Merge pull request #2161 from alexlamsl/harmony-v3.0.20

Merging from master for 3.0.20

.github/ISSUE_TEMPLATE.md

@@ -1,7 +1,20 @@
-- Bug report or feature request?
-- `uglify-js` version (`uglifyjs -V`)
-- JavaScript input - ideally as small as possible.
-- The `uglifyjs` CLI command executed or `minify()` options used.
-- An example of JavaScript output produced and/or the error or warning.
+**Bug report or feature request?** 
 
-Note: the release version of `uglify-js` only supports ES5. Those wishing to minify ES6 should use the experimental [`harmony`](https://github.com/mishoo/UglifyJS2#harmony) branch.
+<!-- Note: sub-optimal but correct code is not a bug -->
+
+**ES5 or ES6+ input?** 
+
+<!-- Note: for ES6 see: https://github.com/mishoo/UglifyJS2/tree/harmony#harmony -->
+
+**Uglify version (`uglifyjs -V`)**
+
+**JavaScript input**  <!-- ideally as small as possible -->
+
+**The `uglifyjs` CLI command executed or `minify()` options used.**
+
+**JavaScript output or error produced.**
+
+<!--
+    Note: `uglify-js` only supports ES5. 
+    Those wishing to minify ES6 should use `uglify-es`.
+-->

.travis.yml

@@ -1,13 +1,14 @@
 language: node_js
-before_install: "npm install -g npm"
 node_js:
     - "0.10"
     - "0.12"
     - "4"
     - "6"
-    - "7"
+    - "8"
 env:
     - UGLIFYJS_TEST_ALL=1
 matrix:
   fast_finish: true
 sudo: false
+cache:
+  directories: tmp

bin/extract-props.js

@@ -1,77 +0,0 @@
-#! /usr/bin/env node
-
-"use strict";
-
-var U2 = require("../tools/node");
-var fs = require("fs");
-var yargs = require("yargs");
-var ARGS = yargs
-    .describe("o", "Output file")
-    .argv;
-var files = ARGS._.slice();
-var output = {
-    vars: {},
-    props: {}
-};
-
-if (ARGS.o) try {
-    output = JSON.parse(fs.readFileSync(ARGS.o, "utf8"));
-} catch(ex) {}
-
-files.forEach(getProps);
-
-if (ARGS.o) {
-    fs.writeFileSync(ARGS.o, JSON.stringify(output, null, 2), "utf8");
-} else {
-    console.log("%s", JSON.stringify(output, null, 2));
-}
-
-function getProps(filename) {
-    var code = fs.readFileSync(filename, "utf8");
-    var ast = U2.parse(code);
-
-    ast.walk(new U2.TreeWalker(function(node){
-        if (node instanceof U2.AST_ObjectKeyVal) {
-            add(node.key);
-        }
-        else if (node instanceof U2.AST_ObjectProperty) {
-            add(node.key.name);
-        }
-        else if (node instanceof U2.AST_Dot) {
-            add(node.property);
-        }
-        else if (node instanceof U2.AST_Sub) {
-            addStrings(node.property);
-        }
-    }));
-
-    function addStrings(node) {
-        var out = {};
-        try {
-            (function walk(node){
-                node.walk(new U2.TreeWalker(function(node){
-                    if (node instanceof U2.AST_Seq) {
-                        walk(node.cdr);
-                        return true;
-                    }
-                    if (node instanceof U2.AST_String) {
-                        add(node.value);
-                        return true;
-                    }
-                    if (node instanceof U2.AST_Conditional) {
-                        walk(node.consequent);
-                        walk(node.alternative);
-                        return true;
-                    }
-                    throw out;
-                }));
-            })(node);
-        } catch(ex) {
-            if (ex !== out) throw ex;
-        }
-    }
-
-    function add(name) {
-        output.props[name] = true;
-    }
-}

lib/ast.js

@@ -157,7 +157,7 @@ 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++) {
@@ -182,21 +182,13 @@ var AST_BlockStatement = DEFNODE("BlockStatement", null, {
 }, AST_Block);
 
 var AST_EmptyStatement = DEFNODE("EmptyStatement", null, {
-    $documentation: "The empty statement (empty block or simply a semicolon)",
-    _walk: function(visitor) {
-        return visitor._visit(this);
-    }
+    $documentation: "The empty statement (empty block or simply a semicolon)"
 }, AST_Statement);
 
 var AST_StatementWithBody = DEFNODE("StatementWithBody", "body", {
     $documentation: "Base class for all statements that contain one nested body: `For`, `ForIn`, `Do`, `While`, `With`",
     $propdoc: {
         body: "[AST_Statement] the body; this should always be present, even if it's an AST_EmptyStatement"
-    },
-    _walk: function(visitor) {
-        return visitor._visit(this, function(){
-            this.body._walk(visitor);
-        });
     }
 }, AST_Statement);
 
@@ -214,12 +206,13 @@ var AST_LabeledStatement = DEFNODE("LabeledStatement", "label", {
     clone: function(deep) {
         var node = this._clone(deep);
         if (deep) {
-            var refs = node.label.references;
-            var label = this.label;
+            var label = node.label;
+            var def = this.label;
             node.walk(new TreeWalker(function(node) {
                 if (node instanceof AST_LoopControl
-                    && node.label && node.label.thedef === label) {
-                    refs.push(node);
+                    && node.label && node.label.thedef === def) {
+                    node.label.thedef = label;
+                    label.references.push(node);
                 }
             }));
         }
@@ -291,6 +284,10 @@ 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: {
@@ -318,6 +315,13 @@ 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.parent_scope) {
+            self = self.parent_scope;
+        }
+        return self;
+    }
 }, AST_Block);
 
 var AST_Toplevel = DEFNODE("Toplevel", "globals", {
@@ -325,74 +329,51 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     $propdoc: {
         globals: "[Object/S] a map of name -> SymbolDef for all undeclared names",
     },
-    wrap_enclose: function(arg_parameter_pairs) {
-        var self = this;
-        var args = [];
-        var parameters = [];
-
-        arg_parameter_pairs.forEach(function(pair) {
-            var splitAt = pair.lastIndexOf(":");
-
-            args.push(pair.substr(0, splitAt));
-            parameters.push(pair.substr(splitAt + 1));
-        });
-
-        var wrapped_tl = "(function(" + parameters.join(",") + "){ '$ORIG'; })(" + args.join(",") + ")";
+    wrap_commonjs: function(name) {
+        var body = this.body;
+        var wrapped_tl = "(function(exports){'$ORIG';})(typeof " + name + "=='undefined'?(" + name + "={}):" + name + ");";
         wrapped_tl = parse(wrapped_tl);
         wrapped_tl = wrapped_tl.transform(new TreeTransformer(function before(node){
             if (node instanceof AST_Directive && node.value == "$ORIG") {
-                return MAP.splice(self.body);
-            }
-        }));
-        return wrapped_tl;
-    },
-    wrap_commonjs: function(name, export_all) {
-        var self = this;
-        var to_export = [];
-        if (export_all) {
-            self.figure_out_scope();
-            self.walk(new TreeWalker(function(node){
-                if (node instanceof AST_SymbolDeclaration && node.definition().global) {
-                    if (!find_if(function(n){ return n.name == node.name }, to_export))
-                        to_export.push(node);
-                }
-            }));
-        }
-        var wrapped_tl = "(function(exports, global){ '$ORIG'; '$EXPORTS'; global['" + name + "'] = exports; }({}, (function(){return this}())))";
-        wrapped_tl = parse(wrapped_tl);
-        wrapped_tl = wrapped_tl.transform(new TreeTransformer(function before(node){
-            if (node instanceof AST_Directive) {
-                switch (node.value) {
-                  case "$ORIG":
-                    return MAP.splice(self.body);
-                  case "$EXPORTS":
-                    var body = [];
-                    to_export.forEach(function(sym){
-                        body.push(new AST_SimpleStatement({
-                            body: new AST_Assign({
-                                left: new AST_Sub({
-                                    expression: new AST_SymbolRef({ name: "exports" }),
-                                    property: new AST_String({ value: sym.name }),
-                                }),
-                                operator: "=",
-                                right: new AST_SymbolRef(sym),
-                            }),
-                        }));
-                    });
-                    return MAP.splice(body);
-                }
+                return MAP.splice(body);
             }
         }));
         return wrapped_tl;
     }
 }, 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_Symbol 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(){
@@ -414,10 +395,78 @@ var AST_Function = DEFNODE("Function", null, {
     $documentation: "A function expression"
 }, AST_Lambda);
 
+var AST_Arrow = DEFNODE("Arrow", null, {
+    $documentation: "An ES6 Arrow function ((a) => b)"
+}, AST_Lambda);
+
 var AST_Defun = DEFNODE("Defun", null, {
     $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_TemplateSegment|AST_Expression]* One or more segments, starting with AST_TemplateSegment. AST_Expression may follow AST_TemplateSegment, but each AST_Expression must be followed by AST_TemplateSegment."
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            this.segments.forEach(function(seg, i){
+                if (i % 2 !== 0) {
+                    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, {
@@ -537,7 +586,7 @@ 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(){
@@ -572,14 +621,83 @@ 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|AST_SymbolConst] name of the variable",
+        name: "[AST_SymbolVar|AST_SymbolConst|AST_Destructuring] name of the variable",
         value: "[AST_Node?] initializer, or null of there's no initializer"
     },
     _walk: function(visitor) {
@@ -600,11 +718,11 @@ var AST_Call = DEFNODE("Call", "expression args", {
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
-            this.expression._walk(visitor);
             var args = this.args;
             for (var i = 0, len = args.length; i < len; i++) {
                 args[i]._walk(visitor);
             }
+            this.expression._walk(visitor);
         });
     }
 });
@@ -613,68 +731,16 @@ var AST_New = DEFNODE("New", null, {
     $documentation: "An object instantiation.  Derives from a function call since it has exactly the same properties"
 }, AST_Call);
 
-var AST_Seq = DEFNODE("Seq", "car cdr", {
-    $documentation: "A sequence expression (two comma-separated expressions)",
+var AST_Sequence = DEFNODE("Sequence", "expressions", {
+    $documentation: "A sequence expression (comma-separated expressions)",
     $propdoc: {
-        car: "[AST_Node] first element in sequence",
-        cdr: "[AST_Node] second element in sequence"
-    },
-    $cons: function(x, y) {
-        var seq = new AST_Seq(x);
-        seq.car = x;
-        seq.cdr = y;
-        return seq;
-    },
-    $from_array: function(array) {
-        if (array.length == 0) return null;
-        if (array.length == 1) return array[0].clone();
-        var list = null;
-        for (var i = array.length; --i >= 0;) {
-            list = AST_Seq.cons(array[i], list);
-        }
-        var p = list;
-        while (p) {
-            if (p.cdr && !p.cdr.cdr) {
-                p.cdr = p.cdr.car;
-                break;
-            }
-            p = p.cdr;
-        }
-        return list;
-    },
-    to_array: function() {
-        var p = this, a = [];
-        while (p) {
-            a.push(p.car);
-            if (p.cdr && !(p.cdr instanceof AST_Seq)) {
-                a.push(p.cdr);
-                break;
-            }
-            p = p.cdr;
-        }
-        return a;
-    },
-    add: function(node) {
-        var p = this;
-        while (p) {
-            if (!(p.cdr instanceof AST_Seq)) {
-                var cell = AST_Seq.cons(p.cdr, node);
-                return p.cdr = cell;
-            }
-            p = p.cdr;
-        }
-    },
-    len: function() {
-        if (this.cdr instanceof AST_Seq) {
-            return this.cdr.len() + 1;
-        } else {
-            return 2;
-        }
+        expressions: "[AST_Node*] array of expressions (at least two)"
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
-            this.car._walk(visitor);
-            if (this.cdr) this.cdr._walk(visitor);
+            this.expressions.forEach(function(node) {
+                node._walk(visitor);
+            });
         });
     }
 });
@@ -727,7 +793,7 @@ var AST_UnaryPostfix = DEFNODE("UnaryPostfix", null, {
     $documentation: "Unary postfix expression, i.e. `i++`"
 }, AST_Unary);
 
-var AST_Binary = DEFNODE("Binary", "left operator right", {
+var AST_Binary = DEFNODE("Binary", "operator left right", {
     $documentation: "Binary expression, i.e. `a + b`",
     $propdoc: {
         left: "[AST_Node] left-hand side expression",
@@ -762,6 +828,10 @@ 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", {
@@ -797,11 +867,13 @@ 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 arbitrary AST_Node.",
-        value: "[AST_Node] property value.  For setters and getters this is an AST_Function."
+        key: "[string|AST_Node] the property name converted to a string for ObjectKeyVal. For setters, getters and computed property this is an arbitrary AST_Node",
+        value: "[AST_Node] property value.  For setters and getters 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);
         });
     }
@@ -814,26 +886,74 @@ 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", {
+    $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/const, function name or argument, symbol in catch)",
@@ -843,9 +963,17 @@ 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_SymbolDeclaration);
+}, 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",
@@ -855,13 +983,33 @@ 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)",
@@ -878,6 +1026,14 @@ 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);
@@ -886,6 +1042,10 @@ var AST_This = DEFNODE("This", null, {
     $documentation: "The `this` symbol",
 }, AST_Symbol);
 
+var AST_Super = DEFNODE("Super", null, {
+    $documentation: "The `super` symbol",
+}, AST_Symbol);
+
 var AST_Constant = DEFNODE("Constant", null, {
     $documentation: "Base class for all constants",
     getValue: function() {
@@ -959,6 +1119,31 @@ 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) {
@@ -981,17 +1166,22 @@ TreeWalker.prototype = {
     parent: function(n) {
         return this.stack[this.stack.length - 2 - (n || 0)];
     },
-    push: function (node) {
+    push: function(node) {
         if (node instanceof AST_Lambda) {
             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) {
+        if (node instanceof AST_Lambda || node instanceof AST_Class) {
             this.directives = Object.getPrototypeOf(this.directives);
         }
     },
@@ -1009,7 +1199,7 @@ 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;
@@ -1035,16 +1225,16 @@ TreeWalker.prototype = {
             self = p;
         }
     },
-    loopcontrol_target: function(label) {
+    loopcontrol_target: function(node) {
         var stack = this.stack;
-        if (label) for (var i = stack.length; --i >= 0;) {
+        if (node.label) for (var i = stack.length; --i >= 0;) {
             var x = stack[i];
-            if (x instanceof AST_LabeledStatement && x.label.name == label.name) {
+            if (x instanceof AST_LabeledStatement && x.label.name == node.label.name)
                 return x.body;
-            }
         } else for (var i = stack.length; --i >= 0;) {
             var x = stack[i];
-            if (x instanceof AST_Switch || x instanceof AST_IterationStatement)
+            if (x instanceof AST_IterationStatement
+                || node instanceof AST_Break && x instanceof AST_Switch)
                 return x;
         }
     }

lib/minify.js

@@ -0,0 +1,181 @@
+"use strict";
+
+var to_ascii = typeof atob == "undefined" ? function(b64) {
+    return new Buffer(b64, "base64").toString();
+} : atob;
+var to_base64 = typeof btoa == "undefined" ? function(str) {
+    return new Buffer(str).toString("base64");
+} : btoa;
+
+function read_source_map(code) {
+    var match = /\n\/\/# sourceMappingURL=data:application\/json(;.*?)?;base64,(.*)/.exec(code);
+    if (!match) {
+        AST_Node.warn("inline source map not found");
+        return null;
+    }
+    return to_ascii(match[2]);
+}
+
+function set_shorthand(name, options, keys) {
+    if (options[name]) {
+        keys.forEach(function(key) {
+            if (options[key]) {
+                if (typeof options[key] != "object") options[key] = {};
+                if (!(name in options[key])) options[key][name] = options[name];
+            }
+        });
+    }
+}
+
+function minify(files, options) {
+    var warn_function = AST_Node.warn_function;
+    try {
+        options = defaults(options, {
+            compress: {},
+            ecma: undefined,
+            ie8: false,
+            keep_fnames: false,
+            mangle: {},
+            output: {},
+            parse: {},
+            sourceMap: false,
+            timings: false,
+            toplevel: false,
+            warnings: false,
+            wrap: false,
+        }, true);
+        var timings = options.timings && {
+            start: Date.now()
+        };
+        set_shorthand("ecma", options, [ "parse", "compress", "output" ]);
+        set_shorthand("ie8", options, [ "compress", "mangle", "output" ]);
+        set_shorthand("keep_fnames", options, [ "compress", "mangle" ]);
+        set_shorthand("toplevel", options, [ "compress", "mangle" ]);
+        set_shorthand("warnings", options, [ "compress" ]);
+        if (options.mangle) {
+            options.mangle = defaults(options.mangle, {
+                cache: null,
+                eval: false,
+                ie8: false,
+                keep_classnames: false,
+                keep_fnames: false,
+                properties: false,
+                reserved: [],
+                safari10: false,
+                toplevel: false,
+            }, true);
+        }
+        if (options.sourceMap) {
+            options.sourceMap = defaults(options.sourceMap, {
+                content: null,
+                filename: null,
+                includeSources: false,
+                root: null,
+                url: null,
+            }, true);
+        }
+        var warnings = [];
+        if (options.warnings && !AST_Node.warn_function) {
+            AST_Node.warn_function = function(warning) {
+                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) if (HOP(files, name)) {
+                options.parse.filename = name;
+                options.parse.toplevel = parse(files[name], options.parse);
+                if (options.sourceMap && options.sourceMap.content == "inline") {
+                    if (Object.keys(files).length > 1)
+                        throw new Error("inline source map only works with singular input");
+                    options.sourceMap.content = read_source_map(files[name]);
+                }
+            }
+            toplevel = options.parse.toplevel;
+        }
+        if (options.wrap) {
+            toplevel = toplevel.wrap_commonjs(options.wrap);
+        }
+        if (timings) timings.scope1 = Date.now();
+        if (options.compress) toplevel.figure_out_scope(options.mangle);
+        if (timings) timings.compress = Date.now();
+        if (options.compress) toplevel = new Compressor(options.compress).compress(toplevel);
+        if (timings) timings.scope2 = Date.now();
+        if (options.mangle) toplevel.figure_out_scope(options.mangle);
+        if (timings) timings.mangle = Date.now();
+        if (options.mangle) {
+            base54.reset();
+            toplevel.compute_char_frequency(options.mangle);
+            toplevel.mangle_names(options.mangle);
+        }
+        if (timings) timings.properties = Date.now();
+        if (options.mangle && options.mangle.properties) {
+            toplevel = mangle_properties(toplevel, options.mangle.properties);
+        }
+        if (timings) timings.output = Date.now();
+        var result = {};
+        if (options.output.ast) {
+            result.ast = toplevel;
+        }
+        if (!HOP(options.output, "code") || options.output.code) {
+            if (options.sourceMap) {
+                if (typeof options.sourceMap.content == "string") {
+                    options.sourceMap.content = JSON.parse(options.sourceMap.content);
+                }
+                options.output.source_map = SourceMap({
+                    file: options.sourceMap.filename,
+                    orig: options.sourceMap.content,
+                    root: options.sourceMap.root
+                });
+                if (options.sourceMap.includeSources) {
+                    if (files instanceof AST_Toplevel) {
+                        throw new Error("original source content unavailable");
+                    } else for (var name in files) if (HOP(files, name)) {
+                        options.output.source_map.get().setSourceContent(name, files[name]);
+                    }
+                }
+            }
+            delete options.output.ast;
+            delete options.output.code;
+            var stream = OutputStream(options.output);
+            toplevel.print(stream);
+            result.code = stream.get();
+            if (options.sourceMap) {
+                result.map = options.output.source_map.toString();
+                if (options.sourceMap.url == "inline") {
+                    result.code += "\n//# sourceMappingURL=data:application/json;charset=utf-8;base64," + to_base64(result.map);
+                } else if (options.sourceMap.url) {
+                    result.code += "\n//# sourceMappingURL=" + options.sourceMap.url;
+                }
+            }
+        }
+        if (timings) {
+            timings.end = Date.now();
+            result.timings = {
+                parse: 1e-3 * (timings.scope1 - timings.parse),
+                scope: 1e-3 * (timings.compress - timings.scope1 + timings.mangle - timings.scope2),
+                compress: 1e-3 * (timings.scope2 - timings.compress),
+                mangle: 1e-3 * (timings.properties - timings.mangle),
+                properties: 1e-3 * (timings.output - timings.properties),
+                output: 1e-3 * (timings.end - timings.output),
+                total: 1e-3 * (timings.end - timings.start)
+            }
+        }
+        if (warnings.length) {
+            result.warnings = warnings;
+        }
+        return result;
+    } catch (ex) {
+        return { error: ex };
+    } finally {
+        AST_Node.warn_function = warn_function;
+    }
+}

lib/mozilla-ast.js

@@ -111,23 +111,19 @@
         },
         Property: function(M) {
             var key = M.key;
-            var name = key.type == "Identifier" ? key.name : key.value;
             var args = {
                 start    : my_start_token(key),
                 end      : my_end_token(M.value),
-                key      : name,
+                key      : key.type == "Identifier" ? key.name : key.value,
                 value    : from_moz(M.value)
             };
-            switch (M.kind) {
-              case "init":
-                return new AST_ObjectKeyVal(args);
-              case "set":
-                args.value.name = from_moz(key);
-                return new AST_ObjectSetter(args);
-              case "get":
-                args.value.name = from_moz(key);
-                return new AST_ObjectGetter(args);
-            }
+            if (M.kind == "init") return new AST_ObjectKeyVal(args);
+            args.key = new AST_SymbolMethod({
+                name: args.key
+            });
+            args.value = new AST_Accessor(args.value);
+            if (M.kind == "get") return new AST_ObjectGetter(args);
+            if (M.kind == "set") return new AST_ObjectSetter(args);
         },
         ArrayExpression: function(M) {
             return new AST_Array({
@@ -149,7 +145,11 @@
             });
         },
         SequenceExpression: function(M) {
-            return AST_Seq.from_array(M.expressions.map(from_moz));
+            return new AST_Sequence({
+                start      : my_start_token(M),
+                end        : my_end_token(M),
+                expressions: M.expressions.map(from_moz)
+            });
         },
         MemberExpression: function(M) {
             return new (M.computed ? AST_Sub : AST_Dot)({
@@ -256,10 +256,7 @@
     map("CallExpression", AST_Call, "callee>expression, arguments@args");
 
     def_to_moz(AST_Toplevel, function To_Moz_Program(M) {
-        return {
-            type: "Program",
-            body: M.body.map(to_moz)
-        };
+        return to_moz_scope("Program", M);
     });
 
     def_to_moz(AST_Defun, function To_Moz_FunctionDeclaration(M) {
@@ -267,7 +264,7 @@
             type: "FunctionDeclaration",
             id: to_moz(M.name),
             params: M.argnames.map(to_moz),
-            body: to_moz_block(M)
+            body: to_moz_scope("BlockStatement", M)
         }
     });
 
@@ -276,7 +273,7 @@
             type: "FunctionExpression",
             id: to_moz(M.name),
             params: M.argnames.map(to_moz),
-            body: to_moz_block(M)
+            body: to_moz_scope("BlockStatement", M)
         }
     });
 
@@ -332,10 +329,10 @@
         };
     });
 
-    def_to_moz(AST_Seq, function To_Moz_SequenceExpression(M) {
+    def_to_moz(AST_Sequence, function To_Moz_SequenceExpression(M) {
         return {
             type: "SequenceExpression",
-            expressions: M.to_array().map(to_moz)
+            expressions: M.expressions.map(to_moz)
         };
     });
 
@@ -382,11 +379,10 @@
     });
 
     def_to_moz(AST_ObjectProperty, function To_Moz_Property(M) {
-        var key = (
-            is_identifier(M.key)
-            ? {type: "Identifier", name: M.key}
-            : {type: "Literal", value: M.key}
-        );
+        var key = {
+            type: "Literal",
+            value: M.key instanceof AST_SymbolMethod ? M.key.name : M.key
+        };
         var kind;
         if (M instanceof AST_ObjectKeyVal) {
             kind = "init";
@@ -547,8 +543,8 @@
         moz_to_me = new Function("U2", "my_start_token", "my_end_token", "from_moz", "return(" + moz_to_me + ")")(
             exports, my_start_token, my_end_token, from_moz
         );
-        me_to_moz = new Function("to_moz", "to_moz_block", "return(" + me_to_moz + ")")(
-            to_moz, to_moz_block
+        me_to_moz = new Function("to_moz", "to_moz_block", "to_moz_scope", "return(" + me_to_moz + ")")(
+            to_moz, to_moz_block, to_moz_scope
         );
         MOZ_TO_ME[moztype] = moz_to_me;
         def_to_moz(mytype, me_to_moz);
@@ -606,4 +602,14 @@
         };
     };
 
+    function to_moz_scope(type, node) {
+        var body = node.body.map(to_moz);
+        if (node.body[0] instanceof AST_SimpleStatement && node.body[0].body instanceof AST_String) {
+            body.unshift(to_moz(new AST_EmptyStatement(node.body[0])));
+        }
+        return {
+            type: type,
+            body: body
+        };
+    };
 })();

lib/output.js

@@ -53,29 +53,37 @@ function is_some_comments(comment) {
 function OutputStream(options) {
 
     options = defaults(options, {
-        indent_start     : 0,
-        indent_level     : 4,
-        quote_keys       : false,
-        space_colon      : true,
         ascii_only       : false,
-        unescape_regexps : false,
-        inline_script    : false,
-        width            : 80,
-        max_line_len     : false,
+        ascii_identifiers: undefined,
         beautify         : false,
-        source_map       : null,
         bracketize       : false,
-        semicolons       : true,
         comments         : false,
-        shebang          : true,
-        preserve_line    : false,
-        screw_ie8        : true,
-        preamble         : null,
-        quote_style      : 0,
+        ecma             : 5,
+        ie8              : false,
+        indent_level     : 4,
+        indent_start     : 0,
+        inline_script    : true,
         keep_quoted_props: false,
+        max_line_len     : false,
+        preamble         : null,
+        preserve_line    : false,
+        quote_keys       : false,
+        quote_style      : 0,
+        semicolons       : true,
+        shebang          : true,
+        shorthand        : undefined,
+        source_map       : null,
+        webkit           : false,
+        width            : 80,
         wrap_iife        : false,
     }, true);
 
+    if (typeof options.ascii_identifiers === 'undefined')
+        options.ascii_identifiers = options.ascii_only;
+
+    if (options.shorthand === undefined)
+        options.shorthand = options.ecma > 5;
+
     // Convert comment option to RegExp if neccessary and set up comments filter
     var comment_filter = return_false; // Default case, throw all comments away
     if (options.comments) {
@@ -111,9 +119,19 @@ function OutputStream(options) {
     var OUTPUT = "";
 
     function to_ascii(str, identifier) {
-        return str.replace(/[\u0000-\u001f\u007f-\uffff]/g, function(ch) {
-            var code = ch.charCodeAt(0).toString(16);
-            if (code.length <= 2 && !identifier) {
+        return str.replace(/[\ud800-\udbff][\udc00-\udfff]|[\u0000-\u001f\u007f-\uffff]/g, function(ch) {
+            var code = get_full_char_code(ch, 0).toString(16);
+
+            if ((identifier && code.length === 1 && options.ecma >= 6) || code.length > 4) {
+                if (options.ecma < 6) {
+                    if (identifier) {
+                        return ch; // no \u{} support
+                    }
+                    return "\\u" + ch.charCodeAt(0).toString(16) + "\\u"
+                        + ch.charCodeAt(1).toString(16);
+                }
+                return "\\u{" + code + "}";
+            } else if (code.length <= 2 && !identifier) {
                 while (code.length < 2) code = "0" + code;
                 return "\\x" + code;
             } else {
@@ -136,12 +154,12 @@ function OutputStream(options) {
               case "\t": return "\\t";
               case "\b": return "\\b";
               case "\f": return "\\f";
-              case "\x0B": return options.screw_ie8 ? "\\v" : "\\x0B";
+              case "\x0B": return options.ie8 ? "\\x0B" : "\\v";
               case "\u2028": return "\\u2028";
               case "\u2029": return "\\u2029";
               case "\ufeff": return "\\ufeff";
               case "\0":
-                  return /[0-7]/.test(str.charAt(i+1)) ? "\\x00" : "\\0";
+                  return /[0-7]/.test(get_full_char(str, i+1)) ? "\\x00" : "\\0";
             }
             return s;
         });
@@ -151,7 +169,11 @@ function OutputStream(options) {
         function quote_double() {
             return '"' + str.replace(/\x22/g, '\\"') + '"';
         }
+        function quote_template() {
+            return '`' + str.replace(/`/g, '\\`') + '`';
+        }
         if (options.ascii_only) str = to_ascii(str);
+        if (quote === "`") return quote_template();
         switch (options.quote_style) {
           case 1:
             return quote_single();
@@ -176,7 +198,7 @@ function OutputStream(options) {
 
     function make_name(name) {
         name = name.toString();
-        if (options.ascii_only)
+        if (options.ascii_identifiers)
             name = to_ascii(name, true);
         return name;
     };
@@ -190,17 +212,44 @@ function OutputStream(options) {
     var might_need_space = false;
     var might_need_semicolon = false;
     var might_add_newline = 0;
-    var last = null;
+    var last = "";
+    var mapping_token, mapping_name, mappings = options.source_map && [];
 
-    function last_char() {
-        return last.charAt(last.length - 1);
-    };
+    var do_add_mapping = mappings ? function() {
+        mappings.forEach(function(mapping) {
+            try {
+                options.source_map.add(
+                    mapping.token.file,
+                    mapping.line, mapping.col,
+                    mapping.token.line, mapping.token.col,
+                    !mapping.name && mapping.token.type == "name" ? mapping.token.value : mapping.name
+                );
+            } catch(ex) {
+                AST_Node.warn("Couldn't figure out mapping for {file}:{line},{col} → {cline},{ccol} [{name}]", {
+                    file: mapping.token.file,
+                    line: mapping.token.line,
+                    col: mapping.token.col,
+                    cline: mapping.line,
+                    ccol: mapping.col,
+                    name: mapping.name || ""
+                })
+            }
+        });
+        mappings = [];
+    } : noop;
 
     var ensure_line_len = options.max_line_len ? function() {
         if (current_col > options.max_line_len) {
             if (might_add_newline) {
                 var left = OUTPUT.slice(0, might_add_newline);
                 var right = OUTPUT.slice(might_add_newline);
+                if (mappings) {
+                    var delta = right.length - current_col;
+                    mappings.forEach(function(mapping) {
+                        mapping.line++;
+                        mapping.col += delta;
+                    });
+                }
                 OUTPUT = left + "\n" + right;
                 current_line++;
                 current_pos++;
@@ -210,18 +259,22 @@ function OutputStream(options) {
                 AST_Node.warn("Output exceeds {max_line_len} characters", options);
             }
         }
-        might_add_newline = 0;
+        if (might_add_newline) {
+            might_add_newline = 0;
+            do_add_mapping();
+        }
     } : noop;
 
     var requireSemicolonChars = makePredicate("( [ + * / - , .");
 
     function print(str) {
         str = String(str);
-        var ch = str.charAt(0);
+        var ch = get_full_char(str, 0);
+        var prev = get_full_char(last, last.length - 1);
         if (might_need_semicolon) {
             might_need_semicolon = false;
 
-            if ((!ch || ";}".indexOf(ch) < 0) && !/[;]$/.test(last)) {
+            if (prev == ":" && ch == "}" || (!ch || ";}".indexOf(ch) < 0) && prev != ";") {
                 if (options.semicolons || requireSemicolonChars(ch)) {
                     OUTPUT += ";";
                     current_col++;
@@ -258,7 +311,6 @@ function OutputStream(options) {
         }
 
         if (might_need_space) {
-            var prev = last_char();
             if ((is_identifier_char(prev)
                     && (is_identifier_char(ch) || ch == "\\"))
                 || (ch == "/" && ch == prev)
@@ -270,6 +322,18 @@ function OutputStream(options) {
             }
             might_need_space = false;
         }
+
+        if (mapping_token) {
+            mappings.push({
+                token: mapping_token,
+                name: mapping_name,
+                line: current_line,
+                col: current_col
+            });
+            mapping_token = false;
+            if (!might_add_newline) do_add_mapping();
+        }
+
         OUTPUT += str;
         current_pos += str.length;
         var a = str.split(/\r?\n/), n = a.length - 1;
@@ -282,6 +346,10 @@ function OutputStream(options) {
         last = str;
     };
 
+    var star = function(){
+        print("*");
+    }
+
     var space = options.beautify ? function() {
         print(" ");
     } : function() {
@@ -361,27 +429,12 @@ function OutputStream(options) {
 
     function colon() {
         print(":");
-        if (options.space_colon) space();
+        space();
     };
 
-    var add_mapping = options.source_map ? function(token, name) {
-        try {
-            if (token) options.source_map.add(
-                token.file || "?",
-                current_line, current_col,
-                token.line, token.col,
-                (!name && token.type == "name") ? token.value : name
-            );
-        } catch(ex) {
-            AST_Node.warn("Couldn't figure out mapping for {file}:{line},{col} → {cline},{ccol} [{name}]", {
-                file: token.file,
-                line: token.line,
-                col: token.col,
-                cline: current_line,
-                ccol: current_col,
-                name: name || ""
-            })
-        }
+    var add_mapping = mappings ? function(token, name) {
+        mapping_token = token;
+        mapping_name = name;
     } : noop;
 
     function get() {
@@ -401,6 +454,7 @@ function OutputStream(options) {
         should_break    : function() { return options.width && this.current_width() >= options.width },
         newline         : newline,
         print           : print,
+        star            : star,
         space           : space,
         comma           : comma,
         colon           : colon,
@@ -420,6 +474,10 @@ function OutputStream(options) {
             }
             print(encoded);
         },
+        print_template_string_chars: function(str) {
+            var encoded = encode_string(str, '`').replace(/\${/g, "\\${");
+            return print(encoded.substr(1, encoded.length - 2));
+        },
         encode_string   : encode_string,
         next_indent     : next_indent,
         with_indent     : with_indent,
@@ -475,6 +533,7 @@ function OutputStream(options) {
             use_asm = prev_use_asm;
         }
     });
+    AST_Node.DEFMETHOD("_print", AST_Node.prototype.print);
 
     AST_Node.DEFMETHOD("print_to_string", function(options){
         var s = OutputStream(options);
@@ -510,8 +569,8 @@ function OutputStream(options) {
                 }));
             }
 
-            if (comments.length > 0 && output.pos() == 0) {
-                if (output.option("shebang") && comments[0].type == "comment5") {
+            if (output.pos() == 0) {
+                if (comments.length > 0 && output.option("shebang") && comments[0].type == "comment5") {
                     output.print("#!" + comments.shift().value + "\n");
                     output.indent();
                 }
@@ -572,6 +631,13 @@ function OutputStream(options) {
             return true;
         }
 
+        if (output.option('webkit')) {
+            var p = output.parent();
+            if (p instanceof AST_PropAccess && p.expression === this) {
+                return true;
+            }
+        }
+
         if (output.option('wrap_iife')) {
             var p = output.parent();
             return p instanceof AST_Call && p.expression === this;
@@ -580,29 +646,46 @@ function OutputStream(options) {
         return false;
     });
 
+    PARENS(AST_Arrow, function(output){
+        var p = output.parent();
+        return p instanceof AST_PropAccess && p.expression === this;
+    });
+
+    PARENS(AST_ClassExpression, function(output){
+        return output.parent() instanceof AST_SimpleStatement;
+    });
+
     // same goes for an object literal, because otherwise it would be
     // interpreted as a block of code.
     PARENS(AST_Object, function(output){
         return first_in_statement(output);
     });
 
-    PARENS([ AST_Unary, AST_Undefined ], function(output){
+    PARENS(AST_Unary, function(output){
         var p = output.parent();
         return p instanceof AST_PropAccess && p.expression === this
-            || p instanceof AST_Call && p.expression === this;
+            || p instanceof AST_Call && p.expression === this
+            || p instanceof AST_Binary
+                && p.operator === "**"
+                && this instanceof AST_UnaryPrefix
+                && p.left === this
+                && this.operator !== "++"
+                && this.operator !== "--";
     });
 
-    PARENS(AST_Seq, function(output){
+    PARENS(AST_Sequence, function(output){
         var p = output.parent();
-        return p instanceof AST_Call             // (foo, bar)() or foo(1, (2, 3), 4)
-            || p instanceof AST_Unary            // !(foo, bar, baz)
-            || p instanceof AST_Binary           // 1 + (2, 3) + 4 ==> 8
-            || p instanceof AST_VarDef           // var a = (1, 2), b = a + a; ==> b == 4
-            || p instanceof AST_PropAccess       // (1, {foo:2}).foo or (1, {foo:2})["foo"] ==> 2
-            || p instanceof AST_Array            // [ 1, (2, 3), 4 ] ==> [ 1, 3, 4 ]
-            || p instanceof AST_ObjectProperty   // { foo: (1, 2) }.foo ==> 2
-            || p instanceof AST_Conditional      /* (false, true) ? (a = 10, b = 20) : (c = 30)
-                                                  * ==> 20 (side effect, set a := 10 and b := 20) */
+        return p instanceof AST_Call                          // (foo, bar)() or foo(1, (2, 3), 4)
+            || p instanceof AST_Unary                         // !(foo, bar, baz)
+            || p instanceof AST_Binary                        // 1 + (2, 3) + 4 ==> 8
+            || p instanceof AST_VarDef                        // var a = (1, 2), b = a + a; ==> b == 4
+            || p instanceof AST_PropAccess                    // (1, {foo:2}).foo or (1, {foo:2})["foo"] ==> 2
+            || p instanceof AST_Array                         // [ 1, (2, 3), 4 ] ==> [ 1, 3, 4 ]
+            || p instanceof AST_ObjectProperty                // { foo: (1, 2) }.foo ==> 2
+            || p instanceof AST_Conditional                   /* (false, true) ? (a = 10, b = 20) : (c = 30)
+                                                               * ==> 20 (side effect, set a := 10 and b := 20) */
+            || p instanceof AST_Arrow                         // x => (x, x)
+            || p instanceof AST_DefaultAssign                 // x => (x = (0, function(){}))
         ;
     });
 
@@ -629,6 +712,24 @@ function OutputStream(options) {
         }
     });
 
+    PARENS(AST_Yield, function(output){
+        var p = output.parent();
+        // (yield 1) + (yield 2)
+        // a = yield 3
+        if (p instanceof AST_Binary && p.operator !== "=")
+            return true;
+        // (yield 1) ? yield 2 : yield 3
+        if (p instanceof AST_Conditional && p.condition === this)
+            return true;
+        // -(yield 4)
+        if (p instanceof AST_Unary)
+            return true;
+        // (yield x).foo
+        // (yield x)['foo']
+        if (p instanceof AST_PropAccess && p.expression === this)
+            return true;
+    });
+
     PARENS(AST_PropAccess, function(output){
         var p = output.parent();
         if (p instanceof AST_New && p.expression === this) {
@@ -681,7 +782,7 @@ function OutputStream(options) {
         }
     });
 
-    PARENS([ AST_Assign, AST_Conditional ], function (output){
+    PARENS([ AST_Assign, AST_Conditional ], function(output){
         var p = output.parent();
         // !(a = false) → true
         if (p instanceof AST_Unary)
@@ -698,6 +799,9 @@ function OutputStream(options) {
         // (a = foo)["prop"] —or— (a = foo).prop
         if (p instanceof AST_PropAccess && p.expression === this)
             return true;
+        // ({a, b} = {a: 1, b: 2}), a destructuring assignment
+        if (this instanceof AST_Assign && this.left instanceof AST_Destructuring && this.left.is_array === false)
+            return true;
     });
 
     /* -----[ PRINTERS ]----- */
@@ -706,6 +810,26 @@ function OutputStream(options) {
         output.print_string(self.value, self.quote);
         output.semicolon();
     });
+
+    DEFPRINT(AST_Expansion, function (self, output) {
+        output.print('...');
+        self.expression.print(output);
+    });
+
+    DEFPRINT(AST_Destructuring, function (self, output) {
+        output.print(self.is_array ? "[" : "{");
+        var len = self.names.length;
+        self.names.forEach(function (name, i) {
+            if (i > 0) output.comma();
+            name.print(output);
+            // If the final element is a hole, we need to make sure it
+            // doesn't look like a trailing comma, by inserting an actual
+            // trailing comma.
+            if (i == len - 1 && name instanceof AST_Hole) output.comma();
+        });
+        output.print(self.is_array ? "]" : "}");
+    });
+
     DEFPRINT(AST_Debugger, function(self, output){
         output.print("debugger");
         output.semicolon();
@@ -799,7 +923,7 @@ function OutputStream(options) {
         output.print("for");
         output.space();
         output.with_parens(function(){
-            if (self.init && !(self.init instanceof AST_EmptyStatement)) {
+            if (self.init) {
                 if (self.init instanceof AST_Definitions) {
                     self.init.print(output);
                 } else {
@@ -830,7 +954,11 @@ function OutputStream(options) {
         output.with_parens(function(){
             self.init.print(output);
             output.space();
-            output.print("in");
+            if (self instanceof AST_ForOf) {
+                output.print("of");
+            } else {
+                output.print("in");
+            }
             output.space();
             self.object.print(output);
         });
@@ -851,11 +979,24 @@ function OutputStream(options) {
     AST_Lambda.DEFMETHOD("_do_print", function(output, nokeyword){
         var self = this;
         if (!nokeyword) {
+            if (self.async) {
+                output.print("async");
+                output.space();
+            }
             output.print("function");
+            if (self.is_generator) {
+                output.star();
+            }
+            if (self.name) {
+                output.space();
+            }
         }
-        if (self.name) {
-            output.space();
+        if (self.name instanceof AST_Symbol) {
             self.name.print(output);
+        } else if (nokeyword && self.name instanceof AST_Node) {
+            output.with_square(function() {
+                self.name.print(output); // Computed method name
+            });
         }
         output.with_parens(function(){
             self.argnames.forEach(function(arg, i){
@@ -870,6 +1011,60 @@ function OutputStream(options) {
         self._do_print(output);
     });
 
+    DEFPRINT(AST_PrefixedTemplateString, function(self, output) {
+        self.prefix.print(output);
+        self.template_string.print(output);
+    });
+    DEFPRINT(AST_TemplateString, function(self, output) {
+        var is_tagged = output.parent() instanceof AST_PrefixedTemplateString;
+
+        output.print("`");
+        for (var i = 0; i < self.segments.length; i++) {
+            if (!(self.segments[i] instanceof AST_TemplateSegment)) {
+                output.print("${");
+                self.segments[i].print(output);
+                output.print("}");
+            } else if (is_tagged) {
+                output.print(self.segments[i].raw);
+            } else {
+                output.print_template_string_chars(self.segments[i].value);
+            }
+        }
+        output.print("`");
+    });
+
+    AST_Arrow.DEFMETHOD("_do_print", function(output){
+        var self = this;
+        var parent = output.parent();
+        var needs_parens = parent instanceof AST_Binary ||
+            parent instanceof AST_Unary ||
+            (parent instanceof AST_Call && self === parent.expression);
+        if (self.async) {
+            output.print("async");
+            output.space();
+        }
+        if (needs_parens) { output.print("(") }
+        if (self.argnames.length === 1 && self.argnames[0] instanceof AST_Symbol) {
+            self.argnames[0].print(output);
+        } else {
+            output.with_parens(function(){
+                self.argnames.forEach(function(arg, i){
+                    if (i) output.comma();
+                    arg.print(output);
+                });
+            });
+        }
+        output.space();
+        output.print('=>');
+        output.space();
+        if (self.body instanceof AST_Node) {
+            self.body.print(output);
+        } else {
+            print_bracketed(self.body, output);
+        }
+        if (needs_parens) { output.print(")") }
+    });
+
     /* -----[ exits ]----- */
     AST_Exit.DEFMETHOD("_do_print", function(output, kind){
         output.print(kind);
@@ -886,6 +1081,33 @@ function OutputStream(options) {
         self._do_print(output, "throw");
     });
 
+    /* -----[ yield ]----- */
+
+    DEFPRINT(AST_Yield, function(self, output){
+        var star = self.is_star ? "*" : "";
+        output.print("yield" + star);
+        if (self.expression) {
+            output.space();
+            self.expression.print(output);
+        }
+    });
+
+    DEFPRINT(AST_Await, function(self, output){
+        output.print("await");
+        output.space();
+        var e = self.expression;
+        var parens = !(
+               e instanceof AST_Call
+            || e instanceof AST_SymbolRef
+            || e instanceof AST_PropAccess
+            || e instanceof AST_Unary
+            || e instanceof AST_Constant
+        );
+        if (parens) output.print("(");
+        self.expression.print(output);
+        if (parens) output.print(")");
+    });
+
     /* -----[ loop control ]----- */
     AST_LoopControl.DEFMETHOD("_do_print", function(output, kind){
         output.print(kind);
@@ -906,7 +1128,7 @@ function OutputStream(options) {
     function make_then(self, output) {
         var b = self.body;
         if (output.option("bracketize")
-            || !output.option("screw_ie8") && b instanceof AST_Do)
+            || output.option("ie8") && b instanceof AST_Do)
             return make_block(b, output);
         // The squeezer replaces "block"-s that contain only a single
         // statement with the statement itself; technically, the AST
@@ -960,24 +1182,24 @@ function OutputStream(options) {
             self.expression.print(output);
         });
         output.space();
-        if (self.body.length > 0) output.with_block(function(){
-            self.body.forEach(function(stmt, i){
-                if (i) output.newline();
+        var last = self.body.length - 1;
+        if (last < 0) output.print("{}");
+        else output.with_block(function(){
+            self.body.forEach(function(branch, i){
                 output.indent(true);
-                stmt.print(output);
+                branch.print(output);
+                if (i < last && branch.body.length > 0)
+                    output.newline();
             });
         });
-        else output.print("{}");
     });
     AST_SwitchBranch.DEFMETHOD("_do_print_body", function(output){
-        if (this.body.length > 0) {
+        output.newline();
+        this.body.forEach(function(stmt){
+            output.indent();
+            stmt.print(output);
             output.newline();
-            this.body.forEach(function(stmt){
-                output.indent();
-                stmt.print(output);
-                output.newline();
-            });
-        }
+        });
     });
     DEFPRINT(AST_Default, function(self, output){
         output.print("default:");
@@ -1034,12 +1256,111 @@ function OutputStream(options) {
         if (!avoid_semicolon)
             output.semicolon();
     });
+    DEFPRINT(AST_Let, function(self, output){
+        self._do_print(output, "let");
+    });
     DEFPRINT(AST_Var, function(self, output){
         self._do_print(output, "var");
     });
     DEFPRINT(AST_Const, function(self, output){
         self._do_print(output, "const");
     });
+    DEFPRINT(AST_Import, function(self, output) {
+        output.print("import");
+        output.space();
+        if (self.imported_name) {
+            self.imported_name.print(output);
+        }
+        if (self.imported_name && self.imported_names) {
+            output.print(",");
+            output.space();
+        }
+        if (self.imported_names) {
+            if (self.imported_names.length === 1 && self.imported_names[0].foreign_name.name === "*") {
+                self.imported_names[0].print(output);
+            } else {
+                output.print("{");
+                self.imported_names.forEach(function (name_import, i) {
+                    output.space();
+                    name_import.print(output);
+                    if (i < self.imported_names.length - 1) {
+                        output.print(",");
+                    }
+                });
+                output.space();
+                output.print("}");
+            }
+        }
+        if (self.imported_name || self.imported_names) {
+            output.space();
+            output.print("from")
+            output.space();
+        }
+        self.module_name.print(output);
+        output.semicolon();
+    });
+
+    DEFPRINT(AST_NameMapping, function(self, output) {
+        var is_import = output.parent() instanceof AST_Import;
+        var definition = self.name.definition();
+        var names_are_different =
+            (definition && definition.mangled_name || self.name.name) !==
+            self.foreign_name.name;
+        if (names_are_different) {
+            if (is_import) {
+                output.print(self.foreign_name.name);
+            } else {
+                self.name.print(output);
+            }
+            output.space();
+            output.print("as");
+            output.space();
+            if (is_import) {
+                self.name.print(output);
+            } else {
+                output.print(self.foreign_name.name);
+            }
+        } else {
+            self.name.print(output);
+        }
+    });
+
+    DEFPRINT(AST_Export, function(self, output) {
+        output.print("export");
+        output.space();
+        if (self.is_default) {
+            output.print("default");
+            output.space();
+        }
+        if (self.exported_names) {
+            if (self.exported_names.length === 1 && self.exported_names[0].name.name === "*") {
+                self.exported_names[0].print(output);
+            } else {
+                output.print("{");
+                self.exported_names.forEach(function(name_export, i) {
+                    output.space();
+                    name_export.print(output);
+                    if (i < self.exported_names.length - 1) {
+                        output.print(",");
+                    }
+                });
+                output.space();
+                output.print("}");
+            }
+        }
+        else if (self.exported_value) {
+            self.exported_value.print(output);
+        } else if (self.exported_definition) {
+            self.exported_definition.print(output);
+        }
+        if (self.module_name) {
+            output.space();
+            output.print("from");
+            output.space();
+            self.module_name.print(output);
+        }
+        output.semicolon();
+    });
 
     function parenthesize_for_noin(node, output, noin) {
         if (!noin) node.print(output);
@@ -1087,18 +1408,19 @@ function OutputStream(options) {
         AST_Call.prototype._codegen(self, output);
     });
 
-    AST_Seq.DEFMETHOD("_do_print", function(output){
-        this.car.print(output);
-        if (this.cdr) {
-            output.comma();
-            if (output.should_break()) {
-                output.newline();
-                output.indent();
+    AST_Sequence.DEFMETHOD("_do_print", function(output){
+        this.expressions.forEach(function(node, index) {
+            if (index > 0) {
+                output.comma();
+                if (output.should_break()) {
+                    output.newline();
+                    output.indent();
+                }
             }
-            this.cdr.print(output);
-        }
+            node.print(output);
+        });
     });
-    DEFPRINT(AST_Seq, function(self, output){
+    DEFPRINT(AST_Sequence, function(self, output){
         self._do_print(output);
         // var p = output.parent();
         // if (p instanceof AST_Statement) {
@@ -1211,9 +1533,50 @@ function OutputStream(options) {
         });
         else output.print("{}");
     });
-    DEFPRINT(AST_ObjectKeyVal, function(self, output){
-        var key = self.key;
-        var quote = self.quote;
+    DEFPRINT(AST_Class, function(self, output){
+        output.print("class");
+        output.space();
+        if (self.name) {
+            self.name.print(output);
+            output.space();
+        }
+        if (self.extends) {
+            var parens = (
+                   !(self.extends instanceof AST_SymbolRef)
+                && !(self.extends instanceof AST_PropAccess)
+                && !(self.extends instanceof AST_ClassExpression)
+                && !(self.extends instanceof AST_Function)
+            );
+            output.print("extends");
+            if (parens) {
+                output.print("(");
+            } else {
+                output.space();
+            }
+            self.extends.print(output);
+            if (parens) {
+                output.print(")");
+            } else {
+                output.space();
+            }
+        }
+        if (self.properties.length > 0) output.with_block(function(){
+            self.properties.forEach(function(prop, i){
+                if (i) {
+                    output.newline();
+                }
+                output.indent();
+                prop.print(output);
+            });
+            output.newline();
+        });
+        else output.print("{}");
+    });
+    DEFPRINT(AST_NewTarget, function(self, output) {
+        output.print("new.target");
+    });
+
+    function print_property_name(key, quote, output) {
         if (output.option("quote_keys")) {
             output.print_string(key + "");
         } else if ((typeof key == "number"
@@ -1221,7 +1584,7 @@ function OutputStream(options) {
                     && +key + "" == key)
                    && parseFloat(key) >= 0) {
             output.print(make_num(key));
-        } else if (RESERVED_WORDS(key) ? output.option("screw_ie8") : is_identifier_string(key)) {
+        } else if (RESERVED_WORDS(key) ? !output.option("ie8") : is_identifier_string(key)) {
             if (quote && output.option("keep_quoted_props")) {
                 output.print_string(key, quote);
             } else {
@@ -1230,38 +1593,90 @@ function OutputStream(options) {
         } else {
             output.print_string(key, quote);
         }
-        output.colon();
-        self.value.print(output);
+    }
+
+    DEFPRINT(AST_ObjectKeyVal, function(self, output){
+        function get_name(self) {
+            var def = self.definition();
+            return def ? def.mangled_name || def.name : self.name;
+        }
+
+        var allowShortHand = output.option("shorthand");
+        if (allowShortHand &&
+            self.value instanceof AST_Symbol &&
+            is_identifier_string(self.key) &&
+            get_name(self.value) === self.key
+        ) {
+            print_property_name(self.key, self.quote, output);
+
+        } else if (allowShortHand &&
+            self.value instanceof AST_DefaultAssign &&
+            self.value.left instanceof AST_Symbol &&
+            is_identifier_string(self.key) &&
+            get_name(self.value.left) === self.key
+        ) {
+            print_property_name(self.key, self.quote, output);
+            output.space();
+            output.print("=");
+            output.space();
+            self.value.right.print(output);
+        } else {
+            if (!(self.key instanceof AST_Node)) {
+                print_property_name(self.key, self.quote, output);
+            } else {
+                output.with_square(function() {
+                    self.key.print(output);
+                });
+            }
+            output.colon();
+            self.value.print(output);
+        }
+    });
+    AST_ObjectProperty.DEFMETHOD("_print_getter_setter", function(type, output) {
+        var self = this;
+        if (self.static) {
+            output.print("static");
+            output.space();
+        }
+        if (type) {
+            output.print(type);
+            output.space();
+        }
+        if (self.key instanceof AST_SymbolMethod) {
+            print_property_name(self.key.name, self.quote, output);
+        } else {
+            output.with_square(function() {
+                self.key.print(output);
+            });
+        }
+        self.value._do_print(output, true);
     });
     DEFPRINT(AST_ObjectSetter, function(self, output){
-        output.print("set");
-        output.space();
-        self.key.print(output);
-        self.value._do_print(output, true);
+        self._print_getter_setter("set", output);
     });
     DEFPRINT(AST_ObjectGetter, function(self, output){
-        output.print("get");
-        output.space();
-        self.key.print(output);
-        self.value._do_print(output, true);
+        self._print_getter_setter("get", output);
     });
-    DEFPRINT(AST_Symbol, function(self, output){
-        var def = self.definition();
-        output.print_name(def ? def.mangled_name || def.name : self.name);
+    DEFPRINT(AST_ConciseMethod, function(self, output){
+        self._print_getter_setter(self.is_generator && "*" || self.async && "async", output);
     });
-    DEFPRINT(AST_Undefined, function(self, output){
-        output.print("void 0");
+    AST_Symbol.DEFMETHOD("_do_print", function(output){
+        var def = this.definition();
+        output.print_name(def ? def.mangled_name || def.name : this.name);
+    });
+    DEFPRINT(AST_Symbol, function (self, output) {
+        self._do_print(output);
+    });
+    DEFPRINT(AST_SymbolDeclaration, function(self, output){
+        self._do_print(output);
     });
     DEFPRINT(AST_Hole, noop);
-    DEFPRINT(AST_Infinity, function(self, output){
-        output.print("Infinity");
-    });
-    DEFPRINT(AST_NaN, function(self, output){
-        output.print("NaN");
-    });
     DEFPRINT(AST_This, function(self, output){
         output.print("this");
     });
+    DEFPRINT(AST_Super, function(self, output){
+        output.print("super");
+    });
     DEFPRINT(AST_Constant, function(self, output){
         output.print(self.getValue());
     });
@@ -1276,45 +1691,14 @@ function OutputStream(options) {
         }
     });
 
-    function regexp_safe_literal(code) {
-        return [
-            0x5c   , // \
-            0x2f   , // /
-            0x2e   , // .
-            0x2b   , // +
-            0x2a   , // *
-            0x3f   , // ?
-            0x28   , // (
-            0x29   , // )
-            0x5b   , // [
-            0x5d   , // ]
-            0x7b   , // {
-            0x7d   , // }
-            0x24   , // $
-            0x5e   , // ^
-            0x3a   , // :
-            0x7c   , // |
-            0x21   , // !
-            0x0a   , // \n
-            0x0d   , // \r
-            0x00   , // \0
-            0xfeff , // Unicode BOM
-            0x2028 , // unicode "line separator"
-            0x2029 , // unicode "paragraph separator"
-        ].indexOf(code) < 0;
-    };
-
     DEFPRINT(AST_RegExp, function(self, output){
-        var str = self.getValue().toString();
+        var regexp = self.getValue();
+        var str = regexp.toString();
+        if (regexp.raw_source) {
+            str = "/" + regexp.raw_source + str.slice(str.lastIndexOf("/"));
+        }
         if (output.option("ascii_only")) {
             str = output.to_ascii(str);
-        } else if (output.option("unescape_regexps")) {
-            str = str.split("\\\\").map(function(str){
-                return str.replace(/\\u[0-9a-fA-F]{4}|\\x[0-9a-fA-F]{2}/g, function(s){
-                    var code = parseInt(s.substr(2), 16);
-                    return regexp_safe_literal(code) ? String.fromCharCode(code) : s;
-                });
-            }).join("\\\\");
         }
         output.print(str);
         var p = output.parent();

lib/propmangle.js

@@ -43,11 +43,37 @@
 
 "use strict";
 
-function find_builtins() {
-    var a = [];
+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",
+        "true",
+        "false",
+        "Infinity",
+        "-Infinity",
+        "undefined",
+    ].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) {
@@ -55,24 +81,24 @@ function find_builtins() {
         }
     });
     function add(name) {
-        push_uniq(a, name);
+        push_uniq(reserved, name);
     }
-    return a;
 }
 
 function mangle_properties(ast, options) {
     options = defaults(options, {
-        reserved : null,
-        cache : null,
-        only_cache : false,
-        regex : null,
-        ignore_quoted : false,
-        debug : false
+        builtins: false,
+        cache: null,
+        debug: false,
+        keep_quoted: false,
+        only_cache: false,
+        regex: null,
+        reserved: null,
     });
 
     var reserved = options.reserved;
-    if (reserved == null)
-        reserved = find_builtins();
+    if (!Array.isArray(reserved)) reserved = [];
+    if (!options.builtins) find_builtins(reserved);
 
     var cache = options.cache;
     if (cache == null) {
@@ -83,12 +109,12 @@ function mangle_properties(ast, options) {
     }
 
     var regex = options.regex;
-    var ignore_quoted = options.ignore_quoted;
+    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'
     // the same as passing an empty string.
-    var debug = (options.debug !== false);
+    var debug = options.debug !== false;
     var debug_name_suffix;
     if (debug) {
         debug_name_suffix = (options.debug === true ? "" : options.debug);
@@ -96,12 +122,12 @@ function mangle_properties(ast, options) {
 
     var names_to_mangle = [];
     var unmangleable = [];
-    var ignored = {};
+    var to_keep = {};
 
     // step 1: find candidates to mangle
     ast.walk(new TreeWalker(function(node){
         if (node instanceof AST_ObjectKeyVal) {
-            add(node.key, ignore_quoted && node.quote);
+            add(node.key, keep_quoted && node.quote);
         }
         else if (node instanceof AST_ObjectProperty) {
             // setter or getter, since KeyVal is handled above
@@ -111,14 +137,17 @@ function mangle_properties(ast, options) {
             add(node.property);
         }
         else if (node instanceof AST_Sub) {
-            addStrings(node.property, ignore_quoted);
+            addStrings(node.property, keep_quoted);
+        }
+        else if (node instanceof AST_ConciseMethod) {
+            add(node.name.name);
         }
     }));
 
     // step 2: transform the tree, renaming properties
     return ast.transform(new TreeTransformer(function(node){
         if (node instanceof AST_ObjectKeyVal) {
-            if (!(ignore_quoted && node.quote))
+            if (!(keep_quoted && node.quote))
                 node.key = mangle(node.key);
         }
         else if (node instanceof AST_ObjectProperty) {
@@ -129,9 +158,14 @@ function mangle_properties(ast, options) {
             node.property = mangle(node.property);
         }
         else if (node instanceof AST_Sub) {
-            if (!ignore_quoted)
+            if (!keep_quoted)
                 node.property = mangleStrings(node.property);
         }
+        else if (node instanceof AST_ConciseMethod) {
+            if (should_mangle(node.name.name)) {
+                node.name.name = mangle(node.name.name);
+            }
+        }
         // else if (node instanceof AST_String) {
         //     if (should_mangle(node.value)) {
         //         AST_Node.warn(
@@ -149,27 +183,26 @@ function mangle_properties(ast, options) {
     // only function declarations after this line
 
     function can_mangle(name) {
-        if (!is_identifier(name)) return false;
         if (unmangleable.indexOf(name) >= 0) return false;
         if (reserved.indexOf(name) >= 0) return false;
         if (options.only_cache) {
             return cache.props.has(name);
         }
-        if (/^[0-9.]+$/.test(name)) return false;
+        if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
         return true;
     }
 
     function should_mangle(name) {
-        if (ignore_quoted && name in ignored) return false;
+        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)
             || names_to_mangle.indexOf(name) >= 0;
     }
 
-    function add(name, ignore) {
-        if (ignore) {
-            ignored[name] = true;
+    function add(name, keep) {
+        if (keep) {
+            to_keep[name] = true;
             return;
         }
 
@@ -192,19 +225,19 @@ function mangle_properties(ast, options) {
                 // 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) && !(ignore_quoted && debug_mangled in ignored)) {
+                if (can_mangle(debug_mangled) && !(keep_quoted && debug_mangled in to_keep)) {
                     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 'ignored' set
-                // (filled with quoted properties when ignore_quoted set). Make sure we add this
+                // 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) || (ignore_quoted && mangled in ignored));
+                } while (!can_mangle(mangled) || keep_quoted && mangled in to_keep);
             }
 
             cache.props.set(name, mangled);
@@ -212,17 +245,17 @@ function mangle_properties(ast, options) {
         return mangled;
     }
 
-    function addStrings(node, ignore) {
+    function addStrings(node, keep) {
         var out = {};
         try {
             (function walk(node){
                 node.walk(new TreeWalker(function(node){
-                    if (node instanceof AST_Seq) {
-                        walk(node.cdr);
+                    if (node instanceof AST_Sequence) {
+                        walk(node.expressions[node.expressions.length - 1]);
                         return true;
                     }
                     if (node instanceof AST_String) {
-                        add(node.value, ignore);
+                        add(node.value, keep);
                         return true;
                     }
                     if (node instanceof AST_Conditional) {
@@ -240,8 +273,9 @@ function mangle_properties(ast, options) {
 
     function mangleStrings(node) {
         return node.transform(new TreeTransformer(function(node){
-            if (node instanceof AST_Seq) {
-                node.cdr = mangleStrings(node.cdr);
+            if (node instanceof AST_Sequence) {
+                var last = node.expressions.length - 1;
+                node.expressions[last] = mangleStrings(node.expressions[last]);
             }
             else if (node instanceof AST_String) {
                 node.value = mangle(node.value);
@@ -253,5 +287,4 @@ function mangle_properties(ast, options) {
             return node;
         }));
     }
-
 }

lib/scope.js

@@ -49,6 +49,7 @@ function SymbolDef(scope, index, orig) {
     this.scope = scope;
     this.references = [];
     this.global = false;
+    this.export = false;
     this.mangled_name = null;
     this.undeclared = false;
     this.index = index;
@@ -62,11 +63,16 @@ 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;
@@ -75,20 +81,29 @@ SymbolDef.prototype = {
         }
         else if (!this.mangled_name && !this.unmangleable(options)) {
             var s = this.scope;
-            if (!options.screw_ie8 && this.orig[0] instanceof AST_SymbolLambda)
+            var sym = this.orig[0];
+            if (options.ie8 && sym instanceof AST_SymbolLambda)
                 s = s.parent_scope;
-            this.mangled_name = s.next_mangled(options, this);
+            var def;
+            if (def = this.redefined()) {
+                this.mangled_name = def.mangled_name || def.name;
+            } else
+                this.mangled_name = s.next_mangled(options, this);
             if (this.global && cache) {
                 cache.set(this.name, this.mangled_name);
             }
         }
+    },
+    redefined: function() {
+        return this.defun && this.defun.variables.get(this.name);
     }
 };
 
 AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
     options = defaults(options, {
-        screw_ie8: true,
-        cache: null
+        cache: null,
+        ie8: false,
+        safari10: false,
     });
 
     // pass 1: setup scope chaining and handle definitions
@@ -96,19 +111,36 @@ 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);
-            scope.init_scope_vars();
-            scope.parent_scope = save_scope;
+            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();
-            var save_scope = node.parent_scope = scope;
+            node.init_scope_vars(scope);
+            var save_scope = scope;
             var save_defun = defun;
             var save_labels = labels;
             defun = scope = node;
@@ -150,14 +182,40 @@ 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);
+            var parent_lambda = defun.parent_scope;
+            while (parent_lambda.is_block_scope()) {
+                parent_lambda = parent_lambda.parent_scope;
+            }
+            mark_export((node.scope = parent_lambda).def_function(node), 1);
+        }
+        else if (node instanceof AST_SymbolClass) {
+            mark_export(defun.def_variable(node), 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), 1);
         }
         else if (node instanceof AST_SymbolVar
-                 || node instanceof AST_SymbolConst) {
-            defun.def_variable(node);
+            || node instanceof AST_SymbolLet
+            || node instanceof AST_SymbolConst) {
+            var def = ((node instanceof AST_SymbolBlockDeclaration) ? scope : defun).def_variable(node);
+            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);
+                if (node.thedef !== def) {
+                    node.thedef = def;
+                    node.reference(options);
+                }
+            }
         }
         else if (node instanceof AST_SymbolCatch) {
-            scope.def_variable(node);
+            scope.def_variable(node).defun = defun;
         }
         else if (node instanceof AST_LabelRef) {
             var sym = labels.get(node.name);
@@ -168,20 +226,32 @@ 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;
@@ -193,27 +263,37 @@ 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);
             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);
 
     // pass 3: fix up any scoping issue with IE8
-    if (!options.screw_ie8) {
+    if (options.ie8) {
         self.walk(new TreeWalker(function(node, descend) {
             if (node instanceof AST_SymbolCatch) {
                 var name = node.name;
                 var refs = node.thedef.references;
-                var scope = node.thedef.scope.parent_scope;
+                var scope = node.thedef.defun;
                 var def = scope.find_variable(name) || self.globals.get(name) || scope.def_variable(node);
                 refs.forEach(function(ref) {
                     ref.thedef = def;
@@ -225,6 +305,19 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
         }));
     }
 
+    // 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);
+            });
+        }
+    }
+
     if (options.cache) {
         this.cname = options.cache.cname;
     }
@@ -243,28 +336,36 @@ AST_Toplevel.DEFMETHOD("def_global", function(node){
     }
 });
 
-AST_Scope.DEFMETHOD("init_scope_vars", function(){
-    this.variables = new Dictionary(); // map name to AST_SymbolVar (variables defined in this scope; includes functions)
-    this.functions = new Dictionary(); // map name to AST_SymbolDefun (functions defined in this scope)
-    this.uses_with = false;   // will be set to true if this or some nested scope uses the `with` statement
-    this.uses_eval = false;   // will be set to true if this or nested scope uses the global `eval`
-    this.parent_scope = null; // the parent scope
-    this.enclosed = [];       // a list of variables from this or outer scope(s) that are referenced from this or inner scopes
-    this.cname = -1;          // the current index for mangling functions/variables
+AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope){
+    this.variables = new Dictionary();  // map name to AST_SymbolVar (variables defined in this scope; includes functions)
+    this.functions = new Dictionary();  // map name to AST_SymbolDefun (functions defined in this scope)
+    this.uses_with = false;             // will be set to true if this or some nested scope uses the `with` statement
+    this.uses_eval = false;             // will be set to true if this or nested scope uses the global `eval`
+    this.parent_scope = parent_scope;   // the parent scope
+    this.enclosed = [];                 // a list of variables from this or outer scope(s) that are referenced from this or inner scopes
+    this.cname = -1;                    // the current index for mangling functions/variables
 });
 
+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;
-
-    var symbol = new AST_VarDef({ name: "arguments", start: this.start, end: this.end });
-    var def = new SymbolDef(this, this.variables.size(), symbol);
-    this.variables.set(symbol.name, def);
+    this.def_variable(new AST_SymbolConst({
+        name: "arguments",
+        start: this.start,
+        end: this.end
+    }));
 });
 
-AST_SymbolRef.DEFMETHOD("reference", function(options) {
+AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
     var def = this.definition();
-    def.references.push(this);
     var s = this.scope;
     while (s) {
         push_uniq(s.enclosed, def);
@@ -278,6 +379,11 @@ AST_SymbolRef.DEFMETHOD("reference", function(options) {
     }
 });
 
+AST_Symbol.DEFMETHOD("reference", function(options) {
+    this.definition().references.push(this);
+    this.mark_enclosed(options);
+});
+
 AST_Scope.DEFMETHOD("find_variable", function(name){
     if (name instanceof AST_Symbol) name = name.name;
     return this.variables.get(name)
@@ -285,7 +391,9 @@ AST_Scope.DEFMETHOD("find_variable", function(name){
 });
 
 AST_Scope.DEFMETHOD("def_function", function(symbol){
-    this.functions.set(symbol.name, this.def_variable(symbol));
+    var def = this.def_variable(symbol);
+    this.functions.set(symbol.name, def);
+    return def;
 });
 
 AST_Scope.DEFMETHOD("def_variable", function(symbol){
@@ -308,8 +416,8 @@ AST_Scope.DEFMETHOD("next_mangled", function(options){
         if (!is_identifier(m)) continue; // skip over "do"
 
         // https://github.com/mishoo/UglifyJS2/issues/242 -- do not
-        // shadow a name excepted from mangling.
-        if (options.except.indexOf(m) >= 0) continue;
+        // shadow a name reserved from mangling.
+        if (options.reserved.indexOf(m) >= 0) continue;
 
         // we must ensure that the mangled name does not shadow a name
         // from some parent scope that is referenced in this or in
@@ -341,18 +449,12 @@ AST_Function.DEFMETHOD("next_mangled", function(options, def){
 });
 
 AST_Symbol.DEFMETHOD("unmangleable", function(options){
-    return this.definition().unmangleable(options);
-});
-
-// property accessors are not mangleable
-AST_SymbolAccessor.DEFMETHOD("unmangleable", function(){
-    return true;
+    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
@@ -363,13 +465,9 @@ AST_Symbol.DEFMETHOD("undeclared", function(){
     return this.definition().undeclared;
 });
 
-AST_LabelRef.DEFMETHOD("undeclared", function(){
-    return false;
-});
+AST_LabelRef.DEFMETHOD("undeclared", return_false);
 
-AST_Label.DEFMETHOD("undeclared", function(){
-    return false;
-});
+AST_Label.DEFMETHOD("undeclared", return_false);
 
 AST_Symbol.DEFMETHOD("definition", function(){
     return this.thedef;
@@ -380,21 +478,23 @@ AST_Symbol.DEFMETHOD("global", function(){
 });
 
 AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options){
-    return defaults(options, {
-        except      : [],
+    options = defaults(options, {
         eval        : false,
-        sort        : false, // Ignored. Flag retained for backwards compatibility.
+        ie8         : false,
+        keep_classnames: false,
+        keep_fnames : false,
+        reserved    : [],
         toplevel    : false,
-        screw_ie8   : true,
-        keep_fnames : false
     });
+    if (!Array.isArray(options.reserved)) options.reserved = [];
+    return options;
 });
 
 AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     options = this._default_mangler_options(options);
 
     // Never mangle arguments
-    options.except.push('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
@@ -405,7 +505,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
 
     if (options.cache) {
         this.globals.each(function(symbol){
-            if (options.except.indexOf(symbol.name) < 0) {
+            if (options.reserved.indexOf(symbol.name) < 0) {
                 to_mangle.push(symbol);
             }
         });
@@ -422,7 +522,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
         if (node instanceof AST_Scope) {
             var p = tw.parent(), a = [];
             node.variables.each(function(symbol){
-                if (options.except.indexOf(symbol.name) < 0) {
+                if (options.reserved.indexOf(symbol.name) < 0) {
                     a.push(symbol);
                 }
             });
@@ -435,13 +535,18 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             node.mangled_name = name;
             return true;
         }
-        if (options.screw_ie8 && node instanceof AST_SymbolCatch) {
+        var mangle_with_block_scope =
+            (!options.ie8 && node instanceof AST_SymbolCatch) ||
+            node instanceof AST_SymbolBlockDeclaration;
+        if (mangle_with_block_scope) {
             to_mangle.push(node.definition());
             return;
         }
     });
     this.walk(tw);
-    to_mangle.forEach(function(def){ def.mangle(options) });
+    to_mangle.forEach(function(def){
+        def.mangle(options);
+    });
 
     if (options.cache) {
         options.cache.cname = this.cname;
@@ -450,105 +555,69 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
 
 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_Const)
-            base54.consider("const");
-        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.expressions[node.expressions.length - 1]);
+        }
+    }
 });
 
 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);
@@ -556,89 +625,3 @@ var base54 = (function() {
     };
     return base54;
 })();
-
-AST_Toplevel.DEFMETHOD("scope_warnings", function(options){
-    options = defaults(options, {
-        undeclared       : false, // this makes a lot of noise
-        unreferenced     : true,
-        assign_to_global : true,
-        func_arguments   : true,
-        nested_defuns    : true,
-        eval             : true
-    });
-    var tw = new TreeWalker(function(node){
-        if (options.undeclared
-            && node instanceof AST_SymbolRef
-            && node.undeclared())
-        {
-            // XXX: this also warns about JS standard names,
-            // i.e. Object, Array, parseInt etc.  Should add a list of
-            // exceptions.
-            AST_Node.warn("Undeclared symbol: {name} [{file}:{line},{col}]", {
-                name: node.name,
-                file: node.start.file,
-                line: node.start.line,
-                col: node.start.col
-            });
-        }
-        if (options.assign_to_global)
-        {
-            var sym = null;
-            if (node instanceof AST_Assign && node.left instanceof AST_SymbolRef)
-                sym = node.left;
-            else if (node instanceof AST_ForIn && node.init instanceof AST_SymbolRef)
-                sym = node.init;
-            if (sym
-                && (sym.undeclared()
-                    || (sym.global() && sym.scope !== sym.definition().scope))) {
-                AST_Node.warn("{msg}: {name} [{file}:{line},{col}]", {
-                    msg: sym.undeclared() ? "Accidental global?" : "Assignment to global",
-                    name: sym.name,
-                    file: sym.start.file,
-                    line: sym.start.line,
-                    col: sym.start.col
-                });
-            }
-        }
-        if (options.eval
-            && node instanceof AST_SymbolRef
-            && node.undeclared()
-            && node.name == "eval") {
-            AST_Node.warn("Eval is used [{file}:{line},{col}]", node.start);
-        }
-        if (options.unreferenced
-            && (node instanceof AST_SymbolDeclaration || node instanceof AST_Label)
-            && !(node instanceof AST_SymbolCatch)
-            && node.unreferenced()) {
-            AST_Node.warn("{type} {name} is declared but not referenced [{file}:{line},{col}]", {
-                type: node instanceof AST_Label ? "Label" : "Symbol",
-                name: node.name,
-                file: node.start.file,
-                line: node.start.line,
-                col: node.start.col
-            });
-        }
-        if (options.func_arguments
-            && node instanceof AST_Lambda
-            && node.uses_arguments) {
-            AST_Node.warn("arguments used in function {name} [{file}:{line},{col}]", {
-                name: node.name ? node.name.name : "anonymous",
-                file: node.start.file,
-                line: node.start.line,
-                col: node.start.col
-            });
-        }
-        if (options.nested_defuns
-            && node instanceof AST_Defun
-            && !(tw.parent() instanceof AST_Scope)) {
-            AST_Node.warn("Function {name} declared in nested statement \"{type}\" [{file}:{line},{col}]", {
-                name: node.name.name,
-                type: tw.parent().TYPE,
-                file: node.start.file,
-                line: node.start.line,
-                col: node.start.col
-            });
-        }
-    });
-    this.walk(tw);
-});

lib/transform.js

@@ -163,10 +163,18 @@ 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){
@@ -174,9 +182,8 @@ TreeTransformer.prototype = new TreeWalker;
         self.args = do_list(self.args, tw);
     });
 
-    _(AST_Seq, function(self, tw){
-        self.car = self.car.transform(tw);
-        self.cdr = self.cdr.transform(tw);
+    _(AST_Sequence, function(self, tw){
+        self.expressions = do_list(self.expressions, tw);
     });
 
     _(AST_Dot, function(self, tw){
@@ -188,6 +195,14 @@ 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);
     });
@@ -212,7 +227,50 @@ 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) {
+        for (var i = 0; i < self.segments.length; i++) {
+            if (!(self.segments[i] instanceof AST_TemplateSegment)) {
+                self.segments[i] = self.segments[i].transform(tw);
+            }
+        }
+    });
+
+    _(AST_PrefixedTemplateString, function(self, tw) {
+        self.template_string = self.template_string.transform(tw);
+    });
+
 })();

lib/utils.js

@@ -43,13 +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);
 };
@@ -346,7 +339,7 @@ function first_in_statement(stack) {
     for (var i = 0, p; p = stack.parent(i); i++) {
         if (p instanceof AST_Statement && p.body === node)
             return true;
-        if ((p instanceof AST_Seq           && p.car === node        ) ||
+        if ((p instanceof AST_Sequence      && p.expressions[0] === node) ||
             (p instanceof AST_Call          && p.expression === node && !(p instanceof AST_New) ) ||
             (p instanceof AST_Dot           && p.expression === node ) ||
             (p instanceof AST_Sub           && p.expression === node ) ||

package.json

@@ -1,10 +1,10 @@
 {
-  "name": "uglify-js",
+  "name": "uglify-es",
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
-  "homepage": "http://lisperator.net/uglifyjs",
+  "homepage": "https://github.com/mishoo/UglifyJS2/tree/harmony",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "2.8.13",
+  "version": "3.0.20",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -29,25 +29,16 @@
     "LICENSE"
   ],
   "dependencies": {
-    "source-map": "~0.5.1",
-    "uglify-to-browserify": "~1.0.0",
-    "yargs": "~3.10.0"
+    "commander": "~2.9.0",
+    "source-map": "~0.5.1"
   },
   "devDependencies": {
-    "acorn": "~0.6.0",
-    "escodegen": "~1.3.3",
-    "esfuzz": "~0.3.1",
-    "estraverse": "~1.5.1",
-    "mocha": "~2.3.4"
-  },
-  "browserify": {
-    "transform": [
-      "uglify-to-browserify"
-    ]
+    "acorn": "~5.0.3",
+    "mocha": "~2.3.4",
+    "semver": "~5.3.0"
   },
   "scripts": {
-    "shrinkwrap": "rm ./npm-shrinkwrap.json; rm -rf ./node_modules; npm i && npm shrinkwrap && npm outdated",
     "test": "node test/run-tests.js"
   },
-  "keywords": ["uglify", "uglify-js", "minify", "minifier"]
+  "keywords": ["uglify", "uglify-js", "uglify-es", "minify", "minifier", "es5", "es6", "es2015"]
 }

test/benchmark.js

@@ -4,15 +4,16 @@
 "use strict";
 
 var createHash = require("crypto").createHash;
+var fetch = require("./fetch");
 var fork = require("child_process").fork;
 var args = process.argv.slice(2);
 if (!args.length) {
-    args.push("-mc", "warnings=false");
+    args.push("-mc");
 }
-args.push("--stats");
+args.push("--timings");
 var urls = [
-    "https://code.jquery.com/jquery-3.1.1.js",
-    "https://code.angularjs.org/1.6.1/angular.js",
+    "https://code.jquery.com/jquery-3.2.1.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.6.4/angular.js",
     "https://cdnjs.cloudflare.com/ajax/libs/mathjs/3.9.0/math.js",
     "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.js",
     "https://unpkg.com/react@15.3.2/dist/react.js",
@@ -30,11 +31,6 @@ function done() {
             console.log();
             console.log(url);
             console.log(info.log);
-            var elapsed = 0;
-            info.log.replace(/: ([0-9]+\.[0-9]{3})s/g, function(match, time) {
-                elapsed += parseFloat(time);
-            });
-            console.log("Run-time:", elapsed.toFixed(3), "s");
             console.log("Original:", info.input, "bytes");
             console.log("Uglified:", info.output, "bytes");
             console.log("SHA1 sum:", info.sha1);
@@ -57,7 +53,8 @@ urls.forEach(function(url) {
         output: 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;

test/compress/angular-inject.js

@@ -1,67 +0,0 @@
-ng_inject_defun: {
-    options = {
-        angular: true
-    };
-    input: {
-        /*@ngInject*/
-        function Controller(dependency) {
-            return dependency;
-        }
-    }
-    expect: {
-        function Controller(dependency) {
-            return dependency;
-        }
-        Controller.$inject=['dependency']
-    }
-}
-
-ng_inject_assignment: {
-    options = {
-        angular: true
-    };
-    input: {
-        /*@ngInject*/
-        var Controller = function(dependency) {
-            return dependency;
-        }
-    }
-    expect: {
-        var Controller = function(dependency) {
-            return dependency;
-        }
-        Controller.$inject=['dependency']
-    }
-}
-
-ng_inject_inline: {
-    options = {
-        angular: true
-    };
-    input: {
-        angular.module('a').
-            factory('b',
-                /*@ngInject*/
-                function(dependency) {
-                    return dependency;
-                }).
-            directive('c',
-                /*@ngInject*/
-                function(anotherDependency) {
-                    return anotherDependency;
-                })
-    }
-    expect: {
-        angular.module('a').
-            factory('b',[
-                'dependency',
-                function(dependency) {
-                    return dependency;
-                }]).
-            directive('c',[
-                'anotherDependency',
-                function(anotherDependency) {
-                    return anotherDependency;
-                }])
-    }
-}

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,

test/compress/arrow.js

@@ -0,0 +1,282 @@
+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 = {
+        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 = {
+        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 = {
+        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);
+    }
+}

test/compress/ascii.js

@@ -2,7 +2,7 @@ ascii_only_true: {
     options = {}
     beautify = {
         ascii_only : true,
-        screw_ie8  : true,
+        ie8        : false,
         beautify   : false,
     }
     input: {
@@ -20,7 +20,7 @@ ascii_only_false: {
     options = {}
     beautify = {
         ascii_only : false,
-        screw_ie8  : true,
+        ie8        : false,
         beautify   : false,
     }
     input: {
@@ -33,4 +33,3 @@ ascii_only_false: {
     }
     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\'}'
 }
-

test/compress/async.js

@@ -0,0 +1,254 @@
+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)}"
+}
+
+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_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);"
+}

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;
+                class Zee {};
+            }
+        }
+        {
+            let y;
+        }
+        {
+            var y;
+        }
+    }
+    expect: {
+        function x(){
+            {
+                let x
+            }
+            var x;
+            {
+                const y;
+                class Zee {}
+            }
+        }
+        {
+            let y
+        }
+        var y;
+    }
+}
+
+remove_unused_in_global_block: {
+    options = {
+        unused: true,
+    }
+    input: {
+        {
+            let x;
+            const y;
+            class Zee {};
+            var w;
+        }
+        let ex;
+        const why;
+        class Zed {};
+        var wut;
+        console.log(x, y, Zee);
+    }
+    expect: {
+        var w;
+        let ex;
+        const why;
+        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 +47,142 @@ 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"
+}
+
+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/concat-strings.js

@@ -51,6 +51,7 @@ concat_2: {
             "1" + "2" + "3"
         );
     }
+    expect_stdout: true
 }
 
 concat_3: {
@@ -79,6 +80,7 @@ concat_3: {
             1 + 2 + "3" + "4" + "5"
         );
     }
+    expect_stdout: true
 }
 
 concat_4: {
@@ -107,6 +109,7 @@ concat_4: {
             1 + "2" + "3" + "4" + "5"
         );
     }
+    expect_stdout: true
 }
 
 concat_5: {
@@ -135,6 +138,7 @@ concat_5: {
             "1" + 2 + "3" + "4" + "5"
         );
     }
+    expect_stdout: true
 }
 
 concat_6: {
@@ -163,6 +167,7 @@ concat_6: {
             "1" + "2" + "3" + "4" + "5"
         );
     }
+    expect_stdout: true
 }
 
 concat_7: {
@@ -188,6 +193,7 @@ concat_7: {
             x += "foo"
         );
     }
+    expect_stdout: true
 }
 
 concat_8: {
@@ -213,4 +219,5 @@ concat_8: {
             x += "foo"
         );
     }
+    expect_stdout: true
 }

test/compress/conditionals.js

@@ -797,3 +797,221 @@ no_evaluate: {
         }
     }
 }
+
+equality_conditionals_false: {
+    options = {
+        conditionals: false,
+        sequences: true,
+    }
+    input: {
+        function f(a, b, c) {
+            console.log(
+                a == (b ? a : a),
+                a == (b ? a : c),
+                a != (b ? a : a),
+                a != (b ? a : c),
+                a === (b ? a : a),
+                a === (b ? a : c),
+                a !== (b ? a : a),
+                a !== (b ? a : c)
+            );
+        }
+        f(0, 0, 0);
+        f(0, true, 0);
+        f(1, 2, 3);
+        f(1, null, 3);
+        f(NaN);
+        f(NaN, "foo");
+    }
+    expect: {
+        function f(a, b, c) {
+            console.log(
+                a == (b ? a : a),
+                a == (b ? a : c),
+                a != (b ? a : a),
+                a != (b ? a : c),
+                a === (b ? a : a),
+                a === (b ? a : c),
+                a !== (b ? a : a),
+                a !== (b ? a : c)
+            );
+        }
+        f(0, 0, 0),
+        f(0, true, 0),
+        f(1, 2, 3),
+        f(1, null, 3),
+        f(NaN),
+        f(NaN, "foo");
+    }
+    expect_stdout: true
+}
+
+equality_conditionals_true: {
+    options = {
+        conditionals: true,
+        sequences: true,
+    }
+    input: {
+        function f(a, b, c) {
+            console.log(
+                a == (b ? a : a),
+                a == (b ? a : c),
+                a != (b ? a : a),
+                a != (b ? a : c),
+                a === (b ? a : a),
+                a === (b ? a : c),
+                a !== (b ? a : a),
+                a !== (b ? a : c)
+            );
+        }
+        f(0, 0, 0);
+        f(0, true, 0);
+        f(1, 2, 3);
+        f(1, null, 3);
+        f(NaN);
+        f(NaN, "foo");
+    }
+    expect: {
+        function f(a, b, c) {
+            console.log(
+                (b, a == a),
+                a == (b ? a : c),
+                (b, a != a),
+                a != (b ? a : c),
+                (b, a === a),
+                a === (b ? a : c),
+                (b, a !== a),
+                a !== (b ? a : c)
+            );
+        }
+        f(0, 0, 0),
+        f(0, true, 0),
+        f(1, 2, 3),
+        f(1, null, 3),
+        f(NaN),
+        f(NaN, "foo");
+    }
+    expect_stdout: true
+}
+
+issue_1645_1: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        (b = a) ? a++ + (b += a) ? b += a : b += a : b ^= a;
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        (b = a) ? (a++ + (b += a), b += a) : b ^= a;
+        console.log(a,b);
+    }
+    expect_stdout: true
+}
+
+issue_1645_2: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a = 0;
+        function f() {
+            return a++;
+        }
+        f() ? a += 2 : a += 4;
+        console.log(a);
+    }
+    expect: {
+        var a = 0;
+        function f(){
+            return a++;
+        }
+        f() ? a += 2 : a += 4;
+        console.log(a);
+    }
+    expect_stdout: true
+}
+
+condition_symbol_matches_consequent: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function foo(x, y) {
+            return x ? x : y;
+        }
+        function bar() {
+            return g ? g : h;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo(3, null), foo(0, 7), foo(true, false), bar());
+    }
+    expect: {
+        function foo(x, y) {
+            return x || y;
+        }
+        function bar() {
+            return g || h;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo(3, null), foo(0, 7), foo(true, false), bar());
+    }
+    expect_stdout: "3 7 true 4"
+}
+
+delete_conditional_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (1 ? undefined : x));
+        console.log(delete (1 ? void 0 : x));
+        console.log(delete (1 ? Infinity : x));
+        console.log(delete (1 ? 1 / 0 : x));
+        console.log(delete (1 ? NaN : x));
+        console.log(delete (1 ? 0 / 0 : x));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}
+
+delete_conditional_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        keep_infinity: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (0 ? x : undefined));
+        console.log(delete (0 ? x : void 0));
+        console.log(delete (0 ? x : Infinity));
+        console.log(delete (0 ? x : 1 / 0));
+        console.log(delete (0 ? x : NaN));
+        console.log(delete (0 ? x : 0 / 0));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}

test/compress/const.js

@@ -162,4 +162,5 @@ regexp_literal_not_const: {
             while (result = REGEXP_LITERAL.exec("acdabcdeabbb")) console.log(result[0]);
         })();
     }
+    expect_stdout: true
 }

test/compress/dead-code.js

@@ -31,7 +31,7 @@ dead_code_2_should_warn: {
         function f() {
             g();
             x = 10;
-            throw "foo";
+            throw new Error("foo");
             // completely discarding the `if` would introduce some
             // bugs.  UglifyJS v1 doesn't deal with this issue; in v2
             // we copy any declarations to the upper scope.
@@ -46,16 +46,60 @@ dead_code_2_should_warn: {
                 })();
             }
         }
+        f();
     }
     expect: {
         function f() {
             g();
             x = 10;
-            throw "foo";
+            throw new Error("foo");
             var x;
-            function g(){};
+            var g;
         }
+        f();
     }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+dead_code_2_should_warn_strict: {
+    options = {
+        dead_code: true
+    };
+    input: {
+        "use strict";
+        function f() {
+            g();
+            x = 10;
+            throw new Error("foo");
+            // completely discarding the `if` would introduce some
+            // bugs.  UglifyJS v1 doesn't deal with this issue; in v2
+            // we copy any declarations to the upper scope.
+            if (x) {
+                y();
+                var x;
+                function g(){};
+                // but nested declarations should not be kept.
+                (function(){
+                    var q;
+                    function y(){};
+                })();
+            }
+        }
+        f();
+    }
+    expect: {
+        "use strict";
+        function f() {
+            g();
+            x = 10;
+            throw new Error("foo");
+            var x;
+        }
+        f();
+    }
+    expect_stdout: true
+    node_version: ">=4"
 }
 
 dead_code_constant_boolean_should_warn_more: {
@@ -78,14 +122,76 @@ dead_code_constant_boolean_should_warn_more: {
             foo();
             var moo;
         }
+        bar();
     }
     expect: {
         var foo;
-        function bar() {}
+        var bar;
         // nothing for the while
         // as for the for, it should keep:
         var x = 10, y;
         var moo;
+        bar();
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+dead_code_constant_boolean_should_warn_more_strict: {
+    options = {
+        dead_code    : true,
+        loops        : true,
+        booleans     : true,
+        conditionals : true,
+        evaluate     : true,
+        side_effects : true,
+    };
+    input: {
+        "use strict";
+        while (!((foo && bar) || (x + "0"))) {
+            console.log("unreachable");
+            var foo;
+            function bar() {}
+        }
+        for (var x = 10, y; x && (y || x) && (!typeof x); ++x) {
+            asdf();
+            foo();
+            var moo;
+        }
+        bar();
+    }
+    expect: {
+        "use strict";
+        var foo;
+        // nothing for the while
+        // as for the for, it should keep:
+        var x = 10, y;
+        var moo;
+        bar();
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+dead_code_block_decls_die: {
+    options = {
+        dead_code    : true,
+        conditionals : true,
+        booleans     : true,
+        evaluate     : true
+    };
+    input: {
+        if (0) {
+            let foo = 6;
+            const bar = 12;
+            class Baz {};
+            var qux;
+        }
+        console.log(foo, bar, Baz);
+    }
+    expect: {
+        var qux;
+        console.log(foo, bar, Baz);
     }
 }
 
@@ -111,8 +217,9 @@ dead_code_const_declaration: {
         var unused;
         const CONST_FOO = !1;
         var moo;
-        function bar() {}
+        var bar;
     }
+    expect_stdout: true
 }
 
 dead_code_const_annotation: {
@@ -138,8 +245,9 @@ dead_code_const_annotation: {
         var unused;
         var CONST_FOO_ANN = !1;
         var moo;
-        function bar() {}
+        var bar;
     }
+    expect_stdout: true
 }
 
 dead_code_const_annotation_regex: {
@@ -163,6 +271,7 @@ dead_code_const_annotation_regex: {
         var CONST_FOO_ANN = !1;
         CONST_FOO_ANN && console.log('reachable');
     }
+    expect_stdout: true
 }
 
 dead_code_const_annotation_complex_scope: {
@@ -203,9 +312,68 @@ dead_code_const_annotation_complex_scope: {
         var CONST_FOO_ANN = !1;
         var unused_var_2;
         var moo;
-        function bar() {}
+        var bar;
         var beef = 'good';
         var meat = 'beef';
         var pork = 'bad';
     }
+    expect_stdout: true
+}
+
+try_catch_finally: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+    }
+    input: {
+        var a = 1;
+        !function() {
+            try {
+                if (false) throw x;
+            } catch (a) {
+                var a = 2;
+                console.log("FAIL");
+            } finally {
+                a = 3;
+                console.log("PASS");
+            }
+        }();
+        try {
+            console.log(a);
+        } finally {
+        }
+    }
+    expect: {
+        var a = 1;
+        !function() {
+            var a;
+            a = 3;
+            console.log("PASS");
+        }();
+        try {
+            console.log(a);
+        } finally {
+        }
+    }
+    expect_stdout: [
+        "PASS",
+        "1",
+    ]
+}
+
+accessor: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        ({
+            get a() {},
+            set a(v){
+                this.b = 2;
+            },
+            b: 1
+        });
+    }
+    expect: {}
 }

test/compress/destructuring.js

@@ -0,0 +1,661 @@
+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 [{a},b] = c;
+        var [{a},b] = c;
+    }
+    expect_exact: 'const[{a},b]=c;let[{a},b]=c;var[{a},b]=c;';
+}
+
+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_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 [{a},b] = c;
+        var [{a},b] = c;
+        [{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 [{a},b] = c;
+        var [{a},b] = c;
+        [{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_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/drop-unused.js

@@ -164,6 +164,87 @@ used_var_in_catch: {
     }
 }
 
+unused_block_decls_in_catch: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                let x = 10;
+                const y = 10;
+                class Zee {};
+            }
+        }
+    }
+    expect: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {}
+        }
+    }
+}
+
+used_block_decls_in_catch: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                let x = 10;
+                const y = 10;
+                class Zee {};
+            }
+            console.log(x, y, Zee);
+        }
+    }
+    expect: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {}
+            console.log(x, y, Zee);
+        }
+    }
+}
+
+unused_block_decls: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            {
+                const x;
+            }
+            {
+                let y;
+            }
+            console.log(x, y);
+        }
+    }
+    expect: {
+        function foo() {
+            console.log(x, y);
+        }
+    }
+}
+
+unused_keep_harmony_destructuring: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            var {x, y} = foo;
+            var a = foo;
+        }
+    }
+    expect:  {
+        function foo() {
+            var {x, y} = foo;
+        }
+    }
+}
+
 keep_fnames: {
     options = { unused: true, keep_fnames: true, unsafe: true };
     input: {
@@ -782,12 +863,549 @@ issue_1583: {
     expect: {
         function m(t) {
             (function(e) {
-                t = (function() {
-                    return (function(a) {
-                        return a;
-                    })(function(a) {});
-                })();
-            })();
+                t = e();
+            })(function() {
+                return (function(a) {
+                    return a;
+                })(function(a) {});
+            });
         }
     }
 }
+
+issue_1656: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        for(var a=0;;);
+    }
+    expect_exact: "for (;;) ;"
+}
+
+issue_1709: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(
+            function x() {
+                var x = 1;
+                return x;
+            }(),
+            function y() {
+                const y = 2;
+                return y;
+            }(),
+            function z() {
+                function z() {}
+                return z;
+            }()
+        );
+    }
+    expect: {
+        console.log(
+            function() {
+                var x = 1;
+                return x;
+            }(),
+            function() {
+                const y = 2;
+                return y;
+            }(),
+            function() {
+                function z() {}
+                return z;
+            }()
+        );
+    }
+    expect_stdout: true
+}
+
+issue_1715_1: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            a++;
+            try {
+                x();
+            } catch (a) {
+                var a;
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            a++;
+            try {
+                x();
+            } catch (a) {
+                var a;
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+issue_1715_2: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            a++;
+            try {
+                x();
+            } catch (a) {
+                var a = 2;
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            a++;
+            try {
+                x();
+            } catch (a) {
+                var a;
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+issue_1715_3: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            a++;
+            try {
+                console;
+            } catch (a) {
+                var a = 2 + x();
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            a++;
+            try {
+                console;
+            } catch (a) {
+                var a;
+                x();
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+issue_1715_4: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        !function a() {
+            a++;
+            try {
+                x();
+            } catch (a) {
+                var a;
+            }
+        }();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        !function() {
+            a++;
+            try {
+                x();
+            } catch (a) {
+                var a;
+            }
+        }();
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+delete_assign_1: {
+    options = {
+        booleans: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        console.log(delete (a = undefined));
+        console.log(delete (a = void 0));
+        console.log(delete (a = Infinity));
+        console.log(delete (a = 1 / 0));
+        console.log(delete (a = NaN));
+        console.log(delete (a = 0 / 0));
+    }
+    expect: {
+        console.log((void 0, !0));
+        console.log((void 0, !0));
+        console.log((1 / 0, !0));
+        console.log((1 / 0, !0));
+        console.log((NaN, !0));
+        console.log((0 / 0, !0));
+    }
+    expect_stdout: true
+}
+
+delete_assign_2: {
+    options = {
+        booleans: true,
+        keep_infinity: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        console.log(delete (a = undefined));
+        console.log(delete (a = void 0));
+        console.log(delete (a = Infinity));
+        console.log(delete (a = 1 / 0));
+        console.log(delete (a = NaN));
+        console.log(delete (a = 0 / 0));
+    }
+    expect: {
+        console.log((void 0, !0));
+        console.log((void 0, !0));
+        console.log((Infinity, !0));
+        console.log((1 / 0, !0));
+        console.log((NaN, !0));
+        console.log((0 / 0, !0));
+    }
+    expect_stdout: true
+}
+
+drop_var: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        console.log(a, b);
+        var a = 1, b = 2;
+        console.log(a, b);
+        var a = 3;
+        console.log(a, b);
+    }
+    expect: {
+        console.log(a, b);
+        var a = 1, b = 2;
+        console.log(a, b);
+        a = 3;
+        console.log(a, b);
+    }
+    expect_stdout: [
+        "undefined undefined",
+        "1 2",
+        "3 2",
+    ]
+}
+
+issue_1830_1: {
+    options = {
+        unused: true,
+    }
+    input: {
+        !function() {
+            L: for (var b = console.log(1); !1;) continue L;
+        }();
+    }
+    expect: {
+        !function() {
+            L: for (console.log(1); !1;) continue L;
+        }();
+    }
+    expect_stdout: "1"
+}
+
+issue_1830_2: {
+    options = {
+        unused: true,
+    }
+    input: {
+        !function() {
+            L: for (var a = 1, b = console.log(a); --a;) continue L;
+        }();
+    }
+    expect: {
+        !function() {
+            var a = 1;
+            L: for (console.log(a); --a;) continue L;
+        }();
+    }
+    expect_stdout: "1"
+}
+
+issue_1838: {
+    options = {
+        join_vars: true,
+        loops: true,
+        unused: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        function f() {
+            var b = a;
+            while (c);
+        }
+    }
+    expect_exact: [
+        "function f() {",
+        "    for (a; c; ) ;",
+        "}",
+    ]
+}
+
+var_catch_toplevel: {
+    options = {
+        conditionals: true,
+        negate_iife: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            a--;
+            try {
+                a++;
+            } catch(a) {
+                if (a) var a;
+                var a = 10;
+            }
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            a--;
+            try {
+                a++;
+            } catch(a) {
+                var a;
+            }
+        }();
+    }
+}
+
+reassign_const: {
+    options = {
+        cascade: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            const a = 1;
+            a = 2;
+            return a;
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            const a = 1;
+            return a = 2, a;
+        }
+        console.log(f());
+    }
+    expect_stdout: true
+}
+
+issue_1968: {
+    options = {
+        unused: true,
+    }
+    input: {
+        function f(c) {
+            var a;
+            if (c) {
+                let b;
+                return (a = 2) + (b = 3);
+            }
+        }
+        console.log(f(1));
+    }
+    expect: {
+        function f(c) {
+            if (c) {
+                let b;
+                return 2 + (b = 3);
+            }
+        }
+        console.log(f(1));
+    }
+    expect_stdout: "5"
+    node_version: ">=6"
+}
+
+issue_2063: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a;
+        var a;
+    }
+    expect: {
+        var a;
+        var a;
+    }
+}
+
+issue_2105: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        reduce_vars: true,
+        side_effects: 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: {
+        !void function() {
+            var quux = function() {
+                console.log("PASS");
+            };
+            return {
+                prop: function() {
+                    console.log;
+                    quux();
+                }
+            };
+        }().prop();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2136_1: {
+    options = {
+        inline: true,
+        unused: true,
+    }
+    input: {
+        !function(a, ...b) {
+            console.log(b);
+        }();
+    }
+    expect: {
+        !function(a, ...b) {
+            console.log(b);
+        }();
+    }
+    expect_stdout: "[]"
+    node_version: ">=6"
+}
+
+issue_2136_2: {
+    options = {
+        collapse_vars: true,
+        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 = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        passes: 3,
+        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"
+}

test/compress/evaluate.js

@@ -196,10 +196,11 @@ negative_zero: {
         console.log(
             -0,
             0,
-            1 / (-0),
-            1 / (-0)
+            -1/0,
+            -1/0
         );
     }
+    expect_stdout: true
 }
 
 positive_zero: {
@@ -216,10 +217,105 @@ positive_zero: {
         console.log(
             0,
             -0,
-            1 / (0),
-            1 / (0)
+            1/0,
+            1/0
         );
     }
+    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: {
@@ -243,6 +339,7 @@ unsafe_constant: {
             (void 0).a
         );
     }
+    expect_stdout: true
 }
 
 unsafe_object: {
@@ -266,6 +363,7 @@ unsafe_object: {
             1..b + 1
         );
     }
+    expect_stdout: true
 }
 
 unsafe_object_nested: {
@@ -289,6 +387,7 @@ unsafe_object_nested: {
             2
         );
     }
+    expect_stdout: true
 }
 
 unsafe_object_complex: {
@@ -312,6 +411,7 @@ unsafe_object_complex: {
             2
         );
     }
+    expect_stdout: true
 }
 
 unsafe_object_repeated: {
@@ -335,6 +435,7 @@ unsafe_object_repeated: {
             1..b + 1
         );
     }
+    expect_stdout: true
 }
 
 unsafe_object_accessor: {
@@ -384,6 +485,7 @@ unsafe_function: {
             ({a:{b:1},b:function(){}}).a.b + 1
         );
     }
+    expect_stdout: true
 }
 
 unsafe_integer_key: {
@@ -411,6 +513,7 @@ unsafe_integer_key: {
             1["1"] + 1
         );
     }
+    expect_stdout: true
 }
 
 unsafe_integer_key_complex: {
@@ -438,6 +541,7 @@ unsafe_integer_key_complex: {
             2
         );
     }
+    expect_stdout: true
 }
 
 unsafe_float_key: {
@@ -465,6 +569,7 @@ unsafe_float_key: {
             1["3.14"] + 1
         );
     }
+    expect_stdout: true
 }
 
 unsafe_float_key_complex: {
@@ -492,6 +597,7 @@ unsafe_float_key_complex: {
             2
         );
     }
+    expect_stdout: true
 }
 
 unsafe_array: {
@@ -527,6 +633,7 @@ unsafe_array: {
             (void 0)[1] + 1
         );
     }
+    expect_stdout: true
 }
 
 unsafe_string: {
@@ -554,6 +661,7 @@ unsafe_string: {
             "11"
         );
     }
+    expect_stdout: true
 }
 
 unsafe_array_bad_index: {
@@ -575,6 +683,7 @@ unsafe_array_bad_index: {
             [1, 2, 3, 4][3.14] + 1
         );
     }
+    expect_stdout: true
 }
 
 unsafe_string_bad_index: {
@@ -596,6 +705,7 @@ unsafe_string_bad_index: {
             "1234"[3.14] + 1
         );
     }
+    expect_stdout: true
 }
 
 unsafe_prototype_function: {
@@ -628,6 +738,7 @@ unsafe_prototype_function: {
 call_args: {
     options = {
         evaluate: true,
+        inline: true,
         reduce_vars: true,
     }
     input: {
@@ -642,11 +753,13 @@ call_args: {
         console.log(1);
         +(1, 1);
     }
+    expect_stdout: true
 }
 
 call_args_drop_param: {
     options = {
         evaluate: true,
+        inline: true,
         keep_fargs: false,
         reduce_vars: true,
         unused: true,
@@ -663,6 +776,7 @@ call_args_drop_param: {
         console.log(1);
         +(b, 1);
     }
+    expect_stdout: true
 }
 
 in_boolean_context: {
@@ -700,4 +814,351 @@ in_boolean_context: {
             (foo(), !1)
         );
     }
+    expect_stdout: true
+}
+
+unsafe_charAt: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            "1234" + 1,
+            "1234".charAt(0) + 1,
+            "1234".charAt(6 - 5) + 1,
+            ("12" + "34").charAt(0) + 1,
+            ("12" + "34").charAt(6 - 5) + 1,
+            [1, 2, 3, 4].join("").charAt(0) + 1
+        );
+    }
+    expect: {
+        console.log(
+            "12341",
+            "11",
+            "21",
+            "11",
+            "21",
+            "11"
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_charAt_bad_index: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            "1234".charAt() + 1,
+            "1234".charAt("a") + 1,
+            "1234".charAt(3.14) + 1
+        );
+    }
+    expect: {
+        console.log(
+            "11",
+            "11",
+            "41"
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_charAt_noop: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            s.charAt(0),
+            "string".charAt(x),
+            (typeof x).charAt()
+        );
+    }
+    expect: {
+        console.log(
+            s.charAt(0),
+            "string".charAt(x),
+            (typeof x)[0]
+        );
+    }
+}
+
+issue_1649: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log(-1 + -1);
+    }
+    expect: {
+        console.log(-2);
+    }
+    expect_stdout: "-2";
+}
+
+issue_1760_1: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        !function(a) {
+            try {
+                throw 0;
+            } catch (NaN) {
+                a = +"foo";
+            }
+            console.log(a);
+        }();
+    }
+    expect: {
+        !function(a) {
+            try {
+                throw 0;
+            } catch (NaN) {
+                a = 0 / 0;
+            }
+            console.log(a);
+        }();
+    }
+    expect_stdout: "NaN"
+}
+
+issue_1760_2: {
+    options = {
+        evaluate: true,
+        keep_infinity: true,
+    }
+    input: {
+        !function(a) {
+            try {
+                throw 0;
+            } catch (Infinity) {
+                a = 123456789 / 0;
+            }
+            console.log(a);
+        }();
+    }
+    expect: {
+        !function(a) {
+            try {
+                throw 0;
+            } catch (Infinity) {
+                a = 1 / 0;
+            }
+            console.log(a);
+        }();
+    }
+    expect_stdout: "Infinity"
+}
+
+delete_expr_1: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        console.log(delete undefined);
+        console.log(delete void 0);
+        console.log(delete Infinity);
+        console.log(delete (1 / 0));
+        console.log(delete NaN);
+        console.log(delete (0 / 0));
+    }
+    expect: {
+        console.log(delete undefined);
+        console.log((void 0, !0));
+        console.log(delete Infinity);
+        console.log((1 / 0, !0));
+        console.log(delete NaN);
+        console.log((0 / 0, !0));
+    }
+    expect_stdout: true
+}
+
+delete_expr_2: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        keep_infinity: true,
+    }
+    input: {
+        console.log(delete undefined);
+        console.log(delete void 0);
+        console.log(delete Infinity);
+        console.log(delete (1 / 0));
+        console.log(delete NaN);
+        console.log(delete (0 / 0));
+    }
+    expect: {
+        console.log(delete undefined);
+        console.log((void 0, !0));
+        console.log(delete Infinity);
+        console.log((1 / 0, !0));
+        console.log(delete NaN);
+        console.log((0 / 0, !0));
+    }
+    expect_stdout: true
+}
+
+delete_binary_1: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (true && undefined));
+        console.log(delete (true && void 0));
+        console.log(delete (true && Infinity));
+        console.log(delete (true && (1 / 0)));
+        console.log(delete (true && NaN));
+        console.log(delete (true && (0 / 0)));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}
+
+delete_binary_2: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        keep_infinity: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (false || undefined));
+        console.log(delete (false || void 0));
+        console.log(delete (false || Infinity));
+        console.log(delete (false || (1 / 0)));
+        console.log(delete (false || NaN));
+        console.log(delete (false || (0 / 0)));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}
+
+Infinity_NaN_undefined_LHS: {
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        function f() {
+            Infinity = Infinity;
+            ++Infinity;
+            Infinity--;
+            NaN *= NaN;
+            ++NaN;
+            NaN--;
+            undefined |= undefined;
+            ++undefined;
+            undefined--;
+        }
+    }
+    expect_exact: [
+        "function f() {",
+        "    Infinity = 1 / 0;",
+        "    ++Infinity;",
+        "    Infinity--;",
+        "    NaN *= NaN;",
+        "    ++NaN;",
+        "    NaN--;",
+        "    undefined |= void 0;",
+        "    ++undefined;",
+        "    undefined--;",
+        "}",
+    ]
+}
+
+issue_1964_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe_regexp: false,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var long_variable_name = /\s/;
+            return "a b c".split(long_variable_name)[1];
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            var long_variable_name = /\s/;
+            return "a b c".split(long_variable_name)[1];
+        }
+        console.log(f());
+    }
+    expect_stdout: "b"
+}
+
+issue_1964_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe_regexp: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var long_variable_name = /\s/;
+            return "a b c".split(long_variable_name)[1];
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            return "a b c".split(/\s/)[1];
+        }
+        console.log(f());
+    }
+    expect_stdout: "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"
 }

test/compress/expansions.js

@@ -0,0 +1,28 @@
+
+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){});"
+}
+

test/compress/export.js

@@ -0,0 +1,228 @@
+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_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_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";
+    }
+}

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/functions.js

@@ -21,6 +21,7 @@ iifes_returning_constants_keep_fargs_true: {
         join_vars     : true,
         reduce_vars   : true,
         cascade       : true,
+        inline        : true,
     }
     input: {
         (function(){ return -1.23; }());
@@ -39,6 +40,7 @@ iifes_returning_constants_keep_fargs_true: {
         console.log(6);
         console.log((a(), b(), 6));
     }
+    expect_stdout: true
 }
 
 iifes_returning_constants_keep_fargs_false: {
@@ -55,6 +57,7 @@ iifes_returning_constants_keep_fargs_false: {
         join_vars     : true,
         reduce_vars   : true,
         cascade       : true,
+        inline        : true,
     }
     input: {
         (function(){ return -1.23; }());
@@ -73,6 +76,7 @@ iifes_returning_constants_keep_fargs_false: {
         console.log(6);
         console.log((a(), b(), 6));
     }
+    expect_stdout: true
 }
 
 issue_485_crashing_1530: {
@@ -80,6 +84,7 @@ issue_485_crashing_1530: {
         conditionals: true,
         dead_code: true,
         evaluate: true,
+        inline: true,
     }
     input: {
         (function(a) {
@@ -91,3 +96,417 @@ issue_485_crashing_1530: {
         this, void 0;
     }
 }
+
+issue_1841_1: {
+    options = {
+        keep_fargs: false,
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var b = 10;
+        !function(arg) {
+            for (var key in "hi")
+                var n = arg.baz, n = [ b = 42 ];
+        }(--b);
+        console.log(b);
+    }
+    expect: {
+        var b = 10;
+        !function() {
+            for (var key in "hi")
+                b = 42;
+        }(--b);
+        console.log(b);
+    }
+    expect_exact: "42"
+}
+
+issue_1841_2: {
+    options = {
+        keep_fargs: false,
+        pure_getters: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var b = 10;
+        !function(arg) {
+            for (var key in "hi")
+                var n = arg.baz, n = [ b = 42 ];
+        }(--b);
+        console.log(b);
+    }
+    expect: {
+        var b = 10;
+        !function(arg) {
+            for (var key in "hi")
+                arg.baz, b = 42;
+        }(--b);
+        console.log(b);
+    }
+    expect_exact: "42"
+}
+
+function_returning_constant_literal: {
+    options = {
+        reduce_vars: true,
+        unsafe: true,
+        toplevel: true,
+        evaluate: true,
+        cascade: true,
+        unused: true,
+        inline: true,
+    }
+    input: {
+        function greeter() {
+            return { message: 'Hello there' };
+        }
+        var greeting = greeter();
+        console.log(greeting.message);
+    }
+    expect: {
+        console.log("Hello there");
+    }
+    expect_stdout: "Hello there"
+}
+
+hoist_funs: {
+    options = {
+        hoist_funs: true,
+    }
+    input: {
+        console.log(1, typeof f, typeof g);
+        if (console.log(2, typeof f, typeof g))
+            console.log(3, typeof f, typeof g);
+        else {
+            console.log(4, typeof f, typeof g);
+            function f() {}
+            console.log(5, typeof f, typeof g);
+        }
+        function g() {}
+        console.log(6, typeof f, typeof g);
+    }
+    expect: {
+        function g() {}
+        console.log(1, typeof f, typeof g);
+        if (console.log(2, typeof f, typeof g))
+            console.log(3, typeof f, typeof g);
+        else {
+            console.log(4, typeof f, typeof g);
+            function f() {}
+            console.log(5, typeof f, typeof g);
+        }
+        console.log(6, typeof f, typeof g);
+    }
+    expect_stdout: [
+        "1 'undefined' 'function'",
+        "2 'undefined' 'function'",
+        "4 'function' 'function'",
+        "5 'function' 'function'",
+        "6 'function' 'function'",
+    ]
+    node_version: ">=6"
+}
+
+hoist_funs_strict: {
+    options = {
+        hoist_funs: true,
+    }
+    input: {
+        "use strict";
+        console.log(1, typeof f, typeof g);
+        if (console.log(2, typeof f, typeof g))
+            console.log(3, typeof f, typeof g);
+        else {
+            console.log(4, typeof f, typeof g);
+            function f() {}
+            console.log(5, typeof f, typeof g);
+        }
+        function g() {}
+        console.log(6, typeof f, typeof g);
+    }
+    expect: {
+        "use strict";
+        function g() {}
+        console.log(1, typeof f, typeof g);
+        if (console.log(2, typeof f, typeof g))
+            console.log(3, typeof f, typeof g);
+        else {
+            console.log(4, typeof f, typeof g);
+            function f() {}
+            console.log(5, typeof f, typeof g);
+        }
+        console.log(6, typeof f, typeof g);
+    }
+    expect_stdout: [
+        "1 'undefined' 'function'",
+        "2 'undefined' 'function'",
+        "4 'function' 'function'",
+        "5 'function' 'function'",
+        "6 'undefined' 'function'",
+    ]
+    node_version: ">=4"
+}
+
+issue_203: {
+    options = {
+        keep_fargs: false,
+        side_effects: true,
+        unsafe_Func: true,
+        unused: true,
+    }
+    input: {
+        var m = {};
+        var fn = Function("require", "module", "exports", "module.exports = 42;");
+        fn(null, m, m.exports);
+        console.log(m.exports);
+    }
+    expect: {
+        var m = {};
+        var fn = Function("n", "o", "o.exports=42");
+        fn(null, m, m.exports);
+        console.log(m.exports);
+    }
+    expect_stdout: "42"
+}
+
+no_webkit: {
+    beautify = {
+        webkit: false,
+    }
+    input: {
+        console.log(function() {
+            1 + 1;
+        }.a = 1);
+    }
+    expect_exact: "console.log(function(){1+1}.a=1);"
+    expect_stdout: "1"
+}
+
+webkit: {
+    beautify = {
+        webkit: true,
+    }
+    input: {
+        console.log(function() {
+            1 + 1;
+        }.a = 1);
+    }
+    expect_exact: "console.log((function(){1+1}).a=1);"
+    expect_stdout: "1"
+}
+
+issue_2084: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        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;
+        !function(c) {
+            c = 1 + c,
+            c = 1 + (c = 0),
+            0 !== 23..toString() && (c = 1 + c);
+        }(-1),
+        console.log(c);
+    }
+    expect_stdout: "0"
+}
+
+issue_2097: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            try {
+                throw 0;
+            } catch (e) {
+                console.log(arguments[0]);
+            }
+        }
+        f(1);
+    }
+    expect: {
+        !function() {
+            try {
+                throw 0;
+            } catch (e) {
+                console.log(arguments[0]);
+            }
+        }(1);
+    }
+    expect_stdout: "1"
+}
+
+issue_2101: {
+    options = {
+        inline: true,
+    }
+    input: {
+        a = {};
+        console.log(function() {
+            return function() {
+                return this.a;
+            }();
+        }() === function() {
+            return a;
+        }());
+    }
+    expect: {
+        a = {};
+        console.log(function() {
+            return this.a;
+        }() === a);
+    }
+    expect_stdout: "true"
+}
+
+inner_ref: {
+    options = {
+        inline: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            return function() {
+                return a;
+            }();
+        }(1), function(a) {
+            return function(a) {
+                return a;
+            }();
+        }(2));
+    }
+    expect: {
+        console.log(function(a) {
+            return a;
+        }(1), function(a) {
+            return a;
+        }());
+    }
+    expect_stdout: "1 undefined"
+}
+
+issue_2107: {
+    options = {
+        cascade: true,
+        collapse_vars: true,
+        inline: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function() {
+            c++;
+        }(c++ + new function() {
+            this.a = 0;
+            var a = (c = c + 1) + (c = 1 + c);
+            return c++ + a;
+        }());
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        c++, new function() {
+            this.a = 0, c = 1 + (c += 1), c++;
+        }(), c++, console.log(c);
+    }
+    expect_stdout: "5"
+}
+
+issue_2114_1: {
+    options = {
+        collapse_vars: true,
+        if_return: true,
+        inline: true,
+        keep_fargs: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function(a) {
+            a = 0;
+        }([ {
+            0: c = c + 1,
+            length: c = 1 + c
+        }, typeof void function a() {
+            var b = function f1(a) {
+            }(b && (b.b += (c = c + 1, 0)));
+        }() ]);
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        !function() {
+            0;
+        }((c += 1, c = 1 + c, function() {
+            var b = void (b && (b.b += (c += 1, 0)));
+        }()));
+        console.log(c);
+    }
+    expect_stdout: "2"
+}
+
+issue_2114_2: {
+    options = {
+        collapse_vars: true,
+        if_return: true,
+        inline: true,
+        keep_fargs: false,
+        passes: 2,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function(a) {
+            a = 0;
+        }([ {
+            0: c = c + 1,
+            length: c = 1 + c
+        }, typeof void function a() {
+            var b = function f1(a) {
+            }(b && (b.b += (c = c + 1, 0)));
+        }() ]);
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        c = 1 + (c += 1), function() {
+            var b = void (b && (b.b += (c += 1, 0)));
+        }();
+        console.log(c);
+    }
+    expect_stdout: "2"
+}

test/compress/global_defs.js

@@ -145,3 +145,32 @@ mixed: {
         'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:129,8]',
     ]
 }
+
+issue_1801: {
+    options = {
+        booleans: true,
+        global_defs: {
+            "CONFIG.FOO.BAR": true,
+        },
+    }
+    input: {
+        console.log(CONFIG.FOO.BAR);
+    }
+    expect: {
+        console.log(!0);
+    }
+}
+
+issue_1986: {
+    options = {
+        global_defs: {
+            "@alert": "console.log",
+        },
+    }
+    input: {
+        alert(42);
+    }
+    expect: {
+        console.log(42);
+    }
+}

test/compress/harmony.js

@@ -0,0 +1,697 @@
+arrow_function_parens: {
+    input: {
+        something && (() => {});
+    }
+    expect_exact: "something&&(()=>{});"
+}
+arrow_function_parens_2: {
+    input: {
+        (() => null)();
+    }
+    expect_exact: "(()=>null)();"
+}
+
+typeof_arrow_functions: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = typeof (x => null);
+        console.log(foo);
+    }
+    expect_exact: "var foo=\"function\";console.log(foo);"
+    expect_stdout: "function"
+    node_version: ">=4"
+}
+
+classes: {
+    input: {
+        class SomeClass {
+            constructor() {
+            };
+            foo() {};
+        };
+        class NoSemi {
+            constructor(...args) {
+            }
+            foo() {}
+        };
+        class ChildClass extends SomeClass {};
+        var asExpression = class AsExpression {};
+        var nameless = class {};
+    }
+    expect_exact: "class SomeClass{constructor(){}foo(){}}class NoSemi{constructor(...args){}foo(){}}class ChildClass extends SomeClass{}var asExpression=class AsExpression{};var nameless=class{};"
+}
+
+class_statics: {
+    input: {
+        x = class {
+            static staticMethod() {}
+            static get foo() {}
+            static set bar() {}
+            static() { /* "static" can be a method name! */ }
+            get() { /* "get" can be a method name! */ }
+            set() { /* "set" can be a method name! */ }
+        }
+    }
+    expect_exact: "x=class{static staticMethod(){}static get foo(){}static set bar(){}static(){}get(){}set(){}};"
+}
+
+class_name_can_be_mangled: {
+    mangle = { };
+    input: {
+        function x() {
+            class Foo {
+            }
+            var class1 = Foo;
+            var class2 = class Bar {};
+        }
+    }
+    expect: {
+        function x() {
+            class a { }
+            var s = a;
+            var c = class a {};
+        }
+    }
+}
+
+class_name_can_be_preserved: {
+    mangle = {
+        keep_classnames: true
+    }
+    input: {
+        function x() {
+            (class Baz { });
+            class Foo {};
+        }
+    }
+    expect: {
+        function x() {
+            (class Baz { });
+            class Foo {};
+        }
+    }
+}
+
+classes_can_have_generators: {
+    input: {
+        class Foo {
+            *bar() {}
+            static *baz() {}
+        }
+    }
+    expect: {
+        class Foo {
+            *bar() {}
+            static *baz() {}
+        }
+    }
+}
+
+classes_can_have_computed_generators: {
+    input: {
+        class C4 {
+            *['constructor']() {}
+        }
+    }
+    expect: {
+        class C4 {
+            *['constructor']() {}
+        }
+    }
+}
+
+classes_can_have_computed_static: {
+    input: {
+        class C4 {
+            static ['constructor']() {}
+        }
+    }
+    expect: {
+        class C4 {
+            static ['constructor']() {}
+        }
+    }
+}
+
+class_methods_and_getters_with_keep_quoted_props_enabled: {
+    beautify = {
+        quote_style: 3,
+        keep_quoted_props: true,
+    }
+    input: {
+        class clss {
+            a() {}
+            "b"() {}
+            get c() { return "c"}
+            get "d"() { return "d"}
+            set e(a) { doSomething(a); }
+            set 'f'(a) { doSomething(b); }
+            static g() {}
+            static "h"() {}
+        }
+    }
+    expect_exact: 'class clss{a(){}"b"(){}get c(){return"c"}get"d"(){return"d"}set e(a){doSomething(a)}set\'f\'(a){doSomething(b)}static g(){}static"h"(){}}'
+}
+
+classes_with_expression_as_expand: {
+    input: {
+        class D extends (calls++, C) {}
+    }
+    expect_exact: "class D extends(calls++,C){}"
+}
+
+new_target: {
+    input: {
+        new.target;
+        new.target.name;
+    }
+    expect_exact: "new.target;new.target.name;"
+}
+
+number_literals: {
+    input: {
+        0b1001;
+        0B1001;
+        0o11;
+        0O11;
+    }
+
+    expect: {
+        9;
+        9;
+        9;
+        9;
+    }
+}
+
+import_statement: {
+    input: {
+        import "mod-name";
+        import Foo from "bar";
+        import { Bar, Baz } from 'lel';
+        import Bar, { Foo } from 'lel';
+        import { Bar as kex, Baz as food } from 'lel';
+    }
+    expect_exact: 'import"mod-name";import Foo from"bar";import{Bar,Baz}from"lel";import Bar,{Foo}from"lel";import{Bar as kex,Baz as food}from"lel";'
+}
+
+import_all_statement: {
+    input: {
+        import * from 'lel';
+        import * as Lel from 'lel';
+    }
+    expect_exact: 'import*from"lel";import*as Lel from"lel";'
+}
+
+export_statement: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default 1 + 2;
+        export var foo = 4;
+        export let foo = 6;
+        export const foo = 6;
+        export function foo() {};
+        export class foo { };
+    }
+    expect_exact: "export default 3;export var foo=4;export let foo=6;export const foo=6;export function foo(){};export class foo{};"
+}
+
+export_default_object_expression: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default {
+            foo: 1 + 2,
+            bar() { return 4; },
+            get baz() { return this.foo; },
+        };
+    }
+    expect_exact: "export default{foo:3,bar(){return 4},get baz(){return this.foo}};"
+}
+
+export_default_array: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default [ 1 + 2, foo ];
+    }
+    expect_exact: "export default[3,foo];"
+}
+
+export_default_anon_function: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default function(){
+            console.log(1 + 2);
+        }
+    }
+    expect_exact: "export default function(){console.log(3)};"
+}
+
+export_default_anon_class: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default class {
+            foo() { console.log(1 + 2); }
+        }
+    }
+    expect_exact: "export default class{foo(){console.log(3)}};"
+}
+
+export_module_statement: {
+    input: {
+        export * from "a.js";
+        export {A} from "a.js";
+        export {A, B} from "a.js";
+        export {C};
+    }
+    expect_exact: 'export*from"a.js";export{A}from"a.js";export{A,B}from"a.js";export{C};'
+}
+
+import_statement_mangling: {
+    mangle = { toplevel: true };
+    input: {
+        import Foo from "foo";
+        import Bar, {Food} from "lel";
+        import {What as Whatever} from "lel";
+        Foo();
+        Bar();
+        Food();
+        Whatever();
+    }
+    expect: {
+        import o from "foo";
+        import m, {Food as r} from "lel";
+        import {What as f} from "lel";
+        o();
+        m();
+        r();
+        f();
+    }
+}
+
+export_statement_mangling: {
+    mangle = { };
+    input: {
+        export var foo = 6;
+        export function bar() { }
+        export class Baz { }
+        bar(foo, Baz)
+    }
+    expect: {
+        export var foo = 6;
+        export function bar() { }
+        export class Baz { }
+        bar(foo, Baz)
+    }
+}
+
+// https://github.com/mishoo/UglifyJS2/issues/1021
+regression_for_of_const: {
+    input: {
+        for (const x of y) {}
+        for (const x in y) {}
+    }
+    expect: {
+        for (const x of y);for (const x in y);
+    }
+}
+
+// Fabio: My patches accidentally caused a crash whenever
+// there's an extraneous set of parens around an object.
+regression_cannot_destructure: {
+    input: {
+        var x = ({ x : 3 });
+        x(({ x: 3 }));
+    }
+    expect_exact: "var x={x:3};x({x:3});";
+}
+
+regression_cannot_use_of: {
+    input: {
+        function of() {
+        }
+        var of = "is a valid variable name";
+        of = { of: "is ok" };
+        x.of;
+        of: foo()
+    }
+    expect: {
+        function of(){}
+        var of="is a valid variable name";
+        of={of:"is ok"};
+        x.of;
+        foo();  /* Label statement missing? No prob. */
+    }
+}
+
+fat_arrow_as_param: {
+    input: {
+        foo(x => x);
+        foo(x => x, y => y);
+
+        foo(x => (x, x));
+        foo(x => (x, x), y => (y, y));
+    }
+    expect_exact: "foo(x=>x);foo(x=>x,y=>y);foo(x=>(x,x));foo(x=>(x,x),y=>(y,y));"
+}
+
+default_assign: {
+    options = {
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        function f(a, b = 3) {
+            console.log(a);
+        }
+
+        g = ([[] = 123]) => {};
+        h = ([[x, y, z] = [4, 5, 6]] = []) => {};
+
+        function i([[x, y, z] = [4, 5, 6]] = []) {
+            console.log(b);
+        };
+    }
+    expect: {
+        function f(a) {
+            console.log(a);
+        }
+
+        g = ([[] = 123]) => {};
+        h = ([[x, y, z] = [4, 5, 6]] = []) => {};
+
+        function i([[x, y, z] = [4, 5, 6]] = []) {
+            console.log(b);
+        };
+    }
+}
+
+expansion: {
+    options = {
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        function f(a, ...b) {
+            console.log(a);
+        }
+    }
+    expect: {
+        function f(a) {
+            console.log(a);
+        }
+    }
+}
+
+issue_1613: {
+  mangle = { toplevel: true };
+  input: {
+    const name = 1;
+    const foo = {
+      name
+    };
+  }
+  expect_exact: "const n=1;const c={name:n};"
+}
+
+format_methods: {
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        class A extends B {constructor(a){x()} static s(b,c){y()} run(d,e,f){z()}}
+    }
+    expect_exact: [
+        "class A extends B {",
+        "    constructor(a) {",
+        "        x();",
+        "    }",
+        "    static s(b, c) {",
+        "        y();",
+        "    }",
+        "    run(d, e, f) {",
+        "        z();",
+        "    }",
+        "}",
+    ]
+}
+
+issue_1898: {
+    options = {
+    }
+    mangle = {
+    }
+    input: {
+        class Foo {
+            bar() {
+                for (const x of [ 6, 5 ]) {
+                    for (let y of [ 4, 3 ]) {
+                        for (var z of [ 2, 1 ]) {
+                            console.log(x, y, z);
+                        }
+                    }
+                }
+            }
+        }
+        new Foo().bar();
+    }
+    expect: {
+        class Foo {
+            bar() {
+                for (const f of [ 6, 5 ])
+                    for (let r of [ 4, 3 ])
+                        for (var o of [ 2, 1 ])
+                            console.log(f, r, o);
+            }
+        }
+        new Foo().bar();
+    }
+}
+
+issue_1753: {
+    mangle = { safari10: true };
+    input: {
+        class SomeClass {
+            constructor(props) {
+                let pickedSets = [];
+                for (let i = 0; i < 6; i++) {
+                    pickedSets.push({
+                        mainDrawNumbers: [],
+                        extraDrawNumbers: []
+                    });
+                }
+            }
+        }
+    }
+    expect: {
+        class SomeClass {
+            constructor(r) {
+                let s = [];
+                for (let a = 0; a < 6; a++)
+                    s.push({
+                        mainDrawNumbers: [],
+                        extraDrawNumbers: []
+                    });
+            }
+        }
+    }
+}
+
+issue_1753_disable: {
+    mangle = { safari10: false }
+    input: {
+        class SomeClass {
+            constructor(props) {
+                let pickedSets = [];
+                for (let i = 0; i < 6; i++) {
+                    pickedSets.push({
+                        mainDrawNumbers: [],
+                        extraDrawNumbers: []
+                    });
+                }
+            }
+        }
+    }
+    expect: {
+        class SomeClass {
+            constructor(r) {
+                let s = [];
+                for (let r = 0; r < 6; r++)
+                    s.push({
+                        mainDrawNumbers: [],
+                        extraDrawNumbers: []
+                    });
+            }
+        }
+    }
+}
+
+class_extends: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        function f() {
+            class foo extends bar {}
+            class pro extends some.prop {}
+            class arr extends stuff[1 - 1] {}
+            class bin extends (a || b) {}
+            class seq extends (a, b) {}
+            class ter extends (a ? b : c) {}
+            class uni extends (!0) {}
+        }
+    }
+    expect_exact: "function f(){class foo extends bar{}class pro extends some.prop{}class arr extends stuff[0]{}class bin extends(a||b){}class seq extends(a,b){}class ter extends(a?b:c){}class uni extends(!0){}}"
+}
+
+class_extends_class: {
+    options = {
+    }
+    input: {
+        class anon extends class {} {}
+        class named extends class base {} {}
+    }
+    expect_exact: "class anon extends class{}{}class named extends class base{}{}"
+}
+
+class_extends_function: {
+    options = {
+    }
+    input: {
+        class anon extends function(){} {}
+        class named extends function base(){} {}
+    }
+    expect_exact: "class anon extends function(){}{}class named extends function base(){}{}"
+}
+
+class_extends_regex: {
+    options = {
+    }
+    input: {
+        function f() {
+            class rx1 extends (/rx/) {}
+            // class rx2 extends /rx/ {}  // FIXME - parse error
+        }
+    }
+    expect_exact: "function f(){class rx1 extends(/rx/){}}"
+}
+
+issue_2028: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        var a = {};
+        (function(x) {
+            x.X = function() {
+                return X;
+            };
+            class X {
+                static hello() {
+                    console.log("hello");
+                }
+            }
+        }(a));
+        a.X().hello();
+    }
+    expect: {
+        var a = {};
+        (function(x) {
+            x.X = function() {
+                return X;
+            };
+            class X {
+                static hello() {
+                    console.log("hello");
+                }
+            }
+        }(a));
+        a.X().hello();
+    }
+    expect_stdout: "hello"
+    node_version: ">=6"
+}
+
+class_expression_statement: {
+    options = {
+        toplevel: false,
+        side_effects: false,
+        unused: false,
+    }
+    input: {
+        (class {});
+        (class NamedClassExpr {});
+        let expr = (class AnotherClassExpr {});
+        class C {}
+    }
+    expect_exact: "(class{});(class NamedClassExpr{});let expr=class AnotherClassExpr{};class C{}"
+}
+
+class_expression_statement_unused: {
+    options = {
+        toplevel: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (class {});
+        (class NamedClassExpr {});
+        let expr = (class AnotherClassExpr {});
+        class C {}
+    }
+    expect_exact: "let expr=class{};class C{}"
+}
+
+class_expression_statement_unused_toplevel: {
+    options = {
+        toplevel: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (class {});
+        (class NamedClassExpr {});
+        let expr = (class AnotherClassExpr {});
+        class C {}
+    }
+    expect_exact: ""
+}
+
+export_default_function_decl: {
+    options = {
+        toplevel: true,
+        passes: 3,
+        unused: true,
+    }
+    input: {
+        // do not drop "unused" exports
+        export default function Foo() {};
+        export function Far() {};
+    }
+    expect_exact: "export default function Foo(){};export function Far(){};"
+}
+
+export_default_class_decl: {
+    options = {
+        toplevel: true,
+        passes: 3,
+        unused: true,
+    }
+    input: {
+        // do not drop "unused" exports
+        export default class Car {};
+        export class Cab {};
+    }
+    expect_exact: "export default class Car{};export class Cab{};"
+}

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/html_comments.js

@@ -47,25 +47,18 @@ html_comment_in_greater_than_or_equal: {
     expect_exact: "function f(a,b){return a-- >=b}";
 }
 
-html_comment_in_right_shift_assign: {
-    input: {
-        // Note: illegal javascript
-        function f(a, b) { return a-- >>= b; }
-    }
-    expect_exact: "function f(a,b){return a-- >>=b}";
-}
-
-html_comment_in_zero_fill_right_shift_assign: {
-    input: {
-        // Note: illegal javascript
-        function f(a, b) { return a-- >>>= b; }
-    }
-    expect_exact: "function f(a,b){return a-- >>>=b}";
-}
-
 html_comment_in_string_literal: {
     input: {
         function f() { return "<!--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 +302,85 @@ 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"
+}

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

@@ -39,7 +39,7 @@ non_hoisted_function_after_return_2a: {
         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,
-        collapse_vars: false, passes: 2
+        collapse_vars: false, passes: 2, warnings: "verbose"
     }
     input: {
         function foo(x) {
@@ -75,7 +75,7 @@ non_hoisted_function_after_return_2a: {
         "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: Dropping unused variable c [test/compress/issue-1034.js:53,16]",
     ]
 }
 
@@ -114,8 +114,139 @@ non_hoisted_function_after_return_2b: {
         "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 unused variable b [test/compress/issue-1034.js:95,20]",
-        "WARN: Dropping unused variable c [test/compress/issue-1034.js:97,16]"
     ]
 }
 
+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, cascade: 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:131,16]',
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:134,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:137,12]",
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:138,21]"
+    ]
+}
+
+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, cascade: 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:173,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:173,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:176,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:176,16]",
+        "WARN: Dropping unused variable a [test/compress/issue-1034.js:173,20]",
+        "WARN: Dropping unused function nope [test/compress/issue-1034.js:180,21]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:178,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:178,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:181,12]",
+        "WARN: Dropping unused variable b [test/compress/issue-1034.js:176,20]",
+        "WARN: Dropping unused variable c [test/compress/issue-1034.js:178,16]",
+    ]
+}
+
+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, cascade: 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:225,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:225,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:227,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:227,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:231,12]",
+    ]
+}

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

@@ -193,13 +193,15 @@ assorted_Infinity_NaN_undefined_in_with_scope: {
         cascade:       true,
         side_effects:  true,
         sequences:     false,
+        keep_infinity: false,
     }
     input: {
+        var f = console.log;
         var o = {
             undefined : 3,
             NaN       : 4,
             Infinity  : 5,
-        }
+        };
         if (o) {
             f(undefined, void 0);
             f(NaN, 0/0);
@@ -216,25 +218,88 @@ assorted_Infinity_NaN_undefined_in_with_scope: {
         }
     }
     expect: {
-        var o = {
+        var f = console.log, o = {
             undefined : 3,
             NaN       : 4,
             Infinity  : 5
-        }
+        };
         if (o) {
             f(void 0, void 0);
             f(NaN, NaN);
             f(1/0, 1/0);
-            f(-(1/0), -(1/0));
+            f(-1/0, -1/0);
             f(NaN, NaN);
         }
         with (o) {
             f(undefined, void 0);
             f(NaN, 0/0);
             f(Infinity, 1/0);
-            f(-Infinity, -(1/0));
+            f(-Infinity, -1/0);
             f(9 + undefined, 9 + void 0);
         }
     }
+    expect_stdout: true
 }
 
+assorted_Infinity_NaN_undefined_in_with_scope_keep_infinity: {
+    options = {
+        unused:        true,
+        evaluate:      true,
+        dead_code:     true,
+        conditionals:  true,
+        comparisons:   true,
+        booleans:      true,
+        hoist_funs:    true,
+        keep_fargs:    true,
+        if_return:     true,
+        join_vars:     true,
+        cascade:       true,
+        side_effects:  true,
+        sequences:     false,
+        keep_infinity: true,
+    }
+    input: {
+        var f = console.log;
+        var o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5,
+        };
+        if (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(2 + 7 + undefined, 2 + 7 + void 0);
+        }
+        with (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(2 + 7 + undefined, 2 + 7 + void 0);
+        }
+    }
+    expect: {
+        var f = console.log, o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5
+        };
+        if (o) {
+            f(void 0, void 0);
+            f(NaN, NaN);
+            f(Infinity, 1/0);
+            f(-Infinity, -1/0);
+            f(NaN, NaN);
+        }
+        with (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -1/0);
+            f(9 + undefined, 9 + void 0);
+        }
+    }
+    expect_stdout: true
+}

test/compress/issue-1202.js

@@ -49,4 +49,3 @@ mangle_keep_fnames_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,
+        cascade       : 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,
+        cascade       : 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

@@ -154,12 +154,12 @@ should_warn: {
         "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: Boolean || always true [test/compress/issue-1261.js:130,8]",
+        "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: Boolean && always false [test/compress/issue-1261.js:132,8]",
+        "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]",

test/compress/issue-1275.js

@@ -46,4 +46,5 @@ string_plus_optimization: {
         }
         foo();
     }
+    expect_stdout: true
 }

test/compress/issue-1321.js

@@ -1,6 +1,6 @@
 issue_1321_no_debug: {
     mangle_props = {
-        ignore_quoted: true
+        keep_quoted: true
     }
     input: {
         var x = {};
@@ -10,15 +10,16 @@ issue_1321_no_debug: {
     }
     expect: {
         var x = {};
-        x.b = 1;
-        x["a"] = 2 * x.b;
-        console.log(x.b, x["a"]);
+        x.o = 1;
+        x["a"] = 2 * x.o;
+        console.log(x.o, x["a"]);
     }
+    expect_stdout: true
 }
 
 issue_1321_debug: {
     mangle_props = {
-        ignore_quoted: true,
+        keep_quoted: true,
         debug: ""
     }
     input: {
@@ -29,15 +30,16 @@ issue_1321_debug: {
     }
     expect: {
         var x = {};
-        x.a = 1;
-        x["_$foo$_"] = 2 * x.a;
-        console.log(x.a, x["_$foo$_"]);
+        x.o = 1;
+        x["_$foo$_"] = 2 * x.o;
+        console.log(x.o, x["_$foo$_"]);
     }
+    expect_stdout: true
 }
 
 issue_1321_with_quoted: {
     mangle_props = {
-        ignore_quoted: false
+        keep_quoted: false
     }
     input: {
         var x = {};
@@ -47,8 +49,9 @@ issue_1321_with_quoted: {
     }
     expect: {
         var x = {};
-        x.a = 1;
-        x["b"] = 2 * x.a;
-        console.log(x.a, x["b"]);
+        x.o = 1;
+        x["x"] = 2 * x.o;
+        console.log(x.o, x["x"]);
     }
+    expect_stdout: true
 }

test/compress/issue-1446.js

@@ -23,7 +23,7 @@ typeof_eq_undefined: {
 typeof_eq_undefined_ie8: {
     options = {
         comparisons: true,
-        screw_ie8: false
+        ie8: true,
     }
     input: {
         var a = typeof b != "undefined";

test/compress/issue-1447.js

@@ -42,4 +42,5 @@ conditional_false_stray_else_in_loop: {
         }
     }
     expect_exact: "for(var i=1;i<=4;++i)if(!(i<=2))console.log(i);"
+    expect_stdout: true
 }

test/compress/issue-1466.js

@@ -0,0 +1,291 @@
+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,
+        cascade: 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
+}
+
+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,
+        cascade: 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
+}
+
+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,
+        cascade: 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
+}
+
+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,
+        cascade: 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
+}
+
+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,
+        cascade: 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
+}
+
+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,
+        cascade: 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
+}
+
+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,
+        cascade: 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
+}

test/compress/issue-1588.js

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

@@ -18,9 +18,7 @@ chained_evaluation_1: {
     expect: {
         (function() {
             (function() {
-                var c;
-                c = f(1);
-                c.bar = 1;
+                f(1).bar = 1;
             })();
         })();
     }
@@ -45,11 +43,9 @@ chained_evaluation_2: {
     }
     expect: {
         (function() {
-            var a = "long piece of string";
             (function() {
-                var c;
-                c = f(a);
-                c.bar = a;
+                var b = "long piece of string";
+                f(b).bar = b;
             })();
         })();
     }

test/compress/issue-1639.js

@@ -0,0 +1,88 @@
+
+issue_1639_1: {
+    options = {
+        booleans: true,
+        cascade: true,
+        conditionals: true,
+        evaluate: true,
+        join_vars: true,
+        loops: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+
+        var L1 = 5;
+        while (--L1 > 0) {
+            if ((--b), false) {
+                if (b) {
+                    var ignore = 0;
+                }
+            }
+        }
+
+        console.log(a, b);
+    }
+    expect: {
+        for (var a = 100, b = 10, L1 = 5; --L1 > 0;)
+            if (--b, !1) var ignore = 0;
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+issue_1639_2: {
+    options = {
+        booleans: true,
+        cascade: true,
+        conditionals: true,
+        evaluate: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+
+        function f19() {
+            if (++a, false)
+                if (a)
+                    if (++a);
+        }
+        f19();
+
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        function f19() {
+            ++a, 1;
+        }
+        f19(),
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+issue_1639_3: {
+    options = {
+        booleans: true,
+        cascade: true,
+        conditionals: true,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        a++ && false && a ? 0 : 0;
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        a++,
+        console.log(a, b);
+    }
+    expect_stdout: true
+}

test/compress/issue-1656.js

@@ -0,0 +1,45 @@
+f7: {
+    options = {
+        booleans: true,
+        cascade: true,
+        collapse_vars: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        drop_debugger: true,
+        evaluate: true,
+        hoist_funs: true,
+        if_return: true,
+        join_vars: true,
+        loops: true,
+        negate_iife: true,
+        passes: 3,
+        properties: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        function f22464() {
+            var brake146670 = 5;
+            while (((b = a) ? !a : ~a ? null : b += a) && --brake146670 > 0) {
+            }
+        }
+        f22464();
+        console.log(a, b);
+    }
+    expect_exact: [
+        "var b = 10;",
+        "",
+        "!function() {",
+        "    for (;b = 100, !1; ) ;",
+        "}(), console.log(100, b);",
+    ]
+    expect_stdout: true
+}

test/compress/issue-1673.js

@@ -0,0 +1,161 @@
+side_effects_catch: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                try {
+                    throw 0;
+                } catch (e) {
+                    console.log("PASS");
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                try {
+                    throw 0;
+                } catch (e) {
+                    console.log("PASS");
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_else: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            function g() {
+                if (x);
+                else console.log("PASS");
+            }
+            g();
+        }
+        f(0);
+    }
+    expect: {
+        function f(x) {
+            (function() {
+                if (x);
+                else console.log("PASS");
+            })();
+        }
+        f(0);
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_finally: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                try {
+                    x();
+                } catch (e) {
+                } finally {
+                    console.log("PASS");
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                try {
+                    x();
+                } catch (e) {
+                } finally {
+                    console.log("PASS");
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_label: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            function g() {
+                L: {
+                    console.log("PASS");
+                    break L;
+                }
+            }
+            g();
+        }
+        f(0);
+    }
+    expect: {
+        function f(x) {
+            (function() {
+                L: {
+                    console.log("PASS");
+                    break L;
+                }
+            })();
+        }
+        f(0);
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_switch: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                switch (0) {
+                  default:
+                  case console.log("PASS"):
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                switch (0) {
+                  default:
+                  case console.log("PASS"):
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}

test/compress/issue-1704.js

@@ -0,0 +1,347 @@
+mangle_catch: {
+    options = {
+        ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        ie8: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(o){a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_ie8: {
+    options = {
+        ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(args){a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var: {
+    options = {
+        ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        ie8: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(o){var a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_ie8: {
+    options = {
+        ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(args){var a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_toplevel: {
+    options = {
+        ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_ie8_toplevel: {
+    options = {
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_toplevel: {
+    options = {
+        ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_ie8_toplevel: {
+    options = {
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1: {
+    options = {
+        ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        ie8: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="PASS";try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_ie8: {
+    options = {
+        ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="PASS";try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_toplevel: {
+    options = {
+        ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="PASS";try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_ie8_toplevel: {
+    options = {
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="PASS";try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_2: {
+    options = {
+        ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        ie8: false,
+        toplevel: false,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_ie8: {
+    options = {
+        ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: false,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_toplevel: {
+    options = {
+        ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: false,
+        toplevel: true,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_ie8_toplevel: {
+    options = {
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "undefined"
+}

test/compress/issue-1733.js

@@ -0,0 +1,97 @@
+function_iife_catch: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        function f(n) {
+            !function() {
+                try {
+                    throw 0;
+                } catch (n) {
+                    var a = 1;
+                    console.log(n, a);
+                }
+            }();
+        }
+        f();
+    }
+    expect_exact: "function f(o){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
+    expect_stdout: "0 1"
+}
+
+function_iife_catch_ie8: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        function f(n) {
+            !function() {
+                try {
+                    throw 0;
+                } catch (n) {
+                    var a = 1;
+                    console.log(n, a);
+                }
+            }();
+        }
+        f();
+    }
+    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
+    expect_stdout: "0 1"
+}
+
+function_catch_catch: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        var o = 0;
+        function f() {
+            try {
+                throw 1;
+            } catch (c) {
+                try {
+                    throw 2;
+                } catch (o) {
+                    var o = 3;
+                    console.log(o);
+                }
+            }
+            console.log(o);
+        }
+        f();
+    }
+    expect_exact: "var o=0;function f(){try{throw 1}catch(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_stdout: [
+        "3",
+        "undefined",
+    ]
+}
+
+function_catch_catch_ie8: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        var o = 0;
+        function f() {
+            try {
+                throw 1;
+            } catch (c) {
+                try {
+                    throw 2;
+                } catch (o) {
+                    var o = 3;
+                    console.log(o);
+                }
+            }
+            console.log(o);
+        }
+        f();
+    }
+    expect_exact: "var o=0;function f(){try{throw 1}catch(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_stdout: [
+        "3",
+        "undefined",
+    ]
+}

test/compress/issue-1750.js

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

test/compress/issue-1770.js

@@ -0,0 +1,105 @@
+mangle_props: {
+    mangle_props = {}
+    input: {
+        var obj = {
+            undefined: 1,
+            NaN: 2,
+            Infinity: 3,
+            "-Infinity": 4,
+            null: 5,
+        };
+        console.log(
+            obj[void 0],
+            obj[undefined],
+            obj["undefined"],
+            obj[0/0],
+            obj[NaN],
+            obj["NaN"],
+            obj[1/0],
+            obj[Infinity],
+            obj["Infinity"],
+            obj[-1/0],
+            obj[-Infinity],
+            obj["-Infinity"],
+            obj[null],
+            obj["null"]
+        );
+    }
+    expect: {
+        var obj = {
+            undefined: 1,
+            NaN: 2,
+            Infinity: 3,
+            "-Infinity": 4,
+            null: 5,
+        };
+        console.log(
+            obj[void 0],
+            obj[void 0],
+            obj["undefined"],
+            obj[0/0],
+            obj[NaN],
+            obj["NaN"],
+            obj[1/0],
+            obj[1/0],
+            obj["Infinity"],
+            obj[-1/0],
+            obj[-1/0],
+            obj["-Infinity"],
+            obj[null],
+            obj["null"]
+        );
+    }
+    expect_stdout: "1 1 1 2 2 2 3 3 3 4 4 4 5 5"
+}
+
+numeric_literal: {
+    beautify = {
+        beautify: true,
+    }
+    mangle_props = {}
+    input: {
+        var obj = {
+            0: 0,
+            "-0": 1,
+            42: 2,
+            "42": 3,
+            0x25: 4,
+            "0x25": 5,
+            1E42: 6,
+            "1E42": 7,
+            "1e+42": 8,
+        };
+        console.log(obj[-0], obj[-""], obj["-0"]);
+        console.log(obj[42], obj["42"]);
+        console.log(obj[0x25], obj["0x25"], obj[37], obj["37"]);
+        console.log(obj[1E42], obj["1E42"], obj["1e+42"]);
+    }
+    expect_exact: [
+        'var obj = {',
+        '    0: 0,',
+        '    "-0": 1,',
+        '    42: 2,',
+        '    "42": 3,',
+        '    37: 4,',
+        '    o: 5,',
+        '    1e42: 6,',
+        '    b: 7,',
+        '    "1e+42": 8',
+        '};',
+        '',
+        'console.log(obj[-0], obj[-""], obj["-0"]);',
+        '',
+        'console.log(obj[42], obj["42"]);',
+        '',
+        'console.log(obj[37], obj["o"], obj[37], obj["37"]);',
+        '',
+        'console.log(obj[1e42], obj["b"], obj["1e+42"]);',
+    ]
+    expect_stdout: [
+        "0 0 1",
+        "3 3",
+        "4 5 4 4",
+        "8 7 8",
+    ]
+}

test/compress/issue-1787.js

@@ -0,0 +1,16 @@
+unary_prefix: {
+    options = {
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var x = -(2 / 3);
+            return x;
+        }());
+    }
+    expect_exact: "console.log(-2/3);"
+    expect_stdout: true
+}

test/compress/issue-1833.js

@@ -0,0 +1,134 @@
+iife_for: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: for (;;) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: for (;;) break L;
+            }();
+        }();
+    }
+}
+
+iife_for_in: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: for (var a in x) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: for (var a in x) break L;
+            }();
+        }();
+    }
+}
+
+iife_do: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: do {
+                    break L;
+                } while (1);
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: do {
+                    break L;
+                } while (1);
+            }();
+        }();
+    }
+}
+
+iife_while: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: while (1) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: while (1) break L;
+            }();
+        }();
+    }
+}
+
+label_do: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        L: do {
+            continue L;
+        } while (0);
+    }
+    expect: {
+        L: do {
+            continue L;
+        } while (0);
+    }
+}
+
+label_while: {
+    options = {
+        evaluate: true,
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        function f() {
+            L: while (0) continue L;
+        }
+    }
+    expect_exact: "function f(){L:;}"
+}

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 +1,281 @@
+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,
+    }
+    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,
+    }
+    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 +1,56 @@
+
+compress_new_function: {
+    options = {
+        unsafe: true,
+        unsafe_Func: true,
+    }
+    input: {
+        new Function("aa, bb", 'return aa;');
+    }
+    expect: {
+        Function("n", "r", "return n");
+    }
+}
+
+compress_new_function_with_destruct: {
+    options = {
+        unsafe: true,
+        unsafe_Func: 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: true,
+        unsafe_Func: 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("aa, [bb]", 'return aa;');
+        Function("aa, {bb}", 'return aa;');
+        Function("[[aa]], [{bb}]", 'return aa;');
+    }
+}

test/compress/issue-281.js

@@ -0,0 +1,483 @@
+collapse_vars_constants: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: 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_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_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_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_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: {
+    options = {
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        /*@__PURE__*/(function() {
+            console.log("hello");
+        }());
+    }
+    expect_exact: ""
+}
+
+drop_fargs: {
+    options = {
+        cascade: 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;
+        !function() {
+            a++;
+        }(++a && a.var);
+        console.log(a);
+    }
+    expect_stdout: "3"
+}
+
+keep_fargs: {
+    options = {
+        cascade: 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;
+        !function(a_1) {
+            a++;
+        }(++a && a.var);
+        console.log(a);
+    }
+    expect_stdout: "3"
+}

test/compress/issue-597.js

@@ -6,7 +6,7 @@ NaN_and_Infinity_must_have_parens: {
     }
     expect: {
         (1/0).toString();
-        NaN.toString();         // transformation to 0/0 dropped
+        NaN.toString();
     }
 }
 
@@ -23,3 +23,135 @@ NaN_and_Infinity_should_not_be_replaced_when_they_are_redefined: {
         NaN.toString();
     }
 }
+
+NaN_and_Infinity_must_have_parens_evaluate: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        (123456789 / 0).toString();
+        (+"foo").toString();
+    }
+    expect: {
+        (1/0).toString();
+        NaN.toString();
+    }
+}
+
+NaN_and_Infinity_should_not_be_replaced_when_they_are_redefined_evaluate: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        var Infinity, NaN;
+        (123456789 / 0).toString();
+        (+"foo").toString();
+    }
+    expect: {
+        var Infinity, NaN;
+        (1/0).toString();
+        (0/0).toString();
+    }
+}
+
+beautify_off_1: {
+    options = {
+        evaluate: true,
+    }
+    beautify = {
+        beautify: false,
+    }
+    input: {
+        var NaN;
+        console.log(
+            null,
+            undefined,
+            Infinity,
+            NaN,
+            Infinity * undefined,
+            Infinity.toString(),
+            NaN.toString(),
+            (Infinity * undefined).toString()
+        );
+    }
+    expect_exact: "var NaN;console.log(null,void 0,1/0,NaN,0/0,(1/0).toString(),NaN.toString(),(0/0).toString());"
+    expect_stdout: true
+}
+
+beautify_off_2: {
+    options = {
+        evaluate: true,
+    }
+    beautify = {
+        beautify: false,
+    }
+    input: {
+        console.log(
+            null.toString(),
+            undefined.toString()
+        );
+    }
+    expect_exact: "console.log(null.toString(),(void 0).toString());"
+}
+
+beautify_on_1: {
+    options = {
+        evaluate: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        var NaN;
+        console.log(
+            null,
+            undefined,
+            Infinity,
+            NaN,
+            Infinity * undefined,
+            Infinity.toString(),
+            NaN.toString(),
+            (Infinity * undefined).toString()
+        );
+    }
+    expect_exact: [
+        "var NaN;",
+        "",
+        "console.log(null, void 0, 1 / 0, NaN, 0 / 0, (1 / 0).toString(), NaN.toString(), (0 / 0).toString());",
+    ]
+    expect_stdout: true
+}
+
+beautify_on_2: {
+    options = {
+        evaluate: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        console.log(
+            null.toString(),
+            undefined.toString()
+        );
+    }
+    expect_exact: "console.log(null.toString(), (void 0).toString());"
+}
+
+issue_1724: {
+    input: {
+        var a = 0;
+        ++a % Infinity | Infinity ? a++ : 0;
+        console.log(a);
+    }
+    expect_exact: "var a=0;++a%(1/0)|1/0?a++:0;console.log(a);"
+    expect_stdout: "2"
+}
+
+issue_1725: {
+    input: {
+        ([].length === 0) % Infinity ? console.log("PASS") : console.log("FAIL");
+    }
+    expect_exact: '(0===[].length)%(1/0)?console.log("PASS"):console.log("FAIL");'
+    expect_stdout: "PASS"
+}

test/compress/issue-640.js

@@ -48,6 +48,7 @@ dead_code_const_annotation_regex: {
         var CONST_FOO_ANN = !1;
         if (CONST_FOO_ANN) console.log('reachable');
     }
+    expect_stdout: true
 }
 
 drop_console_2: {
@@ -158,7 +159,7 @@ negate_iife_4: {
         })();
     }
     expect: {
-        (function(){ return t })() ? console.log(true) : console.log(false), function(){
+        !function(){ return t }() ? console.log(false) : console.log(true), function(){
             console.log("something");
         }();
     }
@@ -182,7 +183,7 @@ negate_iife_5: {
         })();
     }
     expect: {
-        (function(){ return t })() ? foo(true) : bar(false), function(){
+        !function(){ return t }() ? bar(false) : foo(true), function(){
             console.log("something");
         }();
     }
@@ -206,7 +207,7 @@ negate_iife_5_off: {
         })();
     }
     expect: {
-        (function(){ return t })() ? foo(true) : bar(false), function(){
+        !function(){ return t }() ? bar(false) : foo(true), function(){
             console.log("something");
         }();
     }
@@ -225,6 +226,7 @@ issue_1254_negate_iife_true: {
         })()();
     }
     expect_exact: '(function(){return function(){console.log("test")}})()();'
+    expect_stdout: true
 }
 
 issue_1254_negate_iife_nested: {
@@ -240,6 +242,7 @@ issue_1254_negate_iife_nested: {
         })()()()()();
     }
     expect_exact: '(function(){return function(){console.log("test")}})()()()()();'
+    expect_stdout: true
 }
 
 conditional: {

test/compress/issue-747.js

@@ -1,37 +1,41 @@
 dont_reuse_prop: {
     mangle_props = {
         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/
-    };
-
+    }
     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

@@ -29,4 +29,5 @@ dont_mangle_arguments: {
         })(5,6,7);
     }
     expect_exact: "(function(){var arguments=arguments,o=9;console.log(o,arguments)})(5,6,7);"
+    expect_stdout: true
 }

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-976.js

@@ -42,6 +42,7 @@ eval_collapse_vars: {
             eval("console.log(a);");
         })(eval);
     }
+    expect_stdout: true
 }
 
 eval_unused: {

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/labels.js

@@ -9,6 +9,7 @@ labels_1: {
     expect: {
         foo || console.log("bar");
     }
+    expect_stdout: true
 }
 
 labels_2: {
@@ -40,6 +41,7 @@ labels_3: {
         for (var i = 0; i < 5; ++i)
             i < 3 || console.log(i);
     }
+    expect_stdout: true
 }
 
 labels_4: {
@@ -54,6 +56,7 @@ labels_4: {
         for (var i = 0; i < 5; ++i)
             i < 3 || console.log(i);
     }
+    expect_stdout: true
 }
 
 labels_5: {

test/compress/loops.js

@@ -166,6 +166,7 @@ keep_collapse_const_in_own_block_scope: {
             console.log(i);
         console.log(c);
     }
+    expect_stdout: true
 }
 
 keep_collapse_const_in_own_block_scope_2: {
@@ -186,6 +187,7 @@ keep_collapse_const_in_own_block_scope_2: {
             console.log(i);
         console.log(c);
     }
+    expect_stdout: true
 }
 
 evaluate: {
@@ -213,8 +215,7 @@ evaluate: {
             a();
         for(;;)
             c();
-        // rule disabled due to issue_1532
-        do d(); while (false);
+        d();
     }
 }
 
@@ -244,7 +245,7 @@ issue_1532: {
 issue_186: {
     beautify = {
         beautify: false,
-        screw_ie8: true,
+        ie8: false,
     }
     input: {
         var x = 3;
@@ -263,7 +264,7 @@ issue_186: {
 issue_186_ie8: {
     beautify = {
         beautify: false,
-        screw_ie8: false,
+        ie8: true,
     }
     input: {
         var x = 3;
@@ -282,7 +283,7 @@ issue_186_ie8: {
 issue_186_beautify: {
     beautify = {
         beautify: true,
-        screw_ie8: true,
+        ie8: false,
     }
     input: {
         var x = 3;
@@ -309,7 +310,7 @@ issue_186_beautify: {
 issue_186_beautify_ie8: {
     beautify = {
         beautify: true,
-        screw_ie8: false,
+        ie8: true,
     }
     input: {
         var x = 3;
@@ -339,7 +340,7 @@ issue_186_bracketize: {
     beautify = {
         beautify: false,
         bracketize: true,
-        screw_ie8: true,
+        ie8: false,
     }
     input: {
         var x = 3;
@@ -359,7 +360,7 @@ issue_186_bracketize_ie8: {
     beautify = {
         beautify: false,
         bracketize: true,
-        screw_ie8: false,
+        ie8: true,
     }
     input: {
         var x = 3;
@@ -379,7 +380,7 @@ issue_186_beautify_bracketize: {
     beautify = {
         beautify: true,
         bracketize: true,
-        screw_ie8: true,
+        ie8: false,
     }
     input: {
         var x = 3;
@@ -411,7 +412,7 @@ issue_186_beautify_bracketize_ie8: {
     beautify = {
         beautify: true,
         bracketize: true,
-        screw_ie8: false,
+        ie8: true,
     }
     input: {
         var x = 3;
@@ -438,3 +439,44 @@ issue_186_beautify_bracketize_ie8: {
         '}',
     ]
 }
+
+issue_1648: {
+    options = {
+        join_vars: true,
+        loops: true,
+        passes: 2,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            x();
+            var b = 1;
+            while (1);
+        }
+    }
+    expect_exact: "function f(){for(x();1;);}"
+}
+
+do_switch: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        do {
+            switch (a) {
+              case b:
+                continue;
+            }
+        } while (false);
+    }
+    expect: {
+        do {
+            switch (a) {
+              case b:
+                continue;
+            }
+        } while (false);
+    }
+}

test/compress/negate-iife.js

@@ -22,27 +22,25 @@ negate_iife_1_off: {
 
 negate_iife_2: {
     options = {
-        negate_iife: true
+        inline: true,
+        negate_iife: true,
     };
     input: {
-        (function(){ return {} })().x = 10; // should not transform this one
-    }
-    expect: {
         (function(){ return {} })().x = 10;
     }
+    expect_exact: "({}).x=10;"
 }
 
 negate_iife_2_side_effects: {
     options = {
+        inline: true,
         negate_iife: true,
         side_effects: true,
     }
     input: {
-        (function(){ return {} })().x = 10; // should not transform this one
-    }
-    expect: {
         (function(){ return {} })().x = 10;
     }
+    expect_exact: "({}).x=10;"
 }
 
 negate_iife_3: {
@@ -62,6 +60,7 @@ negate_iife_3_evaluate: {
     options = {
         conditionals: true,
         evaluate: true,
+        inline: true,
         negate_iife: true,
     }
     input: {
@@ -70,6 +69,7 @@ negate_iife_3_evaluate: {
     expect: {
         console.log(true);
     }
+    expect_stdout: true
 }
 
 negate_iife_3_side_effects: {
@@ -103,6 +103,7 @@ negate_iife_3_off_evaluate: {
     options = {
         conditionals: true,
         evaluate: true,
+        inline: true,
         negate_iife: false,
     }
     input: {
@@ -111,6 +112,7 @@ negate_iife_3_off_evaluate: {
     expect: {
         console.log(true);
     }
+    expect_stdout: true
 }
 
 negate_iife_4: {
@@ -243,6 +245,7 @@ negate_iife_nested: {
             }(7);
         }).f();
     }
+    expect_stdout: true
 }
 
 negate_iife_nested_off: {
@@ -275,6 +278,7 @@ negate_iife_nested_off: {
             })(7);
         }).f();
     }
+    expect_stdout: true
 }
 
 negate_iife_issue_1073: {
@@ -299,6 +303,7 @@ negate_iife_issue_1073: {
             };
         }(7))();
     }
+    expect_stdout: true
 }
 
 issue_1254_negate_iife_false: {
@@ -313,6 +318,7 @@ issue_1254_negate_iife_false: {
         })()();
     }
     expect_exact: '(function(){return function(){console.log("test")}})()();'
+    expect_stdout: true
 }
 
 issue_1254_negate_iife_true: {
@@ -327,6 +333,7 @@ issue_1254_negate_iife_true: {
         })()();
     }
     expect_exact: '!function(){return function(){console.log("test")}}()();'
+    expect_stdout: true
 }
 
 issue_1254_negate_iife_nested: {
@@ -341,12 +348,14 @@ issue_1254_negate_iife_nested: {
         })()()()()();
     }
     expect_exact: '!function(){return function(){console.log("test")}}()()()()();'
+    expect_stdout: true
 }
 
 issue_1288: {
     options = {
-        negate_iife: true,
         conditionals: true,
+        negate_iife: true,
+        side_effects: false,
     };
     input: {
         if (w) ;
@@ -366,11 +375,11 @@ issue_1288: {
             })(0);
     }
     expect: {
-        w || function f() {}();
-        x || function() {
+        w || !function f() {}();
+        x || !function() {
             x = {};
         }();
-        y ? function() {}() : function(z) {
+        y ? !function() {}() : !function(z) {
             return z;
         }(0);
     }

test/compress/new.js

@@ -82,3 +82,19 @@ 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]);
+    }
+}

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/numbers.js

@@ -153,3 +153,52 @@ evaluate_4: {
         );
     }
 }
+
+issue_1710: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        var x = {};
+        console.log((x += 1) + -x);
+    }
+    expect: {
+        var x = {};
+        console.log((x += 1) + -x);
+    }
+    expect_stdout: true
+}
+
+unary_binary_parenthesis: {
+    input: {
+        var v = [ 0, 1, NaN, Infinity, null, undefined, true, false, "", "foo", /foo/ ];
+        v.forEach(function(x) {
+            v.forEach(function(y) {
+                console.log(
+                    +(x*y),
+                    +(x/y),
+                    +(x%y),
+                    -(x*y),
+                    -(x/y),
+                    -(x%y)
+                );
+            });
+        });
+    }
+    expect: {
+        var v = [ 0, 1, NaN, 1/0, null, void 0, true, false, "", "foo", /foo/ ];
+        v.forEach(function(x) {
+            v.forEach(function(y) {
+                console.log(
+                    +x*y,
+                    +x/y,
+                    +x%y,
+                    -x*y,
+                    -x/y,
+                    -x%y
+                );
+            });
+        });
+    }
+    expect_stdout: true
+}

test/compress/object.js

@@ -0,0 +1,512 @@
+getter_setter: {
+    input: {
+        var get = "bar";
+        var a = {
+            get,
+            set: "foo",
+            get bar() {
+                return this.get;
+            },
+            get 5() {
+                return "five";
+            },
+            get 0xf55() {
+                return "f five five";
+            },
+            get "five"() {
+                return 5;
+            },
+            set one(value) {
+                this._one = value;
+            },
+            set 9(value) {
+                this._nine = value;
+            },
+            set 0b1010(value) {
+                this._ten = value;
+            },
+            set "eleven"(value) {
+                this._eleven = value;
+            }
+        };
+        var b = {
+            get() { return "gift"; },
+            set: function(code) { return "Storing code " + code; }
+        };
+        var c = {
+            ["get"]: "foo",
+            ["set"]: "bar"
+        };
+        var d = {
+            get: "foo",
+            set: "bar"
+        };
+    }
+    expect: {
+        var get = "bar";
+        var a = {
+            get,
+            set: "foo",
+            get bar() {
+                return this.get;
+            },
+            get 5() {
+                return "five";
+            },
+            get 0xf55() {
+                return "f five five";
+            },
+            get "five"() {
+                return 5;
+            },
+            set one(value) {
+                this._one = value;
+            },
+            set 9(value) {
+                this._nine = value;
+            },
+            set 0b1010(value) {
+                this._ten = value;
+            },
+            set "eleven"(value) {
+                this._eleven = value;
+            }
+        };
+        var b = {
+            get() { return "gift"; },
+            set: function(code) { return "Storing code " + code; }
+        };
+        var c = {
+            ["get"]: "foo",
+            ["set"]: "bar"
+        };
+        var d = {
+            get: "foo",
+            set: "bar"
+        };
+    }
+}
+
+getter_setter_mangler: {
+    mangle = {}
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        function f(get,set) {
+            return {
+                get,
+                set,
+                get g(){},
+                set s(n){},
+                c,
+                a:1,
+                m(){}
+            };
+        }
+    }
+    expect_exact: "function f(t,e){return{get:t,set:e,get g(){},set s(t){},c,a:1,m(){}}}"
+}
+
+use_shorthand_opportunity: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        var foo = 123;
+        var obj = {foo: foo};
+    }
+    expect_exact: "var foo=123;var obj={foo};"
+}
+
+computed_property_names: {
+    input: {
+        obj({ ["x" + "x"]: 6 });
+    }
+    expect_exact: 'obj({["x"+"x"]:6});'
+}
+
+computed_property_names_evaluated_1: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        obj({
+            [1 + 1]: 2,
+            ["x" + "x"]: 6
+        });
+    }
+    expect_exact: 'obj({[2]:2,["xx"]:6});'
+}
+
+computed_property_names_evaluated_2: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = something();
+
+        var obj = {
+            [foo]() {
+                return "blah";
+            }
+        }
+    }
+    expect_exact: 'var foo=something();var obj={[foo](){return"blah"}};'
+}
+
+shorthand_properties: {
+    mangle = true;
+    input: {
+        (function() {
+            var prop = 1;
+            const value = {prop};
+            return value;
+        })();
+    }
+    expect: {
+        (function() {
+            var n = 1;
+            const r = {prop:n};
+            return r;
+        })();
+    }
+}
+
+concise_methods: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        x = {
+            foo(a, b) {
+                return x;
+            }
+        }
+        y = {
+            foo([{a}]) {
+                return a;
+            },
+            bar(){}
+        }
+    }
+    expect_exact: "x={foo(a,b){return x}};y={foo([{a}]){return a},bar(){}};"
+}
+
+concise_methods_with_computed_property: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = {
+            [Symbol.iterator]() {
+                return { /* stuff */ }
+            },
+            [1 + 2]() {
+                return 3;
+            },
+            ["1" + "4"]() {
+                return 14;
+            }
+        }
+    }
+    expect: {
+        var foo = {
+            [Symbol.iterator]() {
+                return { /* stuff */ }
+            },
+            [3]() {
+                return 3;
+            },
+            ["14"]() {
+                return 14;
+            }
+        }
+    }
+}
+
+concise_methods_with_computed_property2: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = {
+            [[1]](){
+                return "success";
+            }
+        };
+        doSomething(foo[[1]]());
+    }
+    expect_exact: 'var foo={[[1]](){return"success"}};doSomething(foo[[1]]());'
+}
+
+concise_methods_with_various_property_names: {
+    input: {
+        var get = "bar";
+        var a = {
+            bar() {
+                return this.get;
+            },
+            5() {
+                return "five";
+            },
+            0xf55() {
+                return "f five five";
+            },
+            "five"() {
+                return 5;
+            },
+            0b1010(value) {
+                this._ten = value;
+            }
+        };
+    }
+    expect: {
+        var get = "bar";
+        var a = {
+            bar() {
+                return this.get;
+            },
+            5() {
+                return "five";
+            },
+            0xf55() {
+                return "f five five";
+            },
+            "five"() {
+                return 5;
+            },
+            0b1010(value) {
+                this._ten = value;
+            }
+        };
+    }
+}
+
+concise_methods_and_mangle_props: {
+    mangle_props = {
+        regex: /_/
+    };
+    input: {
+        function x() {
+            obj = {
+                _foo() { return 1; }
+            }
+        }
+    }
+    expect: {
+        function x() {
+            obj = {
+                o() { return 1; }
+            }
+        }
+    }
+}
+
+concise_generators: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        x = {
+            *foo(a, b) {
+                return x;
+            }
+        }
+        y = {
+            *foo([{a}]) {
+                yield a;
+            },
+            bar(){}
+        }
+    }
+    expect_exact: "x={*foo(a,b){return x}};y={*foo([{a}]){yield a},bar(){}};"
+}
+
+concise_methods_and_keyword_names: {
+    input: {
+        x = {
+            catch() {},
+            throw() {}
+        }
+    }
+    expect: {
+        x={catch(){},throw(){}};
+    }
+}
+
+getter_setter_with_computed_value: {
+    input: {
+        class C {
+            get ['a']() {
+                return 'A';
+            }
+            set ['a'](value) {
+                do_something(a);
+            }
+        }
+        var x = {
+            get [a.b]() {
+                return 42;
+            }
+        };
+        class MyArray extends Array {
+            get [Symbol.species]() {
+                return Array;
+            }
+        }
+    }
+    expect_exact: 'class C{get["a"](){return"A"}set["a"](value){do_something(a)}}var x={get[a.b](){return 42}};class MyArray extends Array{get[Symbol.species](){return Array}}'
+}
+
+property_with_operator_value: {
+    input: {
+        var foo = {
+            "*": 1,
+            get "*"() {
+                return 2;
+            },
+            *"*"() {
+                return 3;
+            },
+            "%": 1,
+            get "%"() {
+                return 2;
+            },
+            *"%"() {
+                return 3;
+            }
+        }
+        class bar {
+            get "*"() {
+                return 1
+            }
+            *"*"() {
+                return 2;
+            }
+            get "%"() {
+                return 1
+            }
+            *"%"() {
+                return 2;
+            }
+        }
+    }
+    expect_exact: 'var foo={"*":1,get"*"(){return 2},*"*"(){return 3},"%":1,get"%"(){return 2},*"%"(){return 3}};class bar{get"*"(){return 1}*"*"(){return 2}get"%"(){return 1}*"%"(){return 2}}'
+}
+
+property_with_unprintable: {
+    input: {
+        var foo = {
+            "\x00\x01": "foo",
+            get "\x00\x01"() {
+                return "bar";
+            },
+            set "\x00\x01"(foo) {
+                save(foo);
+            },
+            *"\x00\x01"() {
+                return "foobar";
+            }
+        }
+        class bar {
+            get "\x00\x01"() {
+                return "bar"
+            }
+            set "\x00\x01"(foo) {
+                save(foo);
+            }
+            *"\x00\x01"() {
+                return "foobar";
+            }
+        }
+    }
+    expect_exact: 'var foo={"\\0\x01":"foo",get"\\0\x01"(){return"bar"},set"\\0\x01"(foo){save(foo)},*"\\0\x01"(){return"foobar"}};class bar{get"\\0\x01"(){return"bar"}set"\\0\x01"(foo){save(foo)}*"\\0\x01"(){return"foobar"}}'
+}
+
+property_with_unprintable_ascii_only: {
+    beautify = {
+        ascii_only: true,
+    }
+    input: {
+        var foo = {
+            "\x00\x01": "foo",
+            get "\x00\x01"() {
+                return "bar";
+            },
+            set "\x00\x01"(foo) {
+                save(foo);
+            },
+            *"\x00\x01"() {
+                return "foobar";
+            }
+        }
+        class bar {
+            get "\x00\x01"() {
+                return "bar"
+            }
+            set "\x00\x01"(foo) {
+                save(foo);
+            }
+            *"\x00\x01"() {
+                return "foobar";
+            }
+        }
+    }
+    expect_exact: 'var foo={"\\0\\x01":"foo",get"\\0\\x01"(){return"bar"},set"\\0\\x01"(foo){save(foo)},*"\\0\\x01"(){return"foobar"}};class bar{get"\\0\\x01"(){return"bar"}set"\\0\\x01"(foo){save(foo)}*"\\0\\x01"(){return"foobar"}}'
+}
+
+property_with_unprintable_ascii_only_static: {
+    beautify = {
+        ascii_only: true
+    }
+    input: {
+        class foo {
+            static get "\x02\x03"() {
+                return "bar";
+            }
+            static set "\x04\x05"(foo) {
+                save(foo);
+            }
+        }
+    }
+    expect_exact: 'class foo{static get"\\x02\\x03"(){return"bar"}static set"\\x04\\x05"(foo){save(foo)}}'
+}
+
+methods_and_getters_with_keep_quoted_props_enabled: {
+    beautify = {
+        quote_style: 3,
+        keep_quoted_props: true,
+    }
+    input: {
+        var obj = {
+            a() {},
+            "b"() {},
+            get c() { return "c"},
+            get "d"() { return "d"},
+            set e(a) { doSomething(a); },
+            set f(a) { doSomething(b); }
+        }
+    }
+    expect_exact: 'var obj={a(){},"b"(){},get c(){return"c"},get"d"(){return"d"},set e(a){doSomething(a)},set f(a){doSomething(b)}};'
+}
+
+allow_assignments_to_property_values: {
+    input: {
+        var foo = {123: foo = 123} = {foo: "456"};
+    }
+    expect: {
+        var foo = {123: foo = 123} = {foo: "456"};
+    }
+}
+
+variable_as_computed_property: {
+    input: {
+        function getLine(header) {
+            return {
+                [header]: {}
+            };
+        }
+    }
+    expect_exact: "function getLine(header){return{[header]:{}}}"
+}

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 { cover = (function () {}), xCover = (0, function() {})  } = {};
+        let { cover = (function () {}), xCover = (0, function() {})  } = {};
+        var { cover = (function () {}), xCover = (0, function() {})  } = {};
+    }
+    expect_exact: "function fn3({x:{y:{z:{}=42}}}){}const{cover=function(){},xCover=(0,function(){})}={};let{cover=function(){},xCover=(0,function(){})}={};var{cover=function(){},xCover=(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/properties.js

@@ -13,7 +13,7 @@ keep_properties: {
 dot_properties: {
     options = {
         properties: true,
-        screw_ie8: false
+        ie8: true,
     };
     input: {
         a["foo"] = "bar";
@@ -36,7 +36,7 @@ dot_properties: {
 dot_properties_es5: {
     options = {
         properties: true,
-        screw_ie8: true
+        ie8: false,
     };
     input: {
         a["foo"] = "bar";
@@ -125,7 +125,7 @@ evaluate_string_length: {
 
 mangle_properties: {
     mangle_props = {
-        ignore_quoted: false
+        keep_quoted: false
     };
     input: {
         a["foo"] = "bar";
@@ -135,11 +135,11 @@ mangle_properties: {
         a['run']({color: "blue", foo: "baz"});
     }
     expect: {
-        a["a"] = "bar";
-        a.b = "red";
-        x = {c: 10};
-        a.d(x.c, a.a);
-        a['d']({b: "blue", a: "baz"});
+        a["o"] = "bar";
+        a.a = "red";
+        x = {r: 10};
+        a.b(x.r, a.o);
+        a['b']({a: "blue", o: "baz"});
     }
 }
 
@@ -148,7 +148,8 @@ mangle_unquoted_properties: {
         properties: false
     }
     mangle_props = {
-        ignore_quoted: true
+        builtins: true,
+        keep_quoted: true
     }
     beautify = {
         beautify: false,
@@ -177,16 +178,16 @@ mangle_unquoted_properties: {
         function f1() {
             a["foo"] = "bar";
             a.color = "red";
-            a.b = 2;
-            x = {"bar": 10, c: 7};
-            a.c = 9;
+            a.o = 2;
+            x = {"bar": 10, f: 7};
+            a.f = 9;
         }
         function f2() {
             a.foo = "bar";
             a['color'] = "red";
-            x = {bar: 10, c: 7};
-            a.c = 9;
-            a.b = 3;
+            x = {bar: 10, f: 7};
+            a.f = 9;
+            a.o = 3;
         }
     }
 }
@@ -233,12 +234,13 @@ mangle_debug_suffix: {
     }
 }
 
-mangle_debug_suffix_ignore_quoted: {
+mangle_debug_suffix_keep_quoted: {
     options = {
         properties: false
     }
     mangle_props = {
-        ignore_quoted: true,
+        builtins: true,
+        keep_quoted: true,
         debug: "XYZ",
         reserved: []
     }
@@ -555,3 +557,105 @@ native_prototype: {
         "".indexOf.call(e, "bar");
     }
 }
+
+accessor_boolean: {
+    input: {
+        var a = 1;
+        var b = {
+            get true() {
+                return a;
+            },
+            set false(c) {
+                a = c;
+            }
+        };
+        console.log(b.true, b.false = 2, b.true);
+    }
+    expect_exact: 'var a=1;var b={get true(){return a},set false(c){a=c}};console.log(b.true,b.false=2,b.true);'
+    expect_stdout: "1 2 2"
+}
+
+accessor_get_set: {
+    input: {
+        var a = 1;
+        var b = {
+            get set() {
+                return a;
+            },
+            set get(c) {
+                a = c;
+            }
+        };
+        console.log(b.set, b.get = 2, b.set);
+    }
+    expect_exact: 'var a=1;var b={get set(){return a},set get(c){a=c}};console.log(b.set,b.get=2,b.set);'
+    expect_stdout: "1 2 2"
+}
+
+accessor_null_undefined: {
+    input: {
+        var a = 1;
+        var b = {
+            get null() {
+                return a;
+            },
+            set undefined(c) {
+                a = c;
+            }
+        };
+        console.log(b.null, b.undefined = 2, b.null);
+    }
+    expect_exact: 'var a=1;var b={get null(){return a},set undefined(c){a=c}};console.log(b.null,b.undefined=2,b.null);'
+    expect_stdout: "1 2 2"
+}
+
+accessor_number: {
+    input: {
+        var a = 1;
+        var b = {
+            get 42() {
+                return a;
+            },
+            set 42(c) {
+                a = c;
+            }
+        };
+        console.log(b[42], b[42] = 2, b[42]);
+    }
+    expect_exact: 'var a=1;var b={get 42(){return a},set 42(c){a=c}};console.log(b[42],b[42]=2,b[42]);'
+    expect_stdout: "1 2 2"
+}
+
+accessor_string: {
+    input: {
+        var a = 1;
+        var b = {
+            get "a-b"() {
+                return a;
+            },
+            set "a-b"(c) {
+                a = c;
+            }
+        };
+        console.log(b["a-b"], b["a-b"] = 2, b["a-b"]);
+    }
+    expect_exact: 'var a=1;var b={get"a-b"(){return a},set"a-b"(c){a=c}};console.log(b["a-b"],b["a-b"]=2,b["a-b"]);'
+    expect_stdout: "1 2 2"
+}
+
+accessor_this: {
+    input: {
+        var a = 1;
+        var b = {
+            get this() {
+                return a;
+            },
+            set this(c) {
+                a = c;
+            }
+        };
+        console.log(b.this, b.this = 2, b.this);
+    }
+    expect_exact: 'var a=1;var b={get this(){return a},set this(c){a=c}};console.log(b.this,b.this=2,b.this);'
+    expect_stdout: "1 2 2"
+}

test/compress/pure_getters.js

@@ -0,0 +1,387 @@
+strict: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: false,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a, b = null, c = {};
+        a.prop;
+        b.prop;
+        c.prop;
+        d.prop;
+        null.prop;
+        (void 0).prop;
+        undefined.prop;
+    }
+    expect: {
+        var a, b = null, c = {};
+        a.prop;
+        b.prop;
+        c.prop;
+        d.prop;
+        null.prop;
+        (void 0).prop;
+        (void 0).prop;
+    }
+}
+
+strict_reduce_vars: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a, b = null, c = {};
+        a.prop;
+        b.prop;
+        c.prop;
+        d.prop;
+        null.prop;
+        (void 0).prop;
+        undefined.prop;
+    }
+    expect: {
+        var a, b = null, c = {};
+        a.prop;
+        b.prop;
+        d.prop;
+        null.prop;
+        (void 0).prop;
+        (void 0).prop;
+    }
+}
+
+unsafe: {
+    options = {
+        pure_getters: true,
+        reduce_vars: false,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a, b = null, c = {};
+        a.prop;
+        b.prop;
+        c.prop;
+        d.prop;
+        null.prop;
+        (void 0).prop;
+        undefined.prop;
+    }
+    expect: {
+        var a, b = null, c = {};
+        d;
+        null.prop;
+        (void 0).prop;
+        (void 0).prop;
+    }
+}
+
+unsafe_reduce_vars: {
+    options = {
+        pure_getters: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a, b = null, c = {};
+        a.prop;
+        b.prop;
+        c.prop;
+        d.prop;
+        null.prop;
+        (void 0).prop;
+        undefined.prop;
+    }
+    expect: {
+        var a, b = null, c = {};
+        d;
+        null.prop;
+        (void 0).prop;
+        (void 0).prop;
+    }
+}
+
+chained: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        a.b.c;
+    }
+    expect: {
+        a.b.c;
+    }
+}
+
+impure_getter_1: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).a;
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).b;
+    }
+    expect: {
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).a;
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).b;
+    }
+    expect_stdout: "1"
+}
+
+impure_getter_2: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        // will produce incorrect output because getter is not pure
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).a;
+        ({
+            get a() {
+                console.log(1);
+            },
+            b: 1
+        }).b;
+    }
+    expect: {}
+}
+
+issue_2110_1: {
+    options = {
+        cascade: true,
+        pure_getters: "strict",
+        sequences: true,
+        side_effects: 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_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_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 = {
+        cascade: true,
+        conditionals: true,
+        pure_getters: "strict",
+        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_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 = {
+        cascade: true,
+        conditionals: true,
+        pure_getters: "strict",
+        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_mutable_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        pure_getters: "strict",
+        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 = {
+        cascade: true,
+        conditionals: true,
+        pure_getters: "strict",
+        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"
+}

test/compress/sandbox.js

@@ -0,0 +1,14 @@
+console_log: {
+    input: {
+        console.log("%% %s");
+        console.log("%% %s", "%s");
+    }
+    expect: {
+        console.log("%% %s");
+        console.log("%% %s", "%s");
+    }
+    expect_stdout: [
+        "%% %s",
+        "% %s",
+    ]
+}

test/compress/screw-ie8.js

@@ -1,25 +1,34 @@
 do_screw: {
-    options = { screw_ie8: true };
+    options = {
+        ie8: false,
+    }
     beautify = {
-        screw_ie8: true,
-        ascii_only: true
-    };
-
-    input: f("\v");
-    expect_exact: 'f("\\v");';
+        ie8: false,
+        ascii_only: true,
+    }
+    input: {
+        f("\v");
+    }
+    expect_exact: 'f("\\v");'
 }
 
 dont_screw: {
-    options = { screw_ie8: false };
-    beautify = { screw_ie8: false, ascii_only: true };
-
-    input: f("\v");
-    expect_exact: 'f("\\x0B");';
+    options = {
+        ie8: true,
+    }
+    beautify = {
+        ie8: true,
+        ascii_only: true,
+    }
+    input: {
+        f("\v");
+    }
+    expect_exact: 'f("\\x0B");'
 }
 
 do_screw_constants: {
     options = {
-        screw_ie8: true,
+        ie8: false,
     }
     input: {
         f(undefined, Infinity);
@@ -29,7 +38,7 @@ do_screw_constants: {
 
 dont_screw_constants: {
     options = {
-        screw_ie8: false,
+        ie8: true,
     }
     input: {
         f(undefined, Infinity);
@@ -38,9 +47,15 @@ dont_screw_constants: {
 }
 
 do_screw_try_catch: {
-    options = { screw_ie8: true };
-    mangle = { screw_ie8: true };
-    beautify = { screw_ie8: true };
+    options = {
+        ie8: false,
+    }
+    mangle = {
+        ie8: false,
+    }
+    beautify = {
+        ie8: false,
+    }
     input: {
         good = function(e){
             return function(error){
@@ -66,9 +81,15 @@ do_screw_try_catch: {
 }
 
 dont_screw_try_catch: {
-    options = { screw_ie8: false };
-    mangle = { screw_ie8: false };
-    beautify = { screw_ie8: false };
+    options = {
+        ie8: true,
+    }
+    mangle = {
+        ie8: true,
+    }
+    beautify = {
+        ie8: true,
+    }
     input: {
         bad = function(e){
             return function(error){
@@ -94,9 +115,15 @@ dont_screw_try_catch: {
 }
 
 do_screw_try_catch_undefined: {
-    options = { screw_ie8: true };
-    mangle = { screw_ie8: true };
-    beautify = { screw_ie8: true };
+    options = {
+        ie8: false,
+    }
+    mangle = {
+        ie8: false,
+    }
+    beautify = {
+        ie8: false,
+    }
     input: {
         function a(b){
             try {
@@ -119,12 +146,19 @@ do_screw_try_catch_undefined: {
             return void 0===o
         }
     }
+    expect_stdout: true
 }
 
 dont_screw_try_catch_undefined: {
-    options = { screw_ie8: false };
-    mangle = { screw_ie8: false };
-    beautify = { screw_ie8: false };
+    options = {
+        ie8: true,
+    }
+    mangle = {
+        ie8: true,
+    }
+    beautify = {
+        ie8: true,
+    }
     input: {
         function a(b){
             try {
@@ -147,17 +181,18 @@ dont_screw_try_catch_undefined: {
             return n === undefined
         }
     }
+    expect_stdout: true
 }
 
 reduce_vars: {
     options = {
         evaluate: true,
         reduce_vars: true,
-        screw_ie8: false,
+        ie8: true,
         unused: true,
     }
     mangle = {
-        screw_ie8: false,
+        ie8: true,
     }
     input: {
         function f() {
@@ -185,36 +220,108 @@ reduce_vars: {
 
 issue_1586_1: {
     options = {
-        screw_ie8: false,
+        ie8: true,
     }
     mangle = {
-        screw_ie8: false,
+        ie8: true,
     }
     input: {
         function f() {
             try {
+                x();
             } catch (err) {
                 console.log(err.message);
             }
         }
     }
-    expect_exact: "function f(){try{}catch(c){console.log(c.message)}}"
+    expect_exact: "function f(){try{x()}catch(c){console.log(c.message)}}"
 }
 
 issue_1586_2: {
     options = {
-        screw_ie8: true,
+        ie8: false,
     }
     mangle = {
-        screw_ie8: true,
+        ie8: false,
     }
     input: {
         function f() {
             try {
+                x();
             } catch (err) {
                 console.log(err.message);
             }
         }
     }
-    expect_exact: "function f(){try{}catch(c){console.log(c.message)}}"
+    expect_exact: "function f(){try{x()}catch(c){console.log(c.message)}}"
+}
+
+issue_2120_1: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        "aaaaaaaa";
+        var a = 1, b = "FAIL";
+        try {
+            throw 1;
+        } catch (c) {
+            try {
+                throw 0;
+            } catch (a) {
+                if (c) b = "PASS";
+            }
+        }
+        console.log(b);
+    }
+    expect: {
+        "aaaaaaaa";
+        var a = 1, b = "FAIL";
+        try {
+            throw 1;
+        } catch (t) {
+            try {
+                throw 0;
+            } catch (a) {
+                if (t) b = "PASS";
+            }
+        }
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2120_2: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        "aaaaaaaa";
+        var a = 1, b = "FAIL";
+        try {
+            throw 1;
+        } catch (c) {
+            try {
+                throw 0;
+            } catch (a) {
+                if (c) b = "PASS";
+            }
+        }
+        console.log(b);
+    }
+    expect: {
+        "aaaaaaaa";
+        var a = 1, b = "FAIL";
+        try {
+            throw 1;
+        } catch (c) {
+            try {
+                throw 0;
+            } catch (a) {
+                if (c) b = "PASS";
+            }
+        }
+        console.log(b);
+    }
+    expect_stdout: "PASS"
 }

test/compress/sequences.js

@@ -86,6 +86,7 @@ make_sequences_4: {
         switch (x = 5, y) {}
         with (x = 5, obj);
     }
+    expect_stdout: true
 }
 
 lift_sequences_1: {
@@ -103,15 +104,18 @@ lift_sequences_1: {
 lift_sequences_2: {
     options = { sequences: true, evaluate: true };
     input: {
-        var foo, bar;
+        var foo = 1, bar;
         foo.x = (foo = {}, 10);
         bar = (bar = {}, 10);
+        console.log(foo, bar);
     }
     expect: {
-        var foo, bar;
+        var foo = 1, bar;
         foo.x = (foo = {}, 10),
-        bar = {}, bar = 10;
+        bar = {}, bar = 10,
+        console.log(foo, bar);
     }
+    expect_stdout: true
 }
 
 lift_sequences_3: {
@@ -138,6 +142,23 @@ lift_sequences_4: {
     }
 }
 
+lift_sequences_5: {
+    options = {
+        sequences: true,
+    }
+    input: {
+        var a = 2, b;
+        a *= (b, a = 4, 3);
+        console.log(a);
+    }
+    expect: {
+        var a = 2, b;
+        b, a *= (a = 4, 3),
+        console.log(a);
+    }
+    expect_stdout: "6"
+}
+
 for_sequences: {
     options = { sequences: true };
     input: {
@@ -230,6 +251,7 @@ negate_iife_for: {
         for (!function() {}(), i = 0; i < 5; i++) console.log(i);
         for (function() {}(); i < 5; i++) console.log(i);
     }
+    expect_stdout: true
 }
 
 iife: {
@@ -284,3 +306,451 @@ unsafe_undefined: {
         }
     }
 }
+
+issue_1685: {
+    options = {
+        cascade: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        function f() {
+            var a = (a--, delete a && --b);
+        }
+        f();
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        function f() {
+            var a = (a--, delete a && --b);
+        }
+        f();
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+func_def_1: {
+    options = {
+        cascade: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {
+            return f = 0, !!f;
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            return !!(f = 0);
+        }
+        console.log(f());
+    }
+    expect_stdout: "false"
+}
+
+func_def_2: {
+    options = {
+        cascade: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(function f() {
+            return f = 0, !!f;
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            return f = 0, !!f;
+        }());
+    }
+    expect_stdout: "true"
+}
+
+func_def_3: {
+    options = {
+        cascade: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            return g = 0, !!g;
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            function g() {}
+            return !!(g = 0);
+        }
+        console.log(f());
+    }
+    expect_stdout: "false"
+}
+
+func_def_4: {
+    options = {
+        cascade: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                return g = 0, !!g;
+            }
+            return g();
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            function g() {
+                return !!(g = 0);
+            }
+            return g();
+        }
+        console.log(f());
+    }
+    expect_stdout: "false"
+}
+
+func_def_5: {
+    options = {
+        cascade: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {
+            return function g(){
+                return g = 0, !!g;
+            }();
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            return function g(){
+                return g = 0, !!g;
+            }();
+        }
+        console.log(f());
+    }
+    expect_stdout: "true"
+}
+
+issue_1758: {
+    options = {
+        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 function() {
+                return c--, c--, void c.toString();
+            }();
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+delete_seq_1: {
+    options = {
+        booleans: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (1, undefined));
+        console.log(delete (1, void 0));
+        console.log(delete (1, Infinity));
+        console.log(delete (1, 1 / 0));
+        console.log(delete (1, NaN));
+        console.log(delete (1, 0 / 0));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}
+
+delete_seq_2: {
+    options = {
+        booleans: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (1, 2, undefined));
+        console.log(delete (1, 2, void 0));
+        console.log(delete (1, 2, Infinity));
+        console.log(delete (1, 2, 1 / 0));
+        console.log(delete (1, 2, NaN));
+        console.log(delete (1, 2, 0 / 0));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}
+
+delete_seq_3: {
+    options = {
+        booleans: true,
+        keep_infinity: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (1, 2, undefined));
+        console.log(delete (1, 2, void 0));
+        console.log(delete (1, 2, Infinity));
+        console.log(delete (1, 2, 1 / 0));
+        console.log(delete (1, 2, NaN));
+        console.log(delete (1, 2, 0 / 0));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}
+
+delete_seq_4: {
+    options = {
+        booleans: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {}
+        console.log(delete (f(), undefined));
+        console.log(delete (f(), void 0));
+        console.log(delete (f(), Infinity));
+        console.log(delete (f(), 1 / 0));
+        console.log(delete (f(), NaN));
+        console.log(delete (f(), 0 / 0));
+    }
+    expect: {
+        function f() {}
+        console.log((f(), !0)),
+        console.log((f(), !0)),
+        console.log((f(), !0)),
+        console.log((f(), !0)),
+        console.log((f(), !0)),
+        console.log((f(), !0));
+    }
+    expect_stdout: true
+}
+
+delete_seq_5: {
+    options = {
+        booleans: true,
+        keep_infinity: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {}
+        console.log(delete (f(), undefined));
+        console.log(delete (f(), void 0));
+        console.log(delete (f(), Infinity));
+        console.log(delete (f(), 1 / 0));
+        console.log(delete (f(), NaN));
+        console.log(delete (f(), 0 / 0));
+    }
+    expect: {
+        function f() {}
+        console.log((f(), !0)),
+        console.log((f(), !0)),
+        console.log((f(), !0)),
+        console.log((f(), !0)),
+        console.log((f(), !0)),
+        console.log((f(), !0));
+    }
+    expect_stdout: true
+}
+
+delete_seq_6: {
+    options = {
+        booleans: true,
+        side_effects: true,
+    }
+    input: {
+        var a;
+        console.log(delete (1, a));
+    }
+    expect: {
+        var a;
+        console.log(!0);
+    }
+    expect_stdout: true
+}
+
+side_effects: {
+    options = {
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        0, a(), 1, b(), 2, c(), 3;
+    }
+    expect: {
+        a(), b(), c();
+    }
+}
+
+side_effects_cascade_1: {
+    options = {
+        cascade: true,
+        conditionals: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            a -= 42;
+            if (a < 0) a = 0;
+            b.a = a;
+        }
+    }
+    expect: {
+        function f(a, b) {
+            (a -= 42) < 0 && (a = 0), b.a = a;
+        }
+    }
+}
+
+side_effects_cascade_2: {
+    options = {
+        cascade: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            b = a,
+            !a + (b += a) || (b += a),
+            b = a,
+            b;
+        }
+    }
+    expect: {
+        function f(a, b) {
+            b = a,
+            !a + (b += a) || (b += a),
+            b = a;
+        }
+    }
+}
+
+side_effects_cascade_3: {
+    options = {
+        cascade: true,
+        conditionals: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            "foo" ^ (b += a),
+            b ? false : (b = a) ? -1 : (b -= a) - (b ^= a),
+            a-- || !a,
+            a;
+        }
+    }
+    expect: {
+        function f(a, b) {
+            !(b += a) && ((b = a) || (b -= a, b ^= a)),
+            --a;
+        }
+    }
+}
+
+issue_27: {
+    options = {
+        cascade: true,
+        passes: 2,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function(jQuery) {
+            var $;
+            $ = jQuery;
+            $("body").addClass("foo");
+        })(jQuery);
+    }
+    expect: {
+        (function(jQuery) {
+            jQuery("body").addClass("foo");
+        })(jQuery);
+    }
+}
+
+reassign_const: {
+    options = {
+        cascade: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {
+            const a = 1;
+            a++;
+            return a;
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            const a = 1;
+            return a++, a;
+        }
+        console.log(f());
+    }
+    expect_stdout: true
+}
+
+issue_2062: {
+    options = {
+        booleans: true,
+        cascade: true,
+        conditionals: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 1;
+        if ([ a || a++ + a--, a++ + a--, a && a.var ]);
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        a || (a++, a--), a++, --a && a.var;
+        console.log(a);
+    }
+    expect_stdout: "1"
+}

test/compress/string-literal.js

@@ -8,3 +8,12 @@ octal_escape_sequence: {
         var border_check = "\x20\x30\x38\x30\x00\x30\xc0\x30";
     }
 }
+
+issue_1929: {
+    input: {
+        function f(s) {
+            return s.split(/[\\/]/);
+        }
+    }
+    expect_exact: "function f(s){return s.split(/[\\\\/]/)}"
+}

test/compress/super.js

@@ -0,0 +1,9 @@
+
+super_can_be_parsed: {
+    input: {
+        super(1,2);
+        super.meth();
+    }
+    expect_exact: "super(1,2);super.meth();"
+}
+

test/compress/switch.js

@@ -1,5 +1,10 @@
 constant_switch_1: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         switch (1+1) {
           case 1: foo(); break;
@@ -13,7 +18,12 @@ constant_switch_1: {
 }
 
 constant_switch_2: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         switch (1) {
           case 1: foo();
@@ -28,7 +38,12 @@ constant_switch_2: {
 }
 
 constant_switch_3: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         switch (10) {
           case 1: foo();
@@ -44,7 +59,12 @@ constant_switch_3: {
 }
 
 constant_switch_4: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         switch (2) {
           case 1:
@@ -65,7 +85,12 @@ constant_switch_4: {
 }
 
 constant_switch_5: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         switch (1) {
           case 1:
@@ -94,7 +119,12 @@ constant_switch_5: {
 }
 
 constant_switch_6: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         OUT: {
             foo();
@@ -123,7 +153,12 @@ constant_switch_6: {
 }
 
 constant_switch_7: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         OUT: {
             foo();
@@ -161,7 +196,12 @@ constant_switch_7: {
 }
 
 constant_switch_8: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         OUT: switch (1) {
           case 1:
@@ -185,7 +225,12 @@ constant_switch_8: {
 }
 
 constant_switch_9: {
-    options = { dead_code: true, evaluate: true };
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
     input: {
         OUT: switch (1) {
           case 1:
@@ -210,7 +255,10 @@ constant_switch_9: {
 }
 
 drop_default_1: {
-    options = { dead_code: true };
+    options = {
+        dead_code: true,
+        switches: true,
+    }
     input: {
         switch (foo) {
           case 'bar': baz();
@@ -225,7 +273,10 @@ drop_default_1: {
 }
 
 drop_default_2: {
-    options = { dead_code: true };
+    options = {
+        dead_code: true,
+        switches: true,
+    }
     input: {
         switch (foo) {
           case 'bar': baz(); break;
@@ -241,7 +292,10 @@ drop_default_2: {
 }
 
 keep_default: {
-    options = { dead_code: true };
+    options = {
+        dead_code: true,
+        switches: true,
+    }
     input: {
         switch (foo) {
           case 'bar': baz();
@@ -258,3 +312,507 @@ keep_default: {
         }
     }
 }
+
+issue_1663: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        function f() {
+            switch (1) {
+              case 1:
+                b = a++;
+                return ++b;
+              default:
+                var b;
+            }
+        }
+        f();
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        function f() {
+            var b;
+            b = a++;
+            return ++b;
+        }
+        f();
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+drop_case: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (foo) {
+          case 'bar': baz(); break;
+          case 'moo':
+            break;
+        }
+    }
+    expect: {
+        switch (foo) {
+          case 'bar': baz();
+        }
+    }
+}
+
+keep_case: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (foo) {
+          case 'bar': baz(); break;
+          case moo:
+            break;
+        }
+    }
+    expect: {
+        switch (foo) {
+          case 'bar': baz(); break;
+          case moo:
+        }
+    }
+}
+
+issue_376: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        switch (true) {
+          case boolCondition:
+            console.log(1);
+            break;
+          case false:
+            console.log(2);
+            break;
+        }
+    }
+    expect: {
+        switch (true) {
+          case boolCondition:
+            console.log(1);
+        }
+    }
+}
+
+issue_441_1: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (foo) {
+          case bar:
+            qux();
+            break;
+          case baz:
+            qux();
+            break;
+          default:
+            qux();
+            break;
+        }
+    }
+    expect: {
+        switch (foo) {
+          case bar:
+          case baz:
+          default:
+            qux();
+        }
+    }
+}
+
+issue_441_2: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (foo) {
+          case bar:
+            // TODO: Fold into the case below
+            qux();
+            break;
+          case fall:
+          case baz:
+            qux();
+            break;
+          default:
+            qux();
+            break;
+        }
+    }
+    expect: {
+        switch (foo) {
+          case bar:
+            qux();
+            break;
+          case fall:
+          case baz:
+          default:
+            qux();
+        }
+    }
+}
+
+issue_1674: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        side_effects: true,
+        switches: true,
+    }
+    input: {
+        switch (0) {
+          default:
+            console.log("FAIL");
+            break;
+          case 0:
+            console.log("PASS");
+            break;
+        }
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_1679: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        function f() {
+            switch (--b) {
+              default:
+              case !function x() {}:
+                break;
+              case b--:
+                switch (0) {
+                  default:
+                  case a--:
+                }
+                break;
+              case (a++):
+                break;
+            }
+        }
+        f();
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        function f() {
+            switch (--b) {
+              default:
+              case !function x() {}:
+                break;
+              case b--:
+                switch (0) {
+                  default:
+                  case a--:
+                }
+                break;
+              case (a++):
+            }
+        }
+        f();
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+issue_1680_1: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        function f(x) {
+            console.log(x);
+            return x + 1;
+        }
+        switch (2) {
+          case f(0):
+          case f(1):
+            f(2);
+          case 2:
+          case f(3):
+          case f(4):
+            f(5);
+        }
+    }
+    expect: {
+        function f(x) {
+            console.log(x);
+            return x + 1;
+        }
+        switch (2) {
+          case f(0):
+          case f(1):
+            f(2);
+          case 2:
+            f(5);
+        }
+    }
+    expect_stdout: [
+        "0",
+        "1",
+        "2",
+        "5",
+    ]
+}
+
+issue_1680_2: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        switch (b) {
+          case a--:
+            break;
+          case b:
+            var c;
+            break;
+          case a:
+            break;
+          case a--:
+            break;
+        }
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        switch (b) {
+          case a--:
+            break;
+          case b:
+            var c;
+            break;
+          case a:
+          case a--:
+        }
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+issue_1690_1: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (console.log("PASS")) {}
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_1690_2: {
+    options = {
+        dead_code: false,
+        switches: true,
+    }
+    input: {
+        switch (console.log("PASS")) {}
+    }
+    expect: {
+        switch (console.log("PASS")) {}
+    }
+    expect_stdout: "PASS"
+}
+
+if_switch_typeof: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        side_effects: true,
+        switches: true,
+    }
+    input: {
+        if (a) switch(typeof b) {}
+    }
+    expect: {
+        a;
+    }
+}
+
+issue_1698: {
+    options = {
+        side_effects: true,
+        switches: true,
+    }
+    input: {
+        var a = 1;
+        !function() {
+            switch (a++) {}
+        }();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        !function() {
+            switch (a++) {}
+        }();
+        console.log(a);
+    }
+    expect_stdout: "2"
+}
+
+issue_1705_1: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        var a = 0;
+        switch (a) {
+          default:
+            console.log("FAIL");
+          case 0:
+            break;
+        }
+    }
+    expect: {
+        var a = 0;
+        switch (a) {
+          default:
+            console.log("FAIL");
+          case 0:
+        }
+    }
+    expect_stdout: true
+}
+
+issue_1705_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        switches: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        switch (a) {
+          default:
+            console.log("FAIL");
+          case 0:
+            break;
+        }
+    }
+    expect: {
+    }
+    expect_stdout: true
+}
+
+issue_1705_3: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        switch (a) {
+          case 0:
+            break;
+          default:
+            break;
+        }
+    }
+    expect: {
+        a;
+    }
+    expect_stdout: true
+}
+
+beautify: {
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        switch (a) {
+          case 0:
+          case 1:
+            break;
+          case 2:
+          default:
+        }
+        switch (b) {
+          case 3:
+            foo();
+            bar();
+          default:
+            break;
+        }
+    }
+    expect_exact: [
+        "switch (a) {",
+        "  case 0:",
+        "  case 1:",
+        "    break;",
+        "",
+        "  case 2:",
+        "  default:",
+        "}",
+        "",
+        "switch (b) {",
+        "  case 3:",
+        "    foo();",
+        "    bar();",
+        "",
+        "  default:",
+        "    break;",
+        "}",
+    ]
+}
+
+issue_1758: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        var a = 1, b = 2;
+        switch (a--) {
+          default:
+            b++;
+        }
+        console.log(a, b);
+    }
+    expect: {
+        var a = 1, b = 2;
+        a--;
+        b++;
+        console.log(a, b);
+    }
+    expect_stdout: "0 3"
+}

test/compress/template-string.js

@@ -0,0 +1,402 @@
+template_strings: {
+    beautify = {
+        quote_style: 3
+    }
+    input: {
+        ``;
+        `xx\`x`;
+        `${ foo + 2 }`;
+        ` foo ${ bar + `baz ${ qux }` }`;
+    }
+    expect_exact: "``;`xx\\`x`;`${foo+2}`;` foo ${bar+`baz ${qux}`}`;";
+}
+
+template_string_prefixes: {
+    beautify = {
+        quote_style: 3
+    }
+    input: {
+        String.raw`foo`;
+        foo `bar`;
+    }
+    expect_exact: "String.raw`foo`;foo`bar`;";
+}
+
+template_strings_ascii_only: {
+    beautify = {
+        ascii_only: true,
+        quote_style: 3
+    }
+    input: {
+        var foo = `foo
+        bar
+        ↂωↂ`;
+        var bar = `\``;
+    }
+    expect_exact: "var foo=`foo\\n        bar\\n        \\u2182\\u03c9\\u2182`;var bar=`\\``;"
+}
+
+template_strings_without_ascii_only: {
+    beautify = {
+        quote_style: 3
+    }
+    input: {
+        var foo = `foo
+        bar
+        ↂωↂ`
+    }
+    expect_exact: "var foo=`foo\\n        bar\\n        ↂωↂ`;"
+}
+
+template_string_with_constant_expression: {
+    options = {
+        evaluate: true
+    }
+    beautify = {
+        quote_style: 3
+    }
+    input: {
+        var foo = `${4 + 4} equals 4 + 4`;
+    }
+    expect: {
+        var foo = `8 equals 4 + 4`;
+    }
+}
+
+template_string_with_predefined_constants: {
+    options = {
+        evaluate: true
+    }
+    beautify = {
+        quote_style: 3
+    }
+    input: {
+        var foo = `This is ${undefined}`;
+        var bar = `This is ${NaN}`;
+        var baz = `This is ${null}`;
+        var foofoo = `This is ${Infinity}`;
+        var foobar = "This is ${1/0}";
+        var foobaz = 'This is ${1/0}';
+        var barfoo = "This is ${NaN}";
+        var bazfoo = "This is ${null}";
+        var bazbaz = `This is ${1/0}`;
+        var barbar = `This is ${0/0}`;
+        var barbar = "This is ${0/0}";
+        var barber = 'This is ${0/0}';
+
+        var a = `${4**11}`; // 8 in template vs 7 chars - 4194304
+        var b = `${4**12}`; // 8 in template vs 8 chars - 16777216
+        var c = `${4**14}`; // 8 in template vs 9 chars - 268435456
+    }
+    expect: {
+        var foo = `This is undefined`;
+        var bar = `This is NaN`;
+        var baz = `This is null`;
+        var foofoo = `This is ${1/0}`;
+        var foobar = "This is ${1/0}";
+        var foobaz = 'This is ${1/0}';
+        var barfoo = "This is ${NaN}";
+        var bazfoo = "This is ${null}";
+        var bazbaz = `This is ${1/0}`;
+        var barbar = `This is NaN`;
+        var barbar = "This is ${0/0}";
+        var barber = 'This is ${0/0}';
+
+        var a = `4194304`;
+        var b = `16777216`; // Potential for further concatentation
+        var c = `${4**14}`; // Not worth converting
+    }
+}
+
+template_string_evaluate_with_many_segments: {
+    options = {
+        evaluate: true
+    }
+    beautify = {
+        quote_style: 3
+    }
+    input: {
+        var foo = `Hello ${guest()}, welcome to ${location()}${"."}`;
+        var bar = `${1}${2}${3}${4}${5}${6}${7}${8}${9}${0}`;
+        var baz = `${foobar()}${foobar()}${foobar()}${foobar()}`;
+        var buzz = `${1}${foobar()}${2}${foobar()}${3}${foobar()}`;
+    }
+    expect: {
+        var foo = `Hello ${guest()}, welcome to ${location()}.`;
+        var bar = `1234567890`;
+        var baz = `${foobar()}${foobar()}${foobar()}${foobar()}`;
+        var buzz = `1${foobar()}2${foobar()}3${foobar()}`;
+    }
+}
+
+template_string_with_many_segments: {
+    beautify = {
+        quote_style: 3
+    }
+    input: {
+        var foo = `Hello ${guest()}, welcome to ${location()}${"."}`;
+        var bar = `${1}${2}${3}${4}${5}${6}${7}${8}${9}${0}`;
+        var baz = `${foobar()}${foobar()}${foobar()}${foobar()}`;
+        var buzz = `${1}${foobar()}${2}${foobar()}${3}${foobar()}`;
+    }
+    expect: {
+        var foo = `Hello ${guest()}, welcome to ${location()}${"."}`;
+        var bar = `${1}${2}${3}${4}${5}${6}${7}${8}${9}${0}`;
+        var baz = `${foobar()}${foobar()}${foobar()}${foobar()}`;
+        var buzz = `${1}${foobar()}${2}${foobar()}${3}${foobar()}`;
+    }
+}
+
+template_string_to_normal_string: {
+    options = {
+        evaluate: true
+    }
+    beautify = {
+        quote_style: 0
+    }
+    input: {
+        var foo = `This is ${undefined}`;
+        var bar = "Decimals " + `${1}${2}${3}${4}${5}${6}${7}${8}${9}${0}`;
+    }
+    expect: {
+        var foo = `This is undefined`;
+        var bar = "Decimals 1234567890";
+    }
+}
+
+template_concattenating_string: {
+    options = {
+        evaluate: true
+    }
+    beautify = {
+        quote_style: 3 // Yes, keep quotes
+    }
+    input: {
+        var foo = "Have a nice " + `day. ${`day. ` + `day.`}`;
+        var bar = "Have a nice " + `${day()}`;
+    }
+    expect: {
+        var foo = "Have a nice day. day. day.";
+        var bar = "Have a nice " + `${day()}`;
+    }
+}
+
+evaluate_nested_templates: {
+    options = {
+        evaluate: true
+    }
+    beautify = {
+        quote_style: 0
+    }
+    input: {
+        var baz = `${`${`${`foo`}`}`}`;
+    }
+    expect: {
+        var baz = `foo`;
+    }
+}
+
+enforce_double_quotes: {
+    beautify = {
+        quote_style: 1
+    }
+    input: {
+        var foo = `Hello world`;
+        var bar = `Hello ${'world'}`;
+        var baz = `Hello ${world()}`;
+    }
+    expect: {
+        var foo = `Hello world`;
+        var bar = `Hello ${"world"}`;
+        var baz = `Hello ${world()}`;
+    }
+}
+
+enforce_single_quotes: {
+    beautify = {
+        quote_style: 2
+    }
+    input: {
+        var foo = `Hello world`;
+        var bar = `Hello ${"world"}`;
+        var baz = `Hello ${world()}`;
+    }
+    expect: {
+        var foo = `Hello world`;
+        var bar = `Hello ${'world'}`;
+        var baz = `Hello ${world()}`;
+    }
+}
+
+enforce_double_quotes_and_evaluate: {
+    beautify = {
+        quote_style: 1
+    }
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = `Hello world`;
+        var bar = `Hello ${'world'}`;
+        var baz = `Hello ${world()}`;
+    }
+    expect: {
+        var foo = `Hello world`;
+        var bar = `Hello world`;
+        var baz = `Hello ${world()}`;
+    }
+}
+
+enforce_single_quotes_and_evaluate: {
+    beautify = {
+        quote_style: 2
+    }
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = `Hello world`;
+        var bar = `Hello ${"world"}`;
+        var baz = `Hello ${world()}`;
+    }
+    expect: {
+        var foo = `Hello world`;
+        var bar = `Hello world`;
+        var baz = `Hello ${world()}`;
+    }
+}
+
+respect_inline_script: {
+    beautify = {
+        inline_script: true,
+        quote_style: 3
+    }
+    input: {
+        var foo = `</script>${content}`;
+        var bar = `<!--`;
+        var baz = `-->`;
+    }
+    expect_exact: "var foo=`<\\/script>${content}`;var bar=`\\x3c!--`;var baz=`--\\x3e`;";
+}
+
+do_not_optimize_tagged_template_1: {
+    beautify = {
+        quote_style: 0
+    }
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = tag`Shall not be optimized. ${"But " + "this " + "is " + "fine."}`;
+        var bar = tag`Don't even mind changing my quotes!`;
+    }
+    expect_exact:
+        'var foo=tag`Shall not be optimized. ${"But this is fine."}`;var bar=tag`Don\'t even mind changing my quotes!`;';
+}
+
+do_not_optimize_tagged_template_2: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = tag`test` + " something out";
+    }
+    expect_exact: 'var foo=tag`test`+" something out";';
+}
+
+keep_raw_content_in_tagged_template: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = tag`\u0020\u{20}\u{00020}\x20\40\040 `;
+    }
+    expect_exact: "var foo=tag`\\u0020\\u{20}\\u{00020}\\x20\\40\\040 `;";
+}
+
+allow_chained_templates: {
+    input: {
+        var foo = tag`a``b``c``d`;
+    }
+    expect: {
+        var foo = tag`a``b``c``d`;
+    }
+}
+
+check_escaped_chars: {
+    input: {
+        var foo = `\u0020\u{20}\u{00020}\x20\40\040 `;
+    }
+    expect_exact: "var foo=`       `;";
+}
+
+escape_dollar_curly: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        console.log(`\$\{ beep \}`)
+        console.log(`${1-0}\${2-0}$\{3-0}${4-0}`)
+        console.log(`$${""}{not an expression}`)
+    }
+    expect_exact: "console.log(`\\${ beep }`);console.log(`1\\${2-0}\\${3-0}4`);console.log(`\\${not an expression}`);"
+}
+
+template_starting_with_newline: {
+    options = {
+        dead_code: true
+    }
+    input: {
+        function foo(e) {
+            return `
+this is a template string!`;
+        };
+    }
+    expect_exact: "function foo(e){return`\\nthis is a template string!`}"
+}
+
+template_with_newline: {
+    options = {
+        dead_code: true
+    }
+    input: {
+        function foo(e) {
+            return `yep,
+this is a template string!`;
+        };
+    }
+    expect_exact: "function foo(e){return`yep,\\nthis is a template string!`}"
+}
+
+template_ending_with_newline: {
+    options = {
+        dead_code: true
+    }
+    input: {
+        function foo(e) {
+            return `this is a template string!
+`;
+        };
+    }
+    expect_exact: "function foo(e){return`this is a template string!\\n`}"
+}
+
+issue_1856: {
+    beautify = {
+        ascii_only: false,
+    }
+    input: {
+        console.log(`\\n\\r\\u2028\\u2029\n\r\u2028\u2029`);
+    }
+    expect_exact: "console.log(`\\\\n\\\\r\\\\u2028\\\\u2029\\n\\r\\u2028\\u2029`);"
+}
+
+issue_1856_ascii_only: {
+    beautify = {
+        ascii_only: true,
+    }
+    input: {
+        console.log(`\\n\\r\\u2028\\u2029\n\r\u2028\u2029`);
+    }
+    expect_exact: "console.log(`\\\\n\\\\r\\\\u2028\\\\u2029\\n\\r\\u2028\\u2029`);"
+}

test/compress/transform.js

@@ -13,6 +13,7 @@ booleans_evaluate: {
         console.log(!0, !0);
         console.log(!1, !1);
     }
+    expect_stdout: true
 }
 
 booleans_global_defs: {

test/compress/try-catch.js

@@ -0,0 +1,12 @@
+catch_destructuring_with_sequence: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        try {
+            throw {};
+        } catch ({xCover = (0, function() {})} ) {
+        }
+    }
+    expect_exact: "try{throw{}}catch({xCover=(0,function(){})}){}"
+}

test/compress/typeof.js

@@ -48,3 +48,15 @@ typeof_in_boolean_context: {
         foo();
     }
 }
+
+issue_1668: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        if (typeof bar);
+    }
+    expect: {
+        if (!0);
+    }
+}

test/compress/unicode.js

@@ -15,3 +15,106 @@ unicode_parse_variables: {
         var l০ = 3;
     }
 }
+
+unicode_escaped_identifier: {
+    beautify = {ecma: 6}
+    input: {
+        var \u{61} = "foo";
+        var \u{10000} = "bar";
+    }
+    expect_exact: 'var a="foo";var \u{10000}="bar";';
+}
+
+unicode_identifier_ascii_only: {
+    beautify = {ascii_only: true, ecma: 6}
+    input: {
+        var \u{0061} = "hi";
+        var bar = "h\u{0065}llo";
+        var \u{10000} = "testing \u{101111}";
+    }
+    expect_exact: 'var a="hi";var bar="hello";var \\u{10000}="testing \\u{101111}";'
+}
+
+unicode_string_literals: {
+    beautify = {ascii_only: true, ecma: 6}
+    input: {
+        var a = "6 length unicode character: \u{101111}";
+    }
+    expect_exact: 'var a="6 length unicode character: \\u{101111}";'
+}
+
+// Don't escape identifiers below es6 (or in this case double escaped in expect_exact)
+unicode_output_es5_surrogates: {
+    beautify = {ascii_only: true, ecma: 5}
+    input: {
+        var \u{10000} = "6 length unicode character: \u{10FFFF}";
+    }
+    expect_exact: 'var \u{10000}="6 length unicode character: \\udbff\\udfff";'
+}
+
+check_escape_style: {
+    beautify = {ascii_only: true, ecma: 6}
+    input: {
+        var a = "\x01";
+        var \ua0081 = "\x10"; // \u0081 only in ID_Continue
+        var \u0100 = "\u0100";
+        var \u1000 = "\u1000";
+        var \u{10000} = "\u{10000}";
+        var \u{2f800} = "\u{100000}";
+    }
+    expect_exact: 'var a="\\x01";var \\ua0081="\\x10";var \\u0100="\\u0100";var \\u1000="\\u1000";var \\u{10000}="\\u{10000}";var \\u{2f800}="\\u{100000}";'
+}
+
+// Don't escape identifiers below es6, no escaped identifiers support and no \u{} syntax
+check_escape_style_es5: {
+    beautify = {ascii_only: true, ecma: 5}
+    input: {
+        var a = "\x01";
+        var \ua0081 = "\x10"; // \u0081 only in ID_Continue
+        var \u0100 = "\u0100";
+        var \u1000 = "\u1000";
+        var \u{10000} = "\u{10000}"; // Identifier won't be escaped in es 5.1
+        var \u{2f800} = "\u{100000}"; // Same
+    }
+    expect_exact: 'var a="\\x01";var \\ua0081="\\x10";var \\u0100="\\u0100";var \\u1000="\\u1000";var \ud800\udc00="\\ud800\\udc00";var \ud87e\udc00="\\udbc0\\udc00";'
+}
+
+ID_continue_with_surrogate_pair: {
+    beautify = {ascii_only: true, ecma: 6}
+    input: {
+        var \u{2f800}\u{2f800}\u{2f800}\u{2f800} = "\u{100000}\u{100000}\u{100000}\u{100000}\u{100000}";
+    }
+    expect_exact: 'var \\u{2f800}\\u{2f800}\\u{2f800}\\u{2f800}="\\u{100000}\\u{100000}\\u{100000}\\u{100000}\\u{100000}";'
+}
+
+escape_non_escaped_identifier: {
+    beautify = {ascii_only: true, ecma: 6}
+    input: {
+        var µþ = "µþ";
+    }
+    expect_exact: 'var \\u00b5\\u00fe="\\xb5\\xfe";'
+}
+
+non_escape_2_non_escape: {
+    beautify = {ascii_only: false, ecma: 6}
+    input: {
+        var µþ = "µþ";
+    }
+    expect_exact: 'var µþ="µþ";'
+}
+
+non_escape_2_half_escape1: {
+    beautify = {ascii_only: false, ascii_identifiers: true, ecma: 6}
+    input: {
+        var µþ = "µþ";
+    }
+    expect_exact: 'var \\u00b5\\u00fe="µþ";'
+}
+
+non_escape_2_half_escape2: {
+    beautify = {ascii_only: true, ascii_identifiers: false, ecma: 6}
+    input: {
+        var µþ = "µþ";
+    }
+    expect_exact: 'var µþ="\\xb5\\xfe";'
+}