238,7 +272,7 @@ function run() {
             return value;
         }, 2));
     } else if (program.output == "spidermonkey") {
-        console.log(JSON.stringify(UglifyJS.minify(result.code, {
+        print(JSON.stringify(UglifyJS.minify(result.code, {
             compress: false,
             mangle: false,
             output: {
@@ -252,19 +286,19 @@ function run() {
             fs.writeFileSync(program.output + ".map", result.map);
         }
     } else {
-        console.log(result.code);
+        print(result.code);
     }
     if (program.nameCache) {
-        fs.writeFileSync(program.nameCache, JSON.stringify(cache, function(key, value) {
-            return value instanceof UglifyJS.Dictionary ? value.toObject() : value;
-        }));
+        fs.writeFileSync(program.nameCache, JSON.stringify(options.nameCache));
+    }
+    if (result.timings) for (var phase in result.timings) {
+        print_error("- " + phase + ": " + result.timings[phase].toFixed(3) + "s");
     }
-    if (program.stats) console.error("Elapsed:", Date.now() - program.stats);
 }
 
 function fatal(message) {
     if (message instanceof Error) message = message.stack.replace(/^\S*?Error:/, "ERROR:")
-    console.error(message);
+    print_error(message);
     process.exit(1);
 }
 
@@ -308,7 +342,7 @@ function read_file(path, default_value) {
     }
 }
 
-function parse_js(flag, constants) {
+function parse_js(flag) {
     return function(value, options) {
         options = options || {};
         try {
@@ -326,7 +360,7 @@ function parse_js(flag, constants) {
                 if (node instanceof UglifyJS.AST_Assign) {
                     var name = node.left.print_to_string();
                     var value = node.right;
-                    if (!constants) {
+                    if (flag) {
                         options[name] = value;
                     } else if (value instanceof UglifyJS.AST_Array) {
                         options[name] = value.elements.map(to_string);
@@ -349,37 +383,57 @@ function parse_js(flag, constants) {
                 }
             }));
         } catch(ex) {
-            fatal("Error parsing arguments for '" + flag + "': " + value);
+            if (flag) {
+                fatal("Error parsing arguments for '" + flag + "': " + value);
+            } else {
+                options[value] = null;
+            }
         }
         return options;
     }
 }
 
 function parse_source_map() {
-    var parse = parse_js("sourceMap", true);
+    var parse = parse_js();
     return function(value, options) {
-        var hasContent = options && options.sourceMap && "content" in options.sourceMap;
+        var hasContent = options && "content" in options;
         var settings = parse(value, options);
         if (!hasContent && settings.content && settings.content != "inline") {
-            console.error("INFO: Using input source map:", settings.content);
+            print_error("INFO: Using input source map: " + settings.content);
             settings.content = read_file(settings.content, settings.content);
         }
         return settings;
     }
 }
 
-function to_cache(key) {
-    if (cache[key]) {
-        cache[key].props = UglifyJS.Dictionary.fromObject(cache[key].props);
-    } else {
-        cache[key] = {
-            cname: -1,
-            props: new UglifyJS.Dictionary()
-        };
-    }
-    return cache[key];
-}
-
 function skip_key(key) {
     return skip_keys.indexOf(key) >= 0;
 }
+
+function symdef(def) {
+    var ret = (1e6 + def.id) + " " + def.name;
+    if (def.mangled_name) ret += " " + def.mangled_name;
+    return ret;
+}
+
+function format_object(obj) {
+    var lines = [];
+    var padding = "";
+    Object.keys(obj).map(function(name) {
+        if (padding.length < name.length) padding = Array(name.length + 1).join(" ");
+        return [ name, JSON.stringify(obj[name]) ];
+    }).forEach(function(tokens) {
+        lines.push("  " + tokens[0] + padding.slice(tokens[0].length - 2) + tokens[1]);
+    });
+    return lines.join("\n");
+}
+
+function print_error(msg) {
+    process.stderr.write(msg);
+    process.stderr.write("\n");
+}
+
+function print(txt) {
+    process.stdout.write(txt);
+    process.stdout.write("\n");
+}

lib/ast.js

@@ -87,7 +87,7 @@ function DEFNODE(type, props, methods, base) {
     return ctor;
 };
 
-var AST_Token = DEFNODE("Token", "type value line col pos endline endcol endpos nlb comments_before file raw", {
+var AST_Token = DEFNODE("Token", "type value line col pos endline endcol endpos nlb comments_before comments_after file raw", {
 }, null);
 
 var AST_Node = DEFNODE("Node", "start end", {
@@ -134,11 +134,10 @@ var AST_Debugger = DEFNODE("Debugger", null, {
     $documentation: "Represents a debugger statement",
 }, AST_Statement);
 
-var AST_Directive = DEFNODE("Directive", "value scope quote", {
+var AST_Directive = DEFNODE("Directive", "value quote", {
     $documentation: "Represents a directive, like \"use strict\";",
     $propdoc: {
         value: "[string] The value of this directive as a plain string (it's not an AST_String!)",
-        scope: "[AST_Scope/S] The scope that this directive affects",
         quote: "[string] the original quote character"
     },
 }, AST_Statement);
@@ -157,7 +156,7 @@ var AST_SimpleStatement = DEFNODE("SimpleStatement", "body", {
 
 function walk_body(node, visitor) {
     var body = node.body;
-    if (body instanceof AST_Statement) {
+    if (body instanceof AST_Node) {
         body._walk(visitor);
     }
     else for (var i = 0, len = body.length; i < len; i++) {
@@ -268,11 +267,10 @@ var AST_For = DEFNODE("For", "init condition step", {
     }
 }, AST_IterationStatement);
 
-var AST_ForIn = DEFNODE("ForIn", "init name object", {
+var AST_ForIn = DEFNODE("ForIn", "init object", {
     $documentation: "A `for ... in` statement",
     $propdoc: {
         init: "[AST_Node] the `for/in` initialization code",
-        name: "[AST_SymbolRef?] the loop variable, only if `init` is AST_Var",
         object: "[AST_Node] the object that we're looping through"
     },
     _walk: function(visitor) {
@@ -284,6 +282,10 @@ var AST_ForIn = DEFNODE("ForIn", "init name object", {
     }
 }, AST_IterationStatement);
 
+var AST_ForOf = DEFNODE("ForOf", null, {
+    $documentation: "A `for ... of` statement",
+}, AST_ForIn);
+
 var AST_With = DEFNODE("With", "expression", {
     $documentation: "A `with` statement",
     $propdoc: {
@@ -299,10 +301,9 @@ var AST_With = DEFNODE("With", "expression", {
 
 /* -----[ scope and functions ]----- */
 
-var AST_Scope = DEFNODE("Scope", "directives variables functions uses_with uses_eval parent_scope enclosed cname", {
+var AST_Scope = DEFNODE("Scope", "variables functions uses_with uses_eval parent_scope enclosed cname", {
     $documentation: "Base class for all statements introducing a lexical scope",
     $propdoc: {
-        directives: "[string*/S] an array of directives declared in this scope",
         variables: "[Object/S] a map of name -> SymbolDef for all variables/functions defined in this scope",
         functions: "[Object/S] like `variables`, but only lists function declarations",
         uses_with: "[boolean/S] tells whether this scope uses the `with` statement",
@@ -311,6 +312,20 @@ var AST_Scope = DEFNODE("Scope", "directives variables functions uses_with uses_
         enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any subscopes",
         cname: "[integer/S] current index for mangling variables (used internally by the mangler)",
     },
+    get_defun_scope: function() {
+        var self = this;
+        while (self.is_block_scope()) {
+            self = self.parent_scope;
+        }
+        return self;
+    },
+    clone: function(deep) {
+        var node = this._clone(deep);
+        if (this.variables) node.variables = this.variables.clone();
+        if (this.functions) node.functions = this.functions.clone();
+        if (this.enclosed) node.enclosed = this.enclosed.slice();
+        return node;
+    }
 }, AST_Block);
 
 var AST_Toplevel = DEFNODE("Toplevel", "globals", {
@@ -331,12 +346,38 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     }
 }, AST_Scope);
 
-var AST_Lambda = DEFNODE("Lambda", "name argnames uses_arguments", {
+var AST_Expansion = DEFNODE("Expansion", "expression", {
+    $documentation: "An expandible argument, such as ...rest, a splat, such as [1,2,...all], or an expansion in a variable declaration, such as var [first, ...rest] = list",
+    $propdoc: {
+        expression: "[AST_Node] the thing to be expanded"
+    },
+    _walk: function(visitor) {
+        var self = this;
+        return visitor._visit(this, function(){
+            self.expression.walk(visitor);
+        });
+    }
+});
+
+var AST_Lambda = DEFNODE("Lambda", "name argnames uses_arguments is_generator async", {
     $documentation: "Base class for functions",
     $propdoc: {
         name: "[AST_SymbolDeclaration?] the name of this function",
-        argnames: "[AST_SymbolFunarg*] array of function arguments",
-        uses_arguments: "[boolean/S] tells whether this function accesses the arguments array"
+        argnames: "[AST_SymbolFunarg|AST_Destructuring|AST_Expansion|AST_DefaultAssign*] array of function arguments, destructurings, or expanding arguments",
+        uses_arguments: "[boolean/S] tells whether this function accesses the arguments array",
+        is_generator: "[boolean] is this a generator method",
+        async: "[boolean] is this method async",
+    },
+    args_as_names: function () {
+        var out = [];
+        for (var i = 0; i < this.argnames.length; i++) {
+            if (this.argnames[i] instanceof AST_Destructuring) {
+                out = out.concat(this.argnames[i].all_symbols());
+            } else {
+                out.push(this.argnames[i]);
+            }
+        }
+        return out;
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
@@ -354,14 +395,80 @@ var AST_Accessor = DEFNODE("Accessor", null, {
     $documentation: "A setter/getter function.  The `name` property is always null."
 }, AST_Lambda);
 
-var AST_Function = DEFNODE("Function", null, {
+var AST_Function = DEFNODE("Function", "inlined", {
     $documentation: "A function expression"
 }, AST_Lambda);
 
-var AST_Defun = DEFNODE("Defun", null, {
+var AST_Arrow = DEFNODE("Arrow", "inlined", {
+    $documentation: "An ES6 Arrow function ((a) => b)"
+}, AST_Lambda);
+
+var AST_Defun = DEFNODE("Defun", "inlined", {
     $documentation: "A function definition"
 }, AST_Lambda);
 
+/* -----[ DESTRUCTURING ]----- */
+var AST_Destructuring = DEFNODE("Destructuring", "names is_array", {
+    $documentation: "A destructuring of several names. Used in destructuring assignment and with destructuring function argument names",
+    $propdoc: {
+        "names": "[AST_Node*] Array of properties or elements",
+        "is_array": "[Boolean] Whether the destructuring represents an object or array"
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            this.names.forEach(function(name){
+                name._walk(visitor);
+            });
+        });
+    },
+    all_symbols: function() {
+        var out = [];
+        this.walk(new TreeWalker(function (node) {
+            if (node instanceof AST_Symbol) {
+                out.push(node);
+            }
+            if (node instanceof AST_Expansion) {
+                out.push(node.expression);
+            }
+        }));
+        return out;
+    }
+});
+
+var AST_PrefixedTemplateString = DEFNODE("PrefixedTemplateString", "template_string prefix", {
+    $documentation: "A templatestring with a prefix, such as String.raw`foobarbaz`",
+    $propdoc: {
+        template_string: "[AST_TemplateString] The template string",
+        prefix: "[AST_SymbolRef|AST_PropAccess] The prefix, which can be a symbol such as `foo` or a dotted expression such as `String.raw`."
+    },
+    _walk: function(visitor) {
+        this.prefix._walk(visitor);
+        this.template_string._walk(visitor);
+    }
+})
+
+var AST_TemplateString = DEFNODE("TemplateString", "segments", {
+    $documentation: "A template string literal",
+    $propdoc: {
+        segments: "[AST_Node*] One or more segments, starting with AST_TemplateSegment. AST_Node may follow AST_TemplateSegment, but each AST_Node must be followed by AST_TemplateSegment."
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            this.segments.forEach(function(seg){
+                seg._walk(visitor);
+            });
+        });
+    }
+});
+
+var AST_TemplateSegment = DEFNODE("TemplateSegment", "value raw", {
+    $documentation: "A segment of a template string literal",
+    $propdoc: {
+        value: "Content of the segment",
+        raw: "Raw content of the segment"
+    }
+});
+
 /* -----[ JUMPS ]----- */
 
 var AST_Jump = DEFNODE("Jump", null, {
@@ -481,7 +588,7 @@ var AST_Try = DEFNODE("Try", "bcatch bfinally", {
 var AST_Catch = DEFNODE("Catch", "argname", {
     $documentation: "A `catch` node; only makes sense as part of a `try` statement",
     $propdoc: {
-        argname: "[AST_SymbolCatch] symbol for the exception"
+        argname: "[AST_SymbolCatch|AST_Destructuring|AST_Expansion|AST_DefaultAssign] symbol for the exception"
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
@@ -495,10 +602,10 @@ var AST_Finally = DEFNODE("Finally", null, {
     $documentation: "A `finally` node; only makes sense as part of a `try` statement"
 }, AST_Block);
 
-/* -----[ VAR ]----- */
+/* -----[ VAR/CONST ]----- */
 
 var AST_Definitions = DEFNODE("Definitions", "definitions", {
-    $documentation: "Base class for `var` nodes (variable declarations/initializations)",
+    $documentation: "Base class for `var` or `const` nodes (variable declarations/initializations)",
     $propdoc: {
         definitions: "[AST_VarDef*] array of variable definitions"
     },
@@ -516,10 +623,83 @@ var AST_Var = DEFNODE("Var", null, {
     $documentation: "A `var` statement"
 }, AST_Definitions);
 
+var AST_Let = DEFNODE("Let", null, {
+    $documentation: "A `let` statement"
+}, AST_Definitions);
+
+var AST_Const = DEFNODE("Const", null, {
+    $documentation: "A `const` statement"
+}, AST_Definitions);
+
+var AST_NameMapping = DEFNODE("NameMapping", "foreign_name name", {
+    $documentation: "The part of the export/import statement that declare names from a module.",
+    $propdoc: {
+        foreign_name: "[AST_SymbolExportForeign|AST_SymbolImportForeign] The name being exported/imported (as specified in the module)",
+        name: "[AST_SymbolExport|AST_SymbolImport] The name as it is visible to this module."
+    },
+    _walk: function (visitor) {
+        return visitor._visit(this, function() {
+            this.foreign_name._walk(visitor);
+            this.name._walk(visitor);
+        });
+    }
+})
+
+var AST_Import = DEFNODE("Import", "imported_name imported_names module_name", {
+    $documentation: "An `import` statement",
+    $propdoc: {
+        imported_name: "[AST_SymbolImport] The name of the variable holding the module's default export.",
+        imported_names: "[AST_NameMapping*] The names of non-default imported variables",
+        module_name: "[AST_String] String literal describing where this module came from",
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function() {
+            if (this.imported_name) {
+                this.imported_name._walk(visitor);
+            }
+            if (this.imported_names) {
+                this.imported_names.forEach(function(name_import) {
+                    name_import._walk(visitor);
+                });
+            }
+            this.module_name._walk(visitor);
+        });
+    }
+});
+
+var AST_Export = DEFNODE("Export", "exported_definition exported_value is_default exported_names module_name", {
+    $documentation: "An `export` statement",
+    $propdoc: {
+        exported_definition: "[AST_Defun|AST_Definitions|AST_DefClass?] An exported definition",
+        exported_value: "[AST_Node?] An exported value",
+        exported_names: "[AST_NameMapping*?] List of exported names",
+        module_name: "[AST_String?] Name of the file to load exports from",
+        is_default: "[Boolean] Whether this is the default exported value of this module"
+    },
+    _walk: function (visitor) {
+        visitor._visit(this, function () {
+            if (this.exported_definition) {
+                this.exported_definition._walk(visitor);
+            }
+            if (this.exported_value) {
+                this.exported_value._walk(visitor);
+            }
+            if (this.exported_names) {
+                this.exported_names.forEach(function(name_export) {
+                    name_export._walk(visitor);
+                });
+            }
+            if (this.module_name) {
+                this.module_name._walk(visitor);
+            }
+        });
+    }
+}, AST_Statement);
+
 var AST_VarDef = DEFNODE("VarDef", "name value", {
     $documentation: "A variable declaration; only appears in a AST_Definitions node",
     $propdoc: {
-        name: "[AST_SymbolVar] name of the variable",
+        name: "[AST_Destructuring|AST_SymbolConst|AST_SymbolLet|AST_SymbolVar] name of the variable",
         value: "[AST_Node?] initializer, or null of there's no initializer"
     },
     _walk: function(visitor) {
@@ -650,6 +830,10 @@ var AST_Assign = DEFNODE("Assign", null, {
     $documentation: "An assignment expression — `a = b + 5`",
 }, AST_Binary);
 
+var AST_DefaultAssign = DEFNODE("DefaultAssign", null, {
+    $documentation: "A default assignment expression like in `(a = 3) => a`"
+}, AST_Binary);
+
 /* -----[ LITERALS ]----- */
 
 var AST_Array = DEFNODE("Array", "elements", {
@@ -685,11 +869,13 @@ var AST_Object = DEFNODE("Object", "properties", {
 var AST_ObjectProperty = DEFNODE("ObjectProperty", "key value", {
     $documentation: "Base class for literal object properties",
     $propdoc: {
-        key: "[string] the property name converted to a string for ObjectKeyVal.  For setters and getters this is an AST_SymbolAccessor.",
-        value: "[AST_Node] property value.  For setters and getters this is an AST_Accessor."
+        key: "[string|AST_Node] property name. For ObjectKeyVal this is a string. For getters, setters and computed property this is an AST_Node.",
+        value: "[AST_Node] property value.  For getters and setters this is an AST_Accessor."
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
+            if (this.key instanceof AST_Node)
+                this.key._walk(visitor);
             this.value._walk(visitor);
         });
     }
@@ -702,35 +888,95 @@ var AST_ObjectKeyVal = DEFNODE("ObjectKeyVal", "quote", {
     }
 }, AST_ObjectProperty);
 
-var AST_ObjectSetter = DEFNODE("ObjectSetter", null, {
+var AST_ObjectSetter = DEFNODE("ObjectSetter", "quote static", {
+    $propdoc: {
+        quote: "[string|undefined] the original quote character, if any",
+        static: "[boolean] whether this is a static setter (classes only)"
+    },
     $documentation: "An object setter property",
 }, AST_ObjectProperty);
 
-var AST_ObjectGetter = DEFNODE("ObjectGetter", null, {
+var AST_ObjectGetter = DEFNODE("ObjectGetter", "quote static", {
+    $propdoc: {
+        quote: "[string|undefined] the original quote character, if any",
+        static: "[boolean] whether this is a static getter (classes only)"
+    },
     $documentation: "An object getter property",
 }, AST_ObjectProperty);
 
+var AST_ConciseMethod = DEFNODE("ConciseMethod", "quote static is_generator async", {
+    $propdoc: {
+        quote: "[string|undefined] the original quote character, if any",
+        static: "[boolean] is this method static (classes only)",
+        is_generator: "[boolean] is this a generator method",
+        async: "[boolean] is this method async",
+    },
+    $documentation: "An ES6 concise method inside an object or class"
+}, AST_ObjectProperty);
+
+var AST_Class = DEFNODE("Class", "name extends properties inlined", {
+    $propdoc: {
+        name: "[AST_SymbolClass|AST_SymbolDefClass?] optional class name.",
+        extends: "[AST_Node]? optional parent class",
+        properties: "[AST_ObjectProperty*] array of properties"
+    },
+    $documentation: "An ES6 class",
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            if (this.name) {
+                this.name._walk(visitor);
+            }
+            if (this.extends) {
+                this.extends._walk(visitor);
+            }
+            this.properties.forEach(function(prop){
+                prop._walk(visitor);
+            });
+        });
+    },
+}, AST_Scope);
+
+var AST_DefClass = DEFNODE("DefClass", null, {
+    $documentation: "A class definition",
+}, AST_Class);
+
+var AST_ClassExpression = DEFNODE("ClassExpression", null, {
+    $documentation: "A class expression."
+}, AST_Class);
+
 var AST_Symbol = DEFNODE("Symbol", "scope name thedef", {
     $propdoc: {
         name: "[string] name of this symbol",
         scope: "[AST_Scope/S] the current scope (not necessarily the definition scope)",
         thedef: "[SymbolDef/S] the definition of this symbol"
     },
-    $documentation: "Base class for all symbols",
+    $documentation: "Base class for all symbols"
 });
 
-var AST_SymbolAccessor = DEFNODE("SymbolAccessor", null, {
-    $documentation: "The name of a property accessor (setter/getter function)"
-}, AST_Symbol);
+var AST_NewTarget = DEFNODE("NewTarget", null, {
+    $documentation: "A reference to new.target"
+});
 
 var AST_SymbolDeclaration = DEFNODE("SymbolDeclaration", "init", {
-    $documentation: "A declaration symbol (symbol in var, function name or argument, symbol in catch)",
+    $documentation: "A declaration symbol (symbol in var/const, function name or argument, symbol in catch)",
 }, AST_Symbol);
 
 var AST_SymbolVar = DEFNODE("SymbolVar", null, {
     $documentation: "Symbol defining a variable",
 }, AST_SymbolDeclaration);
 
+var AST_SymbolBlockDeclaration = DEFNODE("SymbolBlockDeclaration", null, {
+    $documentation: "Base class for block-scoped declaration symbols"
+}, AST_SymbolDeclaration);
+
+var AST_SymbolConst = DEFNODE("SymbolConst", null, {
+    $documentation: "A constant declaration"
+}, AST_SymbolBlockDeclaration);
+
+var AST_SymbolLet = DEFNODE("SymbolLet", null, {
+    $documentation: "A block-scoped `let` declaration"
+}, AST_SymbolBlockDeclaration);
+
 var AST_SymbolFunarg = DEFNODE("SymbolFunarg", null, {
     $documentation: "Symbol naming a function argument",
 }, AST_SymbolVar);
@@ -739,13 +985,33 @@ var AST_SymbolDefun = DEFNODE("SymbolDefun", null, {
     $documentation: "Symbol defining a function",
 }, AST_SymbolDeclaration);
 
+var AST_SymbolMethod = DEFNODE("SymbolMethod", null, {
+    $documentation: "Symbol in an object defining a method",
+}, AST_Symbol);
+
 var AST_SymbolLambda = DEFNODE("SymbolLambda", null, {
     $documentation: "Symbol naming a function expression",
 }, AST_SymbolDeclaration);
 
+var AST_SymbolDefClass = DEFNODE("SymbolDefClass", null, {
+    $documentation: "Symbol naming a class's name in a class declaration. Lexically scoped to its containing scope, and accessible within the class."
+}, AST_SymbolBlockDeclaration);
+
+var AST_SymbolClass = DEFNODE("SymbolClass", null, {
+    $documentation: "Symbol naming a class's name. Lexically scoped to the class."
+}, AST_SymbolDeclaration);
+
 var AST_SymbolCatch = DEFNODE("SymbolCatch", null, {
     $documentation: "Symbol naming the exception in catch",
-}, AST_SymbolDeclaration);
+}, AST_SymbolBlockDeclaration);
+
+var AST_SymbolImport = DEFNODE("SymbolImport", null, {
+    $documentation: "Symbol referring to an imported name",
+}, AST_SymbolBlockDeclaration);
+
+var AST_SymbolImportForeign = DEFNODE("SymbolImportForeign", null, {
+    $documentation: "A symbol imported from a module, but it is defined in the other module, and its real name is irrelevant for this module's purposes",
+}, AST_Symbol);
 
 var AST_Label = DEFNODE("Label", "references", {
     $documentation: "Symbol naming a label (declaration)",
@@ -762,6 +1028,14 @@ var AST_SymbolRef = DEFNODE("SymbolRef", null, {
     $documentation: "Reference to some symbol (not definition/declaration)",
 }, AST_Symbol);
 
+var AST_SymbolExport = DEFNODE("SymbolExport", null, {
+    $documentation: "Symbol referring to a name to export",
+}, AST_SymbolRef);
+
+var AST_SymbolExportForeign = DEFNODE("SymbolExportForeign", null, {
+    $documentation: "A symbol exported from this module, but it is used in the other module, and its real name is irrelevant for this module's purposes",
+}, AST_Symbol);
+
 var AST_LabelRef = DEFNODE("LabelRef", null, {
     $documentation: "Reference to a label symbol",
 }, AST_Symbol);
@@ -770,6 +1044,10 @@ var AST_This = DEFNODE("This", null, {
     $documentation: "The `this` symbol",
 }, AST_Symbol);
 
+var AST_Super = DEFNODE("Super", null, {
+    $documentation: "The `super` symbol",
+}, AST_This);
+
 var AST_Constant = DEFNODE("Constant", null, {
     $documentation: "Base class for all constants",
     getValue: function() {
@@ -843,6 +1121,31 @@ var AST_True = DEFNODE("True", null, {
     value: true
 }, AST_Boolean);
 
+var AST_Await = DEFNODE("Await", "expression", {
+    $documentation: "An `await` statement",
+    $propdoc: {
+        expression: "[AST_Node] the mandatory expression being awaited",
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            this.expression._walk(visitor);
+        });
+    }
+});
+
+var AST_Yield = DEFNODE("Yield", "expression is_star", {
+    $documentation: "A `yield` statement",
+    $propdoc: {
+        expression: "[AST_Node?] the value returned or thrown by this statement; could be null (representing undefined) but only when is_star is set to false",
+        is_star: "[Boolean] Whether this is a yield or yield* statement"
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, this.expression && function(){
+            this.expression._walk(visitor);
+        });
+    }
+});
+
 /* -----[ TreeWalker ]----- */
 
 function TreeWalker(callback) {
@@ -859,7 +1162,7 @@ TreeWalker.prototype = {
         if (!ret && descend) {
             descend.call(node);
         }
-        this.pop(node);
+        this.pop();
         return ret;
     },
     parent: function(n) {
@@ -870,12 +1173,17 @@ TreeWalker.prototype = {
             this.directives = Object.create(this.directives);
         } else if (node instanceof AST_Directive && !this.directives[node.value]) {
             this.directives[node.value] = node;
+        } else if (node instanceof AST_Class) {
+            this.directives = Object.create(this.directives);
+            if (!this.directives["use strict"]) {
+                this.directives["use strict"] = node;
+            }
         }
         this.stack.push(node);
     },
-    pop: function(node) {
-        this.stack.pop();
-        if (node instanceof AST_Lambda) {
+    pop: function() {
+        var node = this.stack.pop();
+        if (node instanceof AST_Lambda || node instanceof AST_Class) {
             this.directives = Object.getPrototypeOf(this.directives);
         }
     },
@@ -893,7 +1201,7 @@ TreeWalker.prototype = {
         var dir = this.directives[type];
         if (dir) return dir;
         var node = this.stack[this.stack.length - 1];
-        if (node instanceof AST_Scope) {
+        if (node instanceof AST_Scope && node.body) {
             for (var i = 0; i < node.body.length; ++i) {
                 var st = node.body[i];
                 if (!(st instanceof AST_Directive)) break;
@@ -901,24 +1209,6 @@ TreeWalker.prototype = {
             }
         }
     },
-    in_boolean_context: function() {
-        var stack = this.stack;
-        var i = stack.length, self = stack[--i];
-        while (i > 0) {
-            var p = stack[--i];
-            if ((p instanceof AST_If           && p.condition === self) ||
-                (p instanceof AST_Conditional  && p.condition === self) ||
-                (p instanceof AST_DWLoop       && p.condition === self) ||
-                (p instanceof AST_For          && p.condition === self) ||
-                (p instanceof AST_UnaryPrefix  && p.operator == "!" && p.expression === self))
-            {
-                return true;
-            }
-            if (!(p instanceof AST_Binary && (p.operator == "&&" || p.operator == "||")))
-                return false;
-            self = p;
-        }
-    },
     loopcontrol_target: function(node) {
         var stack = this.stack;
         if (node.label) for (var i = stack.length; --i >= 0;) {

lib/minify.js

@@ -27,38 +27,86 @@ function set_shorthand(name, options, keys) {
     }
 }
 
+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) {
     var warn_function = AST_Node.warn_function;
     try {
-        if (typeof files == "string") {
-            files = [ files ];
-        }
         options = defaults(options, {
             compress: {},
+            ecma: undefined,
             ie8: false,
+            keep_classnames: undefined,
             keep_fnames: false,
             mangle: {},
+            nameCache: null,
             output: {},
             parse: {},
+            rename: undefined,
+            safari10: false,
             sourceMap: false,
+            timings: false,
             toplevel: false,
             warnings: false,
             wrap: false,
         }, true);
+        var timings = options.timings && {
+            start: Date.now()
+        };
+        if (options.keep_classnames === undefined) {
+            options.keep_classnames = options.keep_fnames;
+        }
+        if (options.rename === undefined) {
+            options.rename = options.compress && options.mangle;
+        }
+        set_shorthand("ecma", options, [ "parse", "compress", "output" ]);
         set_shorthand("ie8", options, [ "compress", "mangle", "output" ]);
+        set_shorthand("keep_classnames", options, [ "compress", "mangle" ]);
         set_shorthand("keep_fnames", options, [ "compress", "mangle" ]);
+        set_shorthand("safari10", options, [ "mangle", "output" ]);
         set_shorthand("toplevel", options, [ "compress", "mangle" ]);
         set_shorthand("warnings", options, [ "compress" ]);
+        var quoted_props;
         if (options.mangle) {
             options.mangle = defaults(options.mangle, {
-                cache: null,
+                cache: options.nameCache && (options.nameCache.vars || {}),
                 eval: false,
                 ie8: false,
+                keep_classnames: false,
                 keep_fnames: false,
                 properties: false,
                 reserved: [],
+                safari10: false,
                 toplevel: 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.sourceMap) {
             options.sourceMap = defaults(options.sourceMap, {
@@ -75,13 +123,17 @@ function minify(files, options) {
                 warnings.push(warning);
             };
         }
+        if (timings) timings.parse = Date.now();
         var toplevel;
         if (files instanceof AST_Toplevel) {
             toplevel = files;
         } else {
+            if (typeof files == "string") {
+                files = [ files ];
+            }
             options.parse = options.parse || {};
             options.parse.toplevel = null;
-            for (var name in files) {
+            for (var name in files) if (HOP(files, name)) {
                 options.parse.filename = name;
                 options.parse.toplevel = parse(files[name], options.parse);
                 if (options.sourceMap && options.sourceMap.content == "inline") {
@@ -92,22 +144,34 @@ function minify(files, options) {
             }
             toplevel = options.parse.toplevel;
         }
+        if (quoted_props) {
+            reserve_quoted_keys(toplevel, quoted_props);
+        }
         if (options.wrap) {
             toplevel = toplevel.wrap_commonjs(options.wrap);
         }
-        if (options.compress) {
+        if (timings) timings.rename = Date.now();
+        // disable rename on harmony due to expand_names bug in for-of loops
+        // https://github.com/mishoo/UglifyJS2/issues/2794
+        if (0 && options.rename) {
             toplevel.figure_out_scope(options.mangle);
-            toplevel = new Compressor(options.compress).compress(toplevel);
+            toplevel.expand_names(options.mangle);
         }
+        if (timings) timings.compress = Date.now();
+        if (options.compress) toplevel = new Compressor(options.compress).compress(toplevel);
+        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.figure_out_scope(options.mangle);
             base54.reset();
             toplevel.compute_char_frequency(options.mangle);
             toplevel.mangle_names(options.mangle);
-            if (options.mangle.properties) {
-                toplevel = mangle_properties(toplevel, options.mangle.properties);
-            }
         }
+        if (timings) timings.properties = Date.now();
+        if (options.mangle && options.mangle.properties) {
+            toplevel = mangle_properties(toplevel, options.mangle.properties);
+        }
+        if (timings) timings.output = Date.now();
         var result = {};
         if (options.output.ast) {
             result.ast = toplevel;
@@ -123,7 +187,9 @@ function minify(files, options) {
                     root: options.sourceMap.root
                 });
                 if (options.sourceMap.includeSources) {
-                    for (var name in files) {
+                    if (files instanceof AST_Toplevel) {
+                        throw new Error("original source content unavailable");
+                    } else for (var name in files) if (HOP(files, name)) {
                         options.output.source_map.get().setSourceContent(name, files[name]);
                     }
                 }
@@ -142,6 +208,25 @@ function minify(files, options) {
                 }
             }
         }
+        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;
         }

lib/mozilla-ast.js

@@ -118,7 +118,7 @@
                 value    : from_moz(M.value)
             };
             if (M.kind == "init") return new AST_ObjectKeyVal(args);
-            args.key = new AST_SymbolAccessor({
+            args.key = new AST_SymbolMethod({
                 name: args.key
             });
             args.value = new AST_Accessor(args.value);
@@ -168,7 +168,7 @@
             });
         },
         VariableDeclaration: function(M) {
-            return new AST_Var({
+            return new (M.kind === "const" ? AST_Const : AST_Var)({
                 start       : my_start_token(M),
                 end         : my_end_token(M),
                 definitions : M.declarations.map(from_moz)
@@ -204,7 +204,7 @@
         Identifier: function(M) {
             var p = FROM_MOZ_STACK[FROM_MOZ_STACK.length - 2];
             return new (  p.type == "LabeledStatement" ? AST_Label
-                        : p.type == "VariableDeclarator" && p.id === M ? AST_SymbolVar
+                        : p.type == "VariableDeclarator" && p.id === M ? (p.kind == "const" ? AST_SymbolConst : AST_SymbolVar)
                         : p.type == "FunctionExpression" ? (p.id === M ? AST_SymbolLambda : AST_SymbolFunarg)
                         : p.type == "FunctionDeclaration" ? (p.id === M ? AST_SymbolDefun : AST_SymbolFunarg)
                         : p.type == "CatchClause" ? AST_SymbolCatch
@@ -324,7 +324,7 @@
     def_to_moz(AST_Definitions, function To_Moz_VariableDeclaration(M) {
         return {
             type: "VariableDeclaration",
-            kind: "var",
+            kind: M instanceof AST_Const ? "const" : "var",
             declarations: M.definitions.map(to_moz)
         };
     });
@@ -381,7 +381,7 @@
     def_to_moz(AST_ObjectProperty, function To_Moz_Property(M) {
         var key = {
             type: "Literal",
-            value: M.key instanceof AST_SymbolAccessor ? M.key.name : M.key
+            value: M.key instanceof AST_SymbolMethod ? M.key.name : M.key
         };
         var kind;
         if (M instanceof AST_ObjectKeyVal) {

lib/propmangle.js

@@ -44,6 +44,16 @@
 "use strict";
 
 function find_builtins(reserved) {
+
+    // Compatibility fix for some standard defined globals not defined on every js environment
+    var new_globals = ["Symbol", "Map", "Promise", "Proxy", "Reflect", "Set", "WeakMap", "WeakSet"];
+    var objects = {};
+    var global_ref = typeof global === "object" ? global : self;
+
+    new_globals.forEach(function (new_global) {
+        objects[new_global] = global_ref[new_global] || new Function();
+    });
+
     // NaN will be included due to Number.NaN
     [
         "null",
@@ -55,7 +65,15 @@ function find_builtins(reserved) {
     ].forEach(add);
     [ Object, Array, Function, Number,
       String, Boolean, Error, Math,
-      Date, RegExp
+      Date, RegExp, objects.Symbol, ArrayBuffer,
+      DataView, decodeURI, decodeURIComponent,
+      encodeURI, encodeURIComponent, eval, EvalError,
+      Float32Array, Float64Array, Int8Array, Int16Array,
+      Int32Array, isFinite, isNaN, JSON, objects.Map, parseFloat,
+      parseInt, objects.Promise, objects.Proxy, RangeError, ReferenceError,
+      objects.Reflect, objects.Set, SyntaxError, TypeError, Uint8Array,
+      Uint8ClampedArray, Uint16Array, Uint32Array, URIError,
+      objects.WeakMap, objects.WeakSet
     ].forEach(function(ctor){
         Object.getOwnPropertyNames(ctor).map(add);
         if (ctor.prototype) {
@@ -67,6 +85,36 @@ function find_builtins(reserved) {
     }
 }
 
+function reserve_quoted_keys(ast, reserved) {
+    function add(name) {
+        push_uniq(reserved, name);
+    }
+
+    ast.walk(new TreeWalker(function(node) {
+        if (node instanceof AST_ObjectKeyVal && node.quote) {
+            add(node.key);
+        } else if (node instanceof AST_ObjectProperty && node.quote) {
+            add(node.key.name);
+        } else if (node instanceof AST_Sub) {
+            addStrings(node.property, add);
+        }
+    }));
+}
+
+function addStrings(node, add) {
+    node.walk(new TreeWalker(function(node) {
+        if (node instanceof AST_Sequence) {
+            addStrings(node.tail_node(), add);
+        } else if (node instanceof AST_String) {
+            add(node.value);
+        } else if (node instanceof AST_Conditional) {
+            addStrings(node.consequent, add);
+            addStrings(node.alternative, add);
+        }
+        return true;
+    }));
+}
+
 function mangle_properties(ast, options) {
     options = defaults(options, {
         builtins: false,
@@ -76,21 +124,24 @@ function mangle_properties(ast, options) {
         only_cache: false,
         regex: null,
         reserved: null,
-    });
+    }, true);
 
-    var reserved = options.reserved || [];
+    var reserved = options.reserved;
+    if (!Array.isArray(reserved)) reserved = [];
     if (!options.builtins) find_builtins(reserved);
 
-    var cache = options.cache;
-    if (cache == null) {
-        cache = {
-            cname: -1,
-            props: new Dictionary()
-        };
+    var cname = -1;
+    var cache;
+    if (options.cache) {
+        cache = options.cache.props;
+        cache.each(function(mangled_name) {
+            push_uniq(reserved, mangled_name);
+        });
+    } else {
+        cache = new Dictionary();
     }
 
     var regex = options.regex;
-    var keep_quoted = options.keep_quoted;
 
     // 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'
@@ -103,12 +154,11 @@ function mangle_properties(ast, options) {
 
     var names_to_mangle = [];
     var unmangleable = [];
-    var to_keep = {};
 
     // step 1: find candidates to mangle
     ast.walk(new TreeWalker(function(node){
         if (node instanceof AST_ObjectKeyVal) {
-            add(node.key, keep_quoted && node.quote);
+            add(node.key);
         }
         else if (node instanceof AST_ObjectProperty) {
             // setter or getter, since KeyVal is handled above
@@ -118,15 +168,14 @@ function mangle_properties(ast, options) {
             add(node.property);
         }
         else if (node instanceof AST_Sub) {
-            addStrings(node.property, keep_quoted);
+            addStrings(node.property, add);
         }
     }));
 
     // step 2: transform the tree, renaming properties
     return ast.transform(new TreeTransformer(function(node){
         if (node instanceof AST_ObjectKeyVal) {
-            if (!(keep_quoted && node.quote))
-                node.key = mangle(node.key);
+            node.key = mangle(node.key);
         }
         else if (node instanceof AST_ObjectProperty) {
             // setter or getter
@@ -135,22 +184,9 @@ function mangle_properties(ast, options) {
         else if (node instanceof AST_Dot) {
             node.property = mangle(node.property);
         }
-        else if (node instanceof AST_Sub) {
-            if (!keep_quoted)
-                node.property = mangleStrings(node.property);
+        else if (!options.keep_quoted && node instanceof AST_Sub) {
+            node.property = mangleStrings(node.property);
         }
-        // else if (node instanceof AST_String) {
-        //     if (should_mangle(node.value)) {
-        //         AST_Node.warn(
-        //             "Found \"{prop}\" property candidate for mangling in an arbitrary string [{file}:{line},{col}]", {
-        //                 file : node.start.file,
-        //                 line : node.start.line,
-        //                 col  : node.start.col,
-        //                 prop : node.value
-        //             }
-        //         );
-        //     }
-        // }
     }));
 
     // only function declarations after this line
@@ -159,26 +195,20 @@ function mangle_properties(ast, options) {
         if (unmangleable.indexOf(name) >= 0) return false;
         if (reserved.indexOf(name) >= 0) return false;
         if (options.only_cache) {
-            return cache.props.has(name);
+            return cache.has(name);
         }
         if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
         return true;
     }
 
     function should_mangle(name) {
-        if (keep_quoted && name in to_keep) return false;
         if (regex && !regex.test(name)) return false;
         if (reserved.indexOf(name) >= 0) return false;
-        return cache.props.has(name)
+        return cache.has(name)
             || names_to_mangle.indexOf(name) >= 0;
     }
 
-    function add(name, keep) {
-        if (keep) {
-            to_keep[name] = true;
-            return;
-        }
-
+    function add(name) {
         if (can_mangle(name))
             push_uniq(names_to_mangle, name);
 
@@ -192,58 +222,29 @@ function mangle_properties(ast, options) {
             return name;
         }
 
-        var mangled = cache.props.get(name);
+        var mangled = cache.get(name);
         if (!mangled) {
             if (debug) {
                 // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo -> o._$foo$NNN_.
                 var debug_mangled = "_$" + name + "$" + debug_name_suffix + "_";
 
-                if (can_mangle(debug_mangled) && !(keep_quoted && debug_mangled in to_keep)) {
+                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) {
-                // Note: `can_mangle()` does not check if the name collides with the `to_keep` set
-                // (filled with quoted properties when `keep_quoted` is set). Make sure we add this
-                // check so we don't collide with a quoted name.
                 do {
-                    mangled = base54(++cache.cname);
-                } while (!can_mangle(mangled) || keep_quoted && mangled in to_keep);
+                    mangled = base54(++cname);
+                } while (!can_mangle(mangled));
             }
 
-            cache.props.set(name, mangled);
+            cache.set(name, mangled);
         }
         return mangled;
     }
 
-    function addStrings(node, keep) {
-        var out = {};
-        try {
-            (function walk(node){
-                node.walk(new TreeWalker(function(node){
-                    if (node instanceof AST_Sequence) {
-                        walk(node.expressions[node.expressions.length - 1]);
-                        return true;
-                    }
-                    if (node instanceof AST_String) {
-                        add(node.value, keep);
-                        return true;
-                    }
-                    if (node instanceof AST_Conditional) {
-                        walk(node.consequent);
-                        walk(node.alternative);
-                        return true;
-                    }
-                    throw out;
-                }));
-            })(node);
-        } catch(ex) {
-            if (ex !== out) throw ex;
-        }
-    }
-
     function mangleStrings(node) {
         return node.transform(new TreeTransformer(function(node){
             if (node instanceof AST_Sequence) {

lib/scope.js

@@ -43,15 +43,18 @@
 
 "use strict";
 
-function SymbolDef(scope, index, orig) {
+function SymbolDef(scope, orig, init) {
     this.name = orig.name;
     this.orig = [ orig ];
+    this.init = init;
+    this.eliminated = 0;
     this.scope = scope;
     this.references = [];
+    this.replaced = 0;
     this.global = false;
+    this.export = false;
     this.mangled_name = null;
     this.undeclared = false;
-    this.index = index;
     this.id = SymbolDef.next_id++;
 };
 
@@ -62,11 +65,16 @@ SymbolDef.prototype = {
         if (!options) options = {};
 
         return (this.global && !options.toplevel)
+            || this.export
             || this.undeclared
             || (!options.eval && (this.scope.uses_eval || this.scope.uses_with))
             || (options.keep_fnames
                 && (this.orig[0] instanceof AST_SymbolLambda
-                    || this.orig[0] instanceof AST_SymbolDefun));
+                    || this.orig[0] instanceof AST_SymbolDefun))
+            || this.orig[0] instanceof AST_SymbolMethod
+            || (options.keep_classnames
+                && (this.orig[0] instanceof AST_SymbolClass
+                    || this.orig[0] instanceof AST_SymbolDefClass));
     },
     mangle: function(options) {
         var cache = options.cache && options.cache.props;
@@ -79,7 +87,7 @@ SymbolDef.prototype = {
             if (options.ie8 && sym instanceof AST_SymbolLambda)
                 s = s.parent_scope;
             var def;
-            if (this.defun && (def = this.defun.variables.get(this.name))) {
+            if (def = this.redefined()) {
                 this.mangled_name = def.mangled_name || def.name;
             } else
                 this.mangled_name = s.next_mangled(options, this);
@@ -87,6 +95,9 @@ SymbolDef.prototype = {
                 cache.set(this.name, this.mangled_name);
             }
         }
+    },
+    redefined: function() {
+        return this.defun && this.defun.variables.get(this.name);
     }
 };
 
@@ -94,6 +105,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
     options = defaults(options, {
         cache: null,
         ie8: false,
+        safari10: false,
     });
 
     // pass 1: setup scope chaining and handle definitions
@@ -101,15 +113,33 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
     var scope = self.parent_scope = null;
     var labels = new Dictionary();
     var defun = null;
+    var in_destructuring = null;
+    var for_scopes = [];
     var tw = new TreeWalker(function(node, descend){
-        if (node instanceof AST_Catch) {
+        if (node.is_block_scope()) {
             var save_scope = scope;
-            scope = new AST_Scope(node);
+            node.block_scope = scope = new AST_Scope(node);
             scope.init_scope_vars(save_scope);
+            if (!(node instanceof AST_Scope)) {
+                scope.uses_with = save_scope.uses_with;
+                scope.uses_eval = save_scope.uses_eval;
+                scope.directives = save_scope.directives;
+            }
+            if (options.safari10) {
+                if (node instanceof AST_For || node instanceof AST_ForIn) {
+                    for_scopes.push(scope);
+                }
+            }
             descend();
             scope = save_scope;
             return true;
         }
+        if (node instanceof AST_Destructuring) {
+            in_destructuring = node;  // These don't nest
+            descend();
+            in_destructuring = null;
+            return true;
+        }
         if (node instanceof AST_Scope) {
             node.init_scope_vars(scope);
             var save_scope = scope;
@@ -146,7 +176,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             node.references = [];
         }
         if (node instanceof AST_SymbolLambda) {
-            defun.def_function(node);
+            defun.def_function(node, node.name == "arguments" ? undefined : defun);
         }
         else if (node instanceof AST_SymbolDefun) {
             // Careful here, the scope where this should be defined is
@@ -154,10 +184,45 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             // scope when we encounter the AST_Defun node (which is
             // instanceof AST_Scope) but we get to the symbol a bit
             // later.
-            (node.scope = defun.parent_scope).def_function(node);
+            mark_export((node.scope = defun.parent_scope.get_defun_scope()).def_function(node, defun), 1);
         }
-        else if (node instanceof AST_SymbolVar) {
-            defun.def_variable(node);
+        else if (node instanceof AST_SymbolClass) {
+            mark_export(defun.def_variable(node, defun), 1);
+        }
+        else if (node instanceof AST_SymbolImport) {
+            scope.def_variable(node);
+        }
+        else if (node instanceof AST_SymbolDefClass) {
+            // This deals with the name of the class being available
+            // inside the class.
+            mark_export((node.scope = defun.parent_scope).def_function(node, defun), 1);
+        }
+        else if (node instanceof AST_SymbolVar
+            || node instanceof AST_SymbolLet
+            || node instanceof AST_SymbolConst) {
+            var def;
+            if (node instanceof AST_SymbolBlockDeclaration) {
+                def = scope.def_variable(node, null);
+            } else {
+                def = defun.def_variable(node, node.TYPE == "SymbolVar" ? null : undefined);
+            }
+            if (!all(def.orig, function(sym) {
+                if (sym === node) return true;
+                if (node instanceof AST_SymbolBlockDeclaration) {
+                    return sym instanceof AST_SymbolLambda;
+                }
+                return !(sym instanceof AST_SymbolLet || sym instanceof AST_SymbolConst);
+            })) {
+                js_error(
+                    node.name + " redeclared",
+                    node.start.file,
+                    node.start.line,
+                    node.start.col,
+                    node.start.pos
+                );
+            }
+            if (!(node instanceof AST_SymbolFunarg)) mark_export(def, 2);
+            def.destructuring = in_destructuring;
             if (defun !== scope) {
                 node.mark_enclosed(options);
                 var def = scope.find_variable(node);
@@ -179,20 +244,32 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             }));
             node.thedef = sym;
         }
+        if (!(scope instanceof AST_Toplevel) && (node instanceof AST_Export || node instanceof AST_Import)) {
+            js_error(
+                node.TYPE + " statement may only appear at top level",
+                node.start.file,
+                node.start.line,
+                node.start.col,
+                node.start.pos
+            );
+        }
+
+        function mark_export(def, level) {
+            if (in_destructuring) {
+                var i = 0;
+                do {
+                    level++;
+                } while (tw.parent(i++) !== in_destructuring);
+            }
+            var node = tw.parent(level);
+            def.export = node instanceof AST_Export;
+        }
     });
     self.walk(tw);
 
     // pass 2: find back references and eval
-    var func = null;
-    var globals = self.globals = new Dictionary();
+    self.globals = new Dictionary();
     var tw = new TreeWalker(function(node, descend){
-        if (node instanceof AST_Lambda) {
-            var prev_func = func;
-            func = node;
-            descend();
-            func = prev_func;
-            return true;
-        }
         if (node instanceof AST_LoopControl && node.label) {
             node.label.thedef.references.push(node);
             return true;
@@ -204,17 +281,31 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
                     s.uses_eval = true;
                 }
             }
-            var sym = node.scope.find_variable(name);
-            if (node.scope instanceof AST_Lambda && name == "arguments") {
-                node.scope.uses_arguments = true;
-            }
-            if (!sym) {
+            var sym;
+            if (tw.parent() instanceof AST_NameMapping && tw.parent(1).module_name
+                || !(sym = node.scope.find_variable(name))) {
                 sym = self.def_global(node);
+            } else if (sym.scope instanceof AST_Lambda && name == "arguments") {
+                sym.scope.uses_arguments = true;
             }
             node.thedef = sym;
             node.reference(options);
+            if (node.scope.is_block_scope()
+                && !(sym.orig[0] instanceof AST_SymbolBlockDeclaration)) {
+                node.scope = node.scope.get_defun_scope();
+            }
             return true;
         }
+        // ensure mangling works if catch reuses a scope variable
+        var def;
+        if (node instanceof AST_SymbolCatch && (def = node.definition().redefined())) {
+            var s = node.scope;
+            while (s) {
+                push_uniq(s.enclosed, def);
+                if (s === def.scope) break;
+                s = s.parent_scope;
+            }
+        }
     });
     self.walk(tw);
 
@@ -231,13 +322,23 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
                     ref.reference(options);
                 });
                 node.thedef = def;
+                node.reference(options);
                 return true;
             }
         }));
     }
 
-    if (options.cache) {
-        this.cname = options.cache.cname;
+    // pass 4: add symbol definitions to loop scopes
+    // Safari/Webkit bug workaround - loop init let variable shadowing argument.
+    // https://github.com/mishoo/UglifyJS2/issues/1753
+    // https://bugs.webkit.org/show_bug.cgi?id=171041
+    if (options.safari10) {
+        for (var i = 0; i < for_scopes.length; i++) {
+            var scope = for_scopes[i];
+            scope.parent_scope.variables.each(function(def) {
+                push_uniq(scope.enclosed, def);
+            });
+        }
     }
 });
 
@@ -246,7 +347,7 @@ AST_Toplevel.DEFMETHOD("def_global", function(node){
     if (globals.has(name)) {
         return globals.get(name);
     } else {
-        var g = new SymbolDef(this, globals.size(), node);
+        var g = new SymbolDef(this, node);
         g.undeclared = true;
         g.global = true;
         globals.set(name, g);
@@ -264,6 +365,14 @@ AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope){
     this.cname = -1;                    // the current index for mangling functions/variables
 });
 
+AST_Node.DEFMETHOD("is_block_scope", return_false);
+AST_Class.DEFMETHOD("is_block_scope", return_false);
+AST_Lambda.DEFMETHOD("is_block_scope", return_false);
+AST_Toplevel.DEFMETHOD("is_block_scope", return_false);
+AST_SwitchBranch.DEFMETHOD("is_block_scope", return_false);
+AST_Block.DEFMETHOD("is_block_scope", return_true);
+AST_IterationStatement.DEFMETHOD("is_block_scope", return_true);
+
 AST_Lambda.DEFMETHOD("init_scope_vars", function(){
     AST_Scope.prototype.init_scope_vars.apply(this, arguments);
     this.uses_arguments = false;
@@ -274,6 +383,11 @@ AST_Lambda.DEFMETHOD("init_scope_vars", function(){
     }));
 });
 
+AST_Arrow.DEFMETHOD("init_scope_vars", function(){
+    AST_Scope.prototype.init_scope_vars.apply(this, arguments);
+    this.uses_arguments = false;
+});
+
 AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
     var def = this.definition();
     var s = this.scope;
@@ -300,32 +414,37 @@ AST_Scope.DEFMETHOD("find_variable", function(name){
         || (this.parent_scope && this.parent_scope.find_variable(name));
 });
 
-AST_Scope.DEFMETHOD("def_function", function(symbol){
-    this.functions.set(symbol.name, this.def_variable(symbol));
+AST_Scope.DEFMETHOD("def_function", function(symbol, init){
+    var def = this.def_variable(symbol, init);
+    if (!def.init || def.init instanceof AST_Defun) def.init = init;
+    this.functions.set(symbol.name, def);
+    return def;
 });
 
-AST_Scope.DEFMETHOD("def_variable", function(symbol){
-    var def;
-    if (!this.variables.has(symbol.name)) {
-        def = new SymbolDef(this, this.variables.size(), symbol);
+AST_Scope.DEFMETHOD("def_variable", function(symbol, init){
+    var def = this.variables.get(symbol.name);
+    if (def) {
+        def.orig.push(symbol);
+        if (def.init && (def.scope !== symbol.scope || def.init instanceof AST_Function)) {
+            def.init = init;
+        }
+    } else {
+        def = new SymbolDef(this, symbol, init);
         this.variables.set(symbol.name, def);
         def.global = !this.parent_scope;
-    } else {
-        def = this.variables.get(symbol.name);
-        def.orig.push(symbol);
     }
     return symbol.thedef = def;
 });
 
-AST_Scope.DEFMETHOD("next_mangled", function(options){
-    var ext = this.enclosed;
+function next_mangled(scope, options) {
+    var ext = scope.enclosed;
     out: while (true) {
-        var m = base54(++this.cname);
+        var m = base54(++scope.cname);
         if (!is_identifier(m)) continue; // skip over "do"
 
         // https://github.com/mishoo/UglifyJS2/issues/242 -- do not
         // shadow a name reserved from mangling.
-        if (options.reserved.indexOf(m) >= 0) continue;
+        if (member(m, options.reserved)) continue;
 
         // we must ensure that the mangled name does not shadow a name
         // from some parent scope that is referenced in this or in
@@ -337,6 +456,18 @@ AST_Scope.DEFMETHOD("next_mangled", function(options){
         }
         return m;
     }
+}
+
+AST_Scope.DEFMETHOD("next_mangled", function(options){
+    return next_mangled(this, options);
+});
+
+AST_Toplevel.DEFMETHOD("next_mangled", function(options){
+    var name;
+    do {
+        name = next_mangled(this, options);
+    } while (member(name, this.mangled_names));
+    return name;
 });
 
 AST_Function.DEFMETHOD("next_mangled", function(options, def){
@@ -350,38 +481,25 @@ AST_Function.DEFMETHOD("next_mangled", function(options, def){
     var tricky_name = tricky_def ? tricky_def.mangled_name || tricky_def.name : null;
 
     while (true) {
-        var name = AST_Lambda.prototype.next_mangled.call(this, options, def);
+        var name = next_mangled(this, options);
         if (!tricky_name || tricky_name != name)
             return name;
     }
 });
 
 AST_Symbol.DEFMETHOD("unmangleable", function(options){
-    return this.definition().unmangleable(options);
+    var def = this.definition();
+    return !def || def.unmangleable(options);
 });
 
 // labels are always mangleable
-AST_Label.DEFMETHOD("unmangleable", function(){
-    return false;
-});
+AST_Label.DEFMETHOD("unmangleable", return_false);
 
 AST_Symbol.DEFMETHOD("unreferenced", function(){
     return this.definition().references.length == 0
         && !(this.scope.uses_eval || this.scope.uses_with);
 });
 
-AST_Symbol.DEFMETHOD("undeclared", function(){
-    return this.definition().undeclared;
-});
-
-AST_LabelRef.DEFMETHOD("undeclared", function(){
-    return false;
-});
-
-AST_Label.DEFMETHOD("undeclared", function(){
-    return false;
-});
-
 AST_Symbol.DEFMETHOD("definition", function(){
     return this.thedef;
 });
@@ -390,22 +508,24 @@ AST_Symbol.DEFMETHOD("global", function(){
     return this.definition().global;
 });
 
-AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options){
-    return defaults(options, {
+AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options) {
+    options = defaults(options, {
         eval        : false,
         ie8         : false,
+        keep_classnames: false,
         keep_fnames : false,
         reserved    : [],
         toplevel    : false,
     });
+    if (!Array.isArray(options.reserved)) options.reserved = [];
+    // Never mangle arguments
+    push_uniq(options.reserved, "arguments");
+    return options;
 });
 
 AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     options = this._default_mangler_options(options);
 
-    // Never mangle arguments
-    options.reserved.push('arguments');
-
     // We only need to mangle declaration nodes.  Special logic wired
     // into the code generator will display the mangled name if it's
     // present (and for AST_SymbolRef-s it'll use the mangled name of
@@ -413,12 +533,14 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     var lname = -1;
     var to_mangle = [];
 
+    var mangled_names = this.mangled_names = [];
     if (options.cache) {
-        this.globals.each(function(symbol){
-            if (options.reserved.indexOf(symbol.name) < 0) {
-                to_mangle.push(symbol);
-            }
-        });
+        this.globals.each(collect);
+        if (options.cache.props) {
+            options.cache.props.each(function(mangled_name) {
+                push_uniq(mangled_names, mangled_name);
+            });
+        }
     }
 
     var tw = new TreeWalker(function(node, descend){
@@ -430,13 +552,11 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             return true;        // don't descend again in TreeWalker
         }
         if (node instanceof AST_Scope) {
-            var p = tw.parent(), a = [];
-            node.variables.each(function(symbol){
-                if (options.reserved.indexOf(symbol.name) < 0) {
-                    a.push(symbol);
-                }
-            });
-            to_mangle.push.apply(to_mangle, a);
+            node.variables.each(collect);
+            return;
+        }
+        if (node.is_block_scope()) {
+            node.block_scope.variables.each(collect);
             return;
         }
         if (node instanceof AST_Label) {
@@ -453,110 +573,141 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     this.walk(tw);
     to_mangle.forEach(function(def){ def.mangle(options) });
 
-    if (options.cache) {
-        options.cache.cname = this.cname;
+    function collect(symbol) {
+        if (!member(symbol.name, options.reserved)) {
+            to_mangle.push(symbol);
+        }
     }
 });
 
+AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
+    var cache = options.cache && options.cache.props;
+    var avoid = Object.create(null);
+    options.reserved.forEach(to_avoid);
+    this.globals.each(add_def);
+    this.walk(new TreeWalker(function(node) {
+        if (node instanceof AST_Scope) node.variables.each(add_def);
+        if (node instanceof AST_SymbolCatch) add_def(node.definition());
+    }));
+    return avoid;
+
+    function to_avoid(name) {
+        avoid[name] = true;
+    }
+
+    function add_def(def) {
+        var name = def.name;
+        if (def.global && cache && cache.has(name)) name = cache.get(name);
+        else if (!def.unmangleable(options)) return;
+        to_avoid(name);
+    }
+});
+
+AST_Toplevel.DEFMETHOD("expand_names", function(options) {
+    base54.reset();
+    base54.sort();
+    options = this._default_mangler_options(options);
+    var avoid = this.find_colliding_names(options);
+    var cname = 0;
+    this.globals.each(rename);
+    this.walk(new TreeWalker(function(node) {
+        if (node instanceof AST_Scope) node.variables.each(rename);
+        if (node instanceof AST_SymbolCatch) rename(node.definition());
+    }));
+
+    function next_name() {
+        var name;
+        do {
+            name = base54(cname++);
+        } while (avoid[name] || !is_identifier(name));
+        return name;
+    }
+
+    function rename(def) {
+        if (def.global && options.cache) return;
+        if (def.unmangleable(options)) return;
+        if (member(def.name, options.reserved)) return;
+        var d = def.redefined();
+        def.name = d ? d.name : next_name();
+        def.orig.forEach(function(sym) {
+            sym.name = def.name;
+        });
+        def.references.forEach(function(sym) {
+            sym.name = def.name;
+        });
+    }
+});
+
+AST_Node.DEFMETHOD("tail_node", return_this);
+AST_Sequence.DEFMETHOD("tail_node", function() {
+    return this.expressions[this.expressions.length - 1];
+});
+
 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
     options = this._default_mangler_options(options);
-    var tw = new TreeWalker(function(node){
-        if (node instanceof AST_Constant)
-            base54.consider(node.print_to_string());
-        else if (node instanceof AST_Return)
-            base54.consider("return");
-        else if (node instanceof AST_Throw)
-            base54.consider("throw");
-        else if (node instanceof AST_Continue)
-            base54.consider("continue");
-        else if (node instanceof AST_Break)
-            base54.consider("break");
-        else if (node instanceof AST_Debugger)
-            base54.consider("debugger");
-        else if (node instanceof AST_Directive)
-            base54.consider(node.value);
-        else if (node instanceof AST_While)
-            base54.consider("while");
-        else if (node instanceof AST_Do)
-            base54.consider("do while");
-        else if (node instanceof AST_If) {
-            base54.consider("if");
-            if (node.alternative) base54.consider("else");
-        }
-        else if (node instanceof AST_Var)
-            base54.consider("var");
-        else if (node instanceof AST_Lambda)
-            base54.consider("function");
-        else if (node instanceof AST_For)
-            base54.consider("for");
-        else if (node instanceof AST_ForIn)
-            base54.consider("for in");
-        else if (node instanceof AST_Switch)
-            base54.consider("switch");
-        else if (node instanceof AST_Case)
-            base54.consider("case");
-        else if (node instanceof AST_Default)
-            base54.consider("default");
-        else if (node instanceof AST_With)
-            base54.consider("with");
-        else if (node instanceof AST_ObjectSetter)
-            base54.consider("set" + node.key);
-        else if (node instanceof AST_ObjectGetter)
-            base54.consider("get" + node.key);
-        else if (node instanceof AST_ObjectKeyVal)
-            base54.consider(node.key);
-        else if (node instanceof AST_New)
-            base54.consider("new");
-        else if (node instanceof AST_This)
-            base54.consider("this");
-        else if (node instanceof AST_Try)
-            base54.consider("try");
-        else if (node instanceof AST_Catch)
-            base54.consider("catch");
-        else if (node instanceof AST_Finally)
-            base54.consider("finally");
-        else if (node instanceof AST_Symbol && node.unmangleable(options))
-            base54.consider(node.name);
-        else if (node instanceof AST_Unary || node instanceof AST_Binary)
-            base54.consider(node.operator);
-        else if (node instanceof AST_Dot)
-            base54.consider(node.property);
-    });
-    this.walk(tw);
+    try {
+        AST_Node.prototype.print = function(stream, force_parens) {
+            this._print(stream, force_parens);
+            if (this instanceof AST_Symbol && !this.unmangleable(options)) {
+                base54.consider(this.name, -1);
+            } else if (options.properties) {
+                if (this instanceof AST_Dot) {
+                    base54.consider(this.property, -1);
+                } else if (this instanceof AST_Sub) {
+                    skip_string(this.property);
+                }
+            }
+        };
+        base54.consider(this.print_to_string(), 1);
+    } finally {
+        AST_Node.prototype.print = AST_Node.prototype._print;
+    }
     base54.sort();
+
+    function skip_string(node) {
+        if (node instanceof AST_String) {
+            base54.consider(node.value, -1);
+        } else if (node instanceof AST_Conditional) {
+            skip_string(node.consequent);
+            skip_string(node.alternative);
+        } else if (node instanceof AST_Sequence) {
+            skip_string(node.tail_node());
+        }
+    }
 });
 
 var base54 = (function() {
-    var string = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_0123456789";
+    var leading = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_".split("");
+    var digits = "0123456789".split("");
     var chars, frequency;
     function reset() {
         frequency = Object.create(null);
-        chars = string.split("").map(function(ch){ return ch.charCodeAt(0) });
-        chars.forEach(function(ch){ frequency[ch] = 0 });
+        leading.forEach(function(ch) {
+            frequency[ch] = 0;
+        });
+        digits.forEach(function(ch) {
+            frequency[ch] = 0;
+        });
     }
-    base54.consider = function(str){
+    base54.consider = function(str, delta) {
         for (var i = str.length; --i >= 0;) {
-            var code = str.charCodeAt(i);
-            if (code in frequency) ++frequency[code];
+            frequency[str[i]] += delta;
         }
     };
+    function compare(a, b) {
+        return frequency[b] - frequency[a];
+    }
     base54.sort = function() {
-        chars = mergeSort(chars, function(a, b){
-            if (is_digit(a) && !is_digit(b)) return 1;
-            if (is_digit(b) && !is_digit(a)) return -1;
-            return frequency[b] - frequency[a];
-        });
+        chars = mergeSort(leading, compare).concat(mergeSort(digits, compare));
     };
     base54.reset = reset;
     reset();
-    base54.get = function(){ return chars };
-    base54.freq = function(){ return frequency };
     function base54(num) {
         var ret = "", base = 54;
         num++;
         do {
             num--;
-            ret += String.fromCharCode(chars[num % base]);
+            ret += chars[num % base];
             num = Math.floor(num / base);
             base = 64;
         } while (num > 0);

lib/transform.js

@@ -60,17 +60,14 @@ TreeTransformer.prototype = new TreeWalker;
             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;
-                    descend(x, tw);
+                x = this;
+                descend(x, tw);
+                if (tw.after) {
                     y = tw.after(x, in_list);
                     if (y !== undefined) x = y;
                 }
             }
-            tw.pop(this);
+            tw.pop();
             return x;
         });
     };
@@ -163,10 +160,18 @@ TreeTransformer.prototype = new TreeWalker;
         if (self.value) self.value = self.value.transform(tw);
     });
 
+    _(AST_Destructuring, function(self, tw) {
+        self.names = do_list(self.names, tw);
+    });
+
     _(AST_Lambda, function(self, tw){
         if (self.name) self.name = self.name.transform(tw);
         self.argnames = do_list(self.argnames, tw);
-        self.body = do_list(self.body, tw);
+        if (self.body instanceof AST_Node) {
+            self.body = self.body.transform(tw);
+        } else {
+            self.body = do_list(self.body, tw);
+        }
     });
 
     _(AST_Call, function(self, tw){
@@ -187,6 +192,14 @@ TreeTransformer.prototype = new TreeWalker;
         self.property = self.property.transform(tw);
     });
 
+    _(AST_Yield, function(self, tw){
+        if (self.expression) self.expression = self.expression.transform(tw);
+    });
+
+    _(AST_Await, function(self, tw){
+        self.expression = self.expression.transform(tw);
+    });
+
     _(AST_Unary, function(self, tw){
         self.expression = self.expression.transform(tw);
     });
@@ -211,7 +224,46 @@ TreeTransformer.prototype = new TreeWalker;
     });
 
     _(AST_ObjectProperty, function(self, tw){
+        if (self.key instanceof AST_Node) {
+            self.key = self.key.transform(tw);
+        }
         self.value = self.value.transform(tw);
     });
 
+    _(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);
+    });
+
+    _(AST_Expansion, function(self, tw){
+        self.expression = self.expression.transform(tw);
+    });
+
+    _(AST_NameMapping, function(self, tw) {
+        self.foreign_name = self.foreign_name.transform(tw);
+        self.name = self.name.transform(tw);
+    });
+
+    _(AST_Import, function(self, tw) {
+        if (self.imported_name) self.imported_name = self.imported_name.transform(tw);
+        if (self.imported_names) do_list(self.imported_names, tw);
+        self.module_name = self.module_name.transform(tw);
+    });
+
+    _(AST_Export, function(self, tw) {
+        if (self.exported_definition) self.exported_definition = self.exported_definition.transform(tw);
+        if (self.exported_value) self.exported_value = self.exported_value.transform(tw);
+        if (self.exported_names) do_list(self.exported_names, tw);
+        if (self.module_name) self.module_name = self.module_name.transform(tw);
+    });
+
+    _(AST_TemplateString, function(self, tw) {
+        self.segments = do_list(self.segments, tw);
+    });
+
+    _(AST_PrefixedTemplateString, function(self, tw) {
+        self.template_string = self.template_string.transform(tw);
+    });
+
 })();

lib/utils.js

@@ -43,17 +43,6 @@
 
 "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("");
 };
@@ -221,18 +210,6 @@ function mergeSort(array, cmp) {
     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) {
@@ -326,6 +303,13 @@ Dictionary.prototype = {
             ret.push(f(this._values[i], i.substr(1)));
         return ret;
     },
+    clone: function() {
+        var ret = new Dictionary();
+        for (var i in this._values)
+            ret._values[i] = this._values[i];
+        ret._size = this._size;
+        return ret;
+    },
     toObject: function() { return this._values }
 };
 Dictionary.fromObject = function(obj) {
@@ -347,7 +331,7 @@ function first_in_statement(stack) {
         if (p instanceof AST_Statement && p.body === node)
             return true;
         if ((p instanceof AST_Sequence      && p.expressions[0] === node) ||
-            (p instanceof AST_Call          && p.expression === node && !(p instanceof AST_New) ) ||
+            (p.TYPE == "Call"               && p.expression === node ) ||
             (p instanceof AST_Dot           && p.expression === node ) ||
             (p instanceof AST_Sub           && p.expression === node ) ||
             (p instanceof AST_Conditional   && p.condition === node  ) ||

package.json

@@ -1,23 +1,18 @@
 {
-  "name": "uglify-js",
-  "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
-  "homepage": "http://lisperator.net/uglifyjs",
+  "name": "uglify-es",
+  "description": "JavaScript parser, mangler/compressor and beautifier toolkit for ES6+",
+  "homepage": "https://github.com/mishoo/UglifyJS2/tree/harmony",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.0.5",
+  "version": "3.3.10",
   "engines": {
     "node": ">=0.8.0"
   },
   "maintainers": [
+    "Alex Lam <alexlamsl@gmail.com>",
     "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)"
   ],
-  "repository": {
-    "type": "git",
-    "url": "https://github.com/mishoo/UglifyJS2.git"
-  },
-  "bugs": {
-    "url": "https://github.com/mishoo/UglifyJS2/issues"
-  },
+  "repository": "https://github.com/mishoo/UglifyJS2.git#harmony",
   "main": "tools/node.js",
   "bin": {
     "uglifyjs": "bin/uglifyjs"
@@ -29,15 +24,33 @@
     "LICENSE"
   ],
   "dependencies": {
-    "commander": "~2.9.0",
-    "source-map": "~0.5.1"
+    "commander": "~2.14.1",
+    "source-map": "~0.6.1"
   },
   "devDependencies": {
-    "acorn": "~5.0.3",
-    "mocha": "~2.3.4"
+    "acorn": "~5.4.1",
+    "mocha": "~3.5.1",
+    "semver": "~5.5.0"
   },
   "scripts": {
     "test": "node test/run-tests.js"
   },
-  "keywords": ["uglify", "uglify-js", "minify", "minifier"]
+  "keywords": [
+    "uglify",
+    "uglify-es",
+    "uglify-js",
+    "minify",
+    "minifier",
+    "javascript",
+    "ecmascript",
+    "es5",
+    "es6",
+    "es7",
+    "es8",
+    "es2015",
+    "es2016",
+    "es2017",
+    "async",
+    "await"
+  ]
 }

test/benchmark.js

@@ -4,12 +4,14 @@
 "use strict";
 
 var createHash = require("crypto").createHash;
+var fetch = require("./fetch");
 var fork = require("child_process").fork;
+var zlib = require("zlib");
 var args = process.argv.slice(2);
 if (!args.length) {
     args.push("-mc");
 }
-args.push("--stats");
+args.push("--timings");
 var urls = [
     "https://code.jquery.com/jquery-3.2.1.js",
     "https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.6.4/angular.js",
@@ -19,6 +21,7 @@ var urls = [
     "http://builds.emberjs.com/tags/v2.11.0/ember.prod.js",
     "https://cdn.jsdelivr.net/lodash/4.17.4/lodash.js",
     "https://cdnjs.cloudflare.com/ajax/libs/d3/4.5.0/d3.js",
+    "https://raw.githubusercontent.com/kangax/html-minifier/v3.5.7/dist/htmlminifier.js",
 ];
 var results = {};
 var remaining = 2 * urls.length;
@@ -29,14 +32,10 @@ function done() {
             var info = results[url];
             console.log();
             console.log(url);
-            var elapsed = 0;
-            console.log(info.log.replace(/Elapsed: ([0-9]+)\s*/g, function(match, time) {
-                elapsed += 1e-3 * parseInt(time);
-                return "";
-            }));
-            console.log("Run-time:", elapsed.toFixed(3), "s");
+            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);
@@ -55,15 +54,21 @@ urls.forEach(function(url) {
     results[url] = {
         input: 0,
         output: 0,
+        gzip: 0,
         log: ""
     };
-    require(url.slice(0, url.indexOf(":"))).get(url, function(res) {
+    fetch(url, function(err, res) {
+        if (err) throw err;
         var uglifyjs = fork("bin/uglifyjs", args, { silent: true });
         res.on("data", function(data) {
             results[url].input += data.length;
         }).pipe(uglifyjs.stdin);
         uglifyjs.stdout.on("data", function(data) {
             results[url].output += data.length;
+        }).pipe(zlib.createGzip({
+            level: zlib.Z_BEST_COMPRESSION
+        })).on("data", function(data) {
+            results[url].gzip += data.length;
         }).pipe(createHash("sha1")).on("data", function(data) {
             results[url].sha1 = data.toString("hex");
             done();

test/compress/arrays.js

@@ -1,3 +1,5 @@
+// NOTE trailing comma doesn't contribute to length of an array
+// That also means the array changes length if previous element is a hole too and got cut off
 holes_and_undefined: {
     input: {
         w = [1,,];
@@ -91,6 +93,79 @@ constant_join_2: {
     }
 }
 
+spread_with_variable_as_last_element: {
+    input: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values];
+    }
+    expect: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values];
+    }
+}
+
+spread_with_variable_in_middle: {
+    input: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values, 7,,,];
+    }
+    expect: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values, 7,,,];
+    }
+}
+
+spread_with_variable_at_front: {
+    input: {
+        var values = [1, 2, 3];
+        var a = [...values, 4, 5, 6];
+    }
+    expect: {
+        var values = [1, 2, 3];
+        var a = [...values, 4, 5, 6];
+    }
+}
+
+spread_with_variable_at_front_after_elisions: {
+    input: {
+        var values = [1, 2, 3];
+        var a = [,,,...values, 4, 5, 6];
+    }
+    expect: {
+        var values = [1, 2, 3];
+        var a = [,,,...values, 4, 5, 6];
+    }
+}
+
+spread_with_array_at_end: {
+    input: {
+        var a = [1, 2, ...[4, 5, 6]];
+    }
+    expect: {
+        var a = [1, 2, ...[4, 5, 6]];
+    }
+}
+
+spread_with_logical_expression_at_end: {
+    options = { evaluate: true }
+    input: {
+        var a = [1, 2, 3, ...[2+2]]
+    }
+    expect: {
+        var a = [1, 2, 3, ...[4]]
+    }
+}
+
+spread_with_logical_expression_at_middle: {
+    options = { evaluate: true }
+    input: {
+        var a = [1, 1, ...[1+1, 1+2, 2+3], 8]
+    }
+    expect: {
+        var a = [1, 1, ...[2, 3, 5], 8]
+    }
+}
+
 constant_join_3: {
     options = {
         unsafe: true,
@@ -128,50 +203,114 @@ constant_join_3: {
 
 for_loop: {
     options = {
-        unsafe      : true,
-        unused      : true,
-        evaluate    : true,
-        reduce_vars : true
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
     };
     input: {
         function f0() {
             var a = [1, 2, 3];
-            for (var i = 0; i < a.length; i++) {
-                console.log(a[i]);
-            }
+            var b = 0;
+            for (var i = 0; i < a.length; i++)
+                b += a[i];
+            return b;
         }
-
         function f1() {
             var a = [1, 2, 3];
-            for (var i = 0, len = a.length; i < len; i++) {
-                console.log(a[i]);
-            }
+            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]++;
-            }
-        }
-    }
-    expect: {
-        function f0() {
-            var a = [1, 2, 3];
-            for (var i = 0; i < 3; i++)
-                console.log(a[i]);
-        }
-
-        function f1() {
-            var a = [1, 2, 3];
-            for (var i = 0; i < 3; i++)
-                console.log(a[i]);
-        }
-
         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"
 }

test/compress/arrow.js

@@ -0,0 +1,656 @@
+arrow_functions_without_body: {
+    input: {
+        var a1 = () => 42;
+        var a2 = (p) => p;
+        var a3 = p => p;
+        var a4 = (...p) => p;
+        var a5 = (b, c) => b + c;
+        var a6 = (b, ...c) => b + c[0];
+        var a7 = (...b) => b.join();
+    }
+    expect: {
+        var a1 = () => 42;
+        var a2 = (p) => p;
+        var a3 = p => p;
+        var a4 = (...p) => p;
+        var a5 = (b, c) => b + c;
+        var a6 = (b, ...c) => b + c[0];
+        var a7 = (...b) => b.join();
+    }
+}
+
+arrow_functions_with_body: {
+    input: {
+        var a1 = () => {
+            var a = 42 * Math.random();
+            return a;
+        };
+        var a2 = (p) => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a3 = p => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a4 = (...p) => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a5 = (b, c) => {
+            var result = b * c + b / c;
+            return result
+        };
+        var a6 = (b, ...c) => {
+            var result = b;
+            for (var i = 0; i < c.length; i++)
+                result += c[i];
+            return result
+        };
+        var a7 = (...b) => {
+            b.join();
+        }
+    }
+    expect: {
+        var a1 = () => {
+            var a = 42 * Math.random();
+            return a;
+        };
+        var a2 = (p) => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a3 = p => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a4 = (...p) => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a5 = (b, c) => {
+            var result = b * c + b / c;
+            return result
+        };
+        var a6 = (b, ...c) => {
+            var result = b;
+            for (var i = 0; i < c.length; i++)
+                result += c[i];
+            return result
+        };
+        var a7 = (...b) => {
+            b.join();
+        };
+    }
+}
+
+arrow_function_with_single_parameter_with_default: {
+    input: {
+        var foo = (a = 0) => doSomething(a);
+    }
+    expect_exact: "var foo=(a=0)=>doSomething(a);"
+}
+
+arrow_binding_pattern: {
+    input: {
+        var foo = ([]) => "foo";
+        var bar = ({}) => "bar";
+        var with_default = (foo = "default") => foo;
+        var object_with_default = ({foo = "default", bar: baz = "default"}) => foo;
+        var array_after_spread = (...[foo]) => foo;
+        var array_after_spread = (...{foo}) => foo;
+        var computed = ({ [compute()]: x }) => {};
+        var array_hole = ([, , ...x] = [1, 2]) => {};
+        var object_trailing_elision = ({foo,}) => {};
+        var spread_empty_array = (...[]) => "foo";
+        var spread_empty_object = (...{}) => "foo";
+    }
+    expect: {
+        var foo = ([]) => "foo";
+        var bar = ({}) => "bar";
+        var with_default = (foo = "default") => foo;
+        var object_with_default = ({foo = "default", bar: baz = "default"}) => foo;
+        var array_after_spread = (...[foo]) => foo;
+        var array_after_spread = (...{foo}) => foo;
+        var computed = ({ [compute()]: x }) => {};
+        var array_hole = ([, , ...x] = [1, 2]) => {};
+        var object_trailing_elision = ({foo,}) => {};
+        var spread_empty_array = (...[]) => "foo";
+        var spread_empty_object = (...{}) => "foo";
+    }
+}
+
+arrow_binding_pattern_strict: {
+    input: {
+        var foo = ([,]) => "foo";
+    }
+    expect_exact: 'var foo=([,])=>"foo";'
+}
+
+arrow_with_regexp: {
+    input: {
+        num => /\d{11,14}/.test( num )
+    }
+    expect: {
+        num => /\d{11,14}/.test( num )
+    }
+}
+
+arrow_unused: {
+    options = {
+        toplevel: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        top => dog;
+        let fn = a => { console.log(a * a); };
+        let u = (x, y) => x - y + g;
+        (() => { console.log("0"); })();
+        !function(x) {
+            (() => { console.log("1"); })();
+            let unused = x => { console.log(x); };
+            let baz = e => e + e;
+            console.log(baz(x));
+        }(1);
+        fn(3);
+    }
+    expect: {
+        let fn = a => { console.log(a * a); };
+        let u = (x, y) => x - y + g;
+        (() => { console.log("0"); })();
+        !function(x) {
+            (() => { console.log("1"); })();
+            let baz = e => e + e;
+            console.log(baz(x));
+        }(1);
+        fn(3);
+    }
+    expect_stdout: [ "0", "1", "2", "9" ]
+    node_version: ">=6"
+}
+
+arrow_unused_toplevel: {
+    options = {
+        toplevel: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        top => dog;
+        let fn = a => { console.log(a * a); };
+        let u = (x, y) => x - y + g;
+        (() => { console.log("0"); })();
+        !function(x) {
+            (() => { console.log("1"); })();
+            let unused = x => { console.log(x); };
+            let baz = e => e + e;
+            console.log(baz(x));
+        }(1);
+        fn(3);
+    }
+    expect: {
+        let fn = a => { console.log(a * a); };
+        (() => { console.log("0"); })();
+        !function(x) {
+            (() => { console.log("1"); })();
+            let baz = e => e + e;
+            console.log(baz(x));
+        }(1);
+        fn(3);
+    }
+    expect_stdout: [ "0", "1", "2", "9" ]
+    node_version: ">=6"
+}
+
+no_leading_parentheses: {
+    input: {
+        (x,y) => x(y);
+        async (x,y) => await x(y);
+    }
+    expect_exact: "(x,y)=>x(y);async(x,y)=>await x(y);"
+}
+
+async_identifiers: {
+    options = {
+        unsafe_arrows: true,
+        ecma: 6,
+    }
+    input: {
+        var async = function(x){ console.log("async", x); };
+        var await = function(x){ console.log("await", x); };
+        async(1);
+        await(2);
+    }
+    expect: {
+        var async = x => { console.log("async", x); };
+        var await = x => { console.log("await", x); };
+        async(1);
+        await(2);
+    }
+    expect_stdout: [
+        "async 1",
+        "await 2",
+    ]
+    node_version: ">=4"
+}
+
+async_function_expression: {
+    options = {
+        unsafe_arrows: true,
+        ecma: 6,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        var named = async function foo() {
+            await bar(1 + 0) + (2 + 0);
+        }
+        var anon = async function() {
+            await (1 + 0) + bar(2 + 0);
+        }
+    }
+    expect: {
+        var named = async function foo() {
+            await bar(1);
+        };
+        var anon = async () => {
+            await 1, bar(2);
+        };
+    }
+}
+
+issue_27: {
+    options = {
+        unsafe_arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        unused: true,
+    }
+    input: {
+        (function(jQuery) {
+            var $;
+            $ = jQuery;
+            $("body").addClass("foo");
+        })(jQuery);
+    }
+    expect: {
+        (jQuery => {
+            jQuery("body").addClass("foo");
+        })(jQuery);
+    }
+}
+
+issue_2105_1: {
+    options = {
+        unsafe_arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        inline: true,
+        passes: 3,
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        unsafe_methods: true,
+        unused: true,
+    }
+    input: {
+        !function(factory) {
+            factory();
+        }( function() {
+            return function(fn) {
+                fn()().prop();
+            }( function() {
+                function bar() {
+                    var quux = function() {
+                        console.log("PASS");
+                    }, foo = function() {
+                        console.log;
+                        quux();
+                    };
+                    return { prop: foo };
+                }
+                return bar;
+            } );
+        });
+    }
+    expect: {
+        ({
+            prop() {
+                console.log;
+                console.log("PASS");
+            }
+        }).prop();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_2105_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        ((factory) => {
+            factory();
+        })( () => {
+            return ((fn) => {
+                fn()().prop();
+            })( () => {
+                let bar = () => {
+                    var quux = () => {
+                        console.log("PASS");
+                    }, foo = () => {
+                        console.log;
+                        quux();
+                    };
+                    return { prop: foo };
+                };
+                return bar;
+            } );
+        });
+    }
+    expect: {
+        ({
+            prop: () => {
+                console.log;
+                console.log("PASS");
+            }
+        }).prop();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_2136_2: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        inline: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            console.log(x);
+        }
+        !function(a, ...b) {
+            f(b[0]);
+        }(1, 2, 3);
+    }
+    expect: {
+        function f(x) {
+            console.log(x);
+        }
+        f([2,3][0]);
+    }
+    expect_stdout: "2"
+    node_version: ">=6"
+}
+
+issue_2136_3: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        passes: 3,
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            console.log(x);
+        }
+        !function(a, ...b) {
+            f(b[0]);
+        }(1, 2, 3);
+    }
+    expect: {
+        console.log(2);
+    }
+    expect_stdout: "2"
+    node_version: ">=6"
+}
+
+call_args: {
+    options = {
+        arrows: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+    }
+    input: {
+        const a = 1;
+        console.log(a);
+        +function(a) {
+            return a;
+        }(a);
+    }
+    expect: {
+        const a = 1;
+        console.log(1);
+        +(1, 1);
+    }
+    expect_stdout: true
+}
+
+call_args_drop_param: {
+    options = {
+        arrows: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        keep_fargs: false,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        const a = 1;
+        console.log(a);
+        +function(a) {
+            return a;
+        }(a, b);
+    }
+    expect: {
+        const a = 1;
+        console.log(1);
+        +(b, 1);
+    }
+    expect_stdout: true
+}
+
+issue_485_crashing_1530: {
+    options = {
+        arrows: true,
+        conditionals: true,
+        dead_code: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        (function(a) {
+            if (true) return;
+            var b = 42;
+        })(this);
+    }
+    expect: {}
+}
+
+issue_2084: {
+    options = {
+        unsafe_arrows: true,
+        collapse_vars: true,
+        conditionals: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function() {
+            !function(c) {
+                c = 1 + c;
+                var c = 0;
+                function f14(a_1) {
+                    if (c = 1 + c, 0 !== 23..toString())
+                        c = 1 + c, a_1 && (a_1[0] = 0);
+                }
+                f14();
+            }(-1);
+        }();
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        ((c) => {
+            c = 1 + c,
+            c = 1 + (c = 0),
+            0 !== 23..toString() && (c = 1 + c);
+        })(-1),
+        console.log(c);
+    }
+    expect_stdout: "0"
+    node_version: ">=4"
+}
+
+export_default_object_expression: {
+    options = {
+        arrows: true,
+        evaluate: true,
+    }
+    input: {
+        export default {
+            foo: 1 + 2,
+            bar() { return 4; },
+            get baz() { return this.foo; },
+        };
+    }
+    expect_exact: "export default{foo:3,bar:()=>4,get baz(){return this.foo}};"
+}
+
+concise_methods_with_computed_property2: {
+    options = {
+        arrows: true,
+        evaluate: true,
+    }
+    input: {
+        var foo = {
+            [[1]](v) {
+                return v;
+            }
+        };
+        console.log(foo[[1]]("PASS"));
+    }
+    expect_exact: 'var foo={[[1]]:v=>v};console.log(foo[[1]]("PASS"));'
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+async_object_literal: {
+    options = {
+        arrows: true,
+        unsafe_arrows: true,
+        ecma: 6,
+        evaluate: true,
+    }
+    input: {
+        var obj = {
+            async a() {
+                return await foo(1 + 0);
+            },
+            anon: async function() {
+                return await foo(2 + 0);
+            }
+        };
+    }
+    expect: {
+        var obj = {
+            a: async () => await foo(1),
+            anon: async () => await foo(2)
+        };
+    }
+}
+
+issue_2271: {
+    options = {
+        arrows: true,
+        ecma: 6,
+        evaluate: true,
+        unsafe_arrows: false,
+    }
+    input: {
+        var Foo = function() {};
+        Foo.prototype.set = function(value) {
+            this.value = value;
+            return this;
+        }
+        Foo.prototype.print = function() {
+            console.log(this.value);
+        }
+        new Foo().set("PASS").print();
+    }
+    expect: {
+        var Foo = function() {};
+        Foo.prototype.set = function(value) {
+            this.value = value;
+            return this;
+        }
+        Foo.prototype.print = function() {
+            console.log(this.value);
+        }
+        new Foo().set("PASS").print();
+    }
+    expect_stdout: "PASS"
+}
+
+concise_method_with_super: {
+    options = {
+        arrows: true,
+    }
+    input: {
+        var o = {
+            f: "FAIL",
+            g() {
+                return super.f;
+            }
+        }
+        Object.setPrototypeOf(o, { f: "PASS" });
+        console.log(o.g());
+    }
+    expect: {
+        var o = {
+            f: "FAIL",
+            g() {
+                return super.f;
+            }
+        }
+        Object.setPrototypeOf(o, { f: "PASS" });
+        console.log(o.g());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}

test/compress/ascii.js

@@ -13,7 +13,7 @@ ascii_only_true: {
                    "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\f\\r\\x0e\\x0f"+"\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f"+\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\x008\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\f\\r\\x0e\\x0f"+"\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f"+\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\'}'
 }
 
 ascii_only_false: {
@@ -31,5 +31,5 @@ ascii_only_false: {
                    "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\f\\r\x0e\x0f"+"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"+\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\x008\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\f\\r\x0e\x0f"+"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"+\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
 }

test/compress/asm.js

@@ -16,7 +16,6 @@ asm_mixed: {
         hoist_vars    : true,
         if_return     : true,
         join_vars     : true,
-        cascade       : true,
         side_effects  : true,
         negate_iife   : true
     };
@@ -104,3 +103,65 @@ asm_mixed: {
     }
 }
 
+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;'
+}

test/compress/async.js

@@ -0,0 +1,323 @@
+await_precedence: {
+    input: {
+        async function f1() { await x + y; }
+        async function f2() { await (x + y); }
+    }
+    expect_exact: "async function f1(){await x+y}async function f2(){await(x+y)}"
+}
+
+await_precedence_prop: {
+    input: {
+        async function f1(){ return (await foo()).bar; }
+        async function f2(){ return (await foo().bar); }
+    }
+    expect_exact: "async function f1(){return(await foo()).bar}async function f2(){return await foo().bar}"
+}
+
+await_precedence_call: {
+    input: {
+        async function f3(){ return (await foo())(); }
+        async function f4(){ return await (foo()()); }
+    }
+    expect_exact: "async function f3(){return(await foo())()}async function f4(){return await foo()()}"
+}
+
+async_function_declaration: {
+    options = {
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        async function f0() {}
+        async function f1() { await x + y; }
+        async function f2() { await (x + y); }
+        async function f3() { await x + await y; }
+        async function f4() { await (x + await y); }
+        async function f5() { await x; await y; }
+        async function f6() { await x, await y; }
+    }
+    expect: {
+        async function f0() {}
+        async function f1() { await x, y; }
+        async function f2() { await (x + y); }
+        async function f3() { await x, await y; }
+        async function f4() { await (x + await y); }
+        async function f5() { await x; await y; }
+        async function f6() { await x, await y; }
+    }
+}
+
+async_function_expression: {
+    options = {
+        evaluate: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var named = async function foo() {
+            await bar(1 + 0) + (2 + 0);
+        }
+        var anon = async function() {
+            await (1 + 0) + bar(2 + 0);
+        }
+    }
+    expect: {
+        var named = async function() {
+            await bar(1);
+        };
+        var anon = async function() {
+            await 1, bar(2);
+        };
+    }
+}
+
+async_class: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        class Foo {
+            async m1() {
+                return await foo(1 + 2);
+            }
+            static async m2() {
+                return await foo(3 + 4);
+            }
+        }
+    }
+    expect: {
+        class Foo {
+            async m1() {
+                return await foo(3);
+            }
+            static async m2() {
+                return await foo(7);
+            }
+        }
+    }
+}
+
+async_object_literal: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        var obj = {
+            async a() {
+                await foo(1 + 0);
+            },
+            anon: async function(){
+                await foo(2 + 0);
+            }
+        };
+    }
+    expect: {
+        var obj = {
+            async a() {
+                await foo(1);
+            },
+            anon: async function() {
+                await foo(2);
+            }
+        };
+    }
+}
+
+async_export: {
+    input: {
+        export async function run() {};
+        export default async function def() {};
+    }
+    expect: {
+        export async function run() {};
+        export default async function def() {};
+    }
+}
+
+async_inline: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        inline: true,
+        negate_iife: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        (async function(){ return await 3; })();
+        (async function(x){ await console.log(x); })(4);
+
+        function echo(x) { return x; }
+        echo( async function(){ return await 1; }() );
+        echo( async function(x){ await console.log(x); }(2) );
+
+        function top() { console.log("top"); }
+        top();
+
+        async function async_top() { console.log("async_top"); }
+        async_top();
+    }
+    expect: {
+        !async function(){await 3}();
+        !async function(x){await console.log(4)}();
+
+        function echo(x){return x}
+        echo(async function(){return await 1}());
+        echo(async function(x){await console.log(2)}());
+
+        console.log("top");
+
+        !async function(){console.log("async_top")}();
+    }
+    expect_stdout: [
+        "4",
+        "2",
+        "top",
+        "async_top",
+    ]
+    node_version: ">=8"
+}
+
+async_identifiers: {
+    input: {
+        var async = function(x){ console.log("async", x); };
+        var await = function(x){ console.log("await", x); };
+        async(1);
+        await(2);
+    }
+    expect: {
+        var async = function(x){ console.log("async", x); };
+        var await = function(x){ console.log("await", x); };
+        async(1);
+        await(2);
+    }
+    expect_stdout: [
+        "async 1",
+        "await 2",
+    ]
+}
+
+async_shorthand_property: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        function print(o) { console.log(o.async + " " + o.await); }
+        var async = "Async", await = "Await";
+
+        print({ async });
+        print({ await });
+        print({ async, await });
+        print({ await, async });
+
+        print({ async: async });
+        print({ await: await });
+        print({ async: async, await: await });
+        print({ await: await, async: async });
+    }
+    expect: {
+        function a(a) { console.log(a.async + " " + a.await); }
+        var n = "Async", c = "Await";
+
+        a({ async: n });
+        a({ await: c });
+        a({ async: n, await: c });
+        a({ await: c, async: n });
+
+        a({ async: n });
+        a({ await: c });
+        a({ async: n, await: c });
+        a({ await: c, async: n });
+    }
+    expect_stdout: [
+        "Async undefined",
+        "undefined Await",
+        "Async Await",
+        "Async Await",
+        "Async undefined",
+        "undefined Await",
+        "Async Await",
+        "Async Await",
+    ]
+    node_version: ">=4"
+}
+
+async_arrow: {
+    input: {
+        let a1 = async x => await foo(x);
+        let a2 = async () => await bar();
+        let a3 = async (x) => await baz(x);
+        let a4 = async (x, y) => { await far(x, y); }
+        let a5 = async ({x = [1], y: z = 2}) => { await wow(x, z); }
+    }
+    expect: {
+        let a1 = async x => await foo(x);
+        let a2 = async () => await bar();
+        let a3 = async (x) => await baz(x);
+        let a4 = async (x, y) => { await far(x, y); }
+        let a5 = async ({x = [1], y: z = 2}) => { await wow(x, z); }
+    }
+}
+
+async_arrow_wait: {
+    input: {
+        var a = async (x, y) => await x(y);
+    }
+    expect_exact: "var a=async(x,y)=>await x(y);"
+}
+
+async_arrow_iife: {
+    input: {
+        (async () => {
+            await fetch({});
+        })();
+    }
+    expect_exact: "(async()=>{await fetch({})})();"
+}
+
+async_arrow_iife_negate_iife: {
+    options = {
+        negate_iife: true,
+    }
+    input: {
+        (async () => {
+            await fetch();
+        })();
+        (() => {
+            plain();
+        })();
+    }
+    expect_exact: "(async()=>{await fetch()})();(()=>{plain()})();"
+}
+
+issue_2344_1: {
+    beautify = {
+        safari10: false,
+    }
+    input: {
+        async () => {
+            +await x;
+            await y;
+            return await z;
+        };
+    }
+    expect_exact: "async()=>{+await x;await y;return await z};"
+}
+
+issue_2344_2: {
+    beautify = {
+        safari10: true,
+    }
+    input: {
+        async () => {
+            +await x;
+            await y;
+            return await z;
+        };
+    }
+    expect_exact: "async()=>{+(await x);await y;return await z};"
+}

test/compress/block-scope.js

@@ -0,0 +1,191 @@
+
+let_statement: {
+    input: {
+        let x = 6;
+    }
+    expect_exact: "let x=6;"
+}
+
+do_not_hoist_let: {
+    options = {
+        hoist_vars: true,
+    };
+    input: {
+        function x() {
+            if (FOO) {
+                let let1;
+                let let2;
+                var var1;
+                var var2;
+            }
+        }
+    }
+    expect: {
+        function x() {
+            var var1, var2;
+            if (FOO) {
+                let let1;
+                let let2;
+            }
+        }
+    }
+}
+
+do_not_remove_anon_blocks_if_they_have_decls: {
+    input: {
+        function x() {
+            {
+                let x;
+            }
+            {
+                var x;
+            }
+            {
+                const y = 1;
+                class Zee {};
+            }
+        }
+        {
+            let y;
+        }
+        {
+            var y;
+        }
+    }
+    expect: {
+        function x(){
+            {
+                let x
+            }
+            var x;
+            {
+                const y = 1;
+                class Zee {}
+            }
+        }
+        {
+            let y
+        }
+        var y;
+    }
+}
+
+remove_unused_in_global_block: {
+    options = {
+        unused: true,
+    }
+    input: {
+        {
+            let x;
+            const y = 1;
+            class Zee {};
+            var w;
+        }
+        let ex;
+        const why = 2;
+        class Zed {};
+        var wut;
+        console.log(x, y, Zee);
+    }
+    expect: {
+        var w;
+        let ex;
+        const why = 2;
+        class Zed {};
+        var wut;
+        console.log(x, y, Zee);
+    }
+}
+
+regression_block_scope_resolves: {
+    mangle = { };
+    options = {
+        dead_code: false
+    };
+    input: {
+        (function () {
+            if (1) {
+                let x;
+                const y = 1;
+                class Zee {};
+            }
+            if (1) {
+                let ex;
+                const why = 2;
+                class Zi {};
+            }
+            console.log(typeof x, typeof y, typeof Zee, typeof ex, typeof why, typeof Zi);
+        }());
+    }
+    expect: {
+        (function () {
+            if (1) {
+                let e;
+                const o = 1;
+                class t {};
+            }
+            if (1) {
+                let e;
+                const o = 2;
+                class t {};
+            }
+            console.log(typeof x, typeof y, typeof Zee, typeof ex, typeof why, typeof Zi);
+        }());
+    }
+    expect_stdout: "undefined undefined undefined undefined undefined undefined"
+    node_version: ">=6"
+}
+
+switch_block_scope_mangler: {
+    mangle = {}
+    input: {
+        var fn = function(code) {
+            switch (code) {
+                case 1:
+                    let apple = code + 1;
+                    let dog = code + 4;
+                    console.log(apple, dog);
+                    break;
+                case 2:
+                    let banana = code + 2;
+                    console.log(banana);
+                    break;
+                default:
+                    let cat = code + 3;
+                    console.log(cat);
+            }
+        };
+        fn(1);
+        fn(2);
+        fn(3);
+    }
+    expect: {
+        var fn = function(e) {
+            switch (e) {
+              case 1:
+                let l = e + 1
+                let o = e + 4;
+                console.log(l, o);
+                break;
+
+              case 2:
+                let n = e + 2;
+                console.log(n);
+                break;
+
+              default:
+                let c = e + 3;
+                console.log(c);
+            }
+        };
+        fn(1);
+        fn(2);
+        fn(3);
+    }
+    expect_stdout: [
+        "2 5",
+        "4",
+        "6",
+    ]
+    node_version: ">=6"
+}

test/compress/blocks.js

@@ -47,3 +47,143 @@ keep_some_blocks: {
         } else stuff();
     }
 }
+
+issue_1664: {
+    input: {
+        var a = 1;
+        function f() {
+            if (undefined) a = 2;
+            {
+                function undefined() {}
+                undefined();
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            if (undefined) a = 2;
+            {
+                function undefined() {}
+                undefined();
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect_stdout: "1"
+    node_version: ">=6"
+    reminify: false // FIXME - block scoped function
+}
+
+issue_1672_for: {
+    input: {
+        switch (function() {
+            return xxx;
+        }) {
+          case xxx:
+            for (; console.log("FAIL");) {
+                function xxx() {}
+            }
+            break;
+        }
+    }
+    expect: {
+        switch (function() {
+            return xxx;
+        }) {
+          case xxx:
+            for (; console.log("FAIL");) {
+                function xxx() {}
+            }
+            break;
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_1672_for_strict: {
+    input: {
+        "use strict";
+        switch (function() {
+            return xxx;
+        }) {
+          case xxx:
+            for (; console.log("FAIL");) {
+                function xxx() {}
+            }
+            break;
+        }
+    }
+    expect: {
+        "use strict";
+        switch (function() {
+            return xxx;
+        }) {
+          case xxx:
+            for (; console.log("FAIL");) {
+                function xxx() {}
+            }
+            break;
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_1672_if: {
+    input: {
+        switch (function() {
+            return xxx;
+        }) {
+          case xxx:
+            if (console.log("FAIL")) {
+                function xxx() {}
+            }
+            break;
+        }
+    }
+    expect: {
+        switch (function() {
+            return xxx;
+        }) {
+          case xxx:
+            if (console.log("FAIL")) function xxx() {}
+            break;
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_1672_if_strict: {
+    input: {
+        "use strict";
+        switch (function() {
+            return xxx;
+        }) {
+          case xxx:
+            if (console.log("FAIL")) {
+                function xxx() {}
+            }
+            break;
+        }
+    }
+    expect: {
+        "use strict";
+        switch (function() {
+            return xxx;
+        }) {
+          case xxx:
+            if (console.log("FAIL")) {
+                function xxx() {}
+            }
+            break;
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}

test/compress/comparing.js

@@ -73,4 +73,245 @@ dont_change_in_or_instanceof_expressions: {
         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"
+}
+
+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"
+}

test/compress/concat-strings.js

@@ -21,7 +21,7 @@ concat_1: {
         var c = 1 + x() + 2 + "boo";
         var d = 1 + x() + 2 + 3 + "boo";
         var e = 1 + x() + 2 + "X3boo";
-        var f = "\x00360\08\0";
+        var f = "\x00360\x008\0";
     }
 }
 

test/compress/conditionals.js

@@ -166,22 +166,24 @@ cond_1: {
         conditionals: true
     };
     input: {
-        var do_something; // if undeclared it's assumed to have side-effects
-        if (some_condition()) {
-            do_something(x);
-        } else {
-            do_something(y);
-        }
-        if (some_condition()) {
-            side_effects(x);
-        } else {
-            side_effects(y);
+        function foo(do_something, some_condition) {
+            if (some_condition) {
+                do_something(x);
+            } else {
+                do_something(y);
+            }
+            if (some_condition) {
+                side_effects(x);
+            } else {
+                side_effects(y);
+            }
         }
     }
     expect: {
-        var do_something;
-        do_something(some_condition() ? x : y);
-        some_condition() ? side_effects(x) : side_effects(y);
+        function foo(do_something, some_condition) {
+            do_something(some_condition ? x : y);
+            some_condition ? side_effects(x) : side_effects(y);
+        }
     }
 }
 
@@ -190,16 +192,18 @@ cond_2: {
         conditionals: true
     };
     input: {
-        var x, FooBar;
-        if (some_condition()) {
-            x = new FooBar(1);
-        } else {
-            x = new FooBar(2);
+        function foo(x, FooBar, some_condition) {
+            if (some_condition) {
+                x = new FooBar(1);
+            } else {
+                x = new FooBar(2);
+            }
         }
     }
     expect: {
-        var x, FooBar;
-        x = new FooBar(some_condition() ? 1 : 2);
+        function foo(x, FooBar, some_condition) {
+            x = new FooBar(some_condition ? 1 : 2);
+        }
     }
 }
 
@@ -605,11 +609,47 @@ cond_8c: {
     }
 }
 
+cond_9: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function f(x, y) {
+            g() ? x(1) : x(2);
+            x ? (y || x)() : (y || x)();
+            x ? y(a, b) : y(d, b, c);
+            x ? y(a, b, c) : y(a, b, c);
+            x ? y(a, b, c) : y(a, b, f);
+            x ? y(a, b, c) : y(a, e, c);
+            x ? y(a, b, c) : y(a, e, f);
+            x ? y(a, b, c) : y(d, b, c);
+            x ? y(a, b, c) : y(d, b, f);
+            x ? y(a, b, c) : y(d, e, c);
+            x ? y(a, b, c) : y(d, e, f);
+        }
+    }
+    expect: {
+        function f(x, y) {
+            g() ? x(1) : x(2);
+            x, (y || x)();
+            x ? y(a, b) : y(d, b, c);
+            x, y(a, b, c);
+            y(a, b, x ? c : f);
+            y(a, x ? b : e, c);
+            x ? y(a, b, c) : y(a, e, f);
+            y(x ? a : d, b, c);
+            x ? y(a, b, c) : y(d, b, f);
+            x ? y(a, b, c) : y(d, e, c);
+            x ? y(a, b, c) : y(d, e, f);
+        }
+    }
+}
+
 ternary_boolean_consequent: {
     options = {
         collapse_vars:true, sequences:true, properties:true, dead_code:true, conditionals:true,
         comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
-        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+        keep_fargs:true, if_return:true, join_vars:true, side_effects:true
     }
     input: {
         function f1() { return a == b ? true : x; }
@@ -637,7 +677,7 @@ ternary_boolean_alternative: {
     options = {
         collapse_vars:true, sequences:true, properties:true, dead_code:true, conditionals:true,
         comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
-        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+        keep_fargs:true, if_return:true, join_vars:true, side_effects:true
     }
     input: {
         function f1() { return a == b ? x : true; }
@@ -1015,3 +1055,215 @@ delete_conditional_2: {
     }
     expect_stdout: true
 }
+
+issue_2535_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        passes: 2,
+        side_effects: true,
+    }
+    input: {
+        if (true || x()) y();
+        if (true && x()) y();
+        if (x() || true) y();
+        if (x() && true) y();
+        if (false || x()) y();
+        if (false && x()) y();
+        if (x() || false) y();
+        if (x() && false) y();
+    }
+    expect: {
+        y();
+        x() && y();
+        (x(), 1) && y();
+        x() && y();
+        x() && y();
+        x() && y();
+        (x(), 0) && y();
+    }
+}
+
+issue_2535_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        function x() {}
+        function y() {
+            return "foo";
+        }
+        console.log((x() || true) || y());
+        console.log((y() || true) || x());
+        console.log((x() || true) && y());
+        console.log((y() || true) && x());
+        console.log((x() && true) || y());
+        console.log((y() && true) || x());
+        console.log((x() && true) && y());
+        console.log((y() && true) && x());
+        console.log((x() || false) || y());
+        console.log((y() || false) || x());
+        console.log((x() || false) && y());
+        console.log((y() || false) && x());
+        console.log((x() && false) || y());
+        console.log((y() && false) || x());
+        console.log((x() && false) && y());
+        console.log((y() && false) && x());
+    }
+    expect: {
+        function x() {}
+        function y() {
+            return "foo";
+        }
+        console.log(x() || !0);
+        console.log(y() || !0);
+        console.log((x(), y()));
+        console.log((y(), x()));
+        console.log(!!x() || y());
+        console.log(!!y() || x());
+        console.log(x() && y());
+        console.log(y() && x());
+        console.log(x() || y());
+        console.log(y() || x());
+        console.log(!!x() && y());
+        console.log(!!y() && x());
+        console.log((x(), y()));
+        console.log((y(), x()));
+        console.log(x() && !1);
+        console.log(y() && !1);
+    }
+    expect_stdout: [
+        "true",
+        "foo",
+        "foo",
+        "undefined",
+        "foo",
+        "true",
+        "undefined",
+        "undefined",
+        "foo",
+        "foo",
+        "false",
+        "undefined",
+        "foo",
+        "undefined",
+        "undefined",
+        "false",
+    ]
+}
+
+issue_2560: {
+    options = {
+        conditionals: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function log(x) {
+            console.log(x);
+        }
+        function foo() {
+            return log;
+        }
+        function bar() {
+            if (x !== (x = foo())) {
+                x(1);
+            } else {
+                x(2);
+            }
+        }
+        var x = function() {
+            console.log("init");
+        };
+        bar();
+        bar();
+    }
+    expect: {
+        function log(x) {
+            console.log(x);
+        }
+        function bar() {
+            x !== (x = log) ? x(1) : x(2);
+        }
+        var x = function() {
+            console.log("init");
+        };
+        bar();
+        bar();
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+hoist_decl: {
+    options = {
+        conditionals: true,
+        join_vars: true,
+        sequences: true,
+    }
+    input: {
+        if (x()) {
+            var a;
+            y();
+        } else {
+            z();
+            var b;
+        }
+    }
+    expect: {
+        var a, b;
+        x() ? y() : z();
+    }
+}
+
+to_and_or: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var values = [
+            0,
+            null,
+            true,
+            "foo",
+            false,
+            -1 / 0,
+            void 0,
+        ];
+        values.forEach(function(x) {
+            values.forEach(function(y) {
+                values.forEach(function(z) {
+                    console.log(x ? y || z : z);
+                });
+            });
+        });
+    }
+    expect: {
+        var values = [
+            0,
+            null,
+            true,
+            "foo",
+            false,
+            -1 / 0,
+            void 0,
+        ];
+        values.forEach(function(x) {
+            values.forEach(function(y) {
+                values.forEach(function(z) {
+                    console.log(x && y || z);
+                });
+            });
+        });
+    }
+    expect_stdout: true
+}

test/compress/const.js

@@ -0,0 +1,170 @@
+issue_1191: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+        reduce_funcs  : true,
+        reduce_vars   : true,
+    }
+    input: {
+        function foo(rot) {
+            const rotTol = 5;
+            if (rot < -rotTol || rot > rotTol)
+                bar();
+            baz();
+        }
+    }
+    expect: {
+        function foo(rot) {
+            (rot < -5 || rot > 5) && bar();
+            baz();
+        }
+    }
+}
+
+issue_1194: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+        reduce_funcs  : true,
+        reduce_vars   : true,
+    }
+    input: {
+        function f1() {const a = "X"; return a + a;}
+        function f2() {const aa = "X"; return aa + aa;}
+        function f3() {const aaa = "X"; return aaa + aaa;}
+    }
+    expect: {
+        function f1(){return"XX"}
+        function f2(){return"XX"}
+        function f3(){return"XX"}
+    }
+}
+
+issue_1396: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+        reduce_funcs  : true,
+        reduce_vars   : true,
+    }
+    input: {
+        function foo(a) {
+            const VALUE = 1;
+            console.log(2 | VALUE);
+            console.log(VALUE + 1);
+            console.log(VALUE);
+            console.log(a & VALUE);
+        }
+        function bar() {
+            const s = "01234567890123456789";
+            console.log(s + s + s + s + s);
+
+            const CONSTANT = "abc";
+            console.log(CONSTANT + CONSTANT + CONSTANT + CONSTANT + CONSTANT);
+        }
+    }
+    expect: {
+        function foo(a) {
+            console.log(3);
+            console.log(2);
+            console.log(1);
+            console.log(1 & a);
+        }
+        function bar() {
+            const s = "01234567890123456789";
+            console.log(s + s + s + s + s);
+
+            console.log("abcabcabcabcabc");
+        }
+    }
+}
+
+unused_regexp_literal: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+    }
+    input: {
+        function f(){ var a = /b/; }
+    }
+    expect: {
+        function f(){}
+    }
+}
+
+regexp_literal_not_const: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+        reduce_funcs  : true,
+        reduce_vars   : true,
+    }
+    input: {
+        (function(){
+            var result;
+            const s = 'acdabcdeabbb';
+            const REGEXP_LITERAL = /ab*/g;
+            while (result = REGEXP_LITERAL.exec(s)) {
+                console.log(result[0]);
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            var result;
+            const REGEXP_LITERAL = /ab*/g;
+            while (result = REGEXP_LITERAL.exec("acdabcdeabbb")) console.log(result[0]);
+        })();
+    }
+    expect_stdout: true
+}

test/compress/destructuring.js

@@ -0,0 +1,695 @@
+destructuring_arrays: {
+    input: {
+        {const [aa, bb] = cc;}
+        {const [aa, [bb, cc]] = dd;}
+        {let [aa, bb] = cc;}
+        {let [aa, [bb, cc]] = dd;}
+        var [aa, bb] = cc;
+        var [aa, [bb, cc]] = dd;
+        var [,[,,,,,],,,zz,] = xx; // Trailing comma
+        var [,,zzz,,] = xxx; // Trailing comma after hole
+    }
+    expect: {
+        {const [aa, bb] = cc;}
+        {const [aa, [bb, cc]] = dd;}
+        {let [aa, bb] = cc;}
+        {let [aa, [bb, cc]] = dd;}
+        var [aa, bb] = cc;
+        var [aa, [bb, cc]] = dd;
+        var [,[,,,,,],,,zz] = xx;
+        var [,,zzz,,] = xxx;
+    }
+}
+
+destructuring_arrays_holes: {
+    input: {
+        var [,,,,] = a;
+        var [,,b,] = c;
+        var [d,,]  = e;
+    }
+    expect_exact: "var[,,,,]=a;var[,,b]=c;var[d,,]=e;"
+}
+
+destructuring_objects: {
+    input: {
+        {const {aa, bb} = {aa:1, bb:2};}
+        {const {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        {let {aa, bb} = {aa:1, bb:2};}
+        {let {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        var {aa, bb} = {aa:1, bb:2};
+        var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
+    }
+    expect: {
+        {const {aa, bb} = {aa:1, bb:2};}
+        {const {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        {let {aa, bb} = {aa:1, bb:2};}
+        {let {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        var {aa, bb} = {aa:1, bb:2};
+        var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
+    }
+}
+
+destructuring_objects_trailing_elision: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        var {cc,} = foo;
+    }
+    expect_exact: "var{cc}=foo;"
+}
+
+nested_destructuring_objects: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        const [{a},b] = c;
+        let [{d},e] = f;
+        var [{g},h] = i;
+    }
+    expect_exact: 'const[{a},b]=c;let[{d},e]=f;var[{g},h]=i;';
+}
+
+destructuring_constdef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        for (const [x,y] in pairs);
+        for (const [a] = 0;;);
+        for (const {c} of cees);
+    }
+    expect_exact: "for(const[x,y]in pairs);for(const[a]=0;;);for(const{c}of cees);"
+}
+
+destructuring_letdef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        for (let [x,y] in pairs);
+        for (let [a] = 0;;);
+        for (let {c} of cees);
+    }
+    expect_exact: "for(let[x,y]in pairs);for(let[a]=0;;);for(let{c}of cees);"
+}
+
+destructuring_vardef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        for (var [x,y] in pairs);
+        for (var [a] = 0;;);
+        for (var {c} of cees);
+    }
+    expect_exact: "for(var[x,y]in pairs);for(var[a]=0;;);for(var{c}of cees);"
+}
+
+destructuring_expressions: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        ({a, b});
+        [{a}];
+        f({x});
+    }
+    expect_exact: "({a,b});[{a}];f({x});"
+}
+
+destructuring_remove_unused_1: {
+    options = {
+        unused: true
+    }
+    input: {
+        function a() {
+            var unused = "foo";
+            var a = [1];
+            var [b] = a;
+            f(b);
+        }
+        function b() {
+            var unused = "foo";
+            var a = {b: 1};
+            var {b} = a;
+            f(b);
+        }
+        function c() {
+            var unused = "foo";
+            var a = [[1]];
+            var [[b]] = a;
+            f(b);
+        }
+        function d() {
+            var unused = "foo";
+            var a = {b: {b:1}};
+            var {b:{b}} = a;
+            f(b);
+        }
+        function e() {
+            var unused = "foo";
+            var a = [1, 2, 3, 4, 5];
+            var x = [[1, 2, 3]];
+            var y = {h: 1};
+            var [b, ...c] = a;
+            var [...[e, f]] = x;
+            var [...{g: h}] = y;
+            f(b, c, e, f, g);
+        }
+    }
+    expect: {
+        function a() {
+            var a = [1];
+            var [b] = a;
+            f(b);
+        }
+        function b() {
+            var a = {b: 1};
+            var {b} = a;
+            f(b);
+        }
+        function c() {
+            var a = [[1]];
+            var [[b]] = a;
+            f(b);
+        }
+        function d() {
+            var a = {b: {b:1}};
+            var {b:{b}} = a;
+            f(b);
+        }
+        function e() {
+            var a = [1, 2, 3, 4, 5];
+            var x = [[1, 2, 3]];
+            var y = {h: 1};
+            var [b, ...c] = a;
+            var [...[e, f]] = x;
+            var [...{g: h}] = y;
+            f(b, c, e, f, g);
+        }
+    }
+}
+
+destructuring_remove_unused_2: {
+    options = {
+        unused: true
+    }
+    input: {
+        function a() {
+            var unused = "foo";
+            var a = [,,1];
+            var [b] = a;
+            f(b);
+        }
+        function b() {
+            var unused = "foo";
+            var a = [{a: [1]}];
+            var [{b: a}] = a;
+            f(b);
+        }
+    }
+    expect: {
+        function a() {
+            var a = [,,1];
+            var [b] = a;
+            f(b);
+        }
+        function b() {
+            var a = [{a: [1]}];
+            var [{b: a}] = a;
+            f(b);
+        }
+    }
+}
+
+object_destructuring_may_need_parentheses: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        ({a, b} = {a: 1, b: 2});
+    }
+    expect_exact: "({a,b}={a:1,b:2});"
+}
+
+destructuring_with_undefined_as_default_assignment: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        [foo = undefined] = bar;
+        [foo = void 0] = bar;
+    }
+    expect: {
+        [foo] = bar;
+        [foo] = bar;
+    }
+}
+
+destructuring_dont_evaluate_with_undefined_as_default_assignment: {
+    options = {
+        evaluate: false
+    }
+    input: {
+        [foo = undefined] = bar;
+    }
+    expect: {
+        [foo = void 0] = bar;
+    }
+}
+
+reduce_vars: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+    }
+    input: {
+        {const [aa, [bb, cc]] = dd;}
+        {let [aa, [bb, cc]] = dd;}
+        var [aa, [bb, cc]] = dd;
+        [aa, [bb, cc]] = dd;
+        {const {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        {let {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
+        ({aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}});
+        const [{a},b] = c;
+        let [{d},e] = f;
+        var [{g},h] = i;
+        [{a},b] = c;
+        for (const [x,y] in pairs);
+        for (let [x,y] in pairs);
+        for (var [x,y] in pairs);
+        for ([x,y] in pairs);
+    }
+    expect: {
+        {const [aa, [bb, cc]] = dd;}
+        {let [aa, [bb, cc]] = dd;}
+        var [aa, [bb, cc]] = dd;
+        [aa, [bb, cc]] = dd;
+        {const {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        {let {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
+        ({aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}});
+        const [{a},b] = c;
+        let [{d},e] = f;
+        var [{g},h] = i;
+        [{a},b] = c;
+        for (const [x,y] in pairs);
+        for (let [x,y] in pairs);
+        for (var [x,y] in pairs);
+        for ([x,y] in pairs);
+    }
+}
+
+unused: {
+    options = {
+        unused: true,
+    }
+    input: {
+        let { foo: [, , ...a] } = { foo: [1, 2, 3, 4], bar: 5 };
+        console.log(a);
+    }
+    expect: {
+        let { foo: [, , ...a] } = { foo: [1, 2, 3, 4], bar: 5 };
+        console.log(a);
+    }
+}
+
+issue_1886: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        let [a] = [1];
+        console.log(a);
+    }
+    expect: {
+        let [a] = [1];
+        console.log(a);
+    }
+}
+
+destructuring_decl_of_numeric_key: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    input: {
+        let { 3: x } = { [1 + 2]: 42 };
+        console.log(x);
+    }
+    expect: {
+        let { 3: x } = { [3]: 42 };
+        console.log(x);
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+destructuring_decl_of_computed_key: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    input: {
+        let four = 4;
+        let { [7 - four]: x } = { [1 + 2]: 42 };
+        console.log(x);
+    }
+    expect: {
+        let four = 4;
+        let { [7 - four]: x } = { [3]: 42 };
+        console.log(x);
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+destructuring_assign_of_numeric_key: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    input: {
+        let x;
+        ({ 3: x } = { [1 + 2]: 42 });
+        console.log(x);
+    }
+    expect: {
+        let x;
+        ({ 3: x } = { [3]: 42 });
+        console.log(x);
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+destructuring_assign_of_computed_key: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    input: {
+        let x;
+        let four = 4;
+        ({ [(5 + 2) - four]: x } = { [1 + 2]: 42 });
+        console.log(x);
+    }
+    expect: {
+        let x;
+        let four = 4;
+        ({ [7 - four]: x } = { [3]: 42 });
+        console.log(x);
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+mangle_destructuring_decl: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    mangle = {
+    }
+    input: {
+        function test(opts) {
+            let a = opts.a || { e: 7, n: 8 };
+            let { t, e, n, s =  5 + 4, o, r } = a;
+            console.log(t, e, n, s, o, r);
+        }
+        test({a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 }});
+        test({});
+    }
+    expect: {
+        function test(t) {
+            let e = t.a || { e: 7, n: 8 };
+            let {t: n,  e: o,  n: s,  s: l = 9,  o: a,  r: c} = e;
+            console.log(n, o, s, l, a, c);
+        }
+        test({ a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 } });
+        test({});
+    }
+    expect_stdout: [
+        "1 2 3 4 5 6",
+        "undefined 7 8 9 undefined undefined",
+    ]
+    node_version: ">=6"
+}
+
+mangle_destructuring_decl_collapse_vars: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        unused: true,
+    }
+    mangle = {
+    }
+    input: {
+        function test(opts) {
+            let a = opts.a || { e: 7, n: 8 };
+            let { t, e, n, s =  5 + 4, o, r } = a;
+            console.log(t, e, n, s, o, r);
+        }
+        test({a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 }});
+        test({});
+    }
+    expect: {
+        function test(t) {
+            let e = t.a || { e: 7, n: 8 };
+            let {t: n,  e: o,  n: s,  s: l = 9,  o: a,  r: c} = e;
+            console.log(n, o, s, l, a, c);
+        }
+        test({ a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 } });
+        test({});
+    }
+    expect_stdout: [
+        "1 2 3 4 5 6",
+        "undefined 7 8 9 undefined undefined",
+    ]
+    node_version: ">=6"
+}
+
+mangle_destructuring_assign_toplevel_true: {
+    options = {
+        toplevel: true,
+        evaluate: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        function test(opts) {
+            let s, o, r;
+            let a = opts.a || { e: 7, n: 8 };
+            ({ t, e, n, s =  5 + 4, o, r } = a);
+            console.log(t, e, n, s, o, r);
+        }
+        let t, e, n;
+        test({a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 }});
+        test({});
+    }
+    expect: {
+        function e(e) {
+            let l, s, a;
+            let c = e.a || { e: 7, n: 8 };
+            ({t: n,  e: o,  n: t,  s: l = 9,  o: s,  r: a} = c);
+            console.log(n, o, t, l, s, a);
+        }
+        let n, o, t;
+        e({ a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 } });
+        e({});
+    }
+    expect_stdout: [
+        "1 2 3 4 5 6",
+        "undefined 7 8 9 undefined undefined",
+    ]
+    node_version: ">=6"
+}
+
+mangle_destructuring_assign_toplevel_false: {
+    options = {
+        toplevel: false,
+        evaluate: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: false,
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        function test(opts) {
+            let s, o, r;
+            let a = opts.a || { e: 7, n: 8 };
+            ({ t, e, n, s = 9, o, r } = a);
+            console.log(t, e, n, s, o, r);
+        }
+        let t, e, n;
+        test({a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 }});
+        test({});
+    }
+    expect: {
+        function test(o) {
+            let s, l, a;
+            let c = o.a || { e: 7, n: 8 };
+            ({t,  e,  n,  s = 9,  o: l,  r: a} = c);
+            console.log(t, e, n, s, l, a);
+        }
+        let t, e, n;
+        test({ a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 } });
+        test({});
+    }
+    expect_stdout: [
+        "1 2 3 4 5 6",
+        "undefined 7 8 9 undefined undefined",
+    ]
+    node_version: ">=6"
+}
+
+mangle_destructuring_decl_array: {
+    options = {
+        evaluate: true,
+        unused: true,
+        toplevel: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        var [, t, e, n, s, o = 2, r = [ 1 + 2 ]] = [ 9, 8, 7, 6 ];
+        console.log(t, e, n, s, o, r);
+    }
+    expect: {
+        var [, o,  l,  a,  c,  e = 2,  g = [ 3 ]] = [ 9, 8, 7, 6 ];
+        console.log(o, l, a, c, e, g);
+    }
+    expect_stdout: "8 7 6 undefined 2 [ 3 ]"
+    node_version: ">=6"
+}
+
+anon_func_with_destructuring_args: {
+    options = {
+        evaluate: true,
+        unused: true,
+        toplevel: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    beautify = {
+        ecma: 5,
+    }
+    input: {
+        (function({foo = 1 + 0, bar = 2}, [car = 3, far = 4]) {
+            console.log(foo, bar, car, far);
+        })({bar: 5 - 0}, [, 6]);
+    }
+    expect: {
+        (function({foo: o = 1, bar: n = 2}, [a = 3, b = 4]) {
+            console.log(o, n, a, b);
+        })({bar: 5}, [, 6]);
+    }
+    expect_stdout: "1 5 3 6"
+    node_version: ">=6"
+}
+
+arrow_func_with_destructuring_args: {
+    options = {
+        evaluate: true,
+        unused: true,
+        toplevel: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    beautify = {
+        ecma: 5,
+    }
+    input: {
+        (({foo = 1 + 0, bar = 2}, [car = 3, far = 4]) => {
+            console.log(foo, bar, car, far);
+        })({bar: 5 - 0}, [, 6]);
+    }
+    expect: {
+        (({foo: o = 1, bar: a = 2}, [b = 3, l = 4]) => {
+            console.log(o, a, b, l);
+        })({bar: 5}, [, 6]);
+    }
+    expect_stdout: "1 5 3 6"
+    node_version: ">=6"
+}
+
+issue_2044_ecma_5: {
+    beautify = {
+        beautify: false,
+        ecma: 5,
+    }
+    input: {
+        ({x : a = 1, y = 2 + b, z = 3 - c} = obj);
+    }
+    expect_exact: "({x:a=1,y:y=2+b,z:z=3-c}=obj);"
+}
+
+issue_2044_ecma_6: {
+    beautify = {
+        beautify: false,
+        ecma: 6,
+    }
+    input: {
+        ({x : a = 1, y = 2 + b, z = 3 - c} = obj);
+    }
+    expect_exact: "({x:a=1,y=2+b,z=3-c}=obj);"
+}
+
+issue_2044_ecma_5_beautify: {
+    beautify = {
+        beautify: true,
+        ecma: 5,
+    }
+    input: {
+        ({x : a = 1, y = 2 + b, z = 3 - c} = obj);
+    }
+    expect_exact: "({x: a = 1, y: y = 2 + b, z: z = 3 - c} = obj);"
+}
+
+issue_2044_ecma_6_beautify: {
+    beautify = {
+        beautify: true,
+        ecma: 6,
+    }
+    input: {
+        ({x : a = 1, y = 2 + b, z = 3 - c} = obj);
+    }
+    expect_exact: "({x: a = 1, y = 2 + b, z = 3 - c} = obj);"
+}
+
+issue_2140: {
+    options = {
+        unused: true,
+    }
+    input: {
+        !function() {
+            var t = {};
+            console.log(([t.a] = [42])[0]);
+        }();
+    }
+    expect: {
+        !function() {
+            var t = {};
+            console.log(([t.a] = [42])[0]);
+        }();
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}

test/compress/directives.js

@@ -0,0 +1,10 @@
+class_directives_compression: {
+    input: {
+        class foo {
+            foo() {
+                "use strict";
+            }
+        }
+    }
+    expect_exact: "class foo{foo(){}}"
+}

test/compress/evaluate.js

@@ -1,6 +1,7 @@
 and: {
     options = {
-        evaluate: true
+        evaluate: true,
+        side_effects: true,
     }
     input: {
         var a;
@@ -76,7 +77,8 @@ and: {
 
 or: {
     options = {
-        evaluate: true
+        evaluate: true,
+        side_effects: true,
     }
     input: {
         var a;
@@ -158,7 +160,8 @@ or: {
 
 unary_prefix: {
     options = {
-        evaluate: true
+        evaluate: true,
+        side_effects: true,
     }
     input: {
         a = !0 && b;
@@ -224,6 +227,100 @@ positive_zero: {
     expect_stdout: true
 }
 
+pow: {
+    options = { evaluate: true }
+    input: {
+        var a = 5 ** 3;
+    }
+    expect: {
+        var a = 125;
+    }
+}
+
+pow_sequence: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a = 2 ** 3 ** 2;
+    }
+    expect: {
+        var a = 512;
+    }
+}
+
+pow_mixed: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a = 5 + 2 ** 3 + 5;
+        var b = 5 * 3 ** 2;
+        var c = 5 ** 3 * 2;
+        var d = 5 ** +3;
+    }
+    expect: {
+        var a = 18;
+        var b = 45;
+        var c = 250;
+        var d = 125;
+    }
+}
+
+pow_with_right_side_evaluating_to_unary: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a = (4 - 7) ** foo;
+        var b = ++bar ** 3;
+        var c = --baz ** 2;
+    }
+    expect_exact: "var a=(-3)**foo;var b=++bar**3;var c=--baz**2;"
+}
+
+pow_with_number_constants: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a = 5 ** NaN;
+        /* NaN exponent results to NaN */
+        var b = 42 ** +0;
+        /* +0 exponent results to NaN */
+        var c = 42 ** -0;
+        /* -0 exponent results to NaN */
+        var d = NaN ** 1;
+        /* NaN with non-zero exponent is NaN */
+        var e = 2 ** Infinity;
+        /* abs(base) > 1 with Infinity as exponent is Infinity */
+        var f = 2 ** -Infinity;
+        /* abs(base) > 1 with -Infinity as exponent is +0 */
+        var g = (-7) ** (0.5);
+        var h = 2324334 ** 34343443;
+        var i = (-2324334) ** 34343443;
+        var j = 2 ** (-3);
+        var k = 2.0 ** -3;
+        var l = 2.0 ** (5 - 7);
+        var m = 3 ** -10;  // Result will be 0.000016935087808430286, which is too long
+    }
+    expect: {
+        var a = NaN;
+        var b = 1;
+        var c = 1;
+        var d = NaN;
+        var e = 1/0;
+        var f = 0;
+        var g = NaN;
+        var h = 1/0;
+        var i = -1/0;
+        var j = .125;
+        var k = .125;
+        var l = .25;
+        var m = 3 ** -10;
+    }
+}
+
 unsafe_constant: {
     options = {
         evaluate  : true,
@@ -250,22 +347,27 @@ unsafe_constant: {
 
 unsafe_object: {
     options = {
-        evaluate  : true,
-        unsafe    : true
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
     }
     input: {
+        var o = { a: 1 };
         console.log(
-            ({a:1}) + 1,
-            ({a:1}).a + 1,
-            ({a:1}).b + 1,
-            ({a:1}).a.b + 1
+            o + 1,
+            o.a + 1,
+            o.b + 1,
+            o.a.b + 1
         );
     }
     expect: {
+        var o = { a: 1 };
         console.log(
-            ({a:1}) + 1,
+            o + 1,
             2,
-            ({a:1}).b + 1,
+            o.b + 1,
             1..b + 1
         );
     }
@@ -274,22 +376,27 @@ unsafe_object: {
 
 unsafe_object_nested: {
     options = {
-        evaluate  : true,
-        unsafe    : true
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
     }
     input: {
+        var o = { a: { b: 1 } };
         console.log(
-            ({a:{b:1}}) + 1,
-            ({a:{b:1}}).a + 1,
-            ({a:{b:1}}).b + 1,
-            ({a:{b:1}}).a.b + 1
+            o + 1,
+            o.a + 1,
+            o.b + 1,
+            o.a.b + 1
         );
     }
     expect: {
+        var o = { a: { b: 1 } };
         console.log(
-            ({a:{b:1}}) + 1,
-            ({a:{b:1}}).a + 1,
-            ({a:{b:1}}).b + 1,
+            o + 1,
+            o.a + 1,
+            o.b + 1,
             2
         );
     }
@@ -298,21 +405,26 @@ unsafe_object_nested: {
 
 unsafe_object_complex: {
     options = {
-        evaluate  : true,
-        unsafe    : true
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
     }
     input: {
+        var o = { a: { b: 1 }, b: 1 };
         console.log(
-            ({a:{b:1},b:1}) + 1,
-            ({a:{b:1},b:1}).a + 1,
-            ({a:{b:1},b:1}).b + 1,
-            ({a:{b:1},b:1}).a.b + 1
+            o + 1,
+            o.a + 1,
+            o.b + 1,
+            o.a.b + 1
         );
     }
     expect: {
+        var o = { a: { b: 1 }, b: 1 };
         console.log(
-            ({a:{b:1},b:1}) + 1,
-            ({a:{b:1},b:1}).a + 1,
+            o + 1,
+            o.a + 1,
             2,
             2
         );
@@ -322,22 +434,27 @@ unsafe_object_complex: {
 
 unsafe_object_repeated: {
     options = {
-        evaluate  : true,
-        unsafe    : true
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
     }
     input: {
+        var o = { a: { b: 1 }, a: 1 };
         console.log(
-            ({a:{b:1},a:1}) + 1,
-            ({a:{b:1},a:1}).a + 1,
-            ({a:{b:1},a:1}).b + 1,
-            ({a:{b:1},a:1}).a.b + 1
+            o + 1,
+            o.a + 1,
+            o.b + 1,
+            o.a.b + 1
         );
     }
     expect: {
+        var o = { a: { b: 1 }, a: 1 };
         console.log(
-            ({a:{b:1},a:1}) + 1,
+            o + 1,
             2,
-            ({a:{b:1},a:1}).b + 1,
+            o.b + 1,
             1..b + 1
         );
     }
@@ -347,6 +464,7 @@ unsafe_object_repeated: {
 unsafe_object_accessor: {
     options = {
         evaluate: true,
+        reduce_funcs: true,
         reduce_vars: true,
         unsafe: true,
     }
@@ -370,10 +488,11 @@ unsafe_object_accessor: {
     }
 }
 
-unsafe_function: {
+prop_function: {
     options = {
-        evaluate  : true,
-        unsafe    : true
+        evaluate: true,
+        properties: true,
+        side_effects: true,
     }
     input: {
         console.log(
@@ -386,9 +505,9 @@ unsafe_function: {
     expect: {
         console.log(
             ({a:{b:1},b:function(){}}) + 1,
-            ({a:{b:1},b:function(){}}).a + 1,
-            ({a:{b:1},b:function(){}}).b + 1,
-            ({a:{b:1},b:function(){}}).a.b + 1
+            ({b:1}) + 1,
+            function(){} + 1,
+            2
         );
     }
     expect_stdout: true
@@ -614,10 +733,11 @@ unsafe_string_bad_index: {
     expect_stdout: true
 }
 
-unsafe_prototype_function: {
+prototype_function: {
     options = {
-        evaluate  : true,
-        unsafe    : true
+        evaluate: true,
+        properties: true,
+        side_effects: true,
     }
     input: {
         var a = ({valueOf: 0}) < 1;
@@ -636,26 +756,27 @@ unsafe_prototype_function: {
         var d = ({toString: 0}) + "";
         var e = (({valueOf: 0}) + "")[2];
         var f = (({toString: 0}) + "")[2];
-        var g = ({valueOf: 0}).valueOf();
-        var h = "" + ({toString: 0});
+        var g = 0();
+        var h = 0();
     }
 }
 
 call_args: {
     options = {
         evaluate: true,
+        inline: true,
+        reduce_funcs: true,
         reduce_vars: true,
-        toplevel: true,
     }
     input: {
-        var a = 1;
+        const a = 1;
         console.log(a);
         +function(a) {
             return a;
         }(a);
     }
     expect: {
-        var a = 1;
+        const a = 1;
         console.log(1);
         +(1, 1);
     }
@@ -665,19 +786,21 @@ call_args: {
 call_args_drop_param: {
     options = {
         evaluate: true,
+        inline: true,
         keep_fargs: false,
+        reduce_funcs: true,
         reduce_vars: true,
-        toplevel: true,
         unused: true,
     }
     input: {
-        var a = 1;
+        const a = 1;
         console.log(a);
         +function(a) {
             return a;
         }(a, b);
     }
     expect: {
+        const a = 1;
         console.log(1);
         +(b, 1);
     }
@@ -780,13 +903,15 @@ unsafe_charAt_noop: {
     input: {
         console.log(
             s.charAt(0),
-            "string".charAt(x)
+            "string".charAt(x),
+            (typeof x).charAt()
         );
     }
     expect: {
         console.log(
             s.charAt(0),
-            "string".charAt(x)
+            "string".charAt(x),
+            (typeof x)[0]
         );
     }
 }
@@ -990,3 +1115,410 @@ Infinity_NaN_undefined_LHS: {
         "}",
     ]
 }
+
+issue_1964_1: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unsafe_regexp: false,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var long_variable_name = /\s/;
+            console.log(long_variable_name.source);
+            return "a b c".split(long_variable_name)[1];
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            var long_variable_name = /\s/;
+            console.log(long_variable_name.source);
+            return "a b c".split(long_variable_name)[1];
+        }
+        console.log(f());
+    }
+    expect_stdout: [
+        "\\s",
+        "b",
+    ]
+}
+
+issue_1964_2: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unsafe_regexp: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var long_variable_name = /\s/;
+            console.log(long_variable_name.source);
+            return "a b c".split(long_variable_name)[1];
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            console.log(/\s/.source);
+            return "a b c".split(/\s/)[1];
+        }
+        console.log(f());
+    }
+    expect_stdout: [
+        "\\s",
+        "b",
+    ]
+}
+
+array_slice_index: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log([1,2,3].slice(1)[1]);
+    }
+    expect: {
+        console.log(3);
+    }
+    expect_stdout: "3"
+}
+
+string_charCodeAt: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log("foo".charCodeAt("bar".length));
+    }
+    expect: {
+        console.log(NaN);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_2207_1: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(String.fromCharCode(65));
+        console.log(Math.max(3, 6, 2, 7, 3, 4));
+        console.log(Math.cos(1.2345));
+        console.log(Math.cos(1.2345) - Math.sin(4.321));
+        console.log(Math.pow(Math.PI, Math.E - Math.LN10));
+    }
+    expect: {
+        console.log("A");
+        console.log(7);
+        console.log(Math.cos(1.2345));
+        console.log(1.2543732512566947);
+        console.log(1.6093984514472044);
+    }
+    expect_stdout: true
+}
+
+issue_2207_2: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(Math.E);
+        console.log(Math.LN10);
+        console.log(Math.LN2);
+        console.log(Math.LOG2E);
+        console.log(Math.LOG10E);
+        console.log(Math.PI);
+        console.log(Math.SQRT1_2);
+        console.log(Math.SQRT2);
+    }
+    expect: {
+        console.log(Math.E);
+        console.log(Math.LN10);
+        console.log(Math.LN2);
+        console.log(Math.LOG2E);
+        console.log(Math.LOG10E);
+        console.log(Math.PI);
+        console.log(Math.SQRT1_2);
+        console.log(Math.SQRT2);
+    }
+    expect_stdout: true
+}
+
+issue_2207_3: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(Number.MAX_VALUE);
+        console.log(Number.MIN_VALUE);
+        console.log(Number.NaN);
+        console.log(Number.NEGATIVE_INFINITY);
+        console.log(Number.POSITIVE_INFINITY);
+    }
+    expect: {
+        console.log(Number.MAX_VALUE);
+        console.log(5e-324);
+        console.log(NaN);
+        console.log(-1/0);
+        console.log(1/0);
+    }
+    expect_stdout: true
+}
+
+issue_2231_1: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(Object.keys(void 0));
+    }
+    expect: {
+        console.log(Object.keys(void 0));
+    }
+    expect_stdout: true
+    expect_warnings: [
+        "WARN: Error evaluating Object.keys(void 0) [test/compress/evaluate.js:1284,20]",
+    ]
+}
+
+issue_2231_2: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(Object.getOwnPropertyNames(null));
+    }
+    expect: {
+        console.log(Object.getOwnPropertyNames(null));
+    }
+    expect_stdout: true
+    expect_warnings: [
+        "WARN: Error evaluating Object.getOwnPropertyNames(null) [test/compress/evaluate.js:1301,20]",
+    ]
+}
+
+issue_2231_3: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(Object.keys({ foo: "bar" })[0]);
+    }
+    expect: {
+        console.log("foo");
+    }
+    expect_stdout: "foo"
+}
+
+self_comparison_1: {
+    options = {
+        evaluate: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var o = { n: NaN };
+        console.log(o.n == o.n, o.n === o.n, o.n != o.n, o.n !== o.n, typeof o.n);
+    }
+    expect: {
+        console.log(false, false, true, true, "number");
+    }
+    expect_stdout: "false false true true 'number'"
+}
+
+self_comparison_2: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { n: NaN };
+        console.log(o.n == o.n, o.n === o.n, o.n != o.n, o.n !== o.n, typeof o.n);
+    }
+    expect: {
+        console.log(false, false, true, true, "number");
+    }
+    expect_stdout: "false false true true 'number'"
+}
+
+issue_2535_1: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        if ((x() || true) || y()) z();
+        if ((x() || true) && y()) z();
+        if ((x() && true) || y()) z();
+        if ((x() && true) && y()) z();
+        if ((x() || false) || y()) z();
+        if ((x() || false) && y()) z();
+        if ((x() && false) || y()) z();
+        if ((x() && false) && y()) z();
+    }
+    expect: {
+        if (x(), 1) z();
+        if (x(), y()) z();
+        if (x() || y()) z();
+        if (x() && y()) z();
+        if (x() || y()) z();
+        if (x() && y()) z();
+        if (x(), y()) z();
+        if (x(), 0) z();
+    }
+}
+
+issue_2535_2: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        (x() || true) || y();
+        (x() || true) && y();
+        (x() && true) || y();
+        (x() && true) && y();
+        (x() || false) || y();
+        (x() || false) && y();
+        (x() && false) || y();
+        (x() && false) && y();
+    }
+    expect: {
+        x(),
+        x(), y(),
+        x() || y(),
+        x() && y(),
+        x() || y(),
+        x() && y(),
+        x(), y(),
+        x();
+    }
+}
+
+issue_2535_3: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        console.log(Object(1) && 1 && 2);
+        console.log(Object(1) && true && 1 && 2 && Object(2));
+        console.log(Object(1) && true && 1 && null && 2 && Object(2));
+        console.log(2 == Object(1) || 0 || void 0 || null);
+        console.log(2 == Object(1) || 0 || void 0 || null || Object(2));
+        console.log(2 == Object(1) || 0 || void 0 || "ok" || null || Object(2));
+    }
+    expect: {
+        console.log(Object(1) && 2);
+        console.log(Object(1) && Object(2));
+        console.log(Object(1) && null);
+        console.log(2 == Object(1) || null);
+        console.log(2 == Object(1) || Object(2));
+        console.log(2 == Object(1) || "ok");
+    }
+    expect_stdout: true
+    expect_warnings: [
+        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1429,20]",
+        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1430,20]",
+        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1431,20]",
+        "WARN: Condition left of && always false [test/compress/evaluate.js:1431,20]",
+        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1432,20]",
+        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1433,20]",
+        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1434,20]",
+        "WARN: Condition left of || always true [test/compress/evaluate.js:1434,20]",
+    ]
+}
+
+issue_2822: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log([ function() {}, "PASS", "FAIL" ][1]);
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+string_case: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log("İ".toLowerCase().charCodeAt(0));
+        console.log("I".toLowerCase().charCodeAt(0));
+        console.log("Ş".toLowerCase().charCodeAt(0));
+        console.log("Ğ".toLowerCase().charCodeAt(0));
+        console.log("Ü".toLowerCase().charCodeAt(0));
+        console.log("Ö".toLowerCase().charCodeAt(0));
+        console.log("Ç".toLowerCase().charCodeAt(0));
+        console.log("i".toUpperCase().charCodeAt(0));
+        console.log("ı".toUpperCase().charCodeAt(0));
+        console.log("ş".toUpperCase().charCodeAt(0));
+        console.log("ğ".toUpperCase().charCodeAt(0));
+        console.log("ü".toUpperCase().charCodeAt(0));
+        console.log("ö".toUpperCase().charCodeAt(0));
+        console.log("ç".toUpperCase().charCodeAt(0));
+    }
+    expect: {
+        console.log(105);
+        console.log(105);
+        console.log(351);
+        console.log(287);
+        console.log(252);
+        console.log(246);
+        console.log(231);
+        console.log(73);
+        console.log(73);
+        console.log(350);
+        console.log(286);
+        console.log(220);
+        console.log(214);
+        console.log(199);
+    }
+    expect_stdout: [
+        "105",
+        "105",
+        "351",
+        "287",
+        "252",
+        "246",
+        "231",
+        "73",
+        "73",
+        "350",
+        "286",
+        "220",
+        "214",
+        "199",
+    ]
+}

test/compress/expansions.js

@@ -0,0 +1,71 @@
+
+expand_arguments: {
+    input: {
+        func(a, ...rest);
+        func(...all);
+    }
+    expect_exact: "func(a,...rest);func(...all);"
+}
+
+expand_expression_arguments: {
+    input: {
+        f(...a.b);
+        f(...a.b());
+        f(...(a));
+        f(...(a.b));
+        f(...a[i]);
+    }
+    expect_exact: "f(...a.b);f(...a.b());f(...a);f(...a.b);f(...a[i]);"
+}
+
+expand_parameters: {
+    input: {
+        (function (a, ...b){});
+        (function (...args){});
+    }
+    expect_exact: "(function(a,...b){});(function(...args){});"
+}
+
+avoid_spread_in_ternary: {
+    options = {
+        comparisons: true,
+        conditionals: true,
+        evaluate: true,
+    }
+    input: {
+        function print(...x) {
+            console.log(...x);
+        }
+        var a = [1, 2], b = [3, 4], m = Math;
+
+        if (m)
+            print(a);
+        else
+            print(b);
+
+        if (m)
+            print(...a);
+        else
+            print(b);
+
+        if (m.no_such_property)
+            print(a);
+        else
+            print(...b);
+    }
+    expect: {
+        function print(...x) {
+            console.log(...x);
+        }
+        var a = [ 1, 2 ], b = [ 3, 4 ], m = Math;
+        print(m ? a : b);
+        m ? print(...a) : print(b);
+        m.no_such_property ? print(a) : print(...b);
+    }
+    expect_stdout: [
+        "[ 1, 2 ]",
+        "1 2",
+        "3 4",
+    ]
+    node_version: ">=6"
+}

test/compress/export.js

@@ -0,0 +1,446 @@
+issue_2038_1: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export var V = 1;
+        export let L = 2;
+        export const C = 3;
+    }
+    expect: {
+        export var V = 1;
+        export let L = 2;
+        export const C = 3;
+    }
+}
+
+issue_2038_2: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        let LET = 1;
+        const CONST = 2;
+        var VAR = 3;
+        export { LET, CONST, VAR };
+    }
+    expect: {
+        let t = 1;
+        const e = 2;
+        var o = 3;
+        export { t as LET, e as CONST, o as VAR };
+    }
+}
+
+issue_2126: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        import { foo as bar, cat as dog } from "stuff";
+        console.log(bar, dog);
+        export { bar as qux };
+        export { dog };
+    }
+    expect: {
+        import { foo as o, cat as s } from "stuff";
+        console.log(o, s);
+        export { o as qux };
+        export { s as dog };
+    }
+}
+
+beautify: {
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        export { A as B, C as D };
+    }
+    expect_exact: "export { A as B, C as D };"
+}
+
+issue_2131: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function no() {
+            console.log(42);
+        }
+        function go() {
+            console.log(42);
+        }
+        var X = 1, Y = 2;
+        export function main() {
+            go(X);
+        };
+    }
+    expect: {
+        function go() {
+            console.log(42);
+        }
+        var X = 1;
+        export function main() {
+            go(X);
+        };
+    }
+}
+
+issue_2129: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export const { keys } = Object;
+    }
+    expect: {
+        export const { keys } = Object;
+    }
+}
+
+async_func: {
+    options = {
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        export async function Foo(x){};
+    }
+    expect: {
+        export async function Foo(){};
+    }
+}
+
+issue_2134_1: {
+    options = {
+        keep_fargs: false,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function Foo(x){};
+        Foo.prototype = {};
+    }
+    expect: {
+        export function Foo(){};
+        Foo.prototype = {};
+    }
+}
+
+issue_2134_2: {
+    options = {
+        keep_fargs: false,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export async function Foo(x){};
+        Foo.prototype = {};
+    }
+    expect: {
+        export async function Foo(){};
+        Foo.prototype = {};
+    }
+}
+
+redirection: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        let foo = 1, bar = 2;
+        export { foo as delete };
+        export { bar as default };
+        export { foo as var } from "module.js";
+    }
+    expect: {
+        let e = 1, o = 2;
+        export { e as delete };
+        export { o as default };
+        export { foo as var } from "module.js";
+    }
+}
+
+keyword_invalid_1: {
+    input: {
+        export { default };
+    }
+    expect: {
+        export { default };
+    }
+}
+
+keyword_invalid_2: {
+    input: {
+        export { default as Alias };
+    }
+    expect: {
+        export { default as Alias };
+    }
+}
+
+keyword_invalid_3: {
+    input: {
+        export { default as default };
+    }
+    expect: {
+        export { default as default };
+    }
+}
+
+keyword_valid_1: {
+    input: {
+        export { default } from "module.js";
+    }
+    expect: {
+        export { default } from "module.js";
+    }
+}
+
+keyword_valid_2: {
+    input: {
+        export { default as Alias } from "module.js";
+    }
+    expect: {
+        export { default as Alias } from "module.js";
+    }
+}
+
+keyword_valid_3: {
+    input: {
+        export { default as default } from "module.js";
+    }
+    expect: {
+        export { default as default } from "module.js";
+    }
+}
+
+dynamic_import: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        import traditional from './traditional.js';
+        function imp(x) {
+            return import(x);
+        }
+        import("module_for_side_effects.js");
+        let dynamic = import("some/module.js");
+        dynamic.foo();
+    }
+    expect: {
+        import o from "./traditional.js";
+        function t(o) {
+            return import(o);
+        }
+        import("module_for_side_effects.js");
+        let r = import("some/module.js");
+        r.foo();
+    }
+}
+
+trailing_comma: {
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        export const a = 1;
+    }
+    expect_exact: "export const a = 1;"
+}
+
+export_default_anonymous_function: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function () {
+            foo();
+        }
+    }
+    expect_exact: "export default function(){foo()};"
+}
+
+export_default_arrow: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default () => foo();
+    }
+    expect_exact: "export default()=>foo();"
+}
+
+export_default_anonymous_generator: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function * () {
+            yield foo();
+        }
+    }
+    expect_exact: "export default function*(){yield foo()};"
+}
+
+export_default_anonymous_async_function: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default async function() {
+            return await foo();
+        }
+    }
+    expect_exact: "export default async function(){return await foo()};"
+}
+
+export_default_async_arrow_function: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default async () => await foo();
+    }
+    expect_exact: "export default async()=>await foo();"
+}
+
+export_default_named_generator: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function * gen() {
+            yield foo();
+        }
+    }
+    expect_exact: "export default function*gen(){yield foo()};"
+}
+
+export_default_named_async_function: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default async function bar() {
+            return await foo();
+        }
+    }
+    expect_exact: "export default async function bar(){return await foo()};"
+}
+
+export_default_anonymous_class: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default class {
+            constructor() {
+                foo();
+            }
+        };
+    }
+    expect_exact: "export default class{constructor(){foo()}};"
+}
+
+export_default_anonymous_function_not_call: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function(){}(foo);
+    }
+    // FIXME: should be `export default function(){};foo;`
+    expect_exact: "export default function(){}(foo);"
+}
+
+export_default_anonymous_generator_not_call: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function*(){}(foo);
+    }
+    // agrees with `acorn` and `babylon 7`
+    expect_exact: "export default function*(){};foo;"
+}
+
+export_default_anonymous_async_function_not_call: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default async function(){}(foo);
+    }
+    // agrees with `acorn` and `babylon 7`
+    expect_exact: "export default async function(){};foo;"
+}

test/compress/expression.js

@@ -0,0 +1,52 @@
+pow: {
+    input: {
+        var a = 2 ** 7;
+        var b = 3;
+        b **= 2;
+    }
+    expect: {
+        var a = 2 ** 7;
+        var b = 3;
+        b **= 2;
+    }
+}
+
+pow_with_number_constants: {
+    input: {
+        var a = 5 ** NaN;
+        var b = 42 ** +0;
+        var c = 42 ** -0;
+        var d = NaN ** 1;
+        var e = 2 ** Infinity;
+        var f = 2 ** -Infinity;
+    }
+    expect: {
+        var a = 5 ** NaN;
+        var b = 42 ** +0;
+        var c = 42 ** -0;
+        var d = NaN ** 1;
+        var e = 2 ** (1/0);
+        var f = 2 ** (-1/0);
+    }
+}
+
+pow_with_parentheses: {
+    input: {
+        var g = (-7) ** (0.5);
+        var h = 2324334 ** 34343443;
+        var i = (-2324334) ** 34343443;
+        var j = 2 ** (-3);
+        var k = 2.0 ** -3;
+        var l = 2.0 ** (5 - 7);
+    }
+    expect_exact: "var g=(-7)**.5;var h=2324334**34343443;var i=(-2324334)**34343443;var j=2**-3;var k=2**-3;var l=2**(5-7);"
+}
+
+pow_with_unary_between_brackets: {
+    input: {
+        var a = (-(+5)) ** 3;
+    }
+    expect: {
+        var a = (-+5)**3;
+    }
+}

test/compress/global_defs.js

@@ -37,6 +37,7 @@ object: {
                 VALUE: 42,
             },
         },
+        side_effects: true,
         unsafe: true,
     }
     input: {
@@ -120,7 +121,7 @@ mixed: {
         properties: true,
     }
     input: {
-        var FOO = { BAR: 0 };
+        const FOO = { BAR: 0 };
         console.log(FOO.BAR);
         console.log(++CONFIG.DEBUG);
         console.log(++CONFIG.VALUE);
@@ -130,7 +131,7 @@ mixed: {
         console.log(CONFIG);
     }
     expect: {
-        var FOO = { BAR: 0 };
+        const FOO = { BAR: 0 };
         console.log("moo");
         console.log(++CONFIG.DEBUG);
         console.log(++CONFIG.VALUE);
@@ -140,9 +141,9 @@ mixed: {
         console.log(CONFIG);
     }
     expect_warnings: [
-        'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:126,22]',
         'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:127,22]',
-        'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:129,8]',
+        'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:128,22]',
+        'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:130,8]',
     ]
 }
 
@@ -160,3 +161,39 @@ issue_1801: {
         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();
+    }
+}

test/compress/hoist.js

@@ -0,0 +1,85 @@
+
+hoist_vars: {
+    options = {
+        hoist_vars: true
+    }
+    input: {
+        function a() {
+            bar();
+            var var1;
+            var var2;
+        }
+        function b(anArg) {
+            bar();
+            var var1;
+            var anArg;
+        }
+    }
+    expect: {
+        function a() {
+            var var1, var2;  // Vars go up and are joined
+            bar();
+        }
+        function b(anArg) {
+            var var1;
+            bar();
+            // But vars named like arguments go away!
+        }
+    }
+}
+
+hoist_funs: {
+    options = {
+        hoist_funs: true
+    }
+    input: {
+        function a() {
+            bar();
+            function foo() {}
+        }
+    }
+    expect: {
+        function a() {
+            function foo() {}  // Funs go up
+            bar();
+        }
+    }
+}
+
+hoist_no_destructurings: {
+    options = {
+        hoist_vars: true,
+        hoist_funs: true
+    }
+    input: {
+        function a([anArg]) {
+            bar();
+            var var1;
+            var anArg;  // Because anArg is already declared, this goes away!
+        }
+    }
+    expect: {
+        function a([anArg]) {
+            var var1;
+            bar();
+        }
+    }
+}
+
+dont_hoist_var_destructurings: {
+    options = {
+        hoist_vars: true,
+        hoist_funs: true
+    }
+    input: {
+        function x() {
+            // If foo is null or undefined, this should be an exception
+            var {x,y} = foo;
+        }
+    }
+    expect: {
+        function x() {
+            var {x,y} = foo;
+        }
+    }
+}

test/compress/hoist_props.js

@@ -0,0 +1,921 @@
+issue_2377_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        var obj_foo = 1, obj_cube = function(x) {
+            return x * x * x;
+        };
+        console.log(obj_foo, obj_cube(3));
+    }
+    expect_stdout: "1 27"
+}
+
+issue_2377_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        console.log(1, (x = 3, x * x * x));
+        var x;
+    }
+    expect_stdout: "1 27"
+}
+
+issue_2377_3: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        passes: 4,
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        console.log(1, 27);
+    }
+    expect_stdout: "1 27"
+}
+
+direct_access_1: {
+    options = {
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        var obj = {
+            a: 1,
+            b: 2,
+        };
+        for (var k in obj) a++;
+        console.log(a, obj.a);
+    }
+    expect: {
+        var a = 0;
+        var obj = {
+            a: 1,
+            b: 2,
+        };
+        for (var k in obj) a++;
+        console.log(a, obj.a);
+    }
+    expect_stdout: "2 1"
+}
+
+direct_access_2: {
+    options = {
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { a: 1 };
+        var f = function(k) {
+            if (o[k]) return "PASS";
+        };
+        console.log(f("a"));
+    }
+    expect: {
+        var o = { a: 1 };
+        console.log(function(k) {
+            if (o[k]) return "PASS";
+        }("a"));
+    }
+    expect_stdout: "PASS"
+}
+
+direct_access_3: {
+    options = {
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { a: 1 };
+        o.b;
+        console.log(o.a);
+    }
+    expect: {
+        var o = { a: 1 };
+        o.b;
+        console.log(o.a);
+    }
+    expect_stdout: "1"
+}
+
+single_use: {
+    options = {
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            bar: function() {
+                return 42;
+            },
+        };
+        console.log(obj.bar());
+    }
+    expect: {
+        console.log({
+            bar: function() {
+                return 42;
+            },
+        }.bar());
+    }
+}
+
+name_collision_1: {
+    options = {
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var obj_foo = 1;
+        var obj_bar = 2;
+        function f() {
+            var obj = {
+                foo: 3,
+                bar: 4,
+                "b-r": 5,
+                "b+r": 6,
+                "b!r": 7,
+            };
+            console.log(obj_foo, obj.foo, obj.bar, obj["b-r"], obj["b+r"], obj["b!r"]);
+        }
+        f();
+    }
+    expect: {
+        var obj_foo = 1;
+        var obj_bar = 2;
+        function f() {
+            var obj_foo$0 = 3,
+                obj_bar = 4,
+                obj_b_r = 5,
+                obj_b_r$0 = 6,
+                obj_b_r$1 = 7;
+            console.log(obj_foo, obj_foo$0, obj_bar, obj_b_r, obj_b_r$0, obj_b_r$1);
+        }
+        f();
+    }
+    expect_stdout: "1 3 4 5 6 7"
+}
+
+name_collision_2: {
+    options = {
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            p: 1,
+            0: function(x) {
+                return x;
+            },
+            1: function(x) {
+                return x + 1;
+            }
+        }, o__$0 = 2, o__$1 = 3;
+        console.log(o.p === o.p, o[0](4), o[1](5), o__$0, o__$1);
+    }
+    expect: {
+        var o_p = 1,
+            o__ = function(x) {
+                return x;
+            },
+            o__$2 = function(x) {
+                return x + 1;
+            },
+            o__$0 = 2,
+            o__$1 = 3;
+        console.log(o_p === o_p, o__(4), o__$2(5), o__$0, o__$1);
+    }
+    expect_stdout: "true 4 6 2 3"
+}
+
+name_collision_3: {
+    options = {
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            p: 1,
+            0: function(x) {
+                return x;
+            },
+            1: function(x) {
+                return x + 1;
+            }
+        }, o__$0 = 2, o__$1 = 3;
+        console.log(o.p === o.p, o[0](4), o[1](5));
+    }
+    expect: {
+        var o_p = 1,
+            o__ = function(x) {
+                return x;
+            },
+            o__$2 = function(x) {
+                return x + 1;
+            },
+            o__$0 = 2,
+            o__$1 = 3;
+        console.log(o_p === o_p, o__(4), o__$2(5));
+    }
+    expect_stdout: "true 4 6"
+}
+
+contains_this_1: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p);
+    }
+    expect: {
+        console.log(1, 1);
+    }
+    expect_stdout: "1 1"
+}
+
+contains_this_2: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u);
+    }
+    expect: {
+        console.log(1, 1, function() {
+            return this === this;
+        });
+    }
+    expect_stdout: true
+}
+
+contains_this_3: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u());
+    }
+    expect: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u());
+    }
+    expect_stdout: "1 1 true"
+}
+
+hoist_class: {
+    options = {
+        comparisons: true,
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        keep_classnames: true,
+        keep_fnames: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function run(c, v) {
+            return new c(v).value;
+        }
+        var o = {
+            p: class Foo {
+                constructor(value) {
+                    this.value = value * 10;
+                }
+            },
+            x: 1,
+            y: 2,
+        };
+        console.log(o.p.name, o.p === o.p, run(o.p, o.x), run(o.p, o.y));
+    }
+    expect: {
+        function run(c, v) {
+            return new c(v).value;
+        }
+        var o_p = class Foo {
+            constructor(value) {
+                this.value = 10 * value;
+            }
+        };
+        console.log(o_p.name, true, run(o_p, 1), run(o_p, 2));
+    }
+    node_version: ">=6"
+    expect_stdout: "Foo true 10 20"
+}
+
+hoist_class_with_new: {
+    options = {
+        comparisons: true,
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        keep_classnames: true,
+        keep_fnames: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            p: class Foo {
+                constructor(value) {
+                    this.value = value * 10;
+                }
+            },
+            x: 1,
+            y: 2,
+        };
+        console.log(o.p.name, o.p === o.p, new o.p(o.x).value, new o.p(o.y).value);
+    }
+    expect: {
+        var o_p = class Foo {
+            constructor(value) {
+                this.value = 10 * value;
+            }
+        };
+        console.log(o_p.name, true, new o_p(1).value, new o_p(2).value);
+    }
+    node_version: ">=6"
+    expect_stdout: "Foo true 10 20"
+}
+
+hoist_function_with_call: {
+    options = {
+        comparisons: true,
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        keep_fnames: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            p: function Foo(value) {
+                return 10 * value;
+            },
+            x: 1,
+            y: 2
+        };
+        console.log(o.p.name, o.p === o.p, o.p(o.x), o.p(o.y));
+    }
+    expect: {
+        var o = {
+            p: function Foo(value) {
+                return 10 * value;
+            },
+            x: 1,
+            y: 2
+        };
+        console.log(o.p.name, o.p == o.p, o.p(o.x), o.p(o.y));
+    }
+    expect_stdout: "Foo true 10 20"
+}
+
+new_this: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: 1,
+            b: 2,
+            f: function(a) {
+                this.b = a;
+            }
+        };
+        console.log(new o.f(o.a).b, o.b);
+    }
+    expect: {
+        console.log(new function(a) {
+            this.b = a;
+        }(1).b, 2);
+    }
+    expect_stdout: "1 2"
+}
+
+issue_2462: {
+    options = {
+        hoist_props: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+    }
+    input: {
+        export const Foo = {
+            a: 1,
+            b: () => 2
+        };
+    }
+    expect: {
+        export const Foo = {
+            a: 1,
+            b: () => 2
+        };
+    }
+}
+
+issue_2473_1: {
+    options = {
+        hoist_props: false,
+        reduce_vars: true,
+        top_retain: [ "x", "y" ],
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var x = {};
+        var y = [];
+        var z = {};
+    }
+    expect: {
+        var x = {};
+        var y = [];
+    }
+}
+
+issue_2473_2: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        top_retain: [ "x", "y" ],
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var x = {};
+        var y = [];
+        var z = {};
+    }
+    expect: {
+        var x = {};
+        var y = [];
+    }
+}
+
+issue_2473_3: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        top_retain: "o",
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: 1,
+            b: 2,
+        };
+        console.log(o.a, o.b);
+    }
+    expect: {
+        var o = {
+            a: 1,
+            b: 2,
+        };
+        console.log(o.a, o.b);
+    }
+    expect_stdout: "1 2"
+}
+
+issue_2473_4: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        top_retain: "o",
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var o = {
+                a: 1,
+                b: 2,
+            };
+            console.log(o.a, o.b);
+        })();
+    }
+    expect: {
+        (function() {
+            var o_a = 1, o_b = 2;
+            console.log(o_a, o_b);
+        })();
+    }
+    expect_stdout: "1 2"
+}
+
+issue_2508_1: {
+    options = {
+        collapse_vars: true,
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: [ 1 ],
+            f: function(x) {
+                console.log(x);
+            }
+        };
+        o.f(o.a);
+    }
+    expect: {
+        (function(x) {
+            console.log(x);
+        })([ 1 ]);
+    }
+    expect_stdout: true
+}
+
+issue_2508_2: {
+    options = {
+        collapse_vars: true,
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: { b: 2 },
+            f: function(x) {
+                console.log(x);
+            }
+        };
+        o.f(o.a);
+    }
+    expect: {
+        (function(x) {
+            console.log(x);
+        })({ b: 2 });
+    }
+    expect_stdout: true
+}
+
+issue_2508_3: {
+    options = {
+        collapse_vars: true,
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: [ o ],
+            f: function(x) {
+                console.log(x);
+            }
+        };
+        o.f(o.a);
+    }
+    expect: {
+        var o = {
+            a: [ o ],
+            f: function(x) {
+                console.log(x);
+            }
+        };
+        o.f(o.a);
+    }
+    expect_stdout: true
+}
+
+issue_2508_4: {
+    options = {
+        collapse_vars: true,
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: { b: o },
+            f: function(x) {
+                console.log(x);
+            }
+        };
+        o.f(o.a);
+    }
+    expect: {
+        var o = {
+            a: { b: o },
+            f: function(x) {
+                console.log(x);
+            }
+        };
+        o.f(o.a);
+    }
+    expect_stdout: true
+}
+
+issue_2508_5: {
+    options = {
+        collapse_vars: true,
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            f: function(x) {
+                console.log(x);
+            }
+        };
+        o.f(o.f);
+    }
+    expect: {
+        var o_f = function(x) {
+            console.log(x);
+        };
+        o_f(o_f);
+    }
+    expect_stdout: true
+}
+
+issue_2508_6: {
+    options = {
+        collapse_vars: true,
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            f: x => {
+                console.log(x);
+            }
+        };
+        o.f(o.f);
+    }
+    expect: {
+        var o_f = x => {
+            console.log(x);
+        };
+        o_f(o_f);
+    }
+    expect_stdout: true
+}
+
+issue_2519: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_props: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function testFunc() {
+            var dimensions = {
+                minX: 5,
+                maxX: 6,
+            };
+            var scale = 1;
+            var d = {
+                x: (dimensions.maxX + dimensions.minX) / 2,
+            };
+            return d.x * scale;
+        }
+        console.log(testFunc());
+    }
+    expect: {
+        function testFunc() {
+            return 1 * ((6 + 5) / 2);
+        }
+        console.log(testFunc());
+    }
+    expect_stdout: "5.5"
+}
+
+toplevel_const: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: false,
+    }
+    input: {
+        const a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect: {
+        const a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect_stdout: "3"
+}
+
+toplevel_let: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: false,
+    }
+    input: {
+        let a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect: {
+        let a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect_stdout: "3"
+    node_version: ">=6"
+}
+
+toplevel_var: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: false,
+    }
+    input: {
+        var a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect: {
+        var a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect_stdout: "3"
+}
+
+undefined_key: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        join_vars: true,
+        passes: 4,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, o = {};
+        o[a] = 1;
+        o.b = 2;
+        console.log(o[a] + o.b);
+    }
+    expect: {
+        console.log(3);
+    }
+    expect_stdout: "3"
+}

test/compress/hoist_vars.js

@@ -88,3 +88,24 @@ sequences_funs: {
         }
     }
 }
+
+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;
+        }
+    }
+}

test/compress/html_comments.js

@@ -53,3 +53,12 @@ html_comment_in_string_literal: {
     }
     expect_exact: 'function f(){return"\\x3c!--HTML--\\x3ecomment in\\x3c!--string literal--\\x3e"}';
 }
+
+html_comment_after_multiline_comment: {
+    input: {
+        var foo; /*
+*/-->   var bar;
+        var foobar;
+    }
+    expect_exact: "var foo;var foobar;"
+}

test/compress/if_return.js

@@ -302,3 +302,191 @@ issue_1437_conditionals: {
         }
     }
 }
+
+issue_512: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function a() {
+            if (b()) {
+                c();
+                return;
+            }
+            throw e;
+        }
+    }
+    expect: {
+        function a() {
+            if (!b()) throw e;
+            c();
+        }
+    }
+}
+
+issue_1317: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        !function(a) {
+            if (a) return;
+            let b = 1;
+            function g() {
+                return b;
+            }
+            console.log(g());
+        }();
+    }
+    expect: {
+        !function(a) {
+            if (a) return;
+            let b = 1;
+            function g() {
+                return b;
+            }
+            console.log(g());
+        }();
+    }
+    expect_stdout: "1"
+    node_version: ">=6"
+}
+
+issue_1317_strict: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        !function(a) {
+            if (a) return;
+            let b = 1;
+            function g() {
+                return b;
+            }
+            console.log(g());
+        }();
+    }
+    expect: {
+        "use strict";
+        !function(a) {
+            if (a) return;
+            let b = 1;
+            function g() {
+                return b;
+            }
+            console.log(g());
+        }();
+    }
+    expect_stdout: "1"
+    node_version: ">=4"
+}
+
+if_var_return: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+    }
+    input: {
+        function f() {
+            var a;
+            return;
+            var b;
+        }
+        function g() {
+            var a;
+            if (u()) {
+                var b;
+                return v();
+                var c;
+            }
+            var d;
+            if (w()) {
+                var e;
+                return x();
+                var f;
+            } else {
+                var g;
+                y();
+                var h;
+            }
+            var i;
+            z();
+            var j;
+        }
+    }
+    expect: {
+        function f() {
+            var a, b;
+        }
+        function g() {
+            var a, b, c, d, e, f, g, h, i, j;
+            return u() ? v() : w() ? x() : (y(), z(), void 0);
+        }
+    }
+}
+
+if_if_return_return: {
+    options = {
+        conditionals: true,
+        if_return: true,
+    }
+    input: {
+        function f(a, b) {
+            if (a) {
+                if (b)
+                    return b;
+                return;
+            }
+            g();
+        }
+    }
+    expect: {
+        function f(a, b) {
+            if (a)
+                return b || void 0;
+            g();
+        }
+    }
+}
+
+issue_2747: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function f(baz) {
+            if (baz === 0) {
+                return null;
+            }
+            let r;
+            if (baz > 2) {
+                r = 4;
+            } else {
+                r = 5;
+            }
+            return r;
+        }
+        console.log(f(0), f(1), f(3));
+    }
+    expect: {
+        "use strict";
+        function f(baz) {
+            if (0 === baz) return null;
+            let r;
+            return r = baz > 2 ? 4 : 5, r;
+        }
+        console.log(f(0), f(1), f(3));
+    }
+    expect_stdout: "null 5 4"
+    node_version: ">=4"
+}

test/compress/issue-1001.js

@@ -0,0 +1,8 @@
+parenthesis_strings_in_parenthesis: {
+    input: {
+        var foo = ('(');
+        a(')');
+
+    }
+    expect_exact: 'var foo="(";a(")");'
+}

test/compress/issue-1034.js

@@ -2,7 +2,7 @@ non_hoisted_function_after_return: {
     options = {
         hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
         evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
-        if_return: true, join_vars: true, cascade: true, side_effects: true
+        if_return: true, join_vars: true, side_effects: true
     }
     input: {
         function foo(x) {
@@ -38,7 +38,7 @@ non_hoisted_function_after_return_2a: {
     options = {
         hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
         evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
-        if_return: true, join_vars: true, cascade: true, side_effects: true,
+        if_return: true, join_vars: true, side_effects: true,
         collapse_vars: false, passes: 2, warnings: "verbose"
     }
     input: {
@@ -71,11 +71,13 @@ non_hoisted_function_after_return_2a: {
         "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:51,16]",
         "WARN: Dropping unused variable a [test/compress/issue-1034.js:48,20]",
         "WARN: Dropping unused function nope [test/compress/issue-1034.js:55,21]",
+        "WARN: pass 0: last_count: Infinity, count: 37",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:53,12]",
         "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:53,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:56,12]",
         "WARN: Dropping unused variable b [test/compress/issue-1034.js:51,20]",
         "WARN: Dropping unused variable c [test/compress/issue-1034.js:53,16]",
+        "WARN: pass 1: last_count: 37, count: 18",
     ]
 }
 
@@ -83,7 +85,7 @@ non_hoisted_function_after_return_2b: {
     options = {
         hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
         evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
-        if_return: true, join_vars: true, cascade: true, side_effects: true,
+        if_return: true, join_vars: true, side_effects: true,
         collapse_vars: false
     }
     input: {
@@ -109,10 +111,146 @@ non_hoisted_function_after_return_2b: {
     }
     expect_warnings: [
         // duplicate warnings no longer emitted
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:95,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:95,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:97,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:97,12]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:101,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:97,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:97,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:99,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:99,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:103,12]",
+    ]
+}
+
+non_hoisted_function_after_return_strict: {
+    options = {
+        hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
+        evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
+        if_return: true, join_vars: true, side_effects: 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:133,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:136,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:139,12]",
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:140,21]",
+    ]
+}
+
+non_hoisted_function_after_return_2a_strict: {
+    options = {
+        hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
+        evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
+        if_return: true, join_vars: true, side_effects: true,
+        collapse_vars: false, passes: 2, warnings: "verbose"
+    }
+    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 unreachable code [test/compress/issue-1034.js:175,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:175,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:178,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:178,16]",
+        "WARN: Dropping unused variable a [test/compress/issue-1034.js:175,20]",
+        "WARN: Dropping unused function nope [test/compress/issue-1034.js:182,21]",
+        "WARN: pass 0: last_count: Infinity, count: 48",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:180,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:180,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:183,12]",
+        "WARN: Dropping unused variable b [test/compress/issue-1034.js:178,20]",
+        "WARN: Dropping unused variable c [test/compress/issue-1034.js:180,16]",
+        "WARN: pass 1: last_count: 48, count: 29",
+    ]
+}
+
+non_hoisted_function_after_return_2b_strict: {
+    options = {
+        hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
+        evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
+        if_return: true, join_vars: true, side_effects: true,
+        collapse_vars: false
+    }
+    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: [
+        // duplicate warnings no longer emitted
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:229,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:229,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:231,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:231,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:235,12]",
     ]
 }

test/compress/issue-1041.js

@@ -1,6 +1,20 @@
+const_declaration: {
+    options = {
+        evaluate: true
+    };
+
+    input: {
+        const goog = goog || {};
+    }
+    expect: {
+        const goog = goog || {};
+    }
+}
+
 const_pragma: {
     options = {
         evaluate: true,
+        reduce_funcs: true,
         reduce_vars: true,
     };
 
@@ -16,6 +30,7 @@ const_pragma: {
 not_const: {
     options = {
         evaluate: true,
+        reduce_funcs: true,
         reduce_vars: true,
     };
 

test/compress/issue-1043.js

@@ -0,0 +1,30 @@
+issue_1043: {
+    options = {
+        side_effects: true
+    };
+
+    input: {
+        function* range(start = 0, end = null, step = 1) {
+            if (end == null) {
+                end = start;
+                start = 0;
+            }
+
+            for (let i = start; i < end; i += step) {
+                yield i;
+            }
+        }
+    }
+
+    expect: {
+        function* range(start = 0, end = null, step = 1) {
+            if (null == end) {
+                end = start;
+                start = 0;
+            }
+
+            for (let i = start; i < end; i += step)
+                yield i;
+        }
+    }
+}

test/compress/issue-1044.js

@@ -0,0 +1,9 @@
+issue_1044: {
+    options = { evaluate: true, conditionals: true };
+    input: {
+        const mixed = Base ? class extends Base {} : class {}
+    }
+    expect: {
+        const mixed = Base ? class extends Base {} : class {}
+    }
+}

test/compress/issue-1052.js

@@ -1,90 +1,91 @@
 multiple_functions: {
-    options = { if_return: true, hoist_funs: false };
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
     input: {
         ( function() {
             if ( !window ) {
                 return;
             }
-
             function f() {}
             function g() {}
         } )();
     }
     expect: {
         ( function() {
-            function f() {}
-            function g() {}
-
             // NOTE: other compression steps will reduce this
             // down to just `window`.
             if ( window );
+            function f() {}
+            function g() {}
         } )();
     }
 }
 
 single_function: {
-    options = { if_return: true, hoist_funs: false };
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
     input: {
         ( function() {
             if ( !window ) {
                 return;
             }
-
             function f() {}
         } )();
     }
     expect: {
         ( function() {
-            function f() {}
-
             if ( window );
+            function f() {}
         } )();
     }
 }
 
 deeply_nested: {
-    options = { if_return: true, hoist_funs: false };
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
     input: {
         ( function() {
             if ( !window ) {
                 return;
             }
-
             function f() {}
             function g() {}
-
             if ( !document ) {
                 return;
             }
-
             function h() {}
         } )();
     }
     expect: {
         ( function() {
-            function f() {}
-            function g() {}
-
-            function h() {}
-
             // NOTE: other compression steps will reduce this
             // down to just `window`.
             if ( window )
                 if (document);
+            function f() {}
+            function g() {}
+            function h() {}
         } )();
     }
 }
 
 not_hoisted_when_already_nested: {
-    options = { if_return: true, hoist_funs: false };
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
     input: {
         ( function() {
             if ( !window ) {
                 return;
             }
-
             if ( foo ) function f() {}
-
         } )();
     }
     expect: {
@@ -94,3 +95,69 @@ not_hoisted_when_already_nested: {
         } )();
     }
 }
+
+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) 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 h() {}
+            if (window) function g() {}
+        }
+    }
+}
+
+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

@@ -190,7 +190,6 @@ assorted_Infinity_NaN_undefined_in_with_scope: {
         keep_fargs:    true,
         if_return:     true,
         join_vars:     true,
-        cascade:       true,
         side_effects:  true,
         sequences:     false,
         keep_infinity: false,
@@ -253,7 +252,6 @@ assorted_Infinity_NaN_undefined_in_with_scope_keep_infinity: {
         keep_fargs:    true,
         if_return:     true,
         join_vars:     true,
-        cascade:       true,
         side_effects:  true,
         sequences:     false,
         keep_infinity: true,

test/compress/issue-1212.js

@@ -0,0 +1,76 @@
+issue_1212_debug_false: {
+    options = {
+        global_defs   : { DEBUG: false },
+        sequences     : true,
+        properties    : true,
+        dead_code     : true,
+        conditionals  : true,
+        comparisons   : true,
+        evaluate      : true,
+        booleans      : true,
+        loops         : true,
+        unused        : true,
+        hoist_funs    : true,
+        keep_fargs    : true,
+        if_return     : true,
+        join_vars     : true,
+        collapse_vars : true,
+        side_effects  : true,
+    }
+    input: {
+        class foo {
+            bar() {
+                if (DEBUG)
+                    console.log("DEV");
+                else
+                    console.log("PROD");
+            }
+        }
+        new foo().bar();
+    }
+    expect: {
+        class foo{
+            bar() { console.log("PROD") }
+        }
+        (new foo).bar();
+    }
+}
+
+issue_1212_debug_true: {
+    options = {
+        global_defs   : { DEBUG: true },
+        sequences     : true,
+        properties    : true,
+        dead_code     : true,
+        conditionals  : true,
+        comparisons   : true,
+        evaluate      : true,
+        booleans      : true,
+        loops         : true,
+        unused        : true,
+        hoist_funs    : true,
+        keep_fargs    : true,
+        if_return     : true,
+        join_vars     : true,
+        collapse_vars : true,
+        side_effects  : true,
+    }
+    input: {
+        class foo {
+            bar() {
+                if (DEBUG)
+                    console.log("DEV");
+                else
+                    console.log("PROD");
+            }
+        }
+        new foo().bar();
+    }
+    expect: {
+        class foo{
+            bar() { console.log("DEV") }
+        }
+        (new foo).bar();
+    }
+}
+

test/compress/issue-1261.js

@@ -8,7 +8,6 @@ pure_function_calls: {
         unused       : true,
         if_return    : true,
         join_vars    : true,
-        cascade      : true,
         negate_iife  : true,
     }
     input: {
@@ -49,13 +48,13 @@ pure_function_calls: {
         a.b(), f.g();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:17,8]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:17,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:30,37]",
-        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:30,16]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:28,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:38,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:39,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:16,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:16,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:29,37]",
+        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:29,16]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:27,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:37,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:38,31]",
     ]
 }
 
@@ -69,7 +68,6 @@ pure_function_calls_toplevel: {
         unused       : true,
         if_return    : true,
         join_vars    : true,
-        cascade      : true,
         negate_iife  : true,
         toplevel     : true,
     }
@@ -96,6 +94,13 @@ pure_function_calls_toplevel: {
             })();
         })();
 
+        // 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();
@@ -105,15 +110,17 @@ pure_function_calls_toplevel: {
         a.b(), f.g();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:79,8]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:79,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:92,37]",
-        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:92,16]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:90,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:100,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:101,31]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:84,33]",
-        "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:84,12]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:77,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:77,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:90,37]",
+        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:90,16]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:88,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:105,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:106,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:82,33]",
+        "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:82,12]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:98,45]",
+        "WARN: Dropping unused variable MyClass [test/compress/issue-1261.js:98,12]",
     ]
 }
 
@@ -148,29 +155,29 @@ should_warn: {
         baz();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:128,61]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:128,23]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:128,23]",
-        "WARN: Boolean || always true [test/compress/issue-1261.js:129,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:129,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:129,23]",
-        "WARN: Condition left of || always true [test/compress/issue-1261.js:130,8]",
-        "WARN: Condition always true [test/compress/issue-1261.js:130,8]",
-        "WARN: Boolean && always false [test/compress/issue-1261.js:131,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:131,23]",
-        "WARN: Condition always false [test/compress/issue-1261.js:131,23]",
-        "WARN: Condition left of && always false [test/compress/issue-1261.js:132,8]",
-        "WARN: Condition always false [test/compress/issue-1261.js:132,8]",
-        "WARN: + in boolean context always true [test/compress/issue-1261.js:133,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:133,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:133,23]",
-        "WARN: + in boolean context always true [test/compress/issue-1261.js:134,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:134,31]",
-        "WARN: Condition always true [test/compress/issue-1261.js:134,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,61]",
         "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:136,24]",
-        "WARN: Condition always true [test/compress/issue-1261.js:136,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:137,31]",
-        "WARN: Condition always false [test/compress/issue-1261.js:137,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:135,23]",
+        "WARN: Boolean || always true [test/compress/issue-1261.js:136,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:136,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:136,23]",
+        "WARN: Condition left of || always true [test/compress/issue-1261.js:137,8]",
+        "WARN: Condition always true [test/compress/issue-1261.js:137,8]",
+        "WARN: Boolean && always false [test/compress/issue-1261.js:138,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:138,23]",
+        "WARN: Condition always false [test/compress/issue-1261.js:138,23]",
+        "WARN: Condition left of && always false [test/compress/issue-1261.js:139,8]",
+        "WARN: Condition always false [test/compress/issue-1261.js:139,8]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:140,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:140,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:140,23]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:141,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:141,31]",
+        "WARN: Condition always true [test/compress/issue-1261.js:141,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:142,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:143,24]",
+        "WARN: Condition always true [test/compress/issue-1261.js:143,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:144,31]",
+        "WARN: Condition always false [test/compress/issue-1261.js:144,8]",
     ]
 }

test/compress/issue-1275.js

@@ -9,7 +9,6 @@ string_plus_optimization: {
         unused        : true,
         if_return     : true,
         join_vars     : true,
-        cascade       : true,
         hoist_funs    : true,
     };
     input: {

test/compress/issue-1321.js

@@ -1,6 +1,8 @@
 issue_1321_no_debug: {
-    mangle_props = {
-        keep_quoted: true
+    mangle = {
+        properties: {
+            keep_quoted: true,
+        },
     }
     input: {
         var x = {};
@@ -10,17 +12,19 @@ issue_1321_no_debug: {
     }
     expect: {
         var x = {};
-        x.b = 1;
-        x["a"] = 2 * x.b;
-        console.log(x.b, x["a"]);
+        x.x = 1;
+        x["a"] = 2 * x.x;
+        console.log(x.x, x["a"]);
     }
     expect_stdout: true
 }
 
 issue_1321_debug: {
-    mangle_props = {
-        keep_quoted: true,
-        debug: ""
+    mangle = {
+        properties: {
+            debug: "",
+            keep_quoted: true,
+        },
     }
     input: {
         var x = {};
@@ -30,16 +34,18 @@ issue_1321_debug: {
     }
     expect: {
         var x = {};
-        x.a = 1;
-        x["_$foo$_"] = 2 * x.a;
-        console.log(x.a, x["_$foo$_"]);
+        x.x = 1;
+        x["_$foo$_"] = 2 * x.x;
+        console.log(x.x, x["_$foo$_"]);
     }
     expect_stdout: true
 }
 
 issue_1321_with_quoted: {
-    mangle_props = {
-        keep_quoted: false
+    mangle = {
+        properties: {
+            keep_quoted: false,
+        },
     }
     input: {
         var x = {};
@@ -49,9 +55,9 @@ issue_1321_with_quoted: {
     }
     expect: {
         var x = {};
-        x.a = 1;
-        x["b"] = 2 * x.a;
-        console.log(x.a, x["b"]);
+        x.x = 1;
+        x["o"] = 2 * x.x;
+        console.log(x.x, x["o"]);
     }
     expect_stdout: true
 }

test/compress/issue-1443.js

@@ -4,7 +4,7 @@ unsafe_undefined: {
     options = {
         conditionals: true,
         if_return: true,
-        unsafe: true
+        unsafe_undefined: true,
     }
     mangle = {}
     input: {
@@ -30,7 +30,7 @@ keep_fnames: {
     options = {
         conditionals: true,
         if_return: true,
-        unsafe: true
+        unsafe_undefined: true,
     }
     mangle = {
         keep_fnames: true

test/compress/issue-1446.js

@@ -1,6 +1,7 @@
 typeof_eq_undefined: {
     options = {
-        comparisons: true
+        comparisons: true,
+        typeofs: true,
     }
     input: {
         var a = typeof b != "undefined";
@@ -24,6 +25,7 @@ typeof_eq_undefined_ie8: {
     options = {
         comparisons: true,
         ie8: true,
+        typeofs: true,
     }
     input: {
         var a = typeof b != "undefined";
@@ -45,7 +47,8 @@ typeof_eq_undefined_ie8: {
 
 undefined_redefined: {
     options = {
-        comparisons: true
+        comparisons: true,
+        typeofs: true,
     }
     input: {
         function f(undefined) {
@@ -58,7 +61,8 @@ undefined_redefined: {
 
 undefined_redefined_mangle: {
     options = {
-        comparisons: true
+        comparisons: true,
+        typeofs: true,
     }
     mangle = {}
     input: {

test/compress/issue-1447.js

@@ -32,7 +32,6 @@ conditional_false_stray_else_in_loop: {
         hoist_vars   : true,
         join_vars    : true,
         if_return    : true,
-        cascade      : true,
         conditionals : false,
     }
     input: {

test/compress/issue-1466.js

@@ -0,0 +1,459 @@
+same_variable_in_multiple_for_loop: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        for (let i = 0; i < 3; i++) {
+            let a = 100;
+            console.log(i, a);
+            for (let i = 0; i < 2; i++) {
+                console.log(i, a);
+                let c = 2;
+                console.log(c);
+            }
+        }
+    }
+    expect: {
+        for (let o = 0; o < 3; o++) {
+            let l = 100;
+            console.log(o, l);
+            for (let o = 0; o < 2; o++) {
+                console.log(o, l);
+                let e = 2;
+                console.log(e);
+            }
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forOf: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp of test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let tmp of dd) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let o of test) {
+            console.log(o);
+            let e;
+            e = [ "e", "f", "g" ];
+            for (let o of e)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forIn: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp in test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let tmp in test) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let e in test) {
+            console.log(e);
+            let t;
+            t = [ "e", "f", "g" ];
+            for (let e in test)
+                console.log(e);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+different_variable_in_multiple_for_loop: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        for (let i = 0; i < 3; i++) {
+            let a = 100;
+            console.log(i, a);
+            for (let j = 0; j < 2; j++) {
+                console.log(j, a);
+                let c = 2;
+                console.log(c);
+            }
+        }
+    }
+    expect: {
+        for (let o = 0; o < 3; o++) {
+            let l = 100;
+            console.log(o, l);
+            for (let o = 0; o < 2; o++) {
+                console.log(o, l);
+                let e = 2;
+                console.log(e);
+            }
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+different_variable_in_multiple_forOf: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp of test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let t of dd) {
+                console.log(t);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let o of test) {
+            console.log(o);
+            let e;
+            e = [ "e", "f", "g" ];
+            for (let o of e)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+different_variable_in_multiple_forIn: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp in test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let t in test) {
+                console.log(t);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let e in test) {
+            console.log(e);
+            let t;
+            t = [ "e", "f", "g" ];
+            for (let e in test)
+                console.log(e);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forOf_sequences_let: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp of test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let tmp of dd) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let o of test) {
+            let e;
+            console.log(o), e = [ "e", "f", "g" ];
+            for (let o of e)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forOf_sequences_const: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (const tmp of test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (const tmp of dd) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (const o of test) {
+            let t;
+            console.log(o), t = [ "e", "f", "g" ];
+            for (const o of t)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forIn_sequences_let: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp in test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let tmp in test) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let e in test) {
+            let t;
+            console.log(e), t = [ "e", "f", "g" ];
+            for (let e in test)
+                console.log(e);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forIn_sequences_const: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (const tmp in test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (const tmp in test) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (const o in test) {
+            let t;
+            console.log(o), t = [ "e", "f", "g" ];
+            for (const o in test)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+more_variable_in_multiple_for: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        for (let a = 9, i = 0; i < 20; i += a) {
+            let b = a++ + i;
+            console.log(a, b, i);
+            for (let k = b, m = b*b, i = 0; i < 10; i++) {
+                console.log(a, b, m, k, i);
+            }
+        }
+    }
+    expect: {
+        for (let o = 9, l = 0; l < 20; l += o) {
+            let e = o++ + l;
+            console.log(o, e, l);
+            for (let l = e, t = e * e, c = 0; c < 10; c++)
+                console.log(o, e, t, l, c);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}

test/compress/issue-1588.js

@@ -61,7 +61,7 @@ unsafe_undefined: {
     options = {
         conditionals: true,
         if_return: true,
-        unsafe: true,
+        unsafe_undefined: true,
     }
     mangle = {}
     input: {
@@ -85,3 +85,15 @@ unsafe_undefined: {
     }
     expect_stdout: true
 }
+
+runtime_error: {
+    input: {
+        const a = 1;
+        console.log(a++);
+    }
+    expect: {
+        const a = 1;
+        console.log(a++);
+    }
+    expect_stdout: true
+}

test/compress/issue-1609.js

@@ -2,6 +2,7 @@ chained_evaluation_1: {
     options = {
         collapse_vars: true,
         evaluate: true,
+        reduce_funcs: true,
         reduce_vars: true,
         unused: true,
     }
@@ -28,6 +29,7 @@ chained_evaluation_2: {
     options = {
         collapse_vars: true,
         evaluate: true,
+        reduce_funcs: true,
         reduce_vars: true,
         unused: true,
     }

test/compress/issue-1639.js

@@ -2,7 +2,7 @@
 issue_1639_1: {
     options = {
         booleans: true,
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         evaluate: true,
         join_vars: true,
@@ -26,7 +26,7 @@ issue_1639_1: {
     }
     expect: {
         for (var a = 100, b = 10, L1 = 5; --L1 > 0;)
-            if (--b, !1) var ignore = 0;
+            if (--b, 0) var ignore = 0;
         console.log(a, b);
     }
     expect_stdout: true
@@ -35,7 +35,7 @@ issue_1639_1: {
 issue_1639_2: {
     options = {
         booleans: true,
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         evaluate: true,
         join_vars: true,
@@ -57,7 +57,7 @@ issue_1639_2: {
     expect: {
         var a = 100, b = 10;
         function f19() {
-            ++a, 1;
+            ++a, 0;
         }
         f19(),
         console.log(a, b);
@@ -68,7 +68,7 @@ issue_1639_2: {
 issue_1639_3: {
     options = {
         booleans: true,
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         evaluate: true,
         sequences: true,

test/compress/issue-1656.js

@@ -1,7 +1,6 @@
 f7: {
     options = {
         booleans: true,
-        cascade: true,
         collapse_vars: true,
         comparisons: true,
         conditionals: true,
@@ -15,6 +14,7 @@ f7: {
         negate_iife: true,
         passes: 3,
         properties: true,
+        reduce_funcs: true,
         reduce_vars: true,
         sequences: true,
         side_effects: true,
@@ -38,7 +38,7 @@ f7: {
         "var b = 10;",
         "",
         "!function() {",
-        "    for (;b = 100, !1; ) ;",
+        "    b = 100;",
         "}(), console.log(100, b);",
     ]
     expect_stdout: true

test/compress/issue-1673.js

@@ -1,5 +1,6 @@
 side_effects_catch: {
     options = {
+        reduce_funcs: true,
         reduce_vars: true,
         side_effects: true,
         unused: true,
@@ -34,6 +35,7 @@ side_effects_catch: {
 
 side_effects_else: {
     options = {
+        reduce_funcs: true,
         reduce_vars: true,
         side_effects: true,
         unused: true,
@@ -62,6 +64,7 @@ side_effects_else: {
 
 side_effects_finally: {
     options = {
+        reduce_funcs: true,
         reduce_vars: true,
         side_effects: true,
         unused: true,
@@ -98,6 +101,7 @@ side_effects_finally: {
 
 side_effects_label: {
     options = {
+        reduce_funcs: true,
         reduce_vars: true,
         side_effects: true,
         unused: true,
@@ -130,6 +134,7 @@ side_effects_label: {
 
 side_effects_switch: {
     options = {
+        reduce_funcs: true,
         reduce_vars: true,
         side_effects: true,
         unused: true,

test/compress/issue-1750.js

@@ -7,7 +7,7 @@ case_1: {
     input: {
         var a = 0, b = 1;
         switch (true) {
-          case a, true:
+          case a || true:
           default:
             b = 2;
           case true:
@@ -17,7 +17,7 @@ case_1: {
     expect: {
         var a = 0, b = 1;
         switch (true) {
-          case a, true:
+          case a || true:
             b = 2;
         }
         console.log(a, b);

test/compress/issue-1770.js

@@ -1,5 +1,7 @@
 mangle_props: {
-    mangle_props = {}
+    mangle = {
+        properties: true,
+    }
     input: {
         var obj = {
             undefined: 1,
@@ -54,10 +56,12 @@ mangle_props: {
 }
 
 numeric_literal: {
+    mangle = {
+        properties: true,
+    }
     beautify = {
         beautify: true,
     }
-    mangle_props = {}
     input: {
         var obj = {
             0: 0,
@@ -80,19 +84,19 @@ numeric_literal: {
         '    0: 0,',
         '    "-0": 1,',
         '    42: 2,',
-        '    "42": 3,',
+        '    42: 3,',
         '    37: 4,',
-        '    a: 5,',
+        '    o: 5,',
         '    1e42: 6,',
         '    b: 7,',
-        '    "1e+42": 8',
+        '    1e42: 8',
         '};',
         '',
         'console.log(obj[-0], obj[-""], obj["-0"]);',
         '',
         'console.log(obj[42], obj["42"]);',
         '',
-        'console.log(obj[37], obj["a"], obj[37], obj["37"]);',
+        'console.log(obj[37], obj["o"], obj[37], obj["37"]);',
         '',
         'console.log(obj[1e42], obj["b"], obj["1e+42"]);',
     ]
@@ -103,137 +107,3 @@ numeric_literal: {
         "8 7 8",
     ]
 }
-
-identifier: {
-    mangle_props = {}
-    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 = {
-            a: 1,
-            b: 2,
-            c: 3,
-            d: 4,
-            e: 5,
-            f: 6,
-            g: 7,
-            h: 8,
-            i: 9,
-            j: 10,
-            k: 11,
-            l: 12,
-            m: 13,
-            n: 14,
-            o: 15,
-            p: 16,
-            q: 17,
-            r: 18,
-            s: 19,
-            t: 20,
-            u: 21,
-            v: 22,
-            w: 23,
-            x: 24,
-            y: 25,
-            z: 26,
-            A: 27,
-            B: 28,
-            C: 29,
-            D: 30,
-            F: 31,
-            G: 32,
-            false: 33,
-            null: 34,
-            true: 35,
-            H: 36,
-            I: 37,
-            J: 38,
-            K: 39,
-            L: 40,
-            M: 41,
-            N: 42,
-            O: 43,
-            P: 44,
-            Q: 45,
-            R: 46,
-            S: 47,
-            T: 48,
-            U: 49,
-            V: 50,
-            W: 51,
-            X: 52,
-            Y: 53,
-            Z: 54,
-            $: 55,
-            _: 56,
-            aa: 57,
-            ba: 58,
-            ca: 59,
-            da: 60,
-            ea: 61,
-        };
-    }
-}

test/compress/issue-1787.js

@@ -1,6 +1,8 @@
 unary_prefix: {
     options = {
         evaluate: true,
+        inline: true,
+        reduce_funcs: true,
         reduce_vars: true,
         unused: true,
     }

test/compress/issue-1833.js

@@ -1,6 +1,7 @@
 iife_for: {
     options = {
         negate_iife: true,
+        reduce_funcs: true,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -26,6 +27,7 @@ iife_for: {
 iife_for_in: {
     options = {
         negate_iife: true,
+        reduce_funcs: true,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -51,6 +53,7 @@ iife_for_in: {
 iife_do: {
     options = {
         negate_iife: true,
+        reduce_funcs: true,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -80,6 +83,7 @@ iife_do: {
 iife_while: {
     options = {
         negate_iife: true,
+        reduce_funcs: true,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -130,5 +134,5 @@ label_while: {
             L: while (0) continue L;
         }
     }
-    expect_exact: "function f(){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-2001.js

@@ -0,0 +1,283 @@
+export_func_1: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f(){};
+    }
+    expect_exact: "export function f(){};"
+}
+
+export_func_2: {
+    options = {
+        hoist_funs: true,
+        side_effects: false,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f(){}(1);
+    }
+    expect_exact: "export function f(){};1;"
+}
+
+export_func_3: {
+    options = {
+        hoist_funs: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f(){}(1);
+    }
+    expect_exact: "export function f(){};"
+}
+
+export_default_func_1: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f(){};
+    }
+    expect_exact: "export default function f(){};"
+}
+
+export_default_func_2: {
+    options = {
+        hoist_funs: true,
+        side_effects: false,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f(){}(1);
+    }
+    expect_exact: "export default function f(){};1;"
+}
+
+export_default_func_3: {
+    options = {
+        hoist_funs: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f(){}(1);
+    }
+    expect_exact: "export default function f(){};"
+}
+
+export_class_1: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export class C {};
+    }
+    expect_exact: "export class C{};"
+}
+
+export_class_2: {
+    options = {
+        hoist_funs: true,
+        side_effects: false,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export class C {}(1);
+    }
+    expect_exact: "export class C{};1;"
+}
+
+export_class_3: {
+    options = {
+        hoist_funs: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export class C {}(1);
+    }
+    expect_exact: "export class C{};"
+}
+
+export_default_class_1: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class C {};
+    }
+    expect_exact: "export default class C{};"
+}
+
+export_default_class_2: {
+    options = {
+        hoist_funs: true,
+        side_effects: false,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class C {}(1);
+    }
+    expect_exact: "export default class C{};1;"
+}
+
+export_default_class_3: {
+    options = {
+        hoist_funs: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class C {}(1);
+    }
+    expect_exact: "export default class C{};"
+}
+
+export_mangle_1: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export function foo(one, two) {
+            return one - two;
+        };
+    }
+    expect_exact: "export function foo(o,n){return o-n};"
+}
+
+export_mangle_2: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function foo(one, two) {
+            return one - two;
+        };
+    }
+    expect_exact: "export default function foo(o,t){return o-t};"
+}
+
+export_mangle_3: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export class C {
+            go(one, two) {
+                var z = one;
+                return one - two + z;
+            }
+        };
+    }
+    expect_exact: "export class C{go(r,e){return r-e+r}};"
+}
+
+export_mangle_4: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default class C {
+            go(one, two) {
+                var z = one;
+                return one - two + z;
+            }
+        };
+    }
+    expect_exact: "export default class C{go(e,r){return e-r+e}};"
+}
+
+export_mangle_5: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default {
+            prop: function(one, two) {
+                return one - two;
+            }
+        };
+    }
+    expect_exact: "export default{prop:function(r,t){return r-t}};"
+}
+
+export_mangle_6: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var baz = 2;
+        export let foo = 1, bar = baz;
+    }
+    expect_exact: "var o=2;export let foo=1,bar=o;"
+}
+
+export_toplevel_1: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(){}
+        export function g(){};
+        export default function h(){};
+    }
+    expect: {
+        export function g(){};
+        export default function h(){};
+    }
+}
+
+export_toplevel_2: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        class A {}
+        export class B {};
+        export default class C {};
+    }
+    expect: {
+        export class B {};
+        export default class C {};
+    }
+}
+
+export_default_func_ref: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f(){};
+        f();
+    }
+    expect_exact: "export default function f(){};f();"
+}

test/compress/issue-203.js

@@ -0,0 +1,57 @@
+
+compress_new_function: {
+    options = {
+        unsafe: true,
+        unsafe_Function: true,
+    }
+    input: {
+        new Function("aa, bb", 'return aa;');
+    }
+    expect: {
+        Function("n,r", "return n");
+    }
+}
+
+compress_new_function_with_destruct: {
+    options = {
+        unsafe: true,
+        unsafe_Function: true,
+        ecma: 6
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        new Function("aa, [bb]", 'return aa;');
+        new Function("aa, {bb}", 'return aa;');
+        new Function("[[aa]], [{bb}]", 'return aa;');
+    }
+    expect: {
+        Function("n,[r]", "return n");
+        Function("n,{bb:b}", "return n");
+        Function("[[n]],[{bb:b}]", "return n");
+    }
+}
+
+compress_new_function_with_destruct_arrows: {
+    options = {
+        arrows: true,
+        unsafe_arrows: true,
+        unsafe: true,
+        unsafe_Function: true,
+        ecma: 6,
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        new Function("aa, [bb]", 'return aa;');
+        new Function("aa, {bb}", 'return aa;');
+        new Function("[[aa]], [{bb}]", 'return aa;');
+    }
+    expect: {
+        Function("n,[a]", "return n");
+        Function("b,{bb:n}", "return b");
+        Function("[[b]],[{bb:n}]", "return b");
+    }
+}

test/compress/issue-208.js

@@ -38,7 +38,7 @@ mixed: {
         }
     }
     input: {
-        var ENV = 3;
+        const ENV = 3;
         var FOO = 4;
         f(ENV * 10);
         --FOO;
@@ -49,7 +49,7 @@ mixed: {
         x = DEBUG;
     }
     expect: {
-        var ENV = 3;
+        const ENV = 3;
         var FOO = 4;
         f(10);
         --FOO;
@@ -60,7 +60,7 @@ mixed: {
         x = 0;
     }
     expect_warnings: [
-        'WARN: global_defs ENV redefined [test/compress/issue-208.js:41,12]',
+        'WARN: global_defs ENV redefined [test/compress/issue-208.js:41,14]',
         'WARN: global_defs FOO redefined [test/compress/issue-208.js:42,12]',
         'WARN: global_defs FOO redefined [test/compress/issue-208.js:44,10]',
         'WARN: global_defs DEBUG redefined [test/compress/issue-208.js:45,8]',

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-269.js

@@ -64,3 +64,27 @@ strings_concat: {
 		);
 	}
 }
+
+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:78,2]',
+	]
+}

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.protoype.caller not supported [test/compress/issue-2719.js:17,19]",
+        "WARN: Function.protoype.arguments not supported [test/compress/issue-2719.js:17,19]",
+    ]
+}

test/compress/issue-281.js

@@ -0,0 +1,498 @@
+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: {
+    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: {
+    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: {
+    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: {
+    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 = {
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        /*@__PURE__*/(function() {
+            console.log("hello");
+        }());
+    }
+    expect_exact: ""
+}
+
+pure_annotation_2: {
+    options = {
+        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 && a.var));
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        ++a && a.var, a++;
+        console.log(a);
+    }
+    expect_stdout: "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 && a.var));
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        ++a && a.var, a++;
+        console.log(a);
+    }
+    expect_stdout: "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-368.js

@@ -1,6 +1,6 @@
 collapse: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         sequences: true,
         side_effects: true,
         unused: true,
@@ -41,7 +41,7 @@ collapse: {
             return void 0 !== ('function' === typeof b ? b() : b) && c();
         }
         function f2(b) {
-            return b = c(), 'stirng' == typeof ('function' === typeof b ? b() : b) && d();
+            return 'stirng' == typeof ('function' === typeof (b = c()) ? b() : b) && d();
         }
         function f3(c) {
             var a;

test/compress/issue-637.js

@@ -17,6 +17,6 @@ wrongly_optimized: {
             foo();
         }
         // TODO: optimize to `func(), bar()`
-        (func(), 0) || bar();
+        (func(), 1) && bar();
     }
 }

test/compress/issue-640.js

@@ -100,7 +100,7 @@ wrongly_optimized: {
             foo();
         }
         // TODO: optimize to `func(), bar()`
-        if (func(), !0) bar();
+        if (func(), 1) bar();
     }
 }
 

test/compress/issue-747.js

@@ -1,37 +1,45 @@
 dont_reuse_prop: {
-    mangle_props = {
-        regex: /asd/
-    };
-
+    mangle = {
+        properties: {
+            regex: /asd/,
+        },
+    }
     input: {
+        "aaaaaaaaaabbbbb";
         var obj = {};
         obj.a = 123;
         obj.asd = 256;
         console.log(obj.a);
     }
     expect: {
+        "aaaaaaaaaabbbbb";
         var obj = {};
         obj.a = 123;
         obj.b = 256;
         console.log(obj.a);
     }
+    expect_stdout: "123"
 }
 
 unmangleable_props_should_always_be_reserved: {
-    mangle_props = {
-        regex: /asd/
-    };
-
+    mangle = {
+        properties: {
+            regex: /asd/,
+        },
+    }
     input: {
+        "aaaaaaaaaabbbbb";
         var obj = {};
         obj.asd = 256;
         obj.a = 123;
         console.log(obj.a);
     }
     expect: {
+        "aaaaaaaaaabbbbb";
         var obj = {};
         obj.b = 256;
         obj.a = 123;
         console.log(obj.a);
     }
-}
+    expect_stdout: "123"
+}

test/compress/issue-892.js

@@ -18,7 +18,6 @@ dont_mangle_arguments: {
         hoist_vars    : true,
         if_return     : true,
         join_vars     : true,
-        cascade       : true,
         side_effects  : true,
         negate_iife   : false
     };

test/compress/issue-926.js

@@ -0,0 +1,9 @@
+template_strings: {
+    input: {
+        foo(
+            `<span>${contents}</span>`,
+            `<a href="${url}">${text}</a>`
+        );
+    }
+    expect_exact: "foo(`<span>${contents}</span>`,`<a href=\"${url}\">${text}</a>`);"
+}

test/compress/issue-973.js

@@ -1,7 +1,8 @@
 this_binding_conditionals: {
     options = {
         conditionals: true,
-        evaluate    : true
+        evaluate: true,
+        side_effects: true,
     };
     input: {
         (1 && a)();
@@ -51,6 +52,7 @@ this_binding_collapse_vars: {
     options = {
         collapse_vars: true,
         toplevel: true,
+        unused: true,
     };
     input: {
         var c = a; c();

test/compress/issue-976.js

@@ -2,7 +2,7 @@ eval_collapse_vars: {
     options = {
         collapse_vars:true, sequences:false, properties:true, dead_code:true, conditionals:true,
         comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
-        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+        keep_fargs:true, if_return:true, join_vars:true, side_effects:true
     };
     input: {
         function f1() {

test/compress/issue-979.js

@@ -2,7 +2,7 @@ issue979_reported: {
     options = {
         sequences:true, properties:true, dead_code:true, conditionals:true,
         comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
-        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+        keep_fargs:true, if_return:true, join_vars:true, side_effects:true
     }
     input: {
         function f1() {
@@ -32,7 +32,7 @@ issue979_test_negated_is_best: {
     options = {
         sequences:true, properties:true, dead_code:true, conditionals:true,
         comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
-        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+        keep_fargs:true, if_return:true, join_vars:true, side_effects:true
     }
     input: {
         function f3() {

test/compress/join-vars.js

@@ -0,0 +1,40 @@
+only_vars: {
+    options = { join_vars: true };
+    input: {
+        let netmaskBinary = '';
+        for (let i = 0; i < netmaskBits; ++i) {
+            netmaskBinary += '1';
+        }
+    }
+    expect: {
+        let netmaskBinary = '';
+        for (let i = 0; i < netmaskBits; ++i) netmaskBinary += '1';
+    }
+}
+
+issue_1079_with_vars: {
+    options = { join_vars: true };
+    input: {
+        var netmaskBinary = '';
+        for (var i = 0; i < netmaskBits; ++i) {
+            netmaskBinary += '1';
+        }
+    }
+    expect: {
+        for (var netmaskBinary = '', i = 0; i < netmaskBits; ++i) netmaskBinary += '1';
+    }
+}
+
+issue_1079_with_mixed: {
+    options = { join_vars: true };
+    input: {
+        var netmaskBinary = '';
+        for (let i = 0; i < netmaskBits; ++i) {
+            netmaskBinary += '1';
+        }
+    }
+    expect: {
+        var netmaskBinary = ''
+        for (let i = 0; i < netmaskBits; ++i) netmaskBinary += '1';
+    }
+}

test/compress/loops.js

@@ -146,11 +146,57 @@ parse_do_while_without_semicolon: {
     }
 }
 
+
+keep_collapse_const_in_own_block_scope: {
+    options = {
+        join_vars: true,
+        loops: true
+    }
+    input: {
+        var i=2;
+        const c=5;
+        while(i--)
+            console.log(i);
+        console.log(c);
+    }
+    expect: {
+        var i=2;
+        const c=5;
+        for(;i--;)
+            console.log(i);
+        console.log(c);
+    }
+    expect_stdout: true
+}
+
+keep_collapse_const_in_own_block_scope_2: {
+    options = {
+        join_vars: true,
+        loops: true
+    }
+    input: {
+        const c=5;
+        var i=2; // Moves to loop, while it did not in previous test
+        while(i--)
+            console.log(i);
+        console.log(c);
+    }
+    expect: {
+        const c=5;
+        for(var i=2;i--;)
+            console.log(i);
+        console.log(c);
+    }
+    expect_stdout: true
+}
+
 evaluate: {
     options = {
-        loops: true,
         dead_code: true,
         evaluate: true,
+        loops: true,
+        passes: 2,
+        side_effects: true,
     };
     input: {
         while (true) {
@@ -436,3 +482,236 @@ do_switch: {
         } while (false);
     }
 }
+
+in_parenthesis_1: {
+    input: {
+        for (("foo" in {});0;);
+    }
+    expect_exact: 'for(("foo"in{});0;);'
+}
+
+in_parenthesis_2: {
+    input: {
+        for ((function(){ "foo" in {}; });0;);
+    }
+    expect_exact: 'for(function(){"foo"in{}};0;);'
+}
+
+init_side_effects: {
+    options = {
+        loops: true,
+        side_effects: true,
+    };
+    input: {
+        for (function() {}(), i = 0; i < 5; i++) console.log(i);
+        for (function() {}(); i < 10; i++) console.log(i);
+    }
+    expect: {
+        for (i = 0; i < 5; i++) console.log(i);
+        for (; i < 10; i++) console.log(i);
+    }
+    expect_stdout: true
+}
+
+dead_code_condition: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        loops: true,
+        sequences: true,
+    }
+    input: {
+        for (var a = 0, b = 5; (a += 1, 3) - 3 && b > 0; b--) {
+            var c = function() {
+                b--;
+            }(a++);
+        }
+        console.log(a);
+    }
+    expect: {
+        var c;
+        var a = 0, b = 5;
+        a += 1, 0,
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+issue_2740_1: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        for (; ; ) break;
+        for (a(); ; ) break;
+        for (; b(); ) break;
+        for (c(); d(); ) break;
+        for (; ; e()) break;
+        for (f(); ; g()) break;
+        for (; h(); i()) break;
+        for (j(); k(); l()) break;
+    }
+    expect: {
+        a();
+        b();
+        c();
+        d();
+        f();
+        h();
+        j();
+        k();
+    }
+}
+
+issue_2740_2: {
+    options = {
+        dead_code: true,
+        loops: true,
+        passes: 2,
+    }
+    input: {
+        L1: while (x()) {
+            break L1;
+        }
+    }
+    expect: {
+        x();
+    }
+}
+
+issue_2740_3: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        L1: for (var x = 0; x < 3; x++) {
+            L2: for (var y = 0; y < 2; y++) {
+                break L1;
+            }
+        }
+        console.log(x, y);
+    }
+    expect: {
+        L1: for (var x = 0; x < 3; x++)
+            for (var y = 0; y < 2; y++)
+                break L1;
+        console.log(x, y);
+    }
+    expect_stdout: "0 0"
+}
+
+issue_2740_4: {
+    options = {
+        dead_code: true,
+        loops: true,
+        passes: 2,
+    }
+    input: {
+        L1: for (var x = 0; x < 3; x++) {
+            L2: for (var y = 0; y < 2; y++) {
+                break L2;
+            }
+        }
+        console.log(x, y);
+    }
+    expect: {
+        for (var x = 0; x < 3; x++) {
+            var y = 0;
+            y < 2;
+        }
+        console.log(x, y);
+    }
+    expect_stdout: "3 0"
+}
+
+issue_2740_5: {
+    options = {
+        dead_code: true,
+        loops: true,
+        passes: 2,
+    }
+    input: {
+        L1: for (var x = 0; x < 3; x++) {
+            break L1;
+            L2: for (var y = 0; y < 2; y++) {
+                break L2;
+            }
+        }
+        console.log(x, y);
+    }
+    expect: {
+        var x = 0;
+        x < 3;
+        var y;
+        console.log(x,y);
+    }
+    expect_stdout: "0 undefined"
+}
+
+issue_2740_6: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        const a = 9, b = 0;
+        for (const a = 1; a < 3; ++b) break;
+        console.log(a, b);
+    }
+    expect: {
+        const a = 9, b = 0;
+        {
+            const a = 1;
+            a < 3;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "9 0"
+    node_version: ">=6"
+}
+
+issue_2740_7: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        let a = 9, b = 0;
+        for (const a = 1; a < 3; ++b) break;
+        console.log(a, b);
+    }
+    expect: {
+        let a = 9, b = 0;
+        {
+            const a = 1;
+            a < 3;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "9 0"
+    node_version: ">=6"
+}
+
+issue_2740_8: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        var a = 9, b = 0;
+        for (const a = 1; a < 3; ++b) break;
+        console.log(a, b);
+    }
+    expect: {
+        var a = 9, b = 0;
+        {
+            const a = 1;
+            a < 3;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "9 0"
+    node_version: ">=6"
+}

test/compress/negate-iife.js

@@ -22,7 +22,8 @@ negate_iife_1_off: {
 
 negate_iife_2: {
     options = {
-        negate_iife: true
+        inline: true,
+        negate_iife: true,
     };
     input: {
         (function(){ return {} })().x = 10;
@@ -32,6 +33,7 @@ negate_iife_2: {
 
 negate_iife_2_side_effects: {
     options = {
+        inline: true,
         negate_iife: true,
         side_effects: true,
     }
@@ -58,6 +60,7 @@ negate_iife_3_evaluate: {
     options = {
         conditionals: true,
         evaluate: true,
+        inline: true,
         negate_iife: true,
     }
     input: {
@@ -100,6 +103,7 @@ negate_iife_3_off_evaluate: {
     options = {
         conditionals: true,
         evaluate: true,
+        inline: true,
         negate_iife: false,
     }
     input: {

test/compress/new.js

@@ -82,3 +82,35 @@ new_with_unary_prefix: {
     }
     expect_exact: 'var bar=(+new Date).toString(32);';
 }
+
+new_with_assignement_expression: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a;
+        new x(a = 5 * 2, b = [1, 2, 3], c = {a: "a", b: "b", cd: "c" + "d"});
+        new y([a, b] = [3, 4]);
+    }
+    expect: {
+        var a;
+        new x(a = 10, b = [1, 2, 3], c = {a: "a", b: "b", cd: "cd"});
+        new y([a, b] = [3, 4]);
+    }
+}
+
+dot_parenthesis_1: {
+    input: {
+        console.log(new (Math.random().constructor) instanceof Number);
+    }
+    expect_exact: "console.log(new(Math.random().constructor)instanceof Number);"
+    expect_stdout: "true"
+}
+
+dot_parenthesis_2: {
+    input: {
+        console.log(typeof new function(){Math.random()}.constructor);
+    }
+    expect_exact: "console.log(typeof new function(){Math.random()}.constructor);"
+    expect_stdout: "function"
+}

test/compress/node_version.js

@@ -0,0 +1,38 @@
+eval_let_6: {
+    input: {
+        eval("let a;");
+        console.log();
+    }
+    expect: {
+        eval("let a;");
+        console.log();
+    }
+    expect_stdout: ""
+    node_version: ">=6"
+}
+
+eval_let_4: {
+    input: {
+        eval("let a;");
+        console.log();
+    }
+    expect: {
+        eval("let a;");
+        console.log();
+    }
+    expect_stdout: SyntaxError("Block-scoped declarations (let, const, function, class) not yet supported outside strict mode")
+    node_version: "4"
+}
+
+eval_let_0: {
+    input: {
+        eval("let a;");
+        console.log();
+    }
+    expect: {
+        eval("let a;");
+        console.log();
+    }
+    expect_stdout: SyntaxError("Unexpected identifier")
+    node_version: "<=0.12"
+}

test/compress/parameters.js

@@ -0,0 +1,186 @@
+arrow_functions: {
+    options = {
+        arrows: true,
+    }
+    input: {
+        (a) => b;  // 1 args
+        (a, b) => c;  // n args
+        () => b;  // 0 args
+        (a) => (b) => c;  // func returns func returns func
+        (a) => ((b) => c);  // So these parens are dropped
+        () => (b,c) => d;  // func returns func returns func
+        a=>{return b;}
+        a => 'lel';  // Dropping the parens
+    }
+    expect_exact: "a=>b;(a,b)=>c;()=>b;a=>b=>c;a=>b=>c;()=>(b,c)=>d;a=>b;a=>\"lel\";"
+}
+
+arrow_return: {
+    options = {
+        arrows: true,
+    }
+    input: {
+        () => {};
+        () => { return; };
+        a => { return 1; }
+        a => { return -b }
+        a => { return b; var b; }
+        (x, y) => { return x - y; }
+    }
+    expect_exact: "()=>{};()=>{};a=>1;a=>-b;a=>{return b;var b};(x,y)=>x-y;"
+}
+
+regression_arrow_functions_and_hoist: {
+    options = {
+        hoist_vars: true,
+        hoist_funs: true
+    }
+    input: {
+        (a) => b;
+    }
+    expect_exact: "a=>b;"
+}
+
+regression_assign_arrow_functions: {
+    input: {
+        oninstall = e => false;
+        oninstall = () => false;
+    }
+    expect: {
+        oninstall=e=>false;
+        oninstall=()=>false;
+    }
+}
+
+destructuring_arguments_1: {
+    input: {
+        (function ( a ) { });
+        (function ( [ a ] ) { });
+        (function ( [ a, b ] ) { });
+        (function ( [ [ a ] ] ) { });
+        (function ( [ [ a, b ] ] ) { });
+        (function ( [ a, [ b ] ] ) { });
+        (function ( [ [ b ], a ] ) { });
+
+        (function ( { a } ) { });
+        (function ( { a, b } ) { });
+
+        (function ( [ { a } ] ) { });
+        (function ( [ { a, b } ] ) { });
+        (function ( [ a, { b } ] ) { });
+        (function ( [ { b }, a ] ) { });
+
+        ( [ a ] ) => { };
+        ( [ a, b ] ) => { };
+
+        ( { a } ) => { };
+        ( { a, b, c, d, e } ) => { };
+
+        ( [ a ] ) => b;
+        ( [ a, b ] ) => c;
+
+        ( { a } ) => b;
+        ( { a, b } ) => c;
+    }
+    expect: {
+        (function(a){});
+        (function([a]){});
+        (function([a,b]){});
+        (function([[a]]){});
+        (function([[a,b]]){});
+        (function([a,[b]]){});
+        (function([[b],a]){});
+
+        (function({a}){});
+        (function({a,b}){});
+
+        (function([{a}]){});
+        (function([{a,b}]){});
+        (function([a,{b}]){});
+        (function([{b},a]){});
+
+        ([a])=>{};
+        ([a,b])=>{};
+
+        ({a})=>{};
+        ({a,b,c,d,e})=>{};
+
+        ([a])=>b;
+        ([a,b])=>c;
+
+        ({a})=>b;
+        ({a,b})=>c;
+    }
+}
+
+destructuring_arguments_2: {
+    input: {
+        (function([]) {});
+        (function({}) {});
+        (function([,,,,,]) {});
+        (function ([a, {b: c}]) {});
+        (function ([...args]) {});
+        (function ({x,}) {});
+        class a { *method({ [thrower()]: x } = {}) {}};
+        (function(a, b, c, d, [{e: [...f]}]){})(1, 2, 3, 4, [{e: [1, 2, 3]}]);
+    }
+    expect: {
+        (function([]) {});
+        (function({}) {});
+        (function([,,,,,]) {});
+        (function ([a, {b: c}]) {});
+        (function ([...args]) {});
+        (function ({x,}) {});
+        class a { *method({ [thrower()]: x } = {}) {}};
+        (function(a, b, c, d, [{e: [...f]}]){})(1, 2, 3, 4, [{e: [1, 2, 3]}]);
+    }
+}
+
+destructuring_arguments_3: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        function fn3({x: {y: {z: {} = 42}}}) {}
+        const { a = (function () {}), b = (0, function() {})  } = {};
+        let { c = (function () {}), d = (0, function() {})  } = {};
+        var { e = (function () {}), f = (0, function() {})  } = {};
+    }
+    expect_exact: "function fn3({x:{y:{z:{}=42}}}){}const{a=function(){},b=(0,function(){})}={};let{c=function(){},d=(0,function(){})}={};var{e=function(){},f=(0,function(){})}={};"
+}
+
+default_arguments: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        function x(a = 6) { }
+        function x(a = (6 + 5)) { }
+        function x({ foo } = {}, [ bar ] = [ 1 ]) { }
+    }
+    expect_exact: "function x(a=6){}function x(a=6+5){}function x({foo}={},[bar]=[1]){}"
+}
+
+default_values_in_destructurings: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        function x({a=(4), b}) {}
+        function x([b, c=(12)]) {}
+        var { x = (6), y } = x;
+        var [ x, y = (6) ] = x;
+    }
+    expect_exact: "function x({a=4,b}){}function x([b,c=12]){}var{x=6,y}=x;var[x,y=6]=x;"
+}
+
+accept_duplicated_parameters_in_non_strict_without_spread_or_default_assignment: {
+    input: {
+        function a(b, b){}
+        function b({c: test, c: test}){}
+    }
+    expect: {
+        function a(b, b){}
+        function b({c: test, c: test}){}
+    }
+}

test/compress/pure_funcs.js

@@ -293,3 +293,245 @@ unary: {
         bar();
     }
 }
+
+issue_2629_1: {
+    options = {
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ a();
+        /*@__PURE__*/ (b());
+        (/*@__PURE__*/ c)();
+        (/*@__PURE__*/ d());
+    }
+    expect_exact: [
+        "/* */c();",
+    ]
+}
+
+issue_2629_2: {
+    options = {
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ a(1)(2)(3);
+        /*@__PURE__*/ (b(1))(2)(3);
+        /*@__PURE__*/ (c(1)(2))(3);
+        /*@__PURE__*/ (d(1)(2)(3));
+        (/*@__PURE__*/ e)(1)(2)(3);
+        (/*@__PURE__*/ f(1))(2)(3);
+        (/*@__PURE__*/ g(1)(2))(3);
+        (/*@__PURE__*/ h(1)(2)(3));
+    }
+    expect_exact: [
+        "/* */e(1)(2)(3);",
+        "/* */f(1)(2)(3);",
+        "/* */g(1)(2)(3);",
+    ]
+}
+
+issue_2629_3: {
+    options = {
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ a.x(1).y(2).z(3);
+        /*@__PURE__*/ (b.x)(1).y(2).z(3);
+        /*@__PURE__*/ (c.x(1)).y(2).z(3);
+        /*@__PURE__*/ (d.x(1).y)(2).z(3);
+        /*@__PURE__*/ (e.x(1).y(2)).z(3);
+        /*@__PURE__*/ (f.x(1).y(2).z)(3);
+        /*@__PURE__*/ (g.x(1).y(2).z(3));
+        (/*@__PURE__*/ h).x(1).y(2).z(3);
+        (/*@__PURE__*/ i.x)(1).y(2).z(3);
+        (/*@__PURE__*/ j.x(1)).y(2).z(3);
+        (/*@__PURE__*/ k.x(1).y)(2).z(3);
+        (/*@__PURE__*/ l.x(1).y(2)).z(3);
+        (/*@__PURE__*/ m.x(1).y(2).z)(3);
+        (/*@__PURE__*/ n.x(1).y(2).z(3));
+    }
+    expect_exact: [
+        "/* */h.x(1).y(2).z(3);",
+        "/* */i.x(1).y(2).z(3);",
+        "/* */j.x(1).y(2).z(3);",
+        "/* */k.x(1).y(2).z(3);",
+        "/* */l.x(1).y(2).z(3);",
+        "/* */m.x(1).y(2).z(3);",
+    ]
+}
+
+issue_2629_4: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        (/*@__PURE__*/ x(), y());
+        (w(), /*@__PURE__*/ x(), y());
+    }
+    expect: {
+        y();
+        w(), y();
+    }
+}
+
+issue_2629_5: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        [ /*@__PURE__*/ x() ];
+        [ /*@__PURE__*/ x(), y() ];
+        [ w(), /*@__PURE__*/ x(), y() ];
+    }
+    expect: {
+        y();
+        w(), y();
+    }
+}
+
+issue_2638: {
+    options = {
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/(g() || h())(x(), y());
+        (/*@__PURE__*/ (a() || b()))(c(), d());
+    }
+    expect_exact: [
+        "/* */x(),y();",
+        "/* */(a()||b())(c(),d());",
+    ]
+}
+
+issue_2705_1: {
+    options = {
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ new a();
+        /*@__PURE__*/ (new b());
+        new (/*@__PURE__*/ c)();
+        (/*@__PURE__*/ new d());
+    }
+    expect_exact: [
+        "new/* */c;",
+    ]
+}
+
+issue_2705_2: {
+    options = {
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ new a(1)(2)(3);
+        /*@__PURE__*/ new (b(1))(2)(3);
+        /*@__PURE__*/ new (c(1)(2))(3);
+        /*@__PURE__*/ new (d(1)(2)(3));
+        new (/*@__PURE__*/ e)(1)(2)(3);
+        (/*@__PURE__*/ new f(1))(2)(3);
+        (/*@__PURE__*/ new g(1)(2))(3);
+        (/*@__PURE__*/ new h(1)(2)(3));
+    }
+    expect_exact: [
+        "new/* */e(1)(2)(3);",
+        "/* */new f(1)(2)(3);",
+        "/* */new g(1)(2)(3);",
+    ]
+}
+
+issue_2705_3: {
+    options = {
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/ new a.x(1).y(2).z(3);
+        /*@__PURE__*/ new (b.x)(1).y(2).z(3);
+        /*@__PURE__*/ new (c.x(1)).y(2).z(3);
+        /*@__PURE__*/ new (d.x(1).y)(2).z(3);
+        /*@__PURE__*/ new (e.x(1).y(2)).z(3);
+        /*@__PURE__*/ new (f.x(1).y(2).z)(3);
+        /*@__PURE__*/ new (g.x(1).y(2).z(3));
+        new (/*@__PURE__*/ h).x(1).y(2).z(3);
+        /* */ new (/*@__PURE__*/ i.x)(1).y(2).z(3);
+        (/*@__PURE__*/ new j.x(1)).y(2).z(3);
+        (/*@__PURE__*/ new k.x(1).y)(2).z(3);
+        (/*@__PURE__*/ new l.x(1).y(2)).z(3);
+        (/*@__PURE__*/ new m.x(1).y(2).z)(3);
+        (/*@__PURE__*/ new n.x(1).y(2).z(3));
+    }
+    expect_exact: [
+        "new/* */h.x(1).y(2).z(3);",
+        "/* */new/* */i.x(1).y(2).z(3);",
+        "/* */new j.x(1).y(2).z(3);",
+        "/* */new k.x(1).y(2).z(3);",
+        "/* */new l.x(1).y(2).z(3);",
+        "/* */new m.x(1).y(2).z(3);",
+    ]
+}
+
+issue_2705_4: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        (/*@__PURE__*/ new x(), y());
+        (w(), /*@__PURE__*/ new x(), y());
+    }
+    expect: {
+        y();
+        w(), y();
+    }
+}
+
+issue_2705_5: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        [ /*@__PURE__*/ new x() ];
+        [ /*@__PURE__*/ new x(), y() ];
+        [ w(), /*@__PURE__*/ new x(), y() ];
+    }
+    expect: {
+        y();
+        w(), y();
+    }
+}
+
+issue_2705_6: {
+    options = {
+        side_effects: true,
+    }
+    beautify = {
+        comments: "all",
+    }
+    input: {
+        /*@__PURE__*/new (g() || h())(x(), y());
+        /* */ new (/*@__PURE__*/ (a() || b()))(c(), d());
+    }
+    expect_exact: [
+        "/* */x(),y();",
+        "/* */new(/* */a()||b())(c(),d());",
+    ]
+}

test/compress/pure_getters.js

@@ -1,6 +1,7 @@
 strict: {
     options = {
         pure_getters: "strict",
+        reduce_funcs: false,
         reduce_vars: false,
         side_effects: true,
         toplevel: true,
@@ -30,6 +31,7 @@ strict: {
 strict_reduce_vars: {
     options = {
         pure_getters: "strict",
+        reduce_funcs: true,
         reduce_vars: true,
         side_effects: true,
         toplevel: true,
@@ -58,6 +60,7 @@ strict_reduce_vars: {
 unsafe: {
     options = {
         pure_getters: true,
+        reduce_funcs: false,
         reduce_vars: false,
         side_effects: true,
         toplevel: true,
@@ -84,6 +87,7 @@ unsafe: {
 unsafe_reduce_vars: {
     options = {
         pure_getters: true,
+        reduce_funcs: true,
         reduce_vars: true,
         side_effects: true,
         toplevel: true,
@@ -178,3 +182,666 @@ impure_getter_2: {
     }
     expect: {}
 }
+
+issue_2110_1: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        sequences: true,
+        side_effects: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function f() {}
+            function g() {
+                return this;
+            }
+            f.g = g;
+            return f.g();
+        }
+        console.log(typeof f());
+    }
+    expect: {
+        function f() {
+            function f() {}
+            return f.g = function() {
+                return this;
+            }, f.g();
+        }
+        console.log(typeof f());
+    }
+    expect_stdout: "function"
+}
+
+issue_2110_2: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function f() {}
+            function g() {
+                return this;
+            }
+            f.g = g;
+            return f.g();
+        }
+        console.log(typeof f());
+    }
+    expect: {
+        function f() {
+            function f() {}
+            f.g = function() {
+                return this;
+            };
+            return f.g();
+        }
+        console.log(typeof f());
+    }
+    expect_stdout: "function"
+}
+
+set_immutable_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        1..foo += "";
+        if (1..foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+set_immutable_2: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        var a = 1;
+        a.foo += "", a.foo ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+set_immutable_3: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        "use strict";
+        1..foo += "";
+        if (1..foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect_stdout: true
+}
+
+set_immutable_4: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        "use strict";
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        "use strict";
+        var a = 1;
+        a.foo += "", a.foo ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: true
+}
+
+set_immutable_5: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        "use strict";
+        1..foo += "";
+        1..foo ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: true
+}
+
+set_immutable_6: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        1..foo ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: true
+}
+
+set_mutable_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function a() {
+            a.foo += "";
+            if (a.foo) console.log("PASS");
+            else console.log("FAIL");
+        }();
+    }
+    expect: {
+        !function a() {
+            if (a.foo += "") console.log("PASS");
+            else console.log("FAIL");
+        }();
+    }
+    expect_stdout: "PASS"
+}
+
+set_mutable_2: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        !function a() {
+            a.foo += "";
+            if (a.foo) console.log("PASS");
+            else console.log("FAIL");
+        }();
+    }
+    expect: {
+        !function a() {
+            (a.foo += "") ? console.log("PASS") : console.log("FAIL");
+        }();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2265_1: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        ({ ...{} }).p;
+        ({ ...g }).p;
+    }
+    expect: {
+        ({ ...g }).p;
+    }
+}
+
+issue_2265_2: {
+    options = {
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = {
+            get b() {
+                throw 0;
+            }
+        };
+        ({...a}).b;
+    }
+    expect: {
+        var a = {
+            get b() {
+                throw 0;
+            }
+        };
+        ({...a}).b;
+    }
+}
+
+issue_2265_3: {
+    options = {
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = {
+            set b() {
+                throw 0;
+            }
+        };
+        ({...a}).b;
+    }
+    expect: {}
+}
+
+issue_2265_4: {
+    options = {
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = { b: 1 };
+        ({...a}).b;
+    }
+    expect: {}
+}
+
+issue_2313_1: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: "strict",
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function x() {
+            console.log(1);
+            return {
+                y: function() {
+                    console.log(2);
+                    return {
+                        z: 0
+                    };
+                }
+            };
+        }
+        x().y().z++;
+        if (x().y().z) {
+            console.log(3);
+        }
+    }
+    expect: {
+        function x() {
+            return console.log(1), {
+                y: function() {
+                    return console.log(2), {
+                        z: 0
+                    };
+                }
+            };
+        }
+        x().y().z++,
+        x().y().z && console.log(3);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+        "1",
+        "2",
+    ]
+}
+
+issue_2313_2: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function x() {
+            console.log(1);
+            return {
+                y: function() {
+                    console.log(2);
+                    return {
+                        z: 0
+                    };
+                }
+            };
+        }
+        x().y().z++;
+        if (x().y().z) {
+            console.log(3);
+        }
+    }
+    expect: {
+        function x() {
+            return console.log(1), {
+                y: function() {
+                    return console.log(2), {
+                        z: 0
+                    };
+                }
+            };
+        }
+        x().y().z++,
+        x().y().z && console.log(3);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+        "1",
+        "2",
+    ]
+}
+
+issue_2313_3: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: "strict",
+    }
+    input: {
+        function x() {
+            console.log(1);
+            return {
+                y: function() {
+                    console.log(2);
+                    return {
+                        z: 0
+                    };
+                }
+            };
+        }
+        x().y().z++;
+        if (x().y().z) {
+            console.log(3);
+        }
+    }
+    expect: {
+        function x() {
+            console.log(1);
+            return {
+                y: function() {
+                    console.log(2);
+                    return {
+                        z: 0
+                    };
+                }
+            };
+        }
+        x().y().z++;
+        x().y().z && console.log(3);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+        "1",
+        "2",
+    ]
+}
+
+issue_2313_4: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: true,
+    }
+    input: {
+        function x() {
+            console.log(1);
+            return {
+                y: function() {
+                    console.log(2);
+                    return {
+                        z: 0
+                    };
+                }
+            };
+        }
+        x().y().z++;
+        if (x().y().z) {
+            console.log(3);
+        }
+    }
+    expect: {
+        function x() {
+            console.log(1);
+            return {
+                y: function() {
+                    console.log(2);
+                    return {
+                        z: 0
+                    };
+                }
+            };
+        }
+        x().y().z++;
+        x().y().z && console.log(3);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+        "1",
+        "2",
+    ]
+}
+
+issue_2313_5: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        x().y++;
+        x().y;
+    }
+    expect: {
+        x().y++;
+        x().y;
+    }
+}
+
+issue_2313_6: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        x().y++;
+        x().y;
+    }
+    expect: {
+        x().y++;
+        x();
+    }
+}
+
+issue_2313_7: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        pure_getters: true,
+    }
+    input: {
+        var a = 0, b = 0;
+        class foo {
+            get c() {
+                a++;
+                return 42;
+            }
+            set c(c) {
+                b++;
+            }
+        }
+        class bar extends foo {
+            d() {
+                super.c++;
+                if (super.c) console.log(a, b);
+            }
+        }
+        new bar().d();
+    }
+    expect: {
+        var a = 0, b = 0;
+        class foo {
+            get c() {
+                a++;
+                return 42;
+            }
+            set c(c) {
+                b++;
+            }
+        }
+        class bar extends foo {
+            d() {
+                super.c++;
+                super.c && console.log(a, b);
+            }
+        }
+        new bar().d();
+    }
+    expect_stdout: "2 1"
+    node_version: ">=6"
+}
+
+issue_2678: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        var a = 1, c = "FAIL";
+        (function f() {
+            (a-- && f()).p;
+            return {
+                get p() {
+                    c = "PASS";
+                }
+            };
+        })();
+        console.log(c);
+    }
+    expect: {
+        var a = 1, c = "FAIL";
+        (function f() {
+            (a-- && f()).p;
+            return {
+                get p() {
+                    c = "PASS";
+                }
+            };
+        })();
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2838: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            (a || b).c = "PASS";
+            (function() {
+                return f(a, b);
+            }).prototype.foo = "bar";
+        }
+        var o = {};
+        f(null, o);
+        console.log(o.c);
+    }
+    expect: {
+        function f(a, b) {
+            (a || b).c = "PASS";
+        }
+        var o = {};
+        f(null, o);
+        console.log(o.c);
+    }
+    expect_stdout: "PASS"
+}