fix collapse_vars regression in destructuring (#2897)

fixes #2896

CONTRIBUTING.md

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

LICENSE

@@ -1,6 +1,6 @@
 UglifyJS is released under the BSD license:
 
-Copyright 2012-2013 (c) Mihai Bazon <mihai.bazon@gmail.com>
+Copyright 2012-2018 (c) Mihai Bazon <mihai.bazon@gmail.com>
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions

README.md

@@ -67,7 +67,7 @@ a double dash to prevent input files being used as option arguments:
                                 `debug`  Add debug prefix and suffix.
                                 `domprops`  Mangle property names that overlaps
                                             with DOM properties.
-                                `keep_quoted`  Only mangle unquoted properies.
+                                `keep_quoted`  Only mangle unquoted properties.
                                 `regex`  Only mangle matched property names.
                                 `reserved`  List of names that should not be mangled.
     -b, --beautify [options]    Beautify output/specify output options:
@@ -630,9 +630,6 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 - `booleans` (default: `true`) -- various optimizations for boolean context,
   for example `!!a ? b : c → a ? b : c`
 
-- `cascade` (default: `true`) -- small optimization for sequences, transform
-  `x, x` into `x` and `x = something(), x` into `x = something()`
-
 - `collapse_vars` (default: `true`) -- Collapse single-use non-constant variables,
   side effects permitting.
 
@@ -665,7 +662,7 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 - `global_defs` (default: `{}`) -- see [conditional compilation](#conditional-compilation)
 
-- `hoist_funs` (default: `true`) -- hoist function declarations
+- `hoist_funs` (default: `false`) -- hoist function declarations
 
 - `hoist_props` (default: `true`) -- hoist properties from constant object and
   array literals into regular variables subject to a set of constraints. For example:
@@ -678,7 +675,13 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 - `if_return` (default: `true`) -- optimizations for if/return and if/continue
 
-- `inline` (default: `true`) -- embed simple functions
+- `inline` (default: `true`) -- inline calls to function with simple/`return` statement:
+  - `false` -- same as `0`
+  - `0` -- disabled inlining
+  - `1` -- inline simple functions
+  - `2` -- inline functions with arguments
+  - `3` -- inline functions with arguments and variables
+  - `true` -- same as `3`
 
 - `join_vars` (default: `true`) -- join consecutive `var` statements
 
@@ -779,7 +782,7 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   comparison are switching. Compression only works if both `comparisons` and
   `unsafe_comps` are both set to true.
 
-- `unsafe_Func` (default: `false`) -- compress and mangle `Function(args, code)`
+- `unsafe_Function` (default: `false`) -- compress and mangle `Function(args, code)`
   when both `args` and `code` are string literals.
 
 - `unsafe_math` (default: `false`) -- optimize numerical expressions like
@@ -798,6 +801,10 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 - `unsafe_regexp` (default: `false`) -- enable substitutions of variables with
   `RegExp` values the same way as if they are constants.
 
+- `unsafe_undefined` (default: `false`) -- substitute `void 0` if there is a
+  variable named `undefined` in scope (variable name will be mangled, typically
+  reduced to a single character)
+
 - `unused` (default: `true`) -- drop unreferenced functions and variables (simple
   direct variable assignments do not count as references unless set to `"keep_assign"`)
 
@@ -990,9 +997,6 @@ when this flag is on:
 - `new Object()` → `{}`
 - `String(exp)` or `exp.toString()` → `"" + exp`
 - `new Object/RegExp/Function/Error/Array (...)` → we discard the `new`
-- `void 0` → `undefined` (if there is a variable named "undefined" in
-  scope; we do it because the variable name will be mangled, typically
-  reduced to a single character)
 
 ### Conditional compilation
 
@@ -1169,3 +1173,27 @@ To enable fast minify mode with the API use:
 ```js
 UglifyJS.minify(code, { compress: false, mangle: true });
 ```
+
+#### Source maps and debugging
+
+Various `compress` transforms that simplify, rearrange, inline and remove code
+are known to have an adverse effect on debugging with source maps. This is
+expected as code is optimized and mappings are often simply not possible as
+some code no longer exists. For highest fidelity in source map debugging
+disable the Uglify `compress` option and just use `mangle`.
+
+### Compiler assumptions
+
+To allow for better optimizations, the compiler makes various assumptions:
+
+- `.toString()` and `.valueOf()` don't have side effects, and for built-in
+  objects they have not been overridden.
+- `undefined`, `NaN` and `Infinity` have not been externally redefined.
+- `arguments.callee`, `arguments.caller` and `Function.prototype.caller` are not used.
+- The code doesn't expect the contents of `Function.prototype.toString()` or
+  `Error.prototype.stack` to be anything in particular.
+- Getting and setting properties on a plain object does not cause other side effects
+  (using `.watch()` or `Proxy`).
+- Object properties can be added, removed and modified (not prevented with
+  `Object.defineProperty()`, `Object.defineProperties()`, `Object.freeze()`,
+  `Object.preventExtensions()` or `Object.seal()`).

appveyor.yml

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

bin/uglifyjs

@@ -3,11 +3,7 @@
 
 "use strict";
 
-// workaround for tty output truncation upon process.exit()
-[process.stdout, process.stderr].forEach(function(stream){
-    if (stream._handle && stream._handle.setBlocking)
-        stream._handle.setBlocking(true);
-});
+require("../tools/exit");
 
 var fs = require("fs");
 var info = require("../package.json");
@@ -15,7 +11,7 @@ var path = require("path");
 var program = require("commander");
 var UglifyJS = require("../tools/node");
 
-var skip_keys = [ "cname", "enclosed", "inlined", "parent_scope", "scope", "thedef", "uses_eval", "uses_with" ];
+var skip_keys = [ "cname", "inlined", "parent_scope", "scope", "uses_eval", "uses_with" ];
 var files = {};
 var options = {
     compress: false,
@@ -49,6 +45,7 @@ program.option("--ie8", "Support non-standard Internet Explorer 8.");
 program.option("--keep-classnames", "Do not mangle/drop class names.");
 program.option("--keep-fnames", "Do not mangle/drop function names. Useful for code relying on Function.prototype.name.");
 program.option("--name-cache <file>", "File to hold mangled name mappings.");
+program.option("--rename", "Force symbol expansion.");
 program.option("--no-rename", "Disable symbol expansion.");
 program.option("--safari10", "Support non-standard Safari 10.");
 program.option("--self", "Build UglifyJS as a library (implies --wrap UglifyJS)");
@@ -69,14 +66,12 @@ if (!program.output && program.sourceMap && program.sourceMap.url != "inline") {
     "compress",
     "ie8",
     "mangle",
-    "rename",
     "safari10",
     "sourceMap",
     "toplevel",
     "wrap"
 ].forEach(function(name) {
     if (name in program) {
-        if (name == "rename" && program[name]) return;
         options[name] = program[name];
     }
 });
@@ -136,6 +131,11 @@ if (program.parse) {
         fatal("ERROR: inline source map only works with built-in parser");
     }
 }
+if (~program.rawArgs.indexOf("--rename")) {
+    options.rename = true;
+} else if (!program.rename) {
+    options.rename = false;
+}
 var convert_path = function(name) {
     return name;
 };
@@ -238,7 +238,20 @@ function run() {
         }
         fatal(ex);
     } else if (program.output == "ast") {
+        if (!options.compress && !options.mangle) {
+            result.ast.figure_out_scope({});
+        }
         print(JSON.stringify(result.ast, function(key, value) {
+            if (value) switch (key) {
+              case "thedef":
+                return symdef(value);
+              case "enclosed":
+                return value.length ? value.map(symdef) : undefined;
+              case "variables":
+              case "functions":
+              case "globals":
+                return value.size() ? value.map(symdef) : undefined;
+            }
             if (skip_key(key)) return;
             if (value instanceof UglifyJS.AST_Token) return;
             if (value instanceof UglifyJS.Dictionary) return;
@@ -246,6 +259,11 @@ function run() {
                 var result = {
                     _class: "AST_" + value.TYPE
                 };
+                if (value.block_scope) {
+                    result.variables = value.block_scope.variables;
+                    result.functions = value.block_scope.functions;
+                    result.enclosed = value.block_scope.enclosed;
+                }
                 value.CTOR.PROPS.forEach(function(prop) {
                     result[prop] = value[prop];
                 });
@@ -392,6 +410,12 @@ function skip_key(key) {
     return skip_keys.indexOf(key) >= 0;
 }
 
+function symdef(def) {
+    var ret = (1e6 + def.id) + " " + def.name;
+    if (def.mangled_name) ret += " " + def.mangled_name;
+    return ret;
+}
+
 function format_object(obj) {
     var lines = [];
     var padding = "";

lib/ast.js

@@ -87,7 +87,7 @@ function DEFNODE(type, props, methods, base) {
     return ctor;
 };
 
-var AST_Token = DEFNODE("Token", "type value line col pos endline endcol endpos nlb comments_before file raw", {
+var AST_Token = DEFNODE("Token", "type value line col pos endline endcol endpos nlb comments_before comments_after file raw", {
 }, null);
 
 var AST_Node = DEFNODE("Node", "start end", {
@@ -267,11 +267,10 @@ var AST_For = DEFNODE("For", "init condition step", {
     }
 }, AST_IterationStatement);
 
-var AST_ForIn = DEFNODE("ForIn", "init name object", {
+var AST_ForIn = DEFNODE("ForIn", "init object", {
     $documentation: "A `for ... in` statement",
     $propdoc: {
         init: "[AST_Node] the `for/in` initialization code",
-        name: "[AST_SymbolRef?] the loop variable, only if `init` is AST_Var",
         object: "[AST_Node] the object that we're looping through"
     },
     _walk: function(visitor) {
@@ -319,6 +318,13 @@ var AST_Scope = DEFNODE("Scope", "variables functions uses_with uses_eval parent
             self = self.parent_scope;
         }
         return self;
+    },
+    clone: function(deep) {
+        var node = this._clone(deep);
+        if (this.variables) node.variables = this.variables.clone();
+        if (this.functions) node.functions = this.functions.clone();
+        if (this.enclosed) node.enclosed = this.enclosed.slice();
+        return node;
     }
 }, AST_Block);
 
@@ -863,8 +869,8 @@ var AST_Object = DEFNODE("Object", "properties", {
 var AST_ObjectProperty = DEFNODE("ObjectProperty", "key value", {
     $documentation: "Base class for literal object properties",
     $propdoc: {
-        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."
+        key: "[string|AST_Node] property name. For ObjectKeyVal this is a string. For getters, setters and computed property this is an AST_Node.",
+        value: "[AST_Node] property value.  For getters and setters this is an AST_Accessor."
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){

lib/minify.js

@@ -29,7 +29,6 @@ function set_shorthand(name, options, keys) {
 
 function init_cache(cache) {
     if (!cache) return;
-    if (!("cname" in cache)) cache.cname = -1;
     if (!("props" in cache)) {
         cache.props = new Dictionary();
     } else if (!(cache.props instanceof Dictionary)) {
@@ -39,7 +38,6 @@ function init_cache(cache) {
 
 function to_json(cache) {
     return {
-        cname: cache.cname,
         props: cache.props.toObject()
     };
 }
@@ -153,7 +151,9 @@ function minify(files, options) {
             toplevel = toplevel.wrap_commonjs(options.wrap);
         }
         if (timings) timings.rename = Date.now();
-        if (options.rename) {
+        // disable rename on harmony due to expand_names bug in for-of loops
+        // https://github.com/mishoo/UglifyJS2/issues/2794
+        if (0 && options.rename) {
             toplevel.figure_out_scope(options.mangle);
             toplevel.expand_names(options.mangle);
         }

lib/output.js

@@ -52,6 +52,7 @@ function is_some_comments(comment) {
 
 function OutputStream(options) {
 
+    var readonly = !options;
     options = defaults(options, {
         ascii_only       : false,
         beautify         : false,
@@ -133,11 +134,16 @@ function OutputStream(options) {
             }
         });
     } : function(str) {
-        return str.replace(/[\ud800-\udbff](?![\udc00-\udfff])/g, function(ch) {
-            return "\\u" + ch.charCodeAt(0).toString(16);
-        }).replace(/(^|[^\ud800-\udbff])([\udc00-\udfff])/g, function(match, prefix, ch) {
-            return prefix + "\\u" + ch.charCodeAt(0).toString(16);
-        });
+        var s = "";
+        for (var i = 0, len = str.length; i < len; i++) {
+            if (is_surrogate_pair_head(str[i]) && !is_surrogate_pair_tail(str[i + 1])
+                || is_surrogate_pair_tail(str[i]) && !is_surrogate_pair_head(str[i - 1])) {
+                s += "\\u" + str.charCodeAt(i).toString(16);
+            } else {
+                s += str[i];
+            }
+        }
+        return s;
     };
 
     function make_string(str, quote) {
@@ -210,6 +216,9 @@ function OutputStream(options) {
     var might_need_space = false;
     var might_need_semicolon = false;
     var might_add_newline = 0;
+    var need_newline_indented = false;
+    var need_space = false;
+    var newline_insert = -1;
     var last = "";
     var mapping_token, mapping_name, mappings = options.source_map && [];
 
@@ -269,6 +278,21 @@ function OutputStream(options) {
         str = String(str);
         var ch = get_full_char(str, 0);
         var prev = get_full_char(last, last.length - 1);
+        if (need_newline_indented && ch) {
+            need_newline_indented = false;
+            if (ch != "\n") {
+                print("\n");
+                indent();
+            }
+        }
+        if (need_space && ch) {
+            need_space = false;
+            if (!/[\s;})]/.test(ch)) {
+                space();
+            }
+        }
+        newline_insert = -1;
+        var prev = last.charAt(last.length - 1);
         if (might_need_semicolon) {
             might_need_semicolon = false;
 
@@ -370,7 +394,13 @@ function OutputStream(options) {
     } : function(col, cont) { return cont() };
 
     var newline = options.beautify ? function() {
-        print("\n");
+        if (newline_insert < 0) return print("\n");
+        if (OUTPUT[newline_insert] != "\n") {
+            OUTPUT = OUTPUT.slice(0, newline_insert) + "\n" + OUTPUT.slice(newline_insert);
+            current_pos++;
+            current_line++;
+        }
+        newline_insert++;
     } : options.max_line_len ? function() {
         ensure_line_len();
         might_add_newline = OUTPUT.length;
@@ -442,6 +472,124 @@ function OutputStream(options) {
         return OUTPUT;
     };
 
+    function has_nlb() {
+        var index = OUTPUT.lastIndexOf("\n");
+        return /^ *$/.test(OUTPUT.slice(index + 1));
+    }
+
+    function prepend_comments(node) {
+        var self = this;
+        var start = node.start;
+        if (!start) return;
+        if (start.comments_before && start.comments_before._dumped === self) return;
+        var comments = start.comments_before;
+        if (!comments) {
+            comments = start.comments_before = [];
+        }
+        comments._dumped = self;
+
+        if (node instanceof AST_Exit && node.value) {
+            var tw = new TreeWalker(function(node) {
+                var parent = tw.parent();
+                if (parent instanceof AST_Exit
+                    || parent instanceof AST_Binary && parent.left === node
+                    || parent.TYPE == "Call" && parent.expression === node
+                    || parent instanceof AST_Conditional && parent.condition === node
+                    || parent instanceof AST_Dot && parent.expression === node
+                    || parent instanceof AST_Sequence && parent.expressions[0] === node
+                    || parent instanceof AST_Sub && parent.expression === node
+                    || parent instanceof AST_UnaryPostfix) {
+                    if (!node.start) return;
+                    var text = node.start.comments_before;
+                    if (text && text._dumped !== self) {
+                        text._dumped = self;
+                        comments = comments.concat(text);
+                    }
+                } else {
+                    return true;
+                }
+            });
+            tw.push(node);
+            node.value.walk(tw);
+        }
+
+        if (current_pos == 0) {
+            if (comments.length > 0 && options.shebang && comments[0].type == "comment5") {
+                print("#!" + comments.shift().value + "\n");
+                indent();
+            }
+            var preamble = options.preamble;
+            if (preamble) {
+                print(preamble.replace(/\r\n?|[\n\u2028\u2029]|\s*$/g, "\n"));
+            }
+        }
+
+        comments = comments.filter(comment_filter, node);
+        if (comments.length == 0) return;
+        var last_nlb = has_nlb();
+        comments.forEach(function(c, i) {
+            if (!last_nlb) {
+                if (c.nlb) {
+                    print("\n");
+                    indent();
+                    last_nlb = true;
+                } else if (i > 0) {
+                    space();
+                }
+            }
+            if (/comment[134]/.test(c.type)) {
+                print("//" + c.value.replace(/[@#]__PURE__/g, ' ') + "\n");
+                indent();
+                last_nlb = true;
+            } else if (c.type == "comment2") {
+                print("/*" + c.value.replace(/[@#]__PURE__/g, ' ') + "*/");
+                last_nlb = false;
+            }
+        });
+        if (!last_nlb) {
+            if (start.nlb) {
+                print("\n");
+                indent();
+            } else {
+                space();
+            }
+        }
+    }
+
+    function append_comments(node, tail) {
+        var self = this;
+        var token = node.end;
+        if (!token) return;
+        var comments = token[tail ? "comments_before" : "comments_after"];
+        if (!comments || comments._dumped === self) return;
+        if (!(node instanceof AST_Statement || all(comments, function(c) {
+            return !/comment[134]/.test(c.type);
+        }))) return;
+        comments._dumped = self;
+        var insert = OUTPUT.length;
+        comments.filter(comment_filter, node).forEach(function(c, i) {
+            need_space = false;
+            if (need_newline_indented) {
+                print("\n");
+                indent();
+                need_newline_indented = false;
+            } else if (c.nlb && (i > 0 || !has_nlb())) {
+                print("\n");
+                indent();
+            } else if (i > 0 || !tail) {
+                space();
+            }
+            if (/comment[134]/.test(c.type)) {
+                print("//" + c.value.replace(/[@#]__PURE__/g, ' '));
+                need_newline_indented = true;
+            } else if (c.type == "comment2") {
+                print("/*" + c.value.replace(/[@#]__PURE__/g, ' ') + "*/");
+                need_space = true;
+            }
+        });
+        if (OUTPUT.length > insert) newline_insert = insert;
+    }
+
     var stack = [];
     return {
         get             : get,
@@ -484,7 +632,8 @@ function OutputStream(options) {
         with_square     : with_square,
         add_mapping     : add_mapping,
         option          : function(opt) { return options[opt] },
-        comment_filter  : comment_filter,
+        prepend_comments: readonly ? noop : prepend_comments,
+        append_comments : readonly || comment_filter === return_false ? noop : append_comments,
         line            : function() { return current_line },
         col             : function() { return current_col },
         pos             : function() { return current_pos },
@@ -520,9 +669,10 @@ function OutputStream(options) {
             use_asm = active_scope;
         }
         function doit() {
-            self.add_comments(stream);
+            stream.prepend_comments(self);
             self.add_source_map(stream);
             generator(self, stream);
+            stream.append_comments(self);
         }
         stream.push_node(self);
         if (force_parens || self.needs_parens(stream)) {
@@ -539,77 +689,10 @@ function OutputStream(options) {
 
     AST_Node.DEFMETHOD("print_to_string", function(options){
         var s = OutputStream(options);
-        if (!options) s._readonly = true;
         this.print(s);
         return s.get();
     });
 
-    /* -----[ comments ]----- */
-
-    AST_Node.DEFMETHOD("add_comments", function(output){
-        if (output._readonly) return;
-        var self = this;
-        var start = self.start;
-        if (start && !start._comments_dumped) {
-            start._comments_dumped = true;
-            var comments = start.comments_before || [];
-
-            // XXX: ugly fix for https://github.com/mishoo/UglifyJS2/issues/112
-            //               and https://github.com/mishoo/UglifyJS2/issues/372
-            if (self instanceof AST_Exit && self.value) {
-                self.value.walk(new TreeWalker(function(node){
-                    if (node.start && node.start.comments_before) {
-                        comments = comments.concat(node.start.comments_before);
-                        node.start.comments_before = [];
-                    }
-                    if (node instanceof AST_Function ||
-                        node instanceof AST_Array ||
-                        node instanceof AST_Object)
-                    {
-                        return true; // don't go inside.
-                    }
-                }));
-            }
-
-            if (output.pos() == 0) {
-                if (comments.length > 0 && output.option("shebang") && comments[0].type == "comment5") {
-                    output.print("#!" + comments.shift().value + "\n");
-                    output.indent();
-                }
-                var preamble = output.option("preamble");
-                if (preamble) {
-                    output.print(preamble.replace(/\r\n?|[\n\u2028\u2029]|\s*$/g, "\n"));
-                }
-            }
-
-            comments = comments.filter(output.comment_filter, self);
-
-            // Keep single line comments after nlb, after nlb
-            if (!output.option("beautify") && comments.length > 0 &&
-                /comment[134]/.test(comments[0].type) &&
-                output.col() !== 0 && comments[0].nlb)
-            {
-                output.print("\n");
-            }
-
-            comments.forEach(function(c){
-                if (/comment[134]/.test(c.type)) {
-                    output.print("//" + c.value + "\n");
-                    output.indent();
-                }
-                else if (c.type == "comment2") {
-                    output.print("/*" + c.value + "*/");
-                    if (start.nlb) {
-                        output.print("\n");
-                        output.indent();
-                    } else {
-                        output.space();
-                    }
-                }
-            });
-        }
-    });
-
     /* -----[ PARENTHESES ]----- */
 
     function PARENS(nodetype, func) {
@@ -622,9 +705,7 @@ function OutputStream(options) {
         }
     };
 
-    PARENS(AST_Node, function(){
-        return false;
-    });
+    PARENS(AST_Node, return_false);
 
     // a function expression needs parens around it when it's provably
     // the first token to appear in a statement.
@@ -653,15 +734,9 @@ function OutputStream(options) {
         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_ClassExpression, AST_Object ], first_in_statement);
 
     PARENS(AST_Unary, function(output){
         var p = output.parent();
@@ -696,6 +771,8 @@ function OutputStream(options) {
             || p instanceof AST_Arrow                         // x => (x, x)
             || p instanceof AST_DefaultAssign                 // x => (x = (0, function(){}))
             || p instanceof AST_Expansion                     // [...(a, b)]
+            || p instanceof AST_ForOf && this === p.object    // for (e of (foo, bar)) {}
+            || p instanceof AST_Yield                         // yield (foo, bar)
         ;
     });
 
@@ -728,6 +805,10 @@ function OutputStream(options) {
         // a = yield 3
         if (p instanceof AST_Binary && p.operator !== "=")
             return true;
+        // (yield 1)()
+        // new (yield 1)()
+        if (p instanceof AST_Call && p.expression === this)
+            return true;
         // (yield 1) ? yield 2 : yield 3
         if (p instanceof AST_Conditional && p.condition === this)
             return true;
@@ -897,14 +978,21 @@ function OutputStream(options) {
         self.body.print(output);
         output.semicolon();
     });
-    function print_bracketed(body, output, allow_directives) {
-        if (body.length > 0) output.with_block(function(){
-            display_body(body, false, output, allow_directives);
-        });
-        else output.print("{}");
+    function print_bracketed(self, output, allow_directives) {
+        if (self.body.length > 0) {
+            output.with_block(function() {
+                display_body(self.body, false, output, allow_directives);
+            });
+        } else {
+            output.print("{");
+            output.with_indent(output.next_indent(), function() {
+                output.append_comments(self, true);
+            });
+            output.print("}");
+        }
     };
     DEFPRINT(AST_BlockStatement, function(self, output){
-        print_bracketed(self.body, output);
+        print_bracketed(self, output);
     });
     DEFPRINT(AST_EmptyStatement, function(self, output){
         output.semicolon();
@@ -965,11 +1053,7 @@ function OutputStream(options) {
         output.with_parens(function(){
             self.init.print(output);
             output.space();
-            if (self instanceof AST_ForOf) {
-                output.print("of");
-            } else {
-                output.print("in");
-            }
+            output.print(self instanceof AST_ForOf ? "of" : "in");
             output.space();
             self.object.print(output);
         });
@@ -1016,7 +1100,7 @@ function OutputStream(options) {
             });
         });
         output.space();
-        print_bracketed(self.body, output, true);
+        print_bracketed(self, output, true);
     });
     DEFPRINT(AST_Lambda, function(self, output){
         self._do_print(output);
@@ -1071,7 +1155,7 @@ function OutputStream(options) {
         if (self.body instanceof AST_Node) {
             self.body.print(output);
         } else {
-            print_bracketed(self.body, output);
+            print_bracketed(self, output);
         }
         if (needs_parens) { output.print(")") }
     });
@@ -1228,7 +1312,7 @@ function OutputStream(options) {
     DEFPRINT(AST_Try, function(self, output){
         output.print("try");
         output.space();
-        print_bracketed(self.body, output);
+        print_bracketed(self, output);
         if (self.bcatch) {
             output.space();
             self.bcatch.print(output);
@@ -1245,12 +1329,12 @@ function OutputStream(options) {
             self.argname.print(output);
         });
         output.space();
-        print_bracketed(self.body, output);
+        print_bracketed(self, output);
     });
     DEFPRINT(AST_Finally, function(self, output){
         output.print("finally");
         output.space();
-        print_bracketed(self.body, output);
+        print_bracketed(self, output);
     });
 
     /* -----[ var/const ]----- */
@@ -1599,11 +1683,8 @@ function OutputStream(options) {
 
     function print_property_name(key, quote, output) {
         if (output.option("quote_keys")) {
-            output.print_string(key + "");
-        } else if ((typeof key == "number"
-                    || !output.option("beautify")
-                    && +key + "" == key)
-                   && parseFloat(key) >= 0) {
+            output.print_string(key);
+        } else if ("" + +key == key && key >= 0) {
             output.print(make_num(key));
         } else if (RESERVED_WORDS(key) ? !output.option("ie8") : is_identifier_string(key)) {
             if (quote && output.option("keep_quoted_props")) {

lib/parse.js

@@ -365,11 +365,7 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
         }
         if (!is_comment) {
             ret.comments_before = S.comments_before;
-            S.comments_before = [];
-            // make note of any newlines in the comments that came before
-            for (var i = 0, len = ret.comments_before.length; i < len; i++) {
-                ret.nlb = ret.nlb || ret.comments_before[i].nlb;
-            }
+            ret.comments_after = S.comments_before = [];
         }
         S.newline_before = false;
         return new AST_Token(ret);
@@ -938,10 +934,15 @@ function parse($TEXT, options) {
 
     function expect(punc) { return expect_token("punc", punc); };
 
+    function has_newline_before(token) {
+        return token.nlb || !all(token.comments_before, function(comment) {
+            return !comment.nlb;
+        });
+    }
+
     function can_insert_semicolon() {
-        return !options.strict && (
-            S.token.nlb || is("eof") || is("punc", "}")
-        );
+        return !options.strict
+            && (is("eof") || is("punc", "}") || has_newline_before(S.token));
     };
 
     function is_in_generator() {
@@ -982,17 +983,17 @@ function parse($TEXT, options) {
         }
     };
 
-    var statement = embed_tokens(function() {
+    var statement = embed_tokens(function(is_export_default) {
         handle_regexp();
         switch (S.token.type) {
           case "string":
             if (S.in_directives) {
                 var token = peek();
                 if (S.token.raw.indexOf("\\") == -1
-                    && (token.nlb
-                        || is_token(token, "eof")
-                        || is_token(token, "punc", ";")
-                        || is_token(token, "punc", "}"))) {
+                    && (is_token(token, "punc", ";")
+                        || is_token(token, "punc", "}")
+                        || has_newline_before(token)
+                        || is_token(token, "eof"))) {
                     S.input.add_directive(S.token.value);
                 } else {
                     S.in_directives = false;
@@ -1011,7 +1012,7 @@ function parse($TEXT, options) {
             if (S.token.value == "async" && is_token(peek(), "keyword", "function")) {
                 next();
                 next();
-                return function_(AST_Defun, false, true);
+                return function_(AST_Defun, false, true, is_export_default);
             }
             if (S.token.value == "import" && !is_token(peek(), "punc", "(")) {
                 next();
@@ -1085,7 +1086,7 @@ function parse($TEXT, options) {
 
               case "function":
                 next();
-                return function_(AST_Defun);
+                return function_(AST_Defun, false, false, is_export_default);
 
               case "if":
                 next();
@@ -1115,7 +1116,7 @@ function parse($TEXT, options) {
 
               case "throw":
                 next();
-                if (S.token.nlb)
+                if (has_newline_before(S.token))
                     croak("Illegal newline after 'throw'");
                 var value = expression(true);
                 semicolon();
@@ -1167,10 +1168,6 @@ function parse($TEXT, options) {
 
     function labeled_statement() {
         var label = as_symbol(AST_Label);
-        if (label.name === "yield" && is_in_generator()) {
-            // Ecma-262, 12.1.1 Static Semantics: Early Errors
-            token_error(S.prev, "Yield cannot be used as label inside generators");
-        }
         if (label.name === "await" && is_in_async()) {
             token_error(S.prev, "await cannot be used as label inside async function");
         }
@@ -1279,19 +1276,17 @@ function parse($TEXT, options) {
     };
 
     function for_in(init) {
-        var lhs = init instanceof AST_Definitions ? init.definitions[0].name : null;
         var obj = expression(true);
         expect(")");
         return new AST_ForIn({
             init   : init,
-            name   : lhs,
             object : obj,
             body   : in_loop(statement)
         });
     };
 
     var arrow_function = function(start, argnames, is_async) {
-        if (S.token.nlb) {
+        if (has_newline_before(S.token)) {
             croak("Unexpected newline before arrow (=>)");
         }
 
@@ -1308,9 +1303,9 @@ function parse($TEXT, options) {
         });
     };
 
-    var function_ = function(ctor, is_generator_property, is_async) {
+    var function_ = function(ctor, is_generator_property, is_async, is_export_default) {
         if (is_generator_property && is_async) croak("generators cannot be async");
-        var start = S.token
+        var start = S.token;
 
         var in_statement = ctor === AST_Defun;
         var is_generator = is("operator", "*");
@@ -1319,13 +1314,18 @@ function parse($TEXT, options) {
         }
 
         var name = is("name") ? as_symbol(in_statement ? AST_SymbolDefun : AST_SymbolLambda) : null;
-        if (in_statement && !name)
-            unexpected();
+        if (in_statement && !name) {
+            if (is_export_default) {
+                ctor = AST_Function;
+            } else {
+                unexpected();
+            }
+        }
 
         if (name && ctor !== AST_Accessor && !(name instanceof AST_SymbolDeclaration))
             unexpected(prev());
 
-        var args = parameters();
+        var args = [];
         var body = _function_body(true, is_generator || is_generator_property, is_async, name, args);
         return new ctor({
             start : args.start,
@@ -1396,9 +1396,8 @@ function parse($TEXT, options) {
         return tracker;
     }
 
-    function parameters() {
+    function parameters(params) {
         var start = S.token;
-        var params = [];
         var used_parameters = track_used_binding_identifiers(true, S.input.has_directive("use strict"));
 
         expect("(");
@@ -1418,7 +1417,6 @@ function parse($TEXT, options) {
         }
 
         next();
-        return params;
     }
 
     function parameter(used_parameters, symbol_type) {
@@ -1505,12 +1503,7 @@ function parse($TEXT, options) {
                     }
                 } else if (is("name")) {
                     used_parameters.add_parameter(S.token);
-                    elements.push(new symbol_type({
-                        start: S.token,
-                        name: S.token.value,
-                        end: S.token
-                    }));
-                    next();
+                    elements.push(as_symbol(symbol_type));
                 } else {
                     croak("Invalid function parameter");
                 }
@@ -1560,11 +1553,8 @@ function parse($TEXT, options) {
                 }
                 if (is("name") && (is_token(peek(), "punc") || is_token(peek(), "operator")) && [",", "}", "="].indexOf(peek().value) !== -1) {
                     used_parameters.add_parameter(S.token);
-                    var value = new symbol_type({
-                        start: S.token,
-                        name: S.token.value,
-                        end: S.token,
-                    });
+                    var start = prev();
+                    var value = as_symbol(symbol_type);
                     if (is_expand) {
                         elements.push(new AST_Expansion({
                             start: expand_token,
@@ -1573,13 +1563,12 @@ function parse($TEXT, options) {
                         }));
                     } else {
                         elements.push(new AST_ObjectKeyVal({
-                            start: prev(),
-                            key: S.token.value,
+                            start: start,
+                            key: value.name,
                             value: value,
                             end: value.end,
                         }));
                     }
-                    next();
                 } else if (is("punc", "}")) {
                     continue; // Allow trailing hole
                 } else {
@@ -1636,12 +1625,7 @@ function parse($TEXT, options) {
             });
         } else if (is("name")) {
             used_parameters.add_parameter(S.token);
-            next();
-            return new symbol_type({
-                start: prev(),
-                name: prev().value,
-                end: prev()
-            });
+            return as_symbol(symbol_type);
         } else {
             croak("Invalid function parameter");
         }
@@ -1695,6 +1679,7 @@ function parse($TEXT, options) {
             S.in_generator = S.in_function;
         if (is_async)
             S.in_async = S.in_function;
+        if (args) parameters(args);
         if (block)
             S.in_directives = true;
         S.in_loop = 0;
@@ -1702,10 +1687,8 @@ function parse($TEXT, options) {
         if (block) {
             S.input.push_directives_stack();
             var a = block_();
-            if (S.input.has_directive("use strict")) {
-                if (name) strict_verify_symbol(name);
-                if (args) args.forEach(strict_verify_symbol);
-            }
+            if (name) _verify_symbol(name);
+            if (args) args.forEach(_verify_symbol);
             S.input.pop_directives_stack();
         } else {
             var a = expression(false);
@@ -1877,7 +1860,7 @@ function parse($TEXT, options) {
                     name  : as_symbol(sym_type),
                     value : is("operator", "=")
                         ? (next(), expression(false, no_in))
-                        : !no_in && kind === "const" && S.input.has_directive("use strict")
+                        : !no_in && kind === "const"
                             ? croak("Missing initializer in const declaration") : null,
                     end   : prev()
                 });
@@ -1933,12 +1916,14 @@ function parse($TEXT, options) {
         } else {
             args = [];
         }
-        return subscripts(new AST_New({
+        var call = new AST_New({
             start      : start,
             expression : newexp,
             args       : args,
             end        : prev()
-        }), allow_calls);
+        });
+        mark_pure(call);
+        return subscripts(call, allow_calls);
     };
 
     function as_atom_node() {
@@ -2053,8 +2038,29 @@ function parse($TEXT, options) {
                 }) : exprs.length == 1 ? exprs[0] : new AST_Sequence({
                     expressions: exprs
                 });
+                if (ex.start) {
+                    var len = start.comments_before.length;
+                    [].unshift.apply(ex.start.comments_before, start.comments_before);
+                    start.comments_before = ex.start.comments_before;
+                    start.comments_before_length = len;
+                    if (len == 0 && start.comments_before.length > 0) {
+                        var comment = start.comments_before[0];
+                        if (!comment.nlb) {
+                            comment.nlb = start.nlb;
+                            start.nlb = false;
+                        }
+                    }
+                    start.comments_after = ex.start.comments_after;
+                }
                 ex.start = start;
-                ex.end = S.token;
+                var end = prev();
+                if (ex.end) {
+                    end.comments_before = ex.end.comments_before;
+                    [].push.apply(ex.end.comments_after, end.comments_after);
+                    end.comments_after = ex.end.comments_after;
+                }
+                ex.end = end;
+                if (ex instanceof AST_Call) mark_pure(ex);
                 return subscripts(ex, allow_calls);
               case "[":
                 return subscripts(array_(), allow_calls);
@@ -2218,7 +2224,7 @@ function parse($TEXT, options) {
             a.push(new AST_ObjectKeyVal({
                 start: start,
                 quote: start.quote,
-                key: name,
+                key: name instanceof AST_Node ? name : "" + name,
                 value: value,
                 end: prev()
             }));
@@ -2275,7 +2281,7 @@ function parse($TEXT, options) {
             if (typeof name === "string" || typeof name === "number") {
                 return new AST_SymbolMethod({
                     start: token,
-                    name: name,
+                    name: "" + name,
                     end: prev()
                 });
             } else if (name === null) {
@@ -2528,9 +2534,9 @@ function parse($TEXT, options) {
                 && is_token(peek(), "punc")) {
             exported_value = expression(false);
             semicolon();
-        } else if ((node = statement()) instanceof AST_Definitions && is_default) {
+        } else if ((node = statement(is_default)) instanceof AST_Definitions && is_default) {
             unexpected(node.start);
-        } else if (node instanceof AST_Definitions || node instanceof AST_Defun || node instanceof AST_DefClass) {
+        } else if (node instanceof AST_Definitions || node instanceof AST_Lambda || node instanceof AST_DefClass) {
             exported_definition = node;
         } else if (node instanceof AST_SimpleStatement) {
             exported_value = node.body;
@@ -2566,9 +2572,14 @@ function parse($TEXT, options) {
                 unexpected(tmp);
             }
           case "name":
-            if (tmp.value == "yield" && !is_token(peek(), "punc", ":") && !is_token(peek(), "punc", "(")
-                && S.input.has_directive("use strict") && !is_in_generator()) {
-                token_error(tmp, "Unexpected yield identifier inside strict mode");
+            if (tmp.value == "yield") {
+                if (is_in_generator()) {
+                    token_error(tmp, "Yield cannot be used as identifier inside generators");
+                } else if (!is_token(peek(), "punc", ":")
+                    && !is_token(peek(), "punc", "(")
+                    && S.input.has_directive("use strict")) {
+                    token_error(tmp, "Unexpected yield identifier inside strict mode");
+                }
             }
           case "string":
           case "num":
@@ -2599,9 +2610,19 @@ function parse($TEXT, options) {
         });
     };
 
-    function strict_verify_symbol(sym) {
-        if (sym.name == "arguments" || sym.name == "eval")
-            croak("Unexpected " + sym.name + " in strict mode", sym.start.line, sym.start.col, sym.start.pos);
+    function _verify_symbol(sym) {
+        var name = sym.name;
+        if (is_in_generator() && name == "yield") {
+            token_error(sym.start, "Yield cannot be used as identifier inside generators");
+        }
+        if (S.input.has_directive("use strict")) {
+            if (name == "yield") {
+                token_error(sym.start, "Unexpected yield identifier inside strict mode");
+            }
+            if (sym instanceof AST_SymbolDeclaration && (name == "arguments" || name == "eval")) {
+                token_error(sym.start, "Unexpected " + name + " in strict mode");
+            }
+        }
     }
 
     function as_symbol(type, noerror) {
@@ -2609,17 +2630,25 @@ function parse($TEXT, options) {
             if (!noerror) croak("Name expected");
             return null;
         }
-        if (is("name", "yield") && S.input.has_directive("use strict")) {
-            token_error(S.prev, "Unexpected yield identifier inside strict mode");
-        }
         var sym = _make_symbol(type);
-        if (S.input.has_directive("use strict") && sym instanceof AST_SymbolDeclaration) {
-            strict_verify_symbol(sym);
-        }
+        _verify_symbol(sym);
         next();
         return sym;
     };
 
+    function mark_pure(call) {
+        var start = call.start;
+        var comments = start.comments_before;
+        var i = HOP(start, "comments_before_length") ? start.comments_before_length : comments.length;
+        while (--i >= 0) {
+            var comment = comments[i];
+            if (/[@#]__PURE__/.test(comment.value)) {
+                call.pure = comment;
+                break;
+            }
+        }
+    }
+
     var subscripts = function(expr, allow_calls) {
         var start = expr.start;
         if (is("punc", ".")) {
@@ -2644,12 +2673,14 @@ function parse($TEXT, options) {
         }
         if (allow_calls && is("punc", "(")) {
             next();
-            return subscripts(new AST_Call({
+            var call = new AST_Call({
                 start      : start,
                 expression : expr,
                 args       : call_args(),
                 end        : prev()
-            }), true);
+            });
+            mark_pure(call);
+            return subscripts(call, true);
         }
         if (is("template_head")) {
             return subscripts(new AST_PrefixedTemplateString({
@@ -2701,7 +2732,7 @@ function parse($TEXT, options) {
             return ex;
         }
         var val = expr_atom(allow_calls, allow_arrows);
-        while (is("operator") && UNARY_POSTFIX(S.token.value) && !S.token.nlb) {
+        while (is("operator") && UNARY_POSTFIX(S.token.value) && !has_newline_before(S.token)) {
             if (val instanceof AST_Arrow) unexpected();
             val = make_unary(AST_UnaryPostfix, S.token, val);
             val.start = start;
@@ -2731,7 +2762,8 @@ function parse($TEXT, options) {
         var op = is("operator") ? S.token.value : null;
         if (op == "in" && no_in) op = null;
         if (op == "**" && left instanceof AST_UnaryPrefix
-            && left.end === S.prev /* unary token in front not allowed, but allowed if prev is for example `)` */
+            /* unary token in front not allowed - parenthesis required */
+            && !is_token(left.start, "punc", "(")
             && left.operator !== "--" && left.operator !== "++")
                 unexpected(left.start);
         var prec = op != null ? PRECEDENCE[op] : null;
@@ -2827,7 +2859,7 @@ function parse($TEXT, options) {
                 next();
                 return _yield_expression();
             } else if (S.input.has_directive("use strict")) {
-                token_error(S.token, "Unexpected yield identifier inside strict mode")
+                token_error(S.token, "Unexpected yield identifier inside strict mode");
             }
         }
 

lib/propmangle.js

@@ -130,12 +130,15 @@ function mangle_properties(ast, options) {
     if (!Array.isArray(reserved)) reserved = [];
     if (!options.builtins) find_builtins(reserved);
 
-    var cache = options.cache;
-    if (cache == null) {
-        cache = {
-            cname: -1,
-            props: new Dictionary()
-        };
+    var cname = -1;
+    var cache;
+    if (options.cache) {
+        cache = options.cache.props;
+        cache.each(function(mangled_name) {
+            push_uniq(reserved, mangled_name);
+        });
+    } else {
+        cache = new Dictionary();
     }
 
     var regex = options.regex;
@@ -192,7 +195,7 @@ function mangle_properties(ast, options) {
         if (unmangleable.indexOf(name) >= 0) return false;
         if (reserved.indexOf(name) >= 0) return false;
         if (options.only_cache) {
-            return cache.props.has(name);
+            return cache.has(name);
         }
         if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
         return true;
@@ -201,7 +204,7 @@ function mangle_properties(ast, options) {
     function should_mangle(name) {
         if (regex && !regex.test(name)) return false;
         if (reserved.indexOf(name) >= 0) return false;
-        return cache.props.has(name)
+        return cache.has(name)
             || names_to_mangle.indexOf(name) >= 0;
     }
 
@@ -219,7 +222,7 @@ function mangle_properties(ast, options) {
             return name;
         }
 
-        var mangled = cache.props.get(name);
+        var mangled = cache.get(name);
         if (!mangled) {
             if (debug) {
                 // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo -> o._$foo$NNN_.
@@ -233,11 +236,11 @@ function mangle_properties(ast, options) {
             // either debug mode is off, or it is on and we could not use the mangled name
             if (!mangled) {
                 do {
-                    mangled = base54(++cache.cname);
+                    mangled = base54(++cname);
                 } while (!can_mangle(mangled));
             }
 
-            cache.props.set(name, mangled);
+            cache.set(name, mangled);
         }
         return mangled;
     }

lib/scope.js

@@ -43,9 +43,10 @@
 
 "use strict";
 
-function SymbolDef(scope, orig) {
+function SymbolDef(scope, orig, init) {
     this.name = orig.name;
     this.orig = [ orig ];
+    this.init = init;
     this.eliminated = 0;
     this.scope = scope;
     this.references = [];
@@ -175,7 +176,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             node.references = [];
         }
         if (node instanceof AST_SymbolLambda) {
-            defun.def_function(node);
+            defun.def_function(node, node.name == "arguments" ? undefined : defun);
         }
         else if (node instanceof AST_SymbolDefun) {
             // Careful here, the scope where this should be defined is
@@ -183,10 +184,10 @@ 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.
-            mark_export((node.scope = defun.parent_scope.get_defun_scope()).def_function(node), 1);
+            mark_export((node.scope = defun.parent_scope.get_defun_scope()).def_function(node, defun), 1);
         }
         else if (node instanceof AST_SymbolClass) {
-            mark_export(defun.def_variable(node), 1);
+            mark_export(defun.def_variable(node, defun), 1);
         }
         else if (node instanceof AST_SymbolImport) {
             scope.def_variable(node);
@@ -194,12 +195,17 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
         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);
+            mark_export((node.scope = defun.parent_scope).def_function(node, defun), 1);
         }
         else if (node instanceof AST_SymbolVar
             || node instanceof AST_SymbolLet
             || node instanceof AST_SymbolConst) {
-            var def = ((node instanceof AST_SymbolBlockDeclaration) ? scope : defun).def_variable(node);
+            var def;
+            if (node instanceof AST_SymbolBlockDeclaration) {
+                def = scope.def_variable(node, null);
+            } else {
+                def = defun.def_variable(node, node.TYPE == "SymbolVar" ? null : undefined);
+            }
             if (!all(def.orig, function(sym) {
                 if (sym === node) return true;
                 if (node instanceof AST_SymbolBlockDeclaration) {
@@ -284,6 +290,10 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             }
             node.thedef = sym;
             node.reference(options);
+            if (node.scope.is_block_scope()
+                && !(sym.orig[0] instanceof AST_SymbolBlockDeclaration)) {
+                node.scope = node.scope.get_defun_scope();
+            }
             return true;
         }
         // ensure mangling works if catch reuses a scope variable
@@ -330,10 +340,6 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             });
         }
     }
-
-    if (options.cache) {
-        this.cname = options.cache.cname;
-    }
 });
 
 AST_Toplevel.DEFMETHOD("def_global", function(node){
@@ -377,6 +383,11 @@ AST_Lambda.DEFMETHOD("init_scope_vars", function(){
     }));
 });
 
+AST_Arrow.DEFMETHOD("init_scope_vars", function(){
+    AST_Scope.prototype.init_scope_vars.apply(this, arguments);
+    this.uses_arguments = false;
+});
+
 AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
     var def = this.definition();
     var s = this.scope;
@@ -403,29 +414,32 @@ AST_Scope.DEFMETHOD("find_variable", function(name){
         || (this.parent_scope && this.parent_scope.find_variable(name));
 });
 
-AST_Scope.DEFMETHOD("def_function", function(symbol){
-    var def = this.def_variable(symbol);
+AST_Scope.DEFMETHOD("def_function", function(symbol, init){
+    var def = this.def_variable(symbol, init);
+    if (!def.init || def.init instanceof AST_Defun) def.init = init;
     this.functions.set(symbol.name, def);
     return def;
 });
 
-AST_Scope.DEFMETHOD("def_variable", function(symbol){
-    var def;
-    if (!this.variables.has(symbol.name)) {
-        def = new SymbolDef(this, symbol);
+AST_Scope.DEFMETHOD("def_variable", function(symbol, init){
+    var def = this.variables.get(symbol.name);
+    if (def) {
+        def.orig.push(symbol);
+        if (def.init && (def.scope !== symbol.scope || def.init instanceof AST_Function)) {
+            def.init = init;
+        }
+    } else {
+        def = new SymbolDef(this, symbol, init);
         this.variables.set(symbol.name, def);
         def.global = !this.parent_scope;
-    } else {
-        def = this.variables.get(symbol.name);
-        def.orig.push(symbol);
     }
     return symbol.thedef = def;
 });
 
-AST_Scope.DEFMETHOD("next_mangled", function(options){
-    var ext = this.enclosed;
+function next_mangled(scope, options) {
+    var ext = scope.enclosed;
     out: while (true) {
-        var m = base54(++this.cname);
+        var m = base54(++scope.cname);
         if (!is_identifier(m)) continue; // skip over "do"
 
         // https://github.com/mishoo/UglifyJS2/issues/242 -- do not
@@ -442,6 +456,18 @@ AST_Scope.DEFMETHOD("next_mangled", function(options){
         }
         return m;
     }
+}
+
+AST_Scope.DEFMETHOD("next_mangled", function(options){
+    return next_mangled(this, options);
+});
+
+AST_Toplevel.DEFMETHOD("next_mangled", function(options){
+    var name;
+    do {
+        name = next_mangled(this, options);
+    } while (member(name, this.mangled_names));
+    return name;
 });
 
 AST_Function.DEFMETHOD("next_mangled", function(options, def){
@@ -455,7 +481,7 @@ AST_Function.DEFMETHOD("next_mangled", function(options, def){
     var tricky_name = tricky_def ? tricky_def.mangled_name || tricky_def.name : null;
 
     while (true) {
-        var name = AST_Lambda.prototype.next_mangled.call(this, options, def);
+        var name = next_mangled(this, options);
         if (!tricky_name || tricky_name != name)
             return name;
     }
@@ -507,8 +533,14 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     var lname = -1;
     var to_mangle = [];
 
+    var mangled_names = this.mangled_names = [];
     if (options.cache) {
         this.globals.each(collect);
+        if (options.cache.props) {
+            options.cache.props.each(function(mangled_name) {
+                push_uniq(mangled_names, mangled_name);
+            });
+        }
     }
 
     var tw = new TreeWalker(function(node, descend){
@@ -523,28 +555,23 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             node.variables.each(collect);
             return;
         }
+        if (node.is_block_scope()) {
+            node.block_scope.variables.each(collect);
+            return;
+        }
         if (node instanceof AST_Label) {
             var name;
             do name = base54(++lname); while (!is_identifier(name));
             node.mangled_name = name;
             return true;
         }
-        var mangle_with_block_scope =
-            (!options.ie8 && node instanceof AST_SymbolCatch) ||
-            node instanceof AST_SymbolBlockDeclaration;
-        if (mangle_with_block_scope && options.reserved.indexOf(node.name) < 0) {
+        if (!options.ie8 && node instanceof AST_SymbolCatch) {
             to_mangle.push(node.definition());
             return;
         }
     });
     this.walk(tw);
-    to_mangle.forEach(function(def){
-        def.mangle(options);
-    });
-
-    if (options.cache) {
-        options.cache.cname = this.cname;
-    }
+    to_mangle.forEach(function(def){ def.mangle(options) });
 
     function collect(symbol) {
         if (!member(symbol.name, options.reserved)) {
@@ -553,59 +580,55 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     }
 });
 
-AST_Toplevel.DEFMETHOD("find_unique_prefix", function(options) {
-    var letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_";
+AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
     var cache = options.cache && options.cache.props;
-    var prefixes = Object.create(null);
-    options.reserved.forEach(add_prefix);
+    var avoid = Object.create(null);
+    options.reserved.forEach(to_avoid);
     this.globals.each(add_def);
     this.walk(new TreeWalker(function(node) {
         if (node instanceof AST_Scope) node.variables.each(add_def);
         if (node instanceof AST_SymbolCatch) add_def(node.definition());
     }));
-    var prefix, i = 0;
-    do {
-        prefix = create_name(i++);
-    } while (prefixes[prefix]);
-    return prefix;
+    return avoid;
 
-    function add_prefix(name) {
-        if (/[0-9]$/.test(name)) {
-            prefixes[name.replace(/[0-9]+$/, "")] = true;
-        }
+    function to_avoid(name) {
+        avoid[name] = true;
     }
 
     function add_def(def) {
         var name = def.name;
         if (def.global && cache && cache.has(name)) name = cache.get(name);
         else if (!def.unmangleable(options)) return;
-        add_prefix(name);
-    }
-
-    function create_name(num) {
-        var name = "";
-        do {
-            name += letters[num % letters.length];
-            num = Math.floor(num / letters.length);
-        } while (num);
-        return name;
+        to_avoid(name);
     }
 });
 
 AST_Toplevel.DEFMETHOD("expand_names", function(options) {
+    base54.reset();
+    base54.sort();
     options = this._default_mangler_options(options);
-    var prefix = this.find_unique_prefix(options);
+    var avoid = this.find_colliding_names(options);
+    var cname = 0;
     this.globals.each(rename);
     this.walk(new TreeWalker(function(node) {
         if (node instanceof AST_Scope) node.variables.each(rename);
         if (node instanceof AST_SymbolCatch) rename(node.definition());
     }));
 
+    function next_name() {
+        var name;
+        do {
+            name = base54(cname++);
+        } while (avoid[name] || !is_identifier(name));
+        return name;
+    }
+
     function rename(def) {
-        if (def.global || def.unmangleable(options)) return;
+        if (def.global && options.cache) return;
+        if (def.unmangleable(options)) return;
         if (member(def.name, options.reserved)) return;
         var d = def.redefined();
-        def.name = d ? d.name : prefix + def.id;
+        def.name = d ? d.name : next_name();
         def.orig.forEach(function(sym) {
             sym.name = def.name;
         });

lib/transform.js

@@ -60,12 +60,9 @@ TreeTransformer.prototype = new TreeWalker;
             tw.push(this);
             if (tw.before) x = tw.before(this, descend, in_list);
             if (x === undefined) {
-                if (!tw.after) {
-                    x = this;
-                    descend(x, tw);
-                } else {
-                    tw.stack[tw.stack.length - 1] = x = this;
-                    descend(x, tw);
+                x = this;
+                descend(x, tw);
+                if (tw.after) {
                     y = tw.after(x, in_list);
                     if (y !== undefined) x = y;
                 }

lib/utils.js

@@ -43,10 +43,6 @@
 
 "use strict";
 
-function slice(a, start) {
-    return Array.prototype.slice.call(a, start || 0);
-};
-
 function characters(str) {
     return str.split("");
 };
@@ -214,18 +210,6 @@ function mergeSort(array, cmp) {
     return _ms(array);
 };
 
-function set_difference(a, b) {
-    return a.filter(function(el){
-        return b.indexOf(el) < 0;
-    });
-};
-
-function set_intersection(a, b) {
-    return a.filter(function(el){
-        return b.indexOf(el) >= 0;
-    });
-};
-
 // this function is taken from Acorn [1], written by Marijn Haverbeke
 // [1] https://github.com/marijnh/acorn
 function makePredicate(words) {
@@ -319,6 +303,13 @@ Dictionary.prototype = {
             ret.push(f(this._values[i], i.substr(1)));
         return ret;
     },
+    clone: function() {
+        var ret = new Dictionary();
+        for (var i in this._values)
+            ret._values[i] = this._values[i];
+        ret._size = this._size;
+        return ret;
+    },
     toObject: function() { return this._values }
 };
 Dictionary.fromObject = function(obj) {
@@ -340,7 +331,7 @@ function first_in_statement(stack) {
         if (p instanceof AST_Statement && p.body === node)
             return true;
         if ((p instanceof AST_Sequence      && p.expressions[0] === node) ||
-            (p instanceof AST_Call          && p.expression === node && !(p instanceof AST_New) ) ||
+            (p.TYPE == "Call"               && p.expression === node ) ||
             (p instanceof AST_Dot           && p.expression === node ) ||
             (p instanceof AST_Sub           && p.expression === node ) ||
             (p instanceof AST_Conditional   && p.condition === node  ) ||

package.json

@@ -4,17 +4,15 @@
   "homepage": "https://github.com/mishoo/UglifyJS2/tree/harmony",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.2.1",
+  "version": "3.3.10",
   "engines": {
     "node": ">=0.8.0"
   },
   "maintainers": [
+    "Alex Lam <alexlamsl@gmail.com>",
     "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)"
   ],
-  "repository": "git+https://github.com/mishoo/UglifyJS2.git#harmony",
-  "bugs": {
-    "url": "https://github.com/mishoo/UglifyJS2/issues"
-  },
+  "repository": "https://github.com/mishoo/UglifyJS2.git#harmony",
   "main": "tools/node.js",
   "bin": {
     "uglifyjs": "bin/uglifyjs"
@@ -26,13 +24,13 @@
     "LICENSE"
   ],
   "dependencies": {
-    "commander": "~2.12.1",
+    "commander": "~2.14.1",
     "source-map": "~0.6.1"
   },
   "devDependencies": {
-    "acorn": "~5.2.1",
+    "acorn": "~5.4.1",
     "mocha": "~3.5.1",
-    "semver": "~5.4.1"
+    "semver": "~5.5.0"
   },
   "scripts": {
     "test": "node test/run-tests.js"

test/benchmark.js

@@ -21,6 +21,7 @@ var urls = [
     "http://builds.emberjs.com/tags/v2.11.0/ember.prod.js",
     "https://cdn.jsdelivr.net/lodash/4.17.4/lodash.js",
     "https://cdnjs.cloudflare.com/ajax/libs/d3/4.5.0/d3.js",
+    "https://raw.githubusercontent.com/kangax/html-minifier/v3.5.7/dist/htmlminifier.js",
 ];
 var results = {};
 var remaining = 2 * urls.length;

test/compress/asm.js

@@ -16,7 +16,6 @@ asm_mixed: {
         hoist_vars    : true,
         if_return     : true,
         join_vars     : true,
-        cascade       : true,
         side_effects  : true,
         negate_iife   : true
     };

test/compress/block-scope.js

@@ -41,7 +41,7 @@ do_not_remove_anon_blocks_if_they_have_decls: {
                 var x;
             }
             {
-                const y;
+                const y = 1;
                 class Zee {};
             }
         }
@@ -59,7 +59,7 @@ do_not_remove_anon_blocks_if_they_have_decls: {
             }
             var x;
             {
-                const y;
+                const y = 1;
                 class Zee {}
             }
         }
@@ -77,12 +77,12 @@ remove_unused_in_global_block: {
     input: {
         {
             let x;
-            const y;
+            const y = 1;
             class Zee {};
             var w;
         }
         let ex;
-        const why;
+        const why = 2;
         class Zed {};
         var wut;
         console.log(x, y, Zee);
@@ -90,7 +90,7 @@ remove_unused_in_global_block: {
     expect: {
         var w;
         let ex;
-        const why;
+        const why = 2;
         class Zed {};
         var wut;
         console.log(x, y, Zee);

test/compress/blocks.js

@@ -75,6 +75,7 @@ issue_1664: {
     }
     expect_stdout: "1"
     node_version: ">=6"
+    reminify: false // FIXME - block scoped function
 }
 
 issue_1672_for: {

test/compress/comparing.js

@@ -112,3 +112,206 @@ self_comparison_2: {
     }
     expect_stdout: "false true"
 }
+
+issue_2857_1: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f1(a) {
+            a === undefined || a === null;
+            a === undefined || a !== null;
+            a !== undefined || a === null;
+            a !== undefined || a !== null;
+            a === undefined && a === null;
+            a === undefined && a !== null;
+            a !== undefined && a === null;
+            a !== undefined && a !== null;
+        }
+        function f2(a) {
+            a === null || a === undefined;
+            a === null || a !== undefined;
+            a !== null || a === undefined;
+            a !== null || a !== undefined;
+            a === null && a === undefined;
+            a === null && a !== undefined;
+            a !== null && a === undefined;
+            a !== null && a !== undefined;
+        }
+    }
+    expect: {
+        function f1(a) {
+            null == a;
+            void 0 === a || null !== a;
+            void 0 !== a || null === a;
+            void 0 !== a || null !== a;
+            void 0 === a && null === a;
+            void 0 === a && null !== a;
+            void 0 !== a && null === a;
+            null != a;
+        }
+        function f2(a) {
+            null == a;
+            null === a || void 0 !== a;
+            null !== a || void 0 === a;
+            null !== a || void 0 !== a;
+            null === a && void 0 === a;
+            null === a && void 0 !== a;
+            null !== a && void 0 === a;
+            null != a;
+        }
+    }
+}
+
+issue_2857_2: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            a === undefined || a === null || p;
+            a === undefined || a !== null || p;
+            a !== undefined || a === null || p;
+            a !== undefined || a !== null || p;
+            a === undefined && a === null || p;
+            a === undefined && a !== null || p;
+            a !== undefined && a === null || p;
+            a !== undefined && a !== null || p;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            null == a || p;
+            void 0 === a || null !== a || p;
+            void 0 !== a || null === a || p;
+            void 0 !== a || null !== a || p;
+            void 0 === a && null === a || p;
+            void 0 === a && null !== a || p;
+            void 0 !== a && null === a || p;
+            null != a || p;
+        }
+    }
+}
+
+issue_2857_3: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            a === undefined || a === null && p;
+            a === undefined || a !== null && p;
+            a !== undefined || a === null && p;
+            a !== undefined || a !== null && p;
+            a === undefined && a === null && p;
+            a === undefined && a !== null && p;
+            a !== undefined && a === null && p;
+            a !== undefined && a !== null && p;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            void 0 === a || null === a && p;
+            void 0 === a || null !== a && p;
+            void 0 !== a || null === a && p;
+            void 0 !== a || null !== a && p;
+            void 0 === a && null === a && p;
+            void 0 === a && null !== a && p;
+            void 0 !== a && null === a && p;
+            null != a && p;
+        }
+    }
+}
+
+issue_2857_4: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            p || a === undefined || a === null;
+            p || a === undefined || a !== null;
+            p || a !== undefined || a === null;
+            p || a !== undefined || a !== null;
+            p || a === undefined && a === null;
+            p || a === undefined && a !== null;
+            p || a !== undefined && a === null;
+            p || a !== undefined && a !== null;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            p || null == a;
+            p || void 0 === a || null !== a;
+            p || void 0 !== a || null === a;
+            p || void 0 !== a || null !== a;
+            p || void 0 === a && null === a;
+            p || void 0 === a && null !== a;
+            p || void 0 !== a && null === a;
+            p || null != a;
+        }
+    }
+}
+
+issue_2857_5: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            p && a === undefined || a === null;
+            p && a === undefined || a !== null;
+            p && a !== undefined || a === null;
+            p && a !== undefined || a !== null;
+            p && a === undefined && a === null;
+            p && a === undefined && a !== null;
+            p && a !== undefined && a === null;
+            p && a !== undefined && a !== null;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            p && void 0 === a || null === a;
+            p && void 0 === a || null !== a;
+            p && void 0 !== a || null === a;
+            p && void 0 !== a || null !== a;
+            p && void 0 === a && null === a;
+            p && void 0 === a && null !== a;
+            p && void 0 !== a && null === a;
+            p && null != a;
+        }
+    }
+}
+
+issue_2857_6: {
+    options = {
+        comparisons: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+    }
+    input: {
+        function f(a) {
+            if (({}).b === undefined || {}.b === null)
+                return a.b !== undefined && a.b !== null;
+        }
+        console.log(f({
+            a: [ null ],
+            get b() {
+                return this.a.shift();
+            }
+        }));
+    }
+    expect: {
+        function f(a) {
+            if (null == {}.b)
+                return void 0 !== a.b && null !== a.b;
+        }
+        console.log(f({
+            a: [ null ],
+            get b() {
+                return this.a.shift();
+            }
+        }));
+    }
+    expect_stdout: "true"
+}

test/compress/conditionals.js

@@ -166,22 +166,24 @@ cond_1: {
         conditionals: true
     };
     input: {
-        var do_something; // if undeclared it's assumed to have side-effects
-        if (some_condition()) {
-            do_something(x);
-        } else {
-            do_something(y);
-        }
-        if (some_condition()) {
-            side_effects(x);
-        } else {
-            side_effects(y);
+        function foo(do_something, some_condition) {
+            if (some_condition) {
+                do_something(x);
+            } else {
+                do_something(y);
+            }
+            if (some_condition) {
+                side_effects(x);
+            } else {
+                side_effects(y);
+            }
         }
     }
     expect: {
-        var do_something;
-        do_something(some_condition() ? x : y);
-        some_condition() ? side_effects(x) : side_effects(y);
+        function foo(do_something, some_condition) {
+            do_something(some_condition ? x : y);
+            some_condition ? side_effects(x) : side_effects(y);
+        }
     }
 }
 
@@ -190,16 +192,18 @@ cond_2: {
         conditionals: true
     };
     input: {
-        var x, FooBar;
-        if (some_condition()) {
-            x = new FooBar(1);
-        } else {
-            x = new FooBar(2);
+        function foo(x, FooBar, some_condition) {
+            if (some_condition) {
+                x = new FooBar(1);
+            } else {
+                x = new FooBar(2);
+            }
         }
     }
     expect: {
-        var x, FooBar;
-        x = new FooBar(some_condition() ? 1 : 2);
+        function foo(x, FooBar, some_condition) {
+            x = new FooBar(some_condition ? 1 : 2);
+        }
     }
 }
 
@@ -605,11 +609,47 @@ cond_8c: {
     }
 }
 
+cond_9: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function f(x, y) {
+            g() ? x(1) : x(2);
+            x ? (y || x)() : (y || x)();
+            x ? y(a, b) : y(d, b, c);
+            x ? y(a, b, c) : y(a, b, c);
+            x ? y(a, b, c) : y(a, b, f);
+            x ? y(a, b, c) : y(a, e, c);
+            x ? y(a, b, c) : y(a, e, f);
+            x ? y(a, b, c) : y(d, b, c);
+            x ? y(a, b, c) : y(d, b, f);
+            x ? y(a, b, c) : y(d, e, c);
+            x ? y(a, b, c) : y(d, e, f);
+        }
+    }
+    expect: {
+        function f(x, y) {
+            g() ? x(1) : x(2);
+            x, (y || x)();
+            x ? y(a, b) : y(d, b, c);
+            x, y(a, b, c);
+            y(a, b, x ? c : f);
+            y(a, x ? b : e, c);
+            x ? y(a, b, c) : y(a, e, f);
+            y(x ? a : d, b, c);
+            x ? y(a, b, c) : y(d, b, f);
+            x ? y(a, b, c) : y(d, e, c);
+            x ? y(a, b, c) : y(d, e, f);
+        }
+    }
+}
+
 ternary_boolean_consequent: {
     options = {
         collapse_vars:true, sequences:true, properties:true, dead_code:true, conditionals:true,
         comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
-        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+        keep_fargs:true, if_return:true, join_vars:true, side_effects:true
     }
     input: {
         function f1() { return a == b ? true : x; }
@@ -637,7 +677,7 @@ ternary_boolean_alternative: {
     options = {
         collapse_vars:true, sequences:true, properties:true, dead_code:true, conditionals:true,
         comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
-        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+        keep_fargs:true, if_return:true, join_vars:true, side_effects:true
     }
     input: {
         function f1() { return a == b ? x : true; }
@@ -1115,3 +1155,115 @@ issue_2535_2: {
         "false",
     ]
 }
+
+issue_2560: {
+    options = {
+        conditionals: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function log(x) {
+            console.log(x);
+        }
+        function foo() {
+            return log;
+        }
+        function bar() {
+            if (x !== (x = foo())) {
+                x(1);
+            } else {
+                x(2);
+            }
+        }
+        var x = function() {
+            console.log("init");
+        };
+        bar();
+        bar();
+    }
+    expect: {
+        function log(x) {
+            console.log(x);
+        }
+        function bar() {
+            x !== (x = log) ? x(1) : x(2);
+        }
+        var x = function() {
+            console.log("init");
+        };
+        bar();
+        bar();
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+hoist_decl: {
+    options = {
+        conditionals: true,
+        join_vars: true,
+        sequences: true,
+    }
+    input: {
+        if (x()) {
+            var a;
+            y();
+        } else {
+            z();
+            var b;
+        }
+    }
+    expect: {
+        var a, b;
+        x() ? y() : z();
+    }
+}
+
+to_and_or: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var values = [
+            0,
+            null,
+            true,
+            "foo",
+            false,
+            -1 / 0,
+            void 0,
+        ];
+        values.forEach(function(x) {
+            values.forEach(function(y) {
+                values.forEach(function(z) {
+                    console.log(x ? y || z : z);
+                });
+            });
+        });
+    }
+    expect: {
+        var values = [
+            0,
+            null,
+            true,
+            "foo",
+            false,
+            -1 / 0,
+            void 0,
+        ];
+        values.forEach(function(x) {
+            values.forEach(function(y) {
+                values.forEach(function(z) {
+                    console.log(x && y || z);
+                });
+            });
+        });
+    }
+    expect_stdout: true
+}

test/compress/dead-code.js

@@ -60,6 +60,7 @@ dead_code_2_should_warn: {
     }
     expect_stdout: true
     node_version: ">=6"
+    reminify: false // FIXME - block scoped function
 }
 
 dead_code_2_should_warn_strict: {
@@ -100,6 +101,7 @@ dead_code_2_should_warn_strict: {
     }
     expect_stdout: true
     node_version: ">=4"
+    reminify: false // FIXME - block scoped function
 }
 
 dead_code_constant_boolean_should_warn_more: {
@@ -135,6 +137,7 @@ dead_code_constant_boolean_should_warn_more: {
     }
     expect_stdout: true
     node_version: ">=6"
+    reminify: false // FIXME - block scoped function
 }
 
 dead_code_constant_boolean_should_warn_more_strict: {
@@ -171,6 +174,7 @@ dead_code_constant_boolean_should_warn_more_strict: {
     }
     expect_stdout: true
     node_version: ">=4"
+    reminify: false // FIXME - block scoped function
 }
 
 dead_code_block_decls_die: {
@@ -636,3 +640,579 @@ issue_2383_3: {
     expect_stdout: "undefined undefined 8 undefined 7"
     node_version: ">=6"
 }
+
+collapse_vars_assignment: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        passes: 2,
+        unused: true,
+    }
+    input: {
+        function f0(c) {
+            var a = 3 / c;
+            return a = a;
+        }
+    }
+    expect: {
+        function f0(c) {
+            return 3 / c;
+        }
+    }
+}
+
+collapse_vars_lvalues_drop_assign: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        unused: true,
+    }
+    input: {
+        function f0(x) { var i = ++x; return x += i; }
+        function f1(x) { var a = (x -= 3); return x += a; }
+        function f2(x) { var z = x, a = ++z; return z += a; }
+    }
+    expect: {
+        function f0(x) { var i = ++x; return x + i; }
+        function f1(x) { var a = (x -= 3); return x + a; }
+        function f2(x) { var z = x, a = ++z; return z + a; }
+    }
+}
+
+collapse_vars_misc1: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        unused: true,
+    }
+    input: {
+        function f10(x) { var a = 5, b = 3; return a += b; }
+        function f11(x) { var a = 5, b = 3; return a += --b; }
+    }
+    expect: {
+        function f10(x) { return 5 + 3; }
+        function f11(x) { var b = 3; return 5 + --b; }
+    }
+}
+
+return_assignment: {
+    options = {
+        dead_code: true,
+        unused: true,
+    }
+    input: {
+        function f1(a, b, c) {
+            return a = x(), b = y(), b = a && (c >>= 5);
+        }
+        function f2() {
+            return e = x();
+        }
+        function f3(e) {
+            return e = x();
+        }
+        function f4() {
+            var e;
+            return e = x();
+        }
+        function f5(a) {
+            try {
+                return a = x();
+            } catch (b) {
+                console.log(a);
+            }
+        }
+        function f6(a) {
+            try {
+                return a = x();
+            } finally {
+                console.log(a);
+            }
+        }
+        function y() {
+            console.log("y");
+        }
+        function test(inc) {
+            var counter = 0;
+            x = function() {
+                counter += inc;
+                if (inc < 0) throw counter;
+                return counter;
+            };
+            [ f1, f2, f3, f4, f5, f6 ].forEach(function(f, i) {
+                e = null;
+                try {
+                    i += 1;
+                    console.log("result " + f(10 * i, 100 * i, 1000 * i));
+                } catch (x) {
+                    console.log("caught " + x);
+                }
+                if (null !== e) console.log("e: " + e);
+            });
+        }
+        var x, e;
+        test(1);
+        test(-1);
+    }
+    expect: {
+        function f1(a, b, c) {
+            return a = x(), y(), a && (c >> 5);
+        }
+        function f2() {
+            return e = x();
+        }
+        function f3(e) {
+            return x();
+        }
+        function f4() {
+            return x();
+        }
+        function f5(a) {
+            try {
+                return x();
+            } catch (b) {
+                console.log(a);
+            }
+        }
+        function f6(a) {
+            try {
+                return a = x();
+            } finally {
+                console.log(a);
+            }
+        }
+        function y() {
+            console.log("y");
+        }
+        function test(inc) {
+            var counter = 0;
+            x = function() {
+                counter += inc;
+                if (inc < 0) throw counter;
+                return counter;
+            };
+            [ f1, f2, f3, f4, f5, f6 ].forEach(function(f, i) {
+                e = null;
+                try {
+                    i += 1;
+                    console.log("result " + f(10 * i, 100 * i, 1000 * i));
+                } catch (x) {
+                    console.log("caught " + x);
+                }
+                if (null !== e) console.log("e: " + e);
+            });
+        }
+        var x, e;
+        test(1);
+        test(-1);
+    }
+    expect_stdout: [
+        "y",
+        "result 31",
+        "result 2",
+        "e: 2",
+        "result 3",
+        "result 4",
+        "result 5",
+        "6",
+        "result 6",
+        "caught -1",
+        "caught -2",
+        "caught -3",
+        "caught -4",
+        "50",
+        "result undefined",
+        "60",
+        "caught -6",
+    ]
+}
+
+throw_assignment: {
+    options = {
+        dead_code: true,
+        unused: true,
+    }
+    input: {
+        function f1() {
+            throw a = x();
+        }
+        function f2(a) {
+            throw a = x();
+        }
+        function f3() {
+            var a;
+            throw a = x();
+        }
+        function f4() {
+            try {
+                throw a = x();
+            } catch (b) {
+                console.log(a);
+            }
+        }
+        function f5(a) {
+            try {
+                throw a = x();
+            } catch (b) {
+                console.log(a);
+            }
+        }
+        function f6() {
+            var a;
+            try {
+                throw a = x();
+            } catch (b) {
+                console.log(a);
+            }
+        }
+        function f7() {
+            try {
+                throw a = x();
+            } finally {
+                console.log(a);
+            }
+        }
+        function f8(a) {
+            try {
+                throw a = x();
+            } finally {
+                console.log(a);
+            }
+        }
+        function f9() {
+            var a;
+            try {
+                throw a = x();
+            } finally {
+                console.log(a);
+            }
+        }
+        function test(inc) {
+            var counter = 0;
+            x = function() {
+                counter += inc;
+                if (inc < 0) throw counter;
+                return counter;
+            };
+            [ f1, f2, f3, f4, f5, f6, f7, f8, f9 ].forEach(function(f, i) {
+                a = null;
+                try {
+                    f(10 * (1 + i));
+                } catch (x) {
+                    console.log("caught " + x);
+                }
+                if (null !== a) console.log("a: " + a);
+            });
+        }
+        var x, a;
+        test(1);
+        test(-1);
+    }
+    expect: {
+        function f1() {
+            throw a = x();
+        }
+        function f2(a) {
+            throw x();
+        }
+        function f3() {
+            throw x();
+        }
+        function f4() {
+            try {
+                throw a = x();
+            } catch (b) {
+                console.log(a);
+            }
+        }
+        function f5(a) {
+            try {
+                throw a = x();
+            } catch (b) {
+                console.log(a);
+            }
+        }
+        function f6() {
+            var a;
+            try {
+                throw a = x();
+            } catch (b) {
+                console.log(a);
+            }
+        }
+        function f7() {
+            try {
+                throw a = x();
+            } finally {
+                console.log(a);
+            }
+        }
+        function f8(a) {
+            try {
+                throw a = x();
+            } finally {
+                console.log(a);
+            }
+        }
+        function f9() {
+            var a;
+            try {
+                throw a = x();
+            } finally {
+                console.log(a);
+            }
+        }
+        function test(inc) {
+            var counter = 0;
+            x = function() {
+                counter += inc;
+                if (inc < 0) throw counter;
+                return counter;
+            };
+            [ f1, f2, f3, f4, f5, f6, f7, f8, f9 ].forEach(function(f, i) {
+                a = null;
+                try {
+                    f(10 * (1 + i));
+                } catch (x) {
+                    console.log("caught " + x);
+                }
+                if (null !== a) console.log("a: " + a);
+            });
+        }
+        var x, a;
+        test(1);
+        test(-1);
+    }
+    expect_stdout: [
+        "caught 1",
+        "a: 1",
+        "caught 2",
+        "caught 3",
+        "4",
+        "a: 4",
+        "5",
+        "6",
+        "7",
+        "caught 7",
+        "a: 7",
+        "8",
+        "caught 8",
+        "9",
+        "caught 9",
+        "caught -1",
+        "caught -2",
+        "caught -3",
+        "null",
+        "50",
+        "undefined",
+        "null",
+        "caught -7",
+        "80",
+        "caught -8",
+        "undefined",
+        "caught -9",
+    ]
+}
+
+issue_2597: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        function f(b) {
+            try {
+                try {
+                    throw "foo";
+                } catch (e) {
+                    return b = true;
+                }
+            } finally {
+                b && (a = "PASS");
+            }
+        }
+        var a = "FAIL";
+        f();
+        console.log(a);
+    }
+    expect: {
+        function f(b) {
+            try {
+                try {
+                    throw "foo";
+                } catch (e) {
+                    return b = true;
+                }
+            } finally {
+                b && (a = "PASS");
+            }
+        }
+        var a = "FAIL";
+        f();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2666: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        function f(a) {
+            return a = {
+                p: function() {
+                    return a;
+                }
+            };
+        }
+        console.log(typeof f().p());
+    }
+    expect: {
+        function f(a) {
+            return a = {
+                p: function() {
+                    return a;
+                }
+            };
+        }
+        console.log(typeof f().p());
+    }
+    expect_stdout: "object"
+}
+
+issue_2692: {
+    options = {
+        dead_code: true,
+        reduce_vars: false,
+    }
+    input: {
+        function f(a) {
+            return a = g;
+            function g() {
+                return a;
+            }
+        }
+        console.log(typeof f()());
+    }
+    expect: {
+        function f(a) {
+            return a = g;
+            function g() {
+                return a;
+            }
+        }
+        console.log(typeof f()());
+    }
+    expect_stdout: "function"
+}
+
+issue_2701: {
+    options = {
+        dead_code: true,
+        inline: false,
+    }
+    input: {
+        function f(a) {
+            return a = function() {
+                return function() {
+                    return a;
+                };
+            }();
+        }
+        console.log(typeof f()());
+    }
+    expect: {
+        function f(a) {
+            return a = function() {
+                return function() {
+                    return a;
+                };
+            }();
+        }
+        console.log(typeof f()());
+    }
+    expect_stdout: "function"
+}
+
+issue_2749: {
+    options = {
+        dead_code: true,
+        inline: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 2, c = "PASS";
+        while (a--)
+            (function() {
+                return b ? c = "FAIL" : b = 1;
+                try {
+                } catch (b) {
+                    var b;
+                }
+            })();
+        console.log(c);
+    }
+    expect: {
+        var a = 2, c = "PASS";
+        while (a--)
+            b = void 0, b ? c = "FAIL" : b = 1;
+        var b;
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
+unsafe_builtin: {
+    options = {
+        side_effects: true,
+        unsafe: true,
+    }
+    input: {
+        (!w).constructor(x);
+        Math.abs(y);
+        [ 1, 2, z ].valueOf();
+    }
+    expect: {
+        w, x;
+        y;
+        z;
+    }
+}
+
+issue_2860_1: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a ^= 1;
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            return 1 ^ a;
+        }());
+    }
+    expect_stdout: "1"
+}
+
+issue_2860_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a ^= 1;
+        }());
+    }
+    expect: {
+        console.log(1);
+    }
+    expect_stdout: "1"
+}

test/compress/destructuring.js

@@ -439,6 +439,39 @@ mangle_destructuring_decl: {
     node_version: ">=6"
 }
 
+mangle_destructuring_decl_collapse_vars: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        unused: true,
+    }
+    mangle = {
+    }
+    input: {
+        function test(opts) {
+            let a = opts.a || { e: 7, n: 8 };
+            let { t, e, n, s =  5 + 4, o, r } = a;
+            console.log(t, e, n, s, o, r);
+        }
+        test({a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 }});
+        test({});
+    }
+    expect: {
+        function test(t) {
+            let e = t.a || { e: 7, n: 8 };
+            let {t: n,  e: o,  n: s,  s: l = 9,  o: a,  r: c} = e;
+            console.log(n, o, s, l, a, c);
+        }
+        test({ a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 } });
+        test({});
+    }
+    expect_stdout: [
+        "1 2 3 4 5 6",
+        "undefined 7 8 9 undefined undefined",
+    ]
+    node_version: ">=6"
+}
+
 mangle_destructuring_assign_toplevel_true: {
     options = {
         toplevel: true,

test/compress/drop-unused.js

@@ -215,7 +215,7 @@ unused_block_decls: {
     input: {
         function foo() {
             {
-                const x;
+                const x = 1;
             }
             {
                 let y;
@@ -260,7 +260,9 @@ keep_fnames: {
 }
 
 drop_assign: {
-    options = { unused: true };
+    options = {
+        unused: true,
+    }
     input: {
         function f1() {
             var a;
@@ -281,7 +283,7 @@ drop_assign: {
             var a;
             return function() {
                 a = 1;
-            }
+            };
         }
     }
     expect: {
@@ -298,16 +300,17 @@ drop_assign: {
             return 1;
         }
         function f5() {
-            var a;
             return function() {
-                a = 1;
-            }
+                1;
+            };
         }
     }
 }
 
 keep_assign: {
-    options = { unused: "keep_assign" };
+    options = {
+        unused: "keep_assign",
+    }
     input: {
         function f1() {
             var a;
@@ -328,7 +331,7 @@ keep_assign: {
             var a;
             return function() {
                 a = 1;
-            }
+            };
         }
     }
     expect: {
@@ -351,19 +354,22 @@ keep_assign: {
             var a;
             return function() {
                 a = 1;
-            }
+            };
         }
     }
 }
 
 drop_toplevel_funcs: {
-    options = { toplevel: "funcs", unused: true };
+    options = {
+        toplevel: "funcs",
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -379,13 +385,16 @@ drop_toplevel_funcs: {
 }
 
 drop_toplevel_vars: {
-    options = { toplevel: "vars", unused: true };
+    options = {
+        toplevel: "vars",
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -393,11 +402,10 @@ drop_toplevel_vars: {
         console.log(b = 3);
     }
     expect: {
-        var c = g;
         function f(d) {
             return function() {
-                c = 2;
-            }
+                2;
+            };
         }
         2;
         function g() {}
@@ -407,13 +415,17 @@ drop_toplevel_vars: {
 }
 
 drop_toplevel_vars_fargs: {
-    options = { keep_fargs: false, toplevel: "vars", unused: true };
+    options = {
+        keep_fargs: false,
+        toplevel: "vars",
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -421,11 +433,10 @@ drop_toplevel_vars_fargs: {
         console.log(b = 3);
     }
     expect: {
-        var c = g;
         function f() {
             return function() {
-                c = 2;
-            }
+                2;
+            };
         }
         2;
         function g() {}
@@ -435,13 +446,16 @@ drop_toplevel_vars_fargs: {
 }
 
 drop_toplevel_all: {
-    options = { toplevel: true, unused: true };
+    options = {
+        toplevel: true,
+        unused: true
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -455,13 +469,16 @@ drop_toplevel_all: {
 }
 
 drop_toplevel_retain: {
-    options = { top_retain: "f,a,o", unused: true };
+    options = {
+        top_retain: "f,a,o",
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -469,26 +486,28 @@ drop_toplevel_retain: {
         console.log(b = 3);
     }
     expect: {
-        var a, c = g;
+        var a;
         function f(d) {
             return function() {
-                c = 2;
-            }
+                2;
+            };
         }
         a = 2;
-        function g() {}
         console.log(3);
     }
 }
 
 drop_toplevel_retain_array: {
-    options = { top_retain: [ "f", "a", "o" ], unused: true };
+    options = {
+        top_retain: [ "f", "a", "o" ],
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -496,26 +515,28 @@ drop_toplevel_retain_array: {
         console.log(b = 3);
     }
     expect: {
-        var a, c = g;
+        var a;
         function f(d) {
             return function() {
-                c = 2;
-            }
+                2;
+            };
         }
         a = 2;
-        function g() {}
         console.log(3);
     }
 }
 
 drop_toplevel_retain_regex: {
-    options = { top_retain: /^[fao]$/, unused: true };
+    options = {
+        top_retain: /^[fao]$/,
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -523,26 +544,29 @@ drop_toplevel_retain_regex: {
         console.log(b = 3);
     }
     expect: {
-        var a, c = g;
+        var a;
         function f(d) {
             return function() {
-                c = 2;
-            }
+                2;
+            };
         }
         a = 2;
-        function g() {}
         console.log(3);
     }
 }
 
 drop_toplevel_all_retain: {
-    options = { toplevel: true, top_retain: "f,a,o", unused: true };
+    options = {
+        toplevel: true,
+        top_retain: "f,a,o",
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -550,26 +574,29 @@ drop_toplevel_all_retain: {
         console.log(b = 3);
     }
     expect: {
-        var a, c = g;
+        var a;
         function f(d) {
             return function() {
-                c = 2;
-            }
+                2;
+            };
         }
         a = 2;
-        function g() {}
         console.log(3);
     }
 }
 
 drop_toplevel_funcs_retain: {
-    options = { toplevel: "funcs", top_retain: "f,a,o", unused: true };
+    options = {
+        toplevel: "funcs",
+        top_retain: "f,a,o",
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -581,7 +608,7 @@ drop_toplevel_funcs_retain: {
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -590,13 +617,17 @@ drop_toplevel_funcs_retain: {
 }
 
 drop_toplevel_vars_retain: {
-    options = { toplevel: "vars", top_retain: "f,a,o", unused: true };
+    options = {
+        toplevel: "vars",
+        top_retain: "f,a,o",
+        unused: true,
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -604,11 +635,11 @@ drop_toplevel_vars_retain: {
         console.log(b = 3);
     }
     expect: {
-        var a, c = g;
+        var a;
         function f(d) {
             return function() {
-                c = 2;
-            }
+                2;
+            };
         }
         a = 2;
         function g() {}
@@ -618,13 +649,16 @@ drop_toplevel_vars_retain: {
 }
 
 drop_toplevel_keep_assign: {
-    options = { toplevel: true, unused: "keep_assign" };
+    options = {
+        toplevel: true,
+        unused: "keep_assign",
+    }
     input: {
         var a, b = 1, c = g;
         function f(d) {
             return function() {
                 c = 2;
-            }
+            };
         }
         a = 2;
         function g() {}
@@ -764,7 +798,7 @@ const_assign: {
 
 issue_1539: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         sequences: true,
         side_effects: true,
         unused: true,
@@ -811,7 +845,7 @@ vardef_value: {
 
 assign_binding: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         side_effects: true,
         unused: true,
     }
@@ -866,11 +900,11 @@ issue_1583: {
     expect: {
         function m(t) {
             (function(e) {
-                t = function() {
+                (function() {
                     return (function(a) {
                         return function(a) {};
                     })();
-                }();
+                })();
             })();
         }
     }
@@ -1203,6 +1237,7 @@ var_catch_toplevel: {
     options = {
         conditionals: true,
         negate_iife: true,
+        passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
         side_effects: true,
@@ -1235,7 +1270,7 @@ var_catch_toplevel: {
 
 reassign_const: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         sequences: true,
         side_effects: true,
         unused: true,
@@ -1514,7 +1549,7 @@ issue_2226_1: {
 
 issue_2226_2: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         sequences: true,
         side_effects: true,
         unused: true,
@@ -1527,8 +1562,8 @@ issue_2226_2: {
     }
     expect: {
         console.log(function(a, b) {
-            return a += b;
-        }(1, 2));
+            return a += 2;
+        }(1));
     }
     expect_stdout: "3"
 }
@@ -1752,3 +1787,309 @@ issue_2418_5: {
         (function f() {});
     }
 }
+
+defun_lambda_same_name: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(n) {
+            return n ? n * f(n - 1) : 1;
+        }
+        console.log(function f(n) {
+            return n ? n * f(n - 1) : 1;
+        }(5));
+    }
+    expect: {
+        console.log(function f(n) {
+            return n ? n * f(n - 1) : 1;
+        }(5));
+    }
+    expect_stdout: "120"
+}
+
+issue_2660_1: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 2;
+        function f(b) {
+            return b && f() || a--;
+        }
+        f(1);
+        console.log(a);
+    }
+    expect: {
+        var a = 2;
+        (function f(b) {
+            return b && f() || a--;
+        })(1);
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+issue_2660_2: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        function f(b) {
+            b && f();
+            --a, a.toString();
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        (function f(b) {
+            b && f(),
+            (--a).toString();
+        })(),
+        console.log(a);
+    }
+    expect_stdout: "0"
+}
+
+issue_2665: {
+    options = {
+        evaluate: true,
+        inline: true,
+        keep_fargs: false,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        typeofs: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        function g() {
+            a-- && g();
+        }
+        typeof h == "function" && h();
+        function h() {
+            typeof g == "function" && g();
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        !function g() {
+            a-- && g();
+        }();
+        console.log(a);
+    }
+    expect_stdout: "-1"
+}
+
+double_assign_1: {
+    options = {
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f1() {
+            var a = {};
+            var a = [];
+            return a;
+        }
+        function f2() {
+            var a = {};
+            a = [];
+            return a;
+        }
+        function f3() {
+            a = {};
+            var a = [];
+            return a;
+        }
+        function f4(a) {
+            a = {};
+            a = [];
+            return a;
+        }
+        function f5(a) {
+            var a = {};
+            a = [];
+            return a;
+        }
+        function f6(a) {
+            a = {};
+            var a = [];
+            return a;
+        }
+        console.log(f1(), f2(), f3(), f4(), f5(), f6());
+    }
+    expect: {
+        function f1() {
+            return [];
+        }
+        function f2() {
+            var a;
+            a = [];
+            return a;
+        }
+        function f3() {
+            return [];
+        }
+        function f4(a) {
+            a = [];
+            return a;
+        }
+        function f5(a) {
+            a = [];
+            return a;
+        }
+        function f6(a) {
+            a = [];
+            return a;
+        }
+        console.log(f1(), f2(), f3(), f4(), f5(), f6());
+    }
+    expect_stdout: true
+}
+
+double_assign_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        for (var i = 0; i < 2; i++)
+            a = void 0, a = {}, console.log(a);
+        var a;
+    }
+    expect: {
+        for (var i = 0; i < 2; i++)
+            void 0, a = {}, console.log(a);
+        var a;
+    }
+}
+
+double_assign_3: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        for (var i = 0; i < 2; i++)
+            a = void 0, a = { a: a }, console.log(a);
+        var a;
+    }
+    expect: {
+        for (var i = 0; i < 2; i++)
+            a = void 0, a = { a: a }, console.log(a);
+        var a;
+    }
+}
+
+cascade_drop_assign: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, b = a = "PASS";
+        console.log(b);
+    }
+    expect: {
+        var b = "PASS";
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+chained_3: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a, b) {
+            var c = a, c = b;
+            b++;
+            return c;
+        }(1, 2));
+    }
+    expect: {
+        console.log(function(a, b) {
+            var c = b;
+            b++;
+            return c;
+        }(0, 2));
+    }
+    expect_stdout: "2"
+}
+
+issue_2768: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL", c = 1;
+        var c = function(b) {
+            var d = b = a;
+            var e = --b + (d && (a = "PASS"));
+        }();
+        console.log(a, typeof c);
+    }
+    expect: {
+        var a = "FAIL";
+        var c = (d = a, 0, void (d && (a = "PASS")));
+        var d;
+        console.log(a, typeof c);
+    }
+    expect_stdout: "PASS undefined"
+}
+
+issue_2846: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            var a = 0;
+            b && b(a);
+            return a++;
+        }
+        var c = f();
+        console.log(c);
+    }
+    expect: {
+        var c = function(a, b) {
+            a = 0;
+            b && b(a);
+            return a++;
+        }();
+        console.log(c);
+    }
+    expect_stdout: "0"
+}

test/compress/evaluate.js

@@ -1287,6 +1287,9 @@ issue_2231_1: {
         console.log(Object.keys(void 0));
     }
     expect_stdout: true
+    expect_warnings: [
+        "WARN: Error evaluating Object.keys(void 0) [test/compress/evaluate.js:1284,20]",
+    ]
 }
 
 issue_2231_2: {
@@ -1301,6 +1304,23 @@ issue_2231_2: {
         console.log(Object.getOwnPropertyNames(null));
     }
     expect_stdout: true
+    expect_warnings: [
+        "WARN: Error evaluating Object.getOwnPropertyNames(null) [test/compress/evaluate.js:1301,20]",
+    ]
+}
+
+issue_2231_3: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(Object.keys({ foo: "bar" })[0]);
+    }
+    expect: {
+        console.log("foo");
+    }
+    expect_stdout: "foo"
 }
 
 self_comparison_1: {
@@ -1423,13 +1443,82 @@ issue_2535_3: {
     }
     expect_stdout: true
     expect_warnings: [
-        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1409,20]",
-        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1410,20]",
-        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1411,20]",
-        "WARN: Condition left of && always false [test/compress/evaluate.js:1411,20]",
-        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1412,20]",
-        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1413,20]",
-        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1414,20]",
-        "WARN: Condition left of || always true [test/compress/evaluate.js:1414,20]",
+        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1429,20]",
+        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1430,20]",
+        "WARN: Dropping side-effect-free && [test/compress/evaluate.js:1431,20]",
+        "WARN: Condition left of && always false [test/compress/evaluate.js:1431,20]",
+        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1432,20]",
+        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1433,20]",
+        "WARN: Dropping side-effect-free || [test/compress/evaluate.js:1434,20]",
+        "WARN: Condition left of || always true [test/compress/evaluate.js:1434,20]",
+    ]
+}
+
+issue_2822: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log([ function() {}, "PASS", "FAIL" ][1]);
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+string_case: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log("İ".toLowerCase().charCodeAt(0));
+        console.log("I".toLowerCase().charCodeAt(0));
+        console.log("Ş".toLowerCase().charCodeAt(0));
+        console.log("Ğ".toLowerCase().charCodeAt(0));
+        console.log("Ü".toLowerCase().charCodeAt(0));
+        console.log("Ö".toLowerCase().charCodeAt(0));
+        console.log("Ç".toLowerCase().charCodeAt(0));
+        console.log("i".toUpperCase().charCodeAt(0));
+        console.log("ı".toUpperCase().charCodeAt(0));
+        console.log("ş".toUpperCase().charCodeAt(0));
+        console.log("ğ".toUpperCase().charCodeAt(0));
+        console.log("ü".toUpperCase().charCodeAt(0));
+        console.log("ö".toUpperCase().charCodeAt(0));
+        console.log("ç".toUpperCase().charCodeAt(0));
+    }
+    expect: {
+        console.log(105);
+        console.log(105);
+        console.log(351);
+        console.log(287);
+        console.log(252);
+        console.log(246);
+        console.log(231);
+        console.log(73);
+        console.log(73);
+        console.log(350);
+        console.log(286);
+        console.log(220);
+        console.log(214);
+        console.log(199);
+    }
+    expect_stdout: [
+        "105",
+        "105",
+        "351",
+        "287",
+        "252",
+        "246",
+        "231",
+        "73",
+        "73",
+        "350",
+        "286",
+        "220",
+        "214",
+        "199",
     ]
 }

test/compress/expansions.js

@@ -36,19 +36,19 @@ avoid_spread_in_ternary: {
         function print(...x) {
             console.log(...x);
         }
-        var a = [1, 2], b = [3, 4];
+        var a = [1, 2], b = [3, 4], m = Math;
 
-        if (Math)
+        if (m)
             print(a);
         else
             print(b);
 
-        if (Math)
+        if (m)
             print(...a);
         else
             print(b);
 
-        if (Math.no_such_property)
+        if (m.no_such_property)
             print(a);
         else
             print(...b);
@@ -57,10 +57,10 @@ avoid_spread_in_ternary: {
         function print(...x) {
             console.log(...x);
         }
-        var a = [ 1, 2 ], b = [ 3, 4 ];
-        print(Math ? a : b);
-        Math ? print(...a) : print(b);
-        Math.no_such_property ? print(a) : print(...b);
+        var a = [ 1, 2 ], b = [ 3, 4 ], m = Math;
+        print(m ? a : b);
+        m ? print(...a) : print(b);
+        m.no_such_property ? print(a) : print(...b);
     }
     expect_stdout: [
         "[ 1, 2 ]",

test/compress/export.js

@@ -262,3 +262,185 @@ trailing_comma: {
     }
     expect_exact: "export const a = 1;"
 }
+
+export_default_anonymous_function: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function () {
+            foo();
+        }
+    }
+    expect_exact: "export default function(){foo()};"
+}
+
+export_default_arrow: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default () => foo();
+    }
+    expect_exact: "export default()=>foo();"
+}
+
+export_default_anonymous_generator: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function * () {
+            yield foo();
+        }
+    }
+    expect_exact: "export default function*(){yield foo()};"
+}
+
+export_default_anonymous_async_function: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default async function() {
+            return await foo();
+        }
+    }
+    expect_exact: "export default async function(){return await foo()};"
+}
+
+export_default_async_arrow_function: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default async () => await foo();
+    }
+    expect_exact: "export default async()=>await foo();"
+}
+
+export_default_named_generator: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function * gen() {
+            yield foo();
+        }
+    }
+    expect_exact: "export default function*gen(){yield foo()};"
+}
+
+export_default_named_async_function: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default async function bar() {
+            return await foo();
+        }
+    }
+    expect_exact: "export default async function bar(){return await foo()};"
+}
+
+export_default_anonymous_class: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default class {
+            constructor() {
+                foo();
+            }
+        };
+    }
+    expect_exact: "export default class{constructor(){foo()}};"
+}
+
+export_default_anonymous_function_not_call: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function(){}(foo);
+    }
+    // FIXME: should be `export default function(){};foo;`
+    expect_exact: "export default function(){}(foo);"
+}
+
+export_default_anonymous_generator_not_call: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function*(){}(foo);
+    }
+    // agrees with `acorn` and `babylon 7`
+    expect_exact: "export default function*(){};foo;"
+}
+
+export_default_anonymous_async_function_not_call: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default async function(){}(foo);
+    }
+    // agrees with `acorn` and `babylon 7`
+    expect_exact: "export default async function(){};foo;"
+}

test/compress/harmony.js

@@ -1153,3 +1153,451 @@ array_literal_with_spread_4: {
     ]
     node_version: ">=6"
 }
+
+object_literal_method_using_arguments: {
+    options = {
+        arrows: true,
+    }
+    input: {
+        console.log(({
+            m() {
+                return arguments[0];
+            }
+        }).m("PASS"));
+    }
+    expect: {
+        console.log(({
+            m() {
+                return arguments[0];
+            }
+        }).m("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+class_method_using_arguments: {
+    options = {
+        arrows: true,
+    }
+    input: {
+        console.log(new class {
+            m() {
+                return arguments[0];
+            }
+        }().m("PASS"));
+    }
+    expect: {
+        console.log(new class {
+            m() {
+                return arguments[0];
+            }
+        }().m("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_2676: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        class A {}
+        A.a = 42;
+    }
+    expect: {
+        (class {}).a = 42;
+    }
+}
+
+issue_2762: {
+    mangle = {}
+    input: {
+        var bar = 1, T = true;
+        (function() {
+            if (T) {
+                const a = function() {
+                    var foo = bar;
+                    console.log(foo, a.prop, b.prop);
+                };
+                a.prop = 2;
+                const b = { prop: 3 };
+                a();
+            }
+        })();
+    }
+    expect: {
+        var bar = 1, T = true;
+        (function() {
+            if (T) {
+                const o = function() {
+                    var p = bar;
+                    console.log(p, o.prop, r.prop);
+                };
+                o.prop = 2;
+                const r = { prop: 3 };
+                o();
+            }
+        })();
+    }
+    expect_stdout: "1 2 3"
+}
+
+issue_2794_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        passes: 1,
+        properties: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            for (const a of func(value)) {
+                console.log(a);
+            }
+            function func(va) {
+                return doSomething(va);
+            }
+        }
+        function doSomething(x) {
+            return [ x, 2 * x, 3 * x ];
+        }
+        const value = 10;
+        foo();
+    }
+    expect: {
+        function foo() {
+            for (const a of doSomething(value)) console.log(a);
+        }
+        function doSomething(x) {
+            return [ x, 2 * x, 3 * x ];
+        }
+        const value = 10;
+        foo();
+    }
+    expect_stdout: [
+        "10",
+        "20",
+        "30",
+    ]
+    node_version: ">=6"
+}
+
+issue_2794_2: {
+    mangle = {
+        toplevel: false,
+    }
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        passes: 1,
+        properties: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            for (const a of func(value)) {
+                console.log(a);
+            }
+            function func(va) {
+                return doSomething(va);
+            }
+        }
+        function doSomething(x) {
+            return [ x, 2 * x, 3 * x ];
+        }
+        const value = 10;
+        foo();
+    }
+    expect: {
+        function foo() {
+            for (const o of doSomething(value)) console.log(o);
+        }
+        function doSomething(o) {
+            return [ o, 2 * o, 3 * o ];
+        }
+        const value = 10;
+        foo();
+    }
+    expect_stdout: [
+        "10",
+        "20",
+        "30",
+    ]
+    node_version: ">=6"
+}
+
+issue_2794_3: {
+    mangle = {
+        toplevel: true,
+    }
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: 3,
+        passes: 3,
+        properties: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            for (const a of func(value)) {
+                console.log(a);
+            }
+            function func(va) {
+                return doSomething(va);
+            }
+        }
+        function doSomething(x) {
+            return [ x, 2 * x, 3 * x ];
+        }
+        const value = 10;
+        foo();
+    }
+    expect: {
+        (function() {
+            for (const o of [ 10, 20, 30 ]) console.log(o);
+        })();
+    }
+    expect_stdout: [
+        "10",
+        "20",
+        "30",
+    ]
+    node_version: ">=6"
+}
+
+issue_2794_4: {
+    options = {}
+    input: {
+        for (var x of ([1, 2], [3, 4])) {
+            console.log(x);
+        }
+    }
+    expect_exact: "for(var x of([1,2],[3,4]))console.log(x);"
+    expect_stdout: [
+        "3",
+        "4",
+    ]
+    node_version: ">=6"
+}
+
+issue_2794_5: {
+    mangle = {}
+    options = {
+        evaluate: true,
+        passes: 1,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        for (var x of ([1, 2], [3, 4])) {
+            console.log(x);
+        }
+    }
+    expect_exact: "for(var x of[3,4])console.log(x);"
+    expect_stdout: [
+        "3",
+        "4",
+    ]
+    node_version: ">=6"
+}
+
+issue_2794_6: {
+    options = {
+    }
+    input: {
+        // TODO (or not): have parser flag invalid for-of expression.
+        // Consider it an uglify extension in the meantime.
+        for (let e of [1,2], [3,4,5]) {
+            console.log(e);
+        }
+    }
+    expect_exact: "for(let e of([1,2],[3,4,5]))console.log(e);"
+    expect_stdout: [
+        "3",
+        "4",
+        "5",
+    ]
+    node_version: ">=6"
+}
+
+inline_arrow_using_arguments: {
+    options = {
+        evaluate: true,
+        inline: 1,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function(){
+            ((x) => {
+                console.log.apply(console, arguments),
+                console.log(x);
+            })(4);
+        })(3, 2, 1);
+    }
+    expect: {
+        (function(){
+            console.log.apply(console, arguments),
+            console.log(4);
+        })(3, 2, 1);
+    }
+    expect_stdout: [
+        "3 2 1",
+        "4",
+    ]
+    node_version: ">=6"
+}
+
+issue_2874_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: 3,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            function foo() {
+                let letters = ["A", "B", "C"];
+                let result = [2, 1, 0].map(key => bar(letters[key] + key));
+                return result;
+            }
+            function bar(value) {
+                return () => console.log(value);
+            }
+            foo().map(fn => fn());
+        })();
+    }
+    expect: {
+        (function() {
+            (function() {
+                let letters = [ "A", "B", "C" ];
+                return [ 2, 1, 0 ].map(key => (function(value) {
+                    return () => console.log(value);
+                })(letters[key] + key));
+            })().map(fn => fn());
+        })();
+    }
+    expect_stdout: [
+        "C2",
+        "B1",
+        "A0",
+    ]
+    node_version: ">=6"
+}
+
+issue_2874_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: 3,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            let keys = [];
+            function foo() {
+                var result = [2, 1, 0].map(value => {
+                    keys.push(value);
+                    return bar();
+                });
+                return result;
+            }
+            function bar() {
+                var letters = ["A", "B", "C"], key = keys.shift();
+                return () => console.log(letters[key] + key);
+            }
+            foo().map(fn => fn());
+        })();
+    }
+    expect: {
+        (function() {
+            let keys = [];
+            [ 2, 1, 0 ].map(value => {
+                return keys.push(value), function() {
+                    var letters = [ "A", "B", "C" ], key = keys.shift();
+                    return () => console.log(letters[key] + key);
+                }();
+            }).map(fn => fn());
+        })();
+    }
+    expect_stdout: [
+        "C2",
+        "B1",
+        "A0",
+    ]
+    node_version: ">=6"
+}
+
+issue_2874_3: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: 3,
+        reduce_funcs: false,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return x + y;
+        }
+        let x, y;
+        let a = (z) => {
+            x = "A";
+            y = z;
+            console.log(f());
+        }
+        a(1);
+        a(2);
+    }
+    expect: {
+        let x, y;
+        let a = z => {
+            x = "A",
+            y = z,
+            console.log(x + y);
+        };
+        a(1),
+        a(2);
+    }
+    expect_stdout: [
+        "A1",
+        "A2",
+    ]
+    node_version: ">=6"
+}

test/compress/hoist_props.js

@@ -55,9 +55,8 @@ issue_2377_2: {
         console.log(obj.foo, obj.cube(3));
     }
     expect: {
-        console.log(1, function(x) {
-            return x * x * x;
-        }(3));
+        console.log(1, (x = 3, x * x * x));
+        var x;
     }
     expect_stdout: "1 27"
 }
@@ -67,9 +66,10 @@ issue_2377_3: {
         evaluate: true,
         inline: true,
         hoist_props: true,
-        passes: 3,
+        passes: 4,
         reduce_funcs: true,
         reduce_vars: true,
+        side_effects: true,
         toplevel: true,
         unused: true,
     }
@@ -489,10 +489,14 @@ hoist_function_with_call: {
         console.log(o.p.name, o.p === o.p, o.p(o.x), o.p(o.y));
     }
     expect: {
-        var o_p = function Foo(value){
-            return 10 * value
+        var o = {
+            p: function Foo(value) {
+                return 10 * value;
+            },
+            x: 1,
+            y: 2
         };
-        console.log(o_p.name, true, o_p(1), o_p(2));
+        console.log(o.p.name, o.p == o.p, o.p(o.x), o.p(o.y));
     }
     expect_stdout: "Foo true 10 20"
 }
@@ -823,3 +827,95 @@ issue_2519: {
     }
     expect_stdout: "5.5"
 }
+
+toplevel_const: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: false,
+    }
+    input: {
+        const a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect: {
+        const a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect_stdout: "3"
+}
+
+toplevel_let: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: false,
+    }
+    input: {
+        let a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect: {
+        let a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect_stdout: "3"
+    node_version: ">=6"
+}
+
+toplevel_var: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: false,
+    }
+    input: {
+        var a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect: {
+        var a = {
+            b: 1,
+            c: 2
+        };
+        console.log(a.b + a.c);
+    }
+    expect_stdout: "3"
+}
+
+undefined_key: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        join_vars: true,
+        passes: 4,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, o = {};
+        o[a] = 1;
+        o.b = 2;
+        console.log(o[a] + o.b);
+    }
+    expect: {
+        console.log(3);
+    }
+    expect_stdout: "3"
+}

test/compress/if_return.js

@@ -384,3 +384,109 @@ issue_1317_strict: {
     expect_stdout: "1"
     node_version: ">=4"
 }
+
+if_var_return: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+    }
+    input: {
+        function f() {
+            var a;
+            return;
+            var b;
+        }
+        function g() {
+            var a;
+            if (u()) {
+                var b;
+                return v();
+                var c;
+            }
+            var d;
+            if (w()) {
+                var e;
+                return x();
+                var f;
+            } else {
+                var g;
+                y();
+                var h;
+            }
+            var i;
+            z();
+            var j;
+        }
+    }
+    expect: {
+        function f() {
+            var a, b;
+        }
+        function g() {
+            var a, b, c, d, e, f, g, h, i, j;
+            return u() ? v() : w() ? x() : (y(), z(), void 0);
+        }
+    }
+}
+
+if_if_return_return: {
+    options = {
+        conditionals: true,
+        if_return: true,
+    }
+    input: {
+        function f(a, b) {
+            if (a) {
+                if (b)
+                    return b;
+                return;
+            }
+            g();
+        }
+    }
+    expect: {
+        function f(a, b) {
+            if (a)
+                return b || void 0;
+            g();
+        }
+    }
+}
+
+issue_2747: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function f(baz) {
+            if (baz === 0) {
+                return null;
+            }
+            let r;
+            if (baz > 2) {
+                r = 4;
+            } else {
+                r = 5;
+            }
+            return r;
+        }
+        console.log(f(0), f(1), f(3));
+    }
+    expect: {
+        "use strict";
+        function f(baz) {
+            if (0 === baz) return null;
+            let r;
+            return r = baz > 2 ? 4 : 5, r;
+        }
+        console.log(f(0), f(1), f(3));
+    }
+    expect_stdout: "null 5 4"
+    node_version: ">=4"
+}

test/compress/issue-1034.js

@@ -2,7 +2,7 @@ non_hoisted_function_after_return: {
     options = {
         hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
         evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
-        if_return: true, join_vars: true, cascade: true, side_effects: true
+        if_return: true, join_vars: true, side_effects: true
     }
     input: {
         function foo(x) {
@@ -38,7 +38,7 @@ non_hoisted_function_after_return_2a: {
     options = {
         hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
         evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
-        if_return: true, join_vars: true, cascade: true, side_effects: true,
+        if_return: true, join_vars: true, side_effects: true,
         collapse_vars: false, passes: 2, warnings: "verbose"
     }
     input: {
@@ -85,7 +85,7 @@ non_hoisted_function_after_return_2b: {
     options = {
         hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
         evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
-        if_return: true, join_vars: true, cascade: true, side_effects: true,
+        if_return: true, join_vars: true, side_effects: true,
         collapse_vars: false
     }
     input: {
@@ -123,7 +123,7 @@ 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
+        if_return: true, join_vars: true, side_effects: true
     }
     input: {
         "use strict";
@@ -164,7 +164,7 @@ 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,
+        if_return: true, join_vars: true, side_effects: true,
         collapse_vars: false, passes: 2, warnings: "verbose"
     }
     input: {
@@ -216,7 +216,7 @@ 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,
+        if_return: true, join_vars: true, side_effects: true,
         collapse_vars: false
     }
     input: {

test/compress/issue-1105.js

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

test/compress/issue-1212.js

@@ -14,7 +14,7 @@ issue_1212_debug_false: {
         keep_fargs    : true,
         if_return     : true,
         join_vars     : true,
-        cascade       : true,
+        collapse_vars : true,
         side_effects  : true,
     }
     input: {
@@ -52,7 +52,7 @@ issue_1212_debug_true: {
         keep_fargs    : true,
         if_return     : true,
         join_vars     : true,
-        cascade       : true,
+        collapse_vars : true,
         side_effects  : true,
     }
     input: {

test/compress/issue-1261.js

@@ -8,7 +8,6 @@ pure_function_calls: {
         unused       : true,
         if_return    : true,
         join_vars    : true,
-        cascade      : true,
         negate_iife  : true,
     }
     input: {
@@ -49,13 +48,13 @@ pure_function_calls: {
         a.b(), f.g();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:17,8]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:17,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:30,37]",
-        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:30,16]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:28,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:38,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:39,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:16,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:16,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:29,37]",
+        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:29,16]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:27,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:37,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:38,31]",
     ]
 }
 
@@ -69,7 +68,6 @@ pure_function_calls_toplevel: {
         unused       : true,
         if_return    : true,
         join_vars    : true,
-        cascade      : true,
         negate_iife  : true,
         toplevel     : true,
     }
@@ -112,17 +110,17 @@ pure_function_calls_toplevel: {
         a.b(), f.g();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:79,8]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:79,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:92,37]",
-        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:92,16]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:90,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:107,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:108,31]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:84,33]",
-        "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:84,12]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:100,45]",
-        "WARN: Dropping unused variable MyClass [test/compress/issue-1261.js:100,12]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:77,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:77,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:90,37]",
+        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:90,16]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:88,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:105,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:106,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:82,33]",
+        "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:82,12]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:98,45]",
+        "WARN: Dropping unused variable MyClass [test/compress/issue-1261.js:98,12]",
     ]
 }
 
@@ -157,29 +155,29 @@ should_warn: {
         baz();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:137,61]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:137,23]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:137,23]",
-        "WARN: Boolean || always true [test/compress/issue-1261.js:138,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,61]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,23]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:135,23]",
+        "WARN: Boolean || always true [test/compress/issue-1261.js:136,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:136,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:136,23]",
+        "WARN: Condition left of || always true [test/compress/issue-1261.js:137,8]",
+        "WARN: Condition always true [test/compress/issue-1261.js:137,8]",
+        "WARN: Boolean && always false [test/compress/issue-1261.js:138,23]",
         "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:138,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:138,23]",
-        "WARN: Condition left of || always true [test/compress/issue-1261.js:139,8]",
-        "WARN: Condition always true [test/compress/issue-1261.js:139,8]",
-        "WARN: Boolean && always false [test/compress/issue-1261.js:140,23]",
+        "WARN: Condition always false [test/compress/issue-1261.js:138,23]",
+        "WARN: Condition left of && always false [test/compress/issue-1261.js:139,8]",
+        "WARN: Condition always false [test/compress/issue-1261.js:139,8]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:140,23]",
         "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:140,23]",
-        "WARN: Condition always false [test/compress/issue-1261.js:140,23]",
-        "WARN: Condition left of && always false [test/compress/issue-1261.js:141,8]",
-        "WARN: Condition always false [test/compress/issue-1261.js:141,8]",
-        "WARN: + in boolean context always true [test/compress/issue-1261.js:142,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:140,23]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:141,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:141,31]",
+        "WARN: Condition always true [test/compress/issue-1261.js:141,8]",
         "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:142,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:142,23]",
-        "WARN: + in boolean context always true [test/compress/issue-1261.js:143,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:143,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:143,24]",
         "WARN: Condition always true [test/compress/issue-1261.js:143,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:144,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:145,24]",
-        "WARN: Condition always true [test/compress/issue-1261.js:145,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:146,31]",
-        "WARN: Condition always false [test/compress/issue-1261.js:146,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:144,31]",
+        "WARN: Condition always false [test/compress/issue-1261.js:144,8]",
     ]
 }

test/compress/issue-1275.js

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

test/compress/issue-1443.js

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

test/compress/issue-1447.js

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

test/compress/issue-1466.js

@@ -11,7 +11,6 @@ same_variable_in_multiple_for_loop: {
         keep_fargs: true,
         if_return: true,
         join_vars: true,
-        cascade: true,
         side_effects: true,
         collapse_vars: true,
     }
@@ -39,6 +38,7 @@ same_variable_in_multiple_for_loop: {
         }
     }
     expect_stdout: true
+    node_version: ">=6"
 }
 
 same_variable_in_multiple_forOf: {
@@ -54,7 +54,6 @@ same_variable_in_multiple_forOf: {
         keep_fargs: true,
         if_return: true,
         join_vars: true,
-        cascade: true,
         side_effects: true,
         collapse_vars: true,
     }
@@ -81,6 +80,7 @@ same_variable_in_multiple_forOf: {
         }
     }
     expect_stdout: true
+    node_version: ">=6"
 }
 
 same_variable_in_multiple_forIn: {
@@ -96,7 +96,6 @@ same_variable_in_multiple_forIn: {
         keep_fargs: true,
         if_return: true,
         join_vars: true,
-        cascade: true,
         side_effects: true,
         collapse_vars: true,
     }
@@ -123,6 +122,7 @@ same_variable_in_multiple_forIn: {
         }
     }
     expect_stdout: true
+    node_version: ">=6"
 }
 
 different_variable_in_multiple_for_loop: {
@@ -138,7 +138,6 @@ different_variable_in_multiple_for_loop: {
         keep_fargs: true,
         if_return: true,
         join_vars: true,
-        cascade: true,
         side_effects: true,
         collapse_vars: true,
     }
@@ -166,6 +165,7 @@ different_variable_in_multiple_for_loop: {
         }
     }
     expect_stdout: true
+    node_version: ">=6"
 }
 
 different_variable_in_multiple_forOf: {
@@ -181,7 +181,6 @@ different_variable_in_multiple_forOf: {
         keep_fargs: true,
         if_return: true,
         join_vars: true,
-        cascade: true,
         side_effects: true,
         collapse_vars: true,
     }
@@ -208,6 +207,7 @@ different_variable_in_multiple_forOf: {
         }
     }
     expect_stdout: true
+    node_version: ">=6"
 }
 
 different_variable_in_multiple_forIn: {
@@ -223,7 +223,6 @@ different_variable_in_multiple_forIn: {
         keep_fargs: true,
         if_return: true,
         join_vars: true,
-        cascade: true,
         side_effects: true,
         collapse_vars: true,
     }
@@ -250,6 +249,175 @@ different_variable_in_multiple_forIn: {
         }
     }
     expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forOf_sequences_let: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp of test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let tmp of dd) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let o of test) {
+            let e;
+            console.log(o), e = [ "e", "f", "g" ];
+            for (let o of e)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forOf_sequences_const: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (const tmp of test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (const tmp of dd) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (const o of test) {
+            let t;
+            console.log(o), t = [ "e", "f", "g" ];
+            for (const o of t)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forIn_sequences_let: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp in test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let tmp in test) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let e in test) {
+            let t;
+            console.log(e), t = [ "e", "f", "g" ];
+            for (let e in test)
+                console.log(e);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+same_variable_in_multiple_forIn_sequences_const: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (const tmp in test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (const tmp in test) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (const o in test) {
+            let t;
+            console.log(o), t = [ "e", "f", "g" ];
+            for (const o in test)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+    node_version: ">=6"
 }
 
 more_variable_in_multiple_for: {
@@ -265,7 +433,6 @@ more_variable_in_multiple_for: {
         keep_fargs: true,
         if_return: true,
         join_vars: true,
-        cascade: true,
         side_effects: true,
         collapse_vars: true,
     }
@@ -288,4 +455,5 @@ more_variable_in_multiple_for: {
         }
     }
     expect_stdout: true
+    node_version: ">=6"
 }

test/compress/issue-1588.js

@@ -61,7 +61,7 @@ unsafe_undefined: {
     options = {
         conditionals: true,
         if_return: true,
-        unsafe: true,
+        unsafe_undefined: true,
     }
     mangle = {}
     input: {

test/compress/issue-1639.js

@@ -2,7 +2,7 @@
 issue_1639_1: {
     options = {
         booleans: true,
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         evaluate: true,
         join_vars: true,
@@ -35,7 +35,7 @@ issue_1639_1: {
 issue_1639_2: {
     options = {
         booleans: true,
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         evaluate: true,
         join_vars: true,
@@ -68,7 +68,7 @@ issue_1639_2: {
 issue_1639_3: {
     options = {
         booleans: true,
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         evaluate: true,
         sequences: true,

test/compress/issue-1656.js

@@ -1,7 +1,6 @@
 f7: {
     options = {
         booleans: true,
-        cascade: true,
         collapse_vars: true,
         comparisons: true,
         conditionals: true,

test/compress/issue-1770.js

@@ -84,12 +84,12 @@ numeric_literal: {
         '    0: 0,',
         '    "-0": 1,',
         '    42: 2,',
-        '    "42": 3,',
+        '    42: 3,',
         '    37: 4,',
         '    o: 5,',
         '    1e42: 6,',
         '    b: 7,',
-        '    "1e+42": 8',
+        '    1e42: 8',
         '};',
         '',
         'console.log(obj[-0], obj[-""], obj["-0"]);',

test/compress/issue-203.js

@@ -2,7 +2,7 @@
 compress_new_function: {
     options = {
         unsafe: true,
-        unsafe_Func: true,
+        unsafe_Function: true,
     }
     input: {
         new Function("aa, bb", 'return aa;');
@@ -15,7 +15,7 @@ compress_new_function: {
 compress_new_function_with_destruct: {
     options = {
         unsafe: true,
-        unsafe_Func: true,
+        unsafe_Function: true,
         ecma: 6
     }
     beautify = {
@@ -38,7 +38,7 @@ compress_new_function_with_destruct_arrows: {
         arrows: true,
         unsafe_arrows: true,
         unsafe: true,
-        unsafe_Func: true,
+        unsafe_Function: true,
         ecma: 6,
     }
     beautify = {

test/compress/issue-2652.js

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

test/compress/issue-269.js

@@ -64,3 +64,27 @@ strings_concat: {
 		);
 	}
 }
+
+regexp: {
+	options = {
+		evaluate: true,
+		unsafe: true,
+	}
+	input: {
+		RegExp("foo");
+		RegExp("bar", "ig");
+		RegExp(foo);
+		RegExp("bar", ig);
+		RegExp("should", "fail");
+	}
+	expect: {
+		/foo/;
+		/bar/ig;
+		RegExp(foo);
+		RegExp("bar", ig);
+		RegExp("should", "fail");
+	}
+	expect_warnings: [
+		'WARN: Error converting RegExp("should","fail") [test/compress/issue-269.js:78,2]',
+	]
+}

test/compress/issue-2719.js

@@ -0,0 +1,32 @@
+warn: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return g();
+        }
+        function g() {
+            return g["call" + "er"].arguments;
+        }
+        // 3
+        console.log(f(1, 2, 3).length);
+    }
+    expect: {
+        // TypeError: Cannot read property 'arguments' of null
+        console.log(function g() {
+            return g.caller.arguments;
+        }().length);
+    }
+    expect_warnings: [
+        "WARN: Function.protoype.caller not supported [test/compress/issue-2719.js:17,19]",
+        "WARN: Function.protoype.arguments not supported [test/compress/issue-2719.js:17,19]",
+    ]
+}

test/compress/issue-281.js

@@ -453,7 +453,7 @@ pure_annotation_2: {
 
 drop_fargs: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         inline: true,
         keep_fargs: false,
         side_effects: true,
@@ -476,7 +476,7 @@ drop_fargs: {
 
 keep_fargs: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         inline: true,
         keep_fargs: true,
         side_effects: true,

test/compress/issue-2871.js

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

test/compress/issue-368.js

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

test/compress/issue-892.js

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

test/compress/issue-976.js

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

test/compress/issue-979.js

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

test/compress/loops.js

@@ -536,3 +536,182 @@ dead_code_condition: {
     }
     expect_stdout: "1"
 }
+
+issue_2740_1: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        for (; ; ) break;
+        for (a(); ; ) break;
+        for (; b(); ) break;
+        for (c(); d(); ) break;
+        for (; ; e()) break;
+        for (f(); ; g()) break;
+        for (; h(); i()) break;
+        for (j(); k(); l()) break;
+    }
+    expect: {
+        a();
+        b();
+        c();
+        d();
+        f();
+        h();
+        j();
+        k();
+    }
+}
+
+issue_2740_2: {
+    options = {
+        dead_code: true,
+        loops: true,
+        passes: 2,
+    }
+    input: {
+        L1: while (x()) {
+            break L1;
+        }
+    }
+    expect: {
+        x();
+    }
+}
+
+issue_2740_3: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        L1: for (var x = 0; x < 3; x++) {
+            L2: for (var y = 0; y < 2; y++) {
+                break L1;
+            }
+        }
+        console.log(x, y);
+    }
+    expect: {
+        L1: for (var x = 0; x < 3; x++)
+            for (var y = 0; y < 2; y++)
+                break L1;
+        console.log(x, y);
+    }
+    expect_stdout: "0 0"
+}
+
+issue_2740_4: {
+    options = {
+        dead_code: true,
+        loops: true,
+        passes: 2,
+    }
+    input: {
+        L1: for (var x = 0; x < 3; x++) {
+            L2: for (var y = 0; y < 2; y++) {
+                break L2;
+            }
+        }
+        console.log(x, y);
+    }
+    expect: {
+        for (var x = 0; x < 3; x++) {
+            var y = 0;
+            y < 2;
+        }
+        console.log(x, y);
+    }
+    expect_stdout: "3 0"
+}
+
+issue_2740_5: {
+    options = {
+        dead_code: true,
+        loops: true,
+        passes: 2,
+    }
+    input: {
+        L1: for (var x = 0; x < 3; x++) {
+            break L1;
+            L2: for (var y = 0; y < 2; y++) {
+                break L2;
+            }
+        }
+        console.log(x, y);
+    }
+    expect: {
+        var x = 0;
+        x < 3;
+        var y;
+        console.log(x,y);
+    }
+    expect_stdout: "0 undefined"
+}
+
+issue_2740_6: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        const a = 9, b = 0;
+        for (const a = 1; a < 3; ++b) break;
+        console.log(a, b);
+    }
+    expect: {
+        const a = 9, b = 0;
+        {
+            const a = 1;
+            a < 3;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "9 0"
+    node_version: ">=6"
+}
+
+issue_2740_7: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        let a = 9, b = 0;
+        for (const a = 1; a < 3; ++b) break;
+        console.log(a, b);
+    }
+    expect: {
+        let a = 9, b = 0;
+        {
+            const a = 1;
+            a < 3;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "9 0"
+    node_version: ">=6"
+}
+
+issue_2740_8: {
+    options = {
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        var a = 9, b = 0;
+        for (const a = 1; a < 3; ++b) break;
+        console.log(a, b);
+    }
+    expect: {
+        var a = 9, b = 0;
+        {
+            const a = 1;
+            a < 3;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "9 0"
+    node_version: ">=6"
+}

test/compress/object.js

@@ -812,3 +812,204 @@ prop_arrow_with_nested_this: {
     ]
     node_version: ">=4"
 }
+
+issue_2554_1: {
+    options = {
+        computed_props: true,
+        evaluate: true,
+    }
+    input: {
+        var obj = {
+            ["x" + ""]: 1,
+            ["method" + ""]() {
+                this.s = "PASS";
+            },
+            get ["g" + ""]() {
+                return this.x;
+            },
+            set ["s" + ""](value) {
+                this.x = value;
+            }
+        };
+        obj.method();
+        console.log(obj.g);
+    }
+    expect: {
+        var obj = {
+            x: 1,
+            method() {
+                this.s = "PASS";
+            },
+            get g() {
+                return this.x;
+            },
+            set s(value) {
+                this.x = value;
+            }
+        };
+        obj.method();
+        console.log(obj.g);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_2554_2: {
+    options = {
+        computed_props: true,
+        evaluate: true,
+    }
+    input: {
+        var instance = new class {
+            constructor() {
+                this.x = 2;
+            }
+            ["method" + ""]() {
+                this.s = "PASS";
+            }
+            get ["g" + ""]() {
+                return this.x;
+            }
+            set ["s" + ""](value) {
+                this.x = value;
+            }
+        }();
+        instance.method();
+        console.log(instance.g);
+    }
+    expect: {
+        var instance = new class {
+            constructor() {
+                this.x = 2;
+            }
+            method() {
+                this.s = "PASS";
+            }
+            get g() {
+                return this.x;
+            }
+            set s(value) {
+                this.x = value;
+            }
+        }();
+        instance.method();
+        console.log(instance.g);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_2554_3: {
+    options = {
+        computed_props: true,
+        evaluate: true,
+    }
+    input: {
+        var foo = {
+            [1 + 0]: 1,
+            [2 + 0]() {
+                this[4] = "PASS";
+            },
+            get [3 + 0]() {
+                return this[1];
+            },
+            set [4 + 0](value) {
+                this[1] = value;
+            }
+        };
+        foo[2]();
+        console.log(foo[3]);
+    }
+    expect: {
+        var foo = {
+            1: 1,
+            2() {
+                this[4] = "PASS";
+            },
+            get 3() {
+                return this[1];
+            },
+            set 4(value) {
+                this[1] = value;
+            }
+        };
+        foo[2]();
+        console.log(foo[3]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_2554_4: {
+    options = {
+        computed_props: true,
+        evaluate: true,
+    }
+    input: {
+        var bar = new class {
+            constructor() {
+                this[1] = 2;
+            }
+            [2 + 0]() {
+                this[4] = "PASS";
+            }
+            get [3 + 0]() {
+                return this[1];
+            }
+            set [4 + 0](value) {
+                this[1] = value;
+            }
+        }();
+        bar[2]();
+        console.log(bar[3]);
+    }
+    expect: {
+        var bar = new class {
+            constructor() {
+                this[1] = 2;
+            }
+            2() {
+                this[4] = "PASS";
+            }
+            get 3() {
+                return this[1];
+            }
+            set 4(value) {
+                this[1] = value;
+            }
+        }();
+        bar[2]();
+        console.log(bar[3]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_2554_5: {
+    options = {
+        computed_props: true,
+        evaluate: true,
+    }
+    input: {
+        new class {
+            ["constructor"]() {
+                console.log("FAIL");
+            }
+            "constructor"() {
+                console.log("PASS");
+            }
+        }();
+    }
+    expect: {
+        new class {
+            ["constructor"]() {
+                console.log("FAIL");
+            }
+            constructor() {
+                console.log("PASS");
+            }
+        }();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}

test/compress/properties.js

@@ -569,16 +569,41 @@ native_prototype: {
     }
     input: {
         Array.prototype.splice.apply(a, [1, 2, b, c]);
+        Function.prototype.call.apply(console.log, console, [ "foo" ]);
+        Number.prototype.toFixed.call(Math.PI, 2);
         Object.prototype.hasOwnProperty.call(d, "foo");
+        RegExp.prototype.test.call(/foo/, "bar");
         String.prototype.indexOf.call(e, "bar");
     }
     expect: {
         [].splice.apply(a, [1, 2, b, c]);
+        (function() {}).call.apply(console.log, console, [ "foo" ]);
+        0..toFixed.call(Math.PI, 2);
         ({}).hasOwnProperty.call(d, "foo");
+        /t/.test.call(/foo/, "bar");
         "".indexOf.call(e, "bar");
     }
 }
 
+native_prototype_lhs: {
+    options = {
+        unsafe_proto: true,
+    }
+    input: {
+        console.log(function() {
+            Function.prototype.bar = "PASS";
+            return function() {};
+        }().bar);
+    }
+    expect: {
+        console.log(function() {
+            Function.prototype.bar = "PASS";
+            return function() {};
+        }().bar);
+    }
+    expect_stdout: "PASS"
+}
+
 accessor_boolean: {
     input: {
         var a = 1;
@@ -1331,3 +1356,541 @@ issue_2513: {
         "undefined undefined",
     ]
 }
+
+const_prop_assign_strict: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        function Simulator() {
+            /abc/.index = 1;
+            this._aircraft = [];
+        }
+        (function() {}).prototype.destroy = x();
+    }
+    expect: {
+        function Simulator() {
+            this._aircraft = [];
+        }
+        x();
+    }
+}
+
+const_prop_assign_pure: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        function Simulator() {
+            /abc/.index = 1;
+            this._aircraft = [];
+        }
+        (function() {}).prototype.destroy = x();
+    }
+    expect: {
+        function Simulator() {
+            this._aircraft = [];
+        }
+        x();
+    }
+}
+
+join_object_assignments_1: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var x = {
+                a: 1,
+                c: (console.log("c"), "C"),
+            };
+            x.b = 2;
+            x[3] = function() {
+                console.log(x);
+            },
+            x["a"] = /foo/,
+            x.bar = x;
+            return x;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var x = {
+                a: 1,
+                c: (console.log("c"), "C"),
+                b: 2,
+                3: function() {
+                    console.log(x);
+                },
+                a: /foo/,
+            };
+            x.bar = x;
+            return x;
+        }());
+    }
+    expect_stdout: true
+}
+
+join_object_assignments_2: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        join_vars: true,
+        passes: 3,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            foo: 1,
+        };
+        o.bar = 2;
+        o.baz = 3;
+        console.log(o.foo, o.bar + o.bar, o.foo * o.bar * o.baz);
+    }
+    expect: {
+        console.log(1, 4, 6);
+    }
+    expect_stdout: "1 4 6"
+}
+
+join_object_assignments_3: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                a: "PASS",
+            }, a = o.a;
+            o.a = "FAIL";
+            return a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o = {
+                a: "PASS",
+            }, a = o.a;
+            o.a = "FAIL";
+            return a;
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+join_object_assignments_return_1: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 3
+            };
+            return o.q = "foo";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o = {
+                p: 3,
+                q: "foo"
+            };
+            return o.q;
+        }());
+    }
+    expect_stdout: "foo"
+}
+
+join_object_assignments_return_2: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 3
+            };
+            return o.q = /foo/,
+            o.r = "bar";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o = {
+                p: 3,
+                q: /foo/,
+                r: "bar"
+            };
+            return o.r;
+        }());
+    }
+    expect_stdout: "bar"
+}
+
+join_object_assignments_return_3: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 3
+            };
+            return o.q = "foo",
+            o.p += "",
+            console.log(o.q),
+            o.p;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o = {
+                p: 3,
+                q: "foo"
+            };
+            return o.p += "",
+            console.log(o.q),
+            o.p;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "3",
+    ]
+}
+
+join_object_assignments_for: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 3
+            };
+            for (o.q = "foo"; console.log(o.q););
+            return o.p;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            for (var o = {
+                p: 3,
+                q: "foo"
+            }; console.log(o.q););
+            return o.p;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "3",
+    ]
+}
+
+join_object_assignments_if: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {};
+            if (o.a = "PASS") return o.a;
+        }())
+    }
+    expect: {
+        console.log(function() {
+            var o = { a: "PASS" };
+            if (o.a) return o.a;
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+join_object_assignments_forin: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {};
+            for (var a in o.a = "PASS", o)
+                return o[a];
+        }())
+    }
+    expect: {
+        console.log(function() {
+            var o = { a: "PASS" };
+            for (var a in o)
+                return o[a];
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+join_object_assignments_negative: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+        properties: true,
+    }
+    input: {
+        var o = {};
+        o[0] = 0;
+        o[-0] = 1;
+        o[-1] = 2;
+        console.log(o[0], o[-0], o[-1]);
+    }
+    expect: {
+        var o = {
+            0: 0,
+            0: 1,
+            "-1": 2
+        };
+        console.log(o[0], o[-0], o[-1]);
+    }
+    expect_stdout: "1 1 2"
+}
+
+join_object_assignments_NaN_1: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        var o = {};
+        o[NaN] = 1;
+        o[0/0] = 2;
+        console.log(o[NaN], o[NaN]);
+    }
+    expect: {
+        var o = {};
+        o[NaN] = 1;
+        o[0/0] = 2;
+        console.log(o[NaN], o[NaN]);
+    }
+    expect_stdout: "2 2"
+}
+
+join_object_assignments_NaN_2: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+        properties: true,
+    }
+    input: {
+        var o = {};
+        o[NaN] = 1;
+        o[0/0] = 2;
+        console.log(o[NaN], o[NaN]);
+    }
+    expect: {
+        var o = {
+            NaN: 1,
+            NaN: 2
+        };
+        console.log(o.NaN, o.NaN);
+    }
+    expect_stdout: "2 2"
+}
+
+join_object_assignments_null_0: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        var o = {};
+        o[null] = 1;
+        console.log(o[null]);
+    }
+    expect: {
+        var o = {};
+        o[null] = 1;
+        console.log(o[null]);
+    }
+    expect_stdout: "1"
+}
+
+join_object_assignments_null_1: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+        properties: true,
+    }
+    input: {
+        var o = {};
+        o[null] = 1;
+        console.log(o[null]);
+    }
+    expect: {
+        var o = {
+            null: 1
+        };
+        console.log(o.null);
+    }
+    expect_stdout: "1"
+}
+
+join_object_assignments_void_0: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+    }
+    input: {
+        var o = {};
+        o[void 0] = 1;
+        console.log(o[void 0]);
+    }
+    expect: {
+        var o = {
+            undefined: 1
+        };
+        console.log(o[void 0]);
+    }
+    expect_stdout: "1"
+}
+
+join_object_assignments_undefined_1: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        var o = {};
+        o[undefined] = 1;
+        console.log(o[undefined]);
+    }
+    expect: {
+        var o = {};
+        o[void 0] = 1;
+        console.log(o[void 0]);
+    }
+    expect_stdout: "1"
+}
+
+join_object_assignments_undefined_2: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+        properties: true,
+    }
+    input: {
+        var o = {};
+        o[undefined] = 1;
+        console.log(o[undefined]);
+    }
+    expect: {
+        var o = {
+            undefined : 1
+        };
+        console.log(o[void 0]);
+    }
+    expect_stdout: "1"
+}
+
+join_object_assignments_Infinity: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+        properties: true,
+    }
+    input: {
+        var o = {};
+        o[Infinity] = 1;
+        o[1/0] = 2;
+        o[-Infinity] = 3;
+        o[-1/0] = 4;
+        console.log(o[Infinity], o[1/0], o[-Infinity], o[-1/0]);
+    }
+    expect: {
+        var o = {
+            Infinity: 1,
+            Infinity: 2,
+            "-Infinity": 3,
+            "-Infinity": 4
+        };
+        console.log(o[1/0], o[1/0], o[-1/0], o[-1/0]);
+    }
+    expect_stdout: "2 2 4 4"
+}
+
+join_object_assignments_regex: {
+    options = {
+        evaluate: true,
+        join_vars: true,
+        properties: true,
+    }
+    input: {
+        var o = {};
+        o[/rx/] = 1;
+        console.log(o[/rx/]);
+    }
+    expect: {
+        var o = {
+            "/rx/": 1
+        };
+        console.log(o[/rx/]);
+    }
+    expect_stdout: "1"
+}
+
+issue_2816: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        "use strict";
+        var o = {
+            a: 1
+        };
+        o.b = 2;
+        o.a = 3;
+        o.c = 4;
+        console.log(o.a, o.b, o.c);
+    }
+    expect: {
+        "use strict";
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.a = 3;
+        o.c = 4;
+        console.log(o.a, o.b, o.c);
+    }
+    expect_stdout: "3 2 4"
+}
+
+issue_2816_ecma6: {
+    options = {
+        ecma: "6",
+        join_vars: true,
+    }
+    input: {
+        "use strict";
+        var o = {
+            a: 1
+        };
+        o.b = 2;
+        o.a = 3;
+        o.c = 4;
+        console.log(o.a, o.b, o.c);
+    }
+    expect: {
+        "use strict";
+        var o = {
+            a: 1,
+            b: 2,
+            a: 3,
+            c: 4
+        };
+        console.log(o.a, o.b, o.c);
+    }
+    expect_stdout: "3 2 4"
+    node_version: ">=4"
+}

test/compress/pure_funcs.js

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

test/compress/pure_getters.js

@@ -185,7 +185,7 @@ impure_getter_2: {
 
 issue_2110_1: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         pure_getters: "strict",
         sequences: true,
         side_effects: true,
@@ -274,7 +274,7 @@ set_immutable_1: {
 
 set_immutable_2: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         pure_getters: "strict",
         reduce_funcs: true,
@@ -324,7 +324,7 @@ set_immutable_3: {
 
 set_immutable_4: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         pure_getters: "strict",
         reduce_funcs: true,
@@ -348,6 +348,57 @@ set_immutable_4: {
     expect_stdout: true
 }
 
+set_immutable_5: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        "use strict";
+        1..foo += "";
+        1..foo ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: true
+}
+
+set_immutable_6: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        1..foo ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: true
+}
+
 set_mutable_1: {
     options = {
         collapse_vars: true,
@@ -375,7 +426,7 @@ set_mutable_1: {
 
 set_mutable_2: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         pure_getters: "strict",
         reduce_funcs: true,
@@ -476,7 +527,7 @@ issue_2265_4: {
 
 issue_2313_1: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         pure_getters: "strict",
         sequences: true,
@@ -522,7 +573,7 @@ issue_2313_1: {
 
 issue_2313_2: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         pure_getters: true,
         sequences: true,
@@ -735,3 +786,62 @@ issue_2313_7: {
     expect_stdout: "2 1"
     node_version: ">=6"
 }
+
+issue_2678: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        var a = 1, c = "FAIL";
+        (function f() {
+            (a-- && f()).p;
+            return {
+                get p() {
+                    c = "PASS";
+                }
+            };
+        })();
+        console.log(c);
+    }
+    expect: {
+        var a = 1, c = "FAIL";
+        (function f() {
+            (a-- && f()).p;
+            return {
+                get p() {
+                    c = "PASS";
+                }
+            };
+        })();
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2838: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            (a || b).c = "PASS";
+            (function() {
+                return f(a, b);
+            }).prototype.foo = "bar";
+        }
+        var o = {};
+        f(null, o);
+        console.log(o.c);
+    }
+    expect: {
+        function f(a, b) {
+            (a || b).c = "PASS";
+        }
+        var o = {};
+        f(null, o);
+        console.log(o.c);
+    }
+    expect_stdout: "PASS"
+}

test/compress/return_undefined.js

@@ -17,7 +17,6 @@ return_undefined: {
         keep_fnames   : false,
         hoist_vars    : true,
         join_vars     : true,
-        cascade       : true,
         negate_iife   : true
     };
     input: {
@@ -122,3 +121,25 @@ return_undefined: {
         }
     }
 }
+
+return_void: {
+    options = {
+        if_return: true,
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                h();
+            }
+            return g();
+        }
+    }
+    expect: {
+        function f() {
+            h();
+        }
+    }
+}

test/compress/sequences.js

@@ -288,7 +288,7 @@ unsafe_undefined: {
         if_return: true,
         sequences: true,
         side_effects: true,
-        unsafe: true,
+        unsafe_undefined: true,
     }
     input: {
         function f(undefined) {
@@ -317,7 +317,7 @@ unsafe_undefined: {
 
 issue_1685: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         side_effects: true,
     }
     input: {
@@ -341,7 +341,7 @@ issue_1685: {
 
 func_def_1: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         side_effects: true,
     }
     input: {
@@ -361,7 +361,7 @@ func_def_1: {
 
 func_def_2: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         side_effects: true,
     }
     input: {
@@ -379,7 +379,7 @@ func_def_2: {
 
 func_def_3: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         side_effects: true,
     }
     input: {
@@ -401,7 +401,7 @@ func_def_3: {
 
 func_def_4: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         side_effects: true,
     }
     input: {
@@ -427,7 +427,7 @@ func_def_4: {
 
 func_def_5: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         side_effects: true,
     }
     input: {
@@ -634,7 +634,7 @@ side_effects: {
 
 side_effects_cascade_1: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         sequences: true,
         side_effects: true,
@@ -655,7 +655,7 @@ side_effects_cascade_1: {
 
 side_effects_cascade_2: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         side_effects: true,
     }
     input: {
@@ -677,7 +677,7 @@ side_effects_cascade_2: {
 
 side_effects_cascade_3: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         side_effects: true,
     }
@@ -692,14 +692,14 @@ side_effects_cascade_3: {
     expect: {
         function f(a, b) {
             !(b += a) && ((b = a) || (b -= a, b ^= a)),
-            --a;
+            a--;
         }
     }
 }
 
 issue_27: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         passes: 2,
         sequences: true,
         side_effects: true,
@@ -721,7 +721,7 @@ issue_27: {
 
 reassign_const: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         sequences: true,
         side_effects: true,
     }
@@ -746,7 +746,7 @@ reassign_const: {
 issue_2062: {
     options = {
         booleans: true,
-        cascade: true,
+        collapse_vars: true,
         conditionals: true,
         side_effects: true,
     }
@@ -765,7 +765,7 @@ issue_2062: {
 
 issue_2313: {
     options = {
-        cascade: true,
+        collapse_vars: true,
         sequences: true,
         side_effects: true,
     }
@@ -803,3 +803,101 @@ issue_2313: {
     }
     expect_stdout: "2 1"
 }
+
+cascade_assignment_in_return: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            return a = x(), b(a);
+        }
+    }
+    expect: {
+        function f(a, b) {
+            return b(x());
+        }
+    }
+}
+
+hoist_defun: {
+    options = {
+        join_vars: true,
+        sequences: true,
+    }
+    input: {
+        x();
+        function f() {}
+        y();
+    }
+    expect: {
+        function f() {}
+        x(), y();
+    }
+}
+
+hoist_decl: {
+    options = {
+        join_vars: true,
+        sequences: true,
+    }
+    input: {
+        var a;
+        w();
+        var b = x();
+        y();
+        for (var c; 0;) z();
+        var d;
+    }
+    expect: {
+        var a;
+        w();
+        var b = x(), c, d;
+        for (y(); 0;) z();
+    }
+}
+
+for_init_var: {
+    options = {
+        join_vars: true,
+        unused: false,
+    }
+    input: {
+        var a = "PASS";
+        (function() {
+            var b = 42;
+            for (var c = 5; c > 0;) c--;
+            a = "FAIL";
+            var a;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        (function() {
+            for (var b = 42, c = 5, a; c > 0;) c--;
+            a = "FAIL";
+        })();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+forin: {
+    options = {
+        sequences: true,
+    }
+    input: {
+        var o = [];
+        o.push("PASS");
+        for (var a in o)
+            console.log(o[a]);
+    }
+    expect: {
+        var o = [];
+        for (var a in o.push("PASS"), o)
+            console.log(o[a]);
+    }
+    expect_stdout: "PASS"
+}

test/compress/typeof.js

@@ -100,7 +100,7 @@ typeof_defun_1: {
         g = 42;
         console.log("YES");
         "function" == typeof g && g();
-        h();
+        "function" == typeof h && h();
     }
     expect_stdout: [
         "YES",
@@ -138,3 +138,166 @@ typeof_defun_2: {
         "2",
     ]
 }
+
+duplicate_defun_arg_name: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        typeofs: true,
+    }
+    input: {
+        function long_name(long_name) {
+            return typeof long_name;
+        }
+        console.log(typeof long_name, long_name());
+    }
+    expect: {
+        function long_name(long_name) {
+            return typeof long_name;
+        }
+        console.log(typeof long_name, long_name());
+    }
+    expect_stdout: "function undefined"
+}
+
+duplicate_lambda_arg_name: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        typeofs: true,
+    }
+    input: {
+        console.log(function long_name(long_name) {
+            return typeof long_name;
+        }());
+    }
+    expect: {
+        console.log(function long_name(long_name) {
+            return typeof long_name;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_2728_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        typeofs: true,
+    }
+    input: {
+        (function arguments() {
+            console.log(typeof arguments);
+        })();
+    }
+    expect: {
+        (function arguments() {
+            console.log(typeof arguments);
+        })();
+    }
+    expect_stdout: "object"
+}
+
+issue_2728_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        typeofs: true,
+    }
+    input: {
+        function arguments() {
+            return typeof arguments;
+        }
+        console.log(typeof arguments, arguments());
+    }
+    expect: {
+        function arguments() {
+            return typeof arguments;
+        }
+        console.log(typeof arguments, arguments());
+    }
+    expect_stdout: "function object"
+}
+
+issue_2728_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        typeofs: true,
+    }
+    input: {
+        (function() {
+            function arguments() {
+            }
+            console.log(typeof arguments);
+        })();
+    }
+    expect: {
+        (function() {
+            function arguments() {
+            }
+            console.log("function");
+        })();
+    }
+    expect_stdout: "function"
+}
+
+issue_2728_4: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        typeofs: true,
+    }
+    input: {
+        function arguments() {
+        }
+        console.log(typeof arguments);
+    }
+    expect: {
+        function arguments() {
+        }
+        console.log("function");
+    }
+    expect_stdout: "function"
+}
+
+issue_2728_5: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        typeofs: true,
+    }
+    input: {
+        (function arguments(arguments) {
+            console.log(typeof arguments);
+        })();
+    }
+    expect: {
+        (function arguments(arguments) {
+            console.log(typeof arguments);
+        })();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_2728_6: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        typeofs: true,
+    }
+    input: {
+        function arguments(arguments) {
+            return typeof arguments;
+        }
+        console.log(typeof arguments, arguments());
+    }
+    expect: {
+        function arguments(arguments) {
+            return typeof arguments;
+        }
+        console.log(typeof arguments, arguments());
+    }
+    expect_stdout: "function undefined"
+}

test/compress/unicode.js

@@ -119,3 +119,10 @@ issue_2242_4: {
     }
     expect_exact: 'console.log("\ud83d\ude00","\\ud83d@\\ude00");'
 }
+
+issue_2569: {
+    input: {
+        new RegExp("[\udc42-\udcaa\udd74-\udd96\ude45-\ude4f\udea3-\udecc]");
+    }
+    expect_exact: 'new RegExp("[\\udc42-\\udcaa\\udd74-\\udd96\\ude45-\\ude4f\\udea3-\\udecc]");'
+}

test/compress/yield.js

@@ -88,9 +88,8 @@ yield_before_punctuators: {
         })();
         function* g1() { (yield) }
         function* g2() { [yield] }
-        function* g3() { return {yield} } // Added return to avoid {} drop
-        function* g4() { yield, yield; }
-        function* g5() { (yield) ? yield : yield; }
+        function* g3() { yield, yield; }
+        function* g4() { (yield) ? yield : yield; }
     }
     expect: {
         iter = (function*() {
@@ -98,9 +97,8 @@ yield_before_punctuators: {
         })();
         function* g1() { (yield) }
         function* g2() { [yield] }
-        function* g3() { return {yield} }
-        function* g4() { yield, yield; }
-        function* g5() { (yield) ? yield : yield; }
+        function* g3() { yield, yield; }
+        function* g4() { (yield) ? yield : yield; }
     }
 }
 
@@ -199,3 +197,57 @@ yield_as_ES5_property: {
     expect_exact: '"use strict";console.log({yield:42}.yield);'
     expect_stdout: "42"
 }
+
+issue_2689: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        function* y() {
+            var t = yield x();
+            return new t();
+        }
+    }
+    expect_exact: "function*y(){return new(yield x())}"
+}
+
+issue_2832: {
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        function* gen(i) {
+            const result = yield (x = i, -x);
+            var x;
+            console.log(x);
+            console.log(result);
+            yield 2;
+        }
+        var x = gen(1);
+        console.log(x.next("first").value);
+        console.log(x.next("second").value);
+    }
+    expect_exact: [
+        "function* gen(i) {",
+        "    const result = yield (x = i, -x);",
+        "    var x;",
+        "    console.log(x);",
+        "    console.log(result);",
+        "    yield 2;",
+        "}",
+        "",
+        "var x = gen(1);",
+        "",
+        'console.log(x.next("first").value);',
+        "",
+        'console.log(x.next("second").value);',
+    ]
+    expect_stdout: [
+        "-1",
+        "1",
+        "second",
+        "2",
+    ]
+    node_version: ">=4"
+}

test/input/invalid/const.js

@@ -1,8 +1,3 @@
 function f() {
     const a;
 }
-
-function g() {
-    "use strict";
-    const a;
-}

test/input/issue-1242/qux.js

@@ -1,4 +1,4 @@
-var a = bar(1+2);
-var b = baz(3+9);
-print('q' + 'u' + 'x', a, b);
+var x = bar(1+2);
+var y = baz(3+9);
+print('q' + 'u' + 'x', x, y);
 foo(5+6);

test/input/rename/input.js

@@ -0,0 +1,6 @@
+function f(x) {
+    return g(x);
+    function g(x) {
+        return x;
+    }
+}

test/jetstream.js

@@ -5,11 +5,7 @@
 
 var site = "http://browserbench.org/JetStream";
 if (typeof phantom == "undefined") {
-    // workaround for tty output truncation upon process.exit()
-    [process.stdout, process.stderr].forEach(function(stream){
-        if (stream._handle && stream._handle.setBlocking)
-            stream._handle.setBlocking(true);
-    });
+    require("../tools/exit");
     var args = process.argv.slice(2);
     var debug = args.indexOf("--debug");
     if (debug >= 0) {

test/mocha.js

@@ -1,29 +1,24 @@
-var Mocha = require('mocha'),
-    fs = require('fs'),
-    path = require('path');
+var fs = require("fs");
+var Mocha = require("mocha");
+var path = require("path");
 
-// Instantiate a Mocha instance.
-var mocha = new Mocha({});
+// Instantiate a Mocha instance
+var mocha = new Mocha({
+    timeout: 5000
+});
+var testDir = __dirname + "/mocha/";
 
-var testDir = __dirname + '/mocha/';
-
-// Add each .js file to the mocha instance
-fs.readdirSync(testDir).filter(function(file){
-    // Only keep the .js files
-    return file.substr(-3) === '.js';
-
-}).forEach(function(file){
-    mocha.addFile(
-        path.join(testDir, file)
-    );
+// Add each .js file to the Mocha instance
+fs.readdirSync(testDir).filter(function(file) {
+    return /\.js$/.test(file);
+}).forEach(function(file) {
+    mocha.addFile(path.join(testDir, file));
 });
 
 module.exports = function() {
     mocha.run(function(failures) {
-        if (failures !== 0) {
-            process.on('exit', function () {
-                process.exit(failures);
-            });
-        }
+        if (failures) process.on("exit", function() {
+            process.exit(failures);
+        });
     });
-};
+};

test/mocha/cli.js

@@ -408,7 +408,7 @@ describe("bin/uglifyjs", function () {
             assert.ok(err);
             assert.strictEqual(stdout, "");
             assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
-                "Parse error at test/input/invalid/const.js:7,11",
+                "Parse error at test/input/invalid/const.js:2,11",
                 "    const a;",
                 "           ^",
                 "ERROR: Missing initializer in const declaration"

test/mocha/comment-filter.js

@@ -14,7 +14,7 @@ describe("comment filters", function() {
 
     it("Should be able to filter commments with the 'some' option", function() {
         var ast = UglifyJS.parse("// foo\n/*@preserve*/\n// bar\n/*@license*/\n//@license with the wrong comment type\n/*@cc_on something*/");
-        assert.strictEqual(ast.print_to_string({comments: "some"}), "/*@preserve*/\n/*@license*/\n/*@cc_on something*/\n");
+        assert.strictEqual(ast.print_to_string({comments: "some"}), "/*@preserve*/\n/*@license*/\n/*@cc_on something*/");
     });
 
     it("Should be able to filter comments by passing a function", function() {
@@ -55,12 +55,12 @@ describe("comment filters", function() {
             return true;
         };
 
-        assert.strictEqual(ast.print_to_string({comments: f}), "#!Random comment\n//test1\n/*test2*/\n");
+        assert.strictEqual(ast.print_to_string({comments: f}), "#!Random comment\n//test1\n/*test2*/");
     });
 
     it("Should never be able to filter comment5 when using 'some' as filter", function() {
         var ast = UglifyJS.parse("#!foo\n//foo\n/*@preserve*/\n/* please hide me */");
-        assert.strictEqual(ast.print_to_string({comments: "some"}), "#!foo\n/*@preserve*/\n");
+        assert.strictEqual(ast.print_to_string({comments: "some"}), "#!foo\n/*@preserve*/");
     });
 
     it("Should have no problem on multiple calls", function() {

test/mocha/comment.js

@@ -48,4 +48,196 @@ describe("Comment", function() {
             }, fail, tests[i]);
         }
     });
+
+    it("Should handle comment within return correctly", function() {
+        var result = uglify.minify([
+            "function unequal(x, y) {",
+            "    return (",
+            "        // Either one",
+            "        x < y",
+            "        ||",
+            "        y < x",
+            "    );",
+            "}",
+        ].join("\n"), {
+            compress: false,
+            mangle: false,
+            output: {
+                beautify: true,
+                comments: "all",
+            },
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "function unequal(x, y) {",
+            "    // Either one",
+            "    return x < y || y < x;",
+            "}",
+        ].join("\n"));
+    });
+
+    it("Should handle comment folded into return correctly", function() {
+        var result = uglify.minify([
+            "function f() {",
+            "    /* boo */ x();",
+            "    return y();",
+            "}",
+        ].join("\n"), {
+            mangle: false,
+            output: {
+                beautify: true,
+                comments: "all",
+            },
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "function f() {",
+            "    /* boo */",
+            "    return x(), y();",
+            "}",
+        ].join("\n"));
+    });
+
+    it("Should not drop comments after first OutputStream", function() {
+        var code = "/* boo */\nx();";
+        var ast = uglify.parse(code);
+        var out1 = uglify.OutputStream({
+            beautify: true,
+            comments: "all",
+        });
+        ast.print(out1);
+        var out2 = uglify.OutputStream({
+            beautify: true,
+            comments: "all",
+        });
+        ast.print(out2);
+        assert.strictEqual(out1.get(), code);
+        assert.strictEqual(out2.get(), out1.get());
+    });
+
+    it("Should retain trailing comments", function() {
+        var code = [
+            "if (foo /* lost comment */ && bar /* lost comment */) {",
+            "    // this one is kept",
+            "    {/* lost comment */}",
+            "    !function() {",
+            "        // lost comment",
+            "    }();",
+            "    function baz() {/* lost comment */}",
+            "    // lost comment",
+            "}",
+            "// comments right before EOF are lost as well",
+        ].join("\n");
+        var result = uglify.minify(code, {
+            compress: false,
+            mangle: false,
+            output: {
+                beautify: true,
+                comments: "all",
+            },
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, code);
+    });
+
+    it("Should correctly preserve new lines around comments", function() {
+        var tests = [
+            [
+                "// foo",
+                "// bar",
+                "x();",
+            ].join("\n"),
+            [
+                "// foo",
+                "/* bar */",
+                "x();",
+            ].join("\n"),
+            [
+                "// foo",
+                "/* bar */ x();",
+            ].join("\n"),
+            [
+                "/* foo */",
+                "// bar",
+                "x();",
+            ].join("\n"),
+            [
+                "/* foo */ // bar",
+                "x();",
+            ].join("\n"),
+            [
+                "/* foo */",
+                "/* bar */",
+                "x();",
+            ].join("\n"),
+            [
+                "/* foo */",
+                "/* bar */ x();",
+            ].join("\n"),
+            [
+                "/* foo */ /* bar */",
+                "x();",
+            ].join("\n"),
+            "/* foo */ /* bar */ x();",
+        ].forEach(function(code) {
+            var result = uglify.minify(code, {
+                compress: false,
+                mangle: false,
+                output: {
+                    beautify: true,
+                    comments: "all",
+                },
+            });
+            if (result.error) throw result.error;
+            assert.strictEqual(result.code, code);
+        });
+    });
+
+    it("Should preserve new line before comment without beautify", function() {
+        var code = [
+            "function f(){",
+            "/* foo */bar()}",
+        ].join("\n");
+        var result = uglify.minify(code, {
+            compress: false,
+            mangle: false,
+            output: {
+                comments: "all",
+            },
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, code);
+    });
+
+    it("Should preserve comments around IIFE", function() {
+        var result = uglify.minify("/*a*/(/*b*/function(){/*c*/}/*d*/)/*e*/();", {
+            compress: false,
+            mangle: false,
+            output: {
+                comments: "all",
+            },
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, "/*a*/ /*b*/(function(){/*c*/}/*d*/ /*e*/)();");
+    });
+
+    it("Should output line comments after statements", function() {
+        var result = uglify.minify([
+            "x()//foo",
+            "{y()//bar",
+            "}",
+        ].join("\n"), {
+            compress: false,
+            mangle: false,
+            output: {
+                comments: "all",
+            },
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "x();//foo",
+            "{y();//bar",
+            "}",
+        ].join("\n"));
+    });
 });

test/mocha/glob.js

@@ -11,7 +11,7 @@ describe("bin/uglifyjs with input file globs", function() {
         exec(command, function(err, stdout) {
             if (err) throw err;
 
-            assert.strictEqual(stdout, 'function foo(o){print("Foo:",2*o)}var print=console.log.bind(console);\n');
+            assert.strictEqual(stdout, 'var print=console.log.bind(console);function foo(o){print("Foo:",2*o)}\n');
             done();
         });
     });
@@ -26,7 +26,7 @@ describe("bin/uglifyjs with input file globs", function() {
         });
     });
     it("bin/uglifyjs with multiple input file globs.", function(done) {
-        var command = uglifyjscmd + ' "test/input/issue-1242/???.es5" "test/input/issue-1242/*.js" -mc toplevel,passes=2';
+        var command = uglifyjscmd + ' "test/input/issue-1242/???.es5" "test/input/issue-1242/*.js" -mc toplevel,passes=3';
 
         exec(command, function(err, stdout) {
             if (err) throw err;

test/mocha/minify.js

@@ -42,8 +42,15 @@ describe("minify", function() {
             original += code;
             compressed += result.code;
         });
-        assert.strictEqual(JSON.stringify(cache).slice(0, 20), '{"cname":5,"props":{');
-        assert.strictEqual(compressed, 'function n(n){return 3*n}function r(n){return n/2}function c(o){l("Foo:",2*o)}var l=console.log.bind(console);var f=n(3),i=r(12);l("qux",f,i),c(11);');
+        assert.strictEqual(JSON.stringify(cache).slice(0, 10), '{"props":{');
+        assert.strictEqual(compressed, [
+            "function n(n){return 3*n}",
+            "function r(n){return n/2}",
+            "var o=console.log.bind(console);",
+            'function c(n){o("Foo:",2*n)}',
+            "var a=n(3),b=r(12);",
+            'o("qux",a,b),c(11);',
+        ].join(""));
         assert.strictEqual(run_code(compressed), run_code(original));
     });
 
@@ -68,12 +75,48 @@ describe("minify", function() {
             original += code;
             compressed += result.code;
         });
-        assert.strictEqual(JSON.stringify(cache).slice(0, 28), '{"vars":{"cname":5,"props":{');
-        assert.strictEqual(compressed, 'function n(n){return 3*n}function r(n){return n/2}function c(o){l("Foo:",2*o)}var l=console.log.bind(console);var f=n(3),i=r(12);l("qux",f,i),c(11);');
+        assert.strictEqual(JSON.stringify(cache).slice(0, 18), '{"vars":{"props":{');
+        assert.strictEqual(compressed, [
+            "function n(n){return 3*n}",
+            "function r(n){return n/2}",
+            "var o=console.log.bind(console);",
+            'function c(n){o("Foo:",2*n)}',
+            "var a=n(3),b=r(12);",
+            'o("qux",a,b),c(11);',
+        ].join(""));
         assert.strictEqual(run_code(compressed), run_code(original));
     });
 
-    it("should not parse invalid use of reserved words", function() {
+    it("Should avoid mangled names in cache", function() {
+        var cache = {};
+        var original = "";
+        var compressed = "";
+        [
+            '"xxxyy";var i={s:1};',
+            '"xxyyy";var j={t:2,u:3},k=4;',
+            'console.log(i.s,j.t,j.u,k);',
+        ].forEach(function(code) {
+            var result = Uglify.minify(code, {
+                compress: false,
+                mangle: {
+                    properties: true,
+                    toplevel: true
+                },
+                nameCache: cache
+            });
+            if (result.error) throw result.error;
+            original += code;
+            compressed += result.code;
+        });
+        assert.strictEqual(compressed, [
+            '"xxxyy";var x={x:1};',
+            '"xxyyy";var y={y:2,a:3},a=4;',
+            'console.log(x.x,y.y,y.a,a);',
+        ].join(""));
+        assert.strictEqual(run_code(compressed), run_code(original));
+    });
+
+    it("Should not parse invalid use of reserved words", function() {
         assert.strictEqual(Uglify.minify("function enum(){}").error, undefined);
         assert.strictEqual(Uglify.minify("function static(){}").error, undefined);
         assert.strictEqual(Uglify.minify("function super(){}").error.message, "Unexpected token: name (super)");
@@ -248,7 +291,7 @@ describe("minify", function() {
             var code = result.code;
             assert.strictEqual(code, "//  comment1   comment2\nbar();");
         });
-        it("should not drop #__PURE__ hint if function is retained", function() {
+        it("should drop #__PURE__ hint if function is retained", function() {
             var result = Uglify.minify("var a = /*#__PURE__*/(function(){ foo(); })();", {
                 output: {
                     comments: "all",
@@ -256,7 +299,7 @@ describe("minify", function() {
                 }
             });
             var code = result.code;
-            assert.strictEqual(code, "var a=/*#__PURE__*/function(){foo()}();");
+            assert.strictEqual(code, "var a=/* */function(){foo()}();");
         })
     });
 
@@ -361,4 +404,19 @@ describe("minify", function() {
             assert.strictEqual(stat.print_to_string(), "a=x()");
         });
     });
+
+    // rename is disabled on harmony due to expand_names bug in for-of loops
+    if (0) describe("rename", function() {
+        it("Should be repeatable", function() {
+            var code = "!function(x){return x(x)}(y);";
+            for (var i = 0; i < 2; i++) {
+                assert.strictEqual(Uglify.minify(code, {
+                    compress: {
+                        toplevel: true,
+                    },
+                    rename: true,
+                }).code, "var a;(a=y)(a);");
+            }
+        });
+    });
 });

test/mocha/yield.js

@@ -8,18 +8,6 @@ describe("Yield", function() {
         assert.strictEqual(result.code, 'function*foo(e){return yield 1,yield 2,3}');
     });
 
-    it("Should not allow yield as labelIdentifier within generators", function() {
-        var js = "function* g() {yield: 1}"
-        var test = function() {
-            UglifyJS.parse(js);
-        }
-        var expect = function(e) {
-            return e instanceof UglifyJS.JS_Parse_Error &&
-                e.message === "Yield cannot be used as label inside generators";
-        }
-        assert.throws(test, expect);
-    });
-
     it("Should not allow yield* followed by a semicolon in generators", function() {
         var js = "function* test() {yield*\n;}";
         var test = function() {
@@ -65,42 +53,68 @@ describe("Yield", function() {
         );
     });
 
+    var identifiers = [
+        // Fail in as_symbol
+        'import yield from "bar";',
+        'yield = 123;',
+        'yield: "123";',
+        'for(;;){break yield;}',
+        'for(;;){continue yield;}',
+        'function yield(){}',
+        'try { new Error("")} catch (yield) {}',
+        'var yield = "foo";',
+        'class yield {}',
+        // Fail in as_property_name
+        'var foo = {yield};',
+    ];
+
     it("Should not allow yield to be used as symbol, identifier or shorthand property outside generators in strict mode", function() {
-        var tests = [
-            // Fail in as_symbol
-            '"use strict"; import yield from "bar";',
-            '"use strict"; yield = 123;',
-            '"use strict"; yield: "123";',
-            '"use strict"; for(;;){break yield;}',
-            '"use strict"; for(;;){continue yield;}',
-            '"use strict"; function yield(){}',
-            '"use strict"; function foo(...yield){}',
-            '"use strict"; try { new Error("")} catch (yield) {}',
-            '"use strict"; var yield = "foo";',
-            '"use strict"; class yield {}',
-
-            // Fail in maybe_assign
-            '"use strict"; var foo = yield;',
-            '"use strict"; var foo = bar = yield',
-
-            // Fail in as_property_name
-            '"use strict"; var foo = {yield};',
-        ];
-
-        var fail = function(e) {
+        function fail(e) {
             return e instanceof UglifyJS.JS_Parse_Error &&
                 /^Unexpected yield identifier (?:as parameter )?inside strict mode/.test(e.message);
         }
 
-        var test = function(input) {
+        function test(input) {
             return function() {
                 UglifyJS.parse(input);
             }
         }
 
-        for (var i = 0; i < tests.length; i++) {
-            assert.throws(test(tests[i]), fail, tests[i]);
+        identifiers.concat([
+            // Fail in as_symbol
+            "function foo(...yield){}",
+            // Fail in maybe_assign
+            'var foo = yield;',
+            'var foo = bar = yield',
+        ]).map(function(code) {
+            return '"use strict"; ' + code;
+        }).forEach(function(code) {
+            assert.throws(test(code), fail, code);
+        });
+    });
+
+    it("Should not allow yield to be used as symbol, identifier or shorthand property inside generators", function() {
+        function fail(e) {
+            return e instanceof UglifyJS.JS_Parse_Error && [
+                "Unexpected token: operator (=)",
+                "Yield cannot be used as identifier inside generators",
+            ].indexOf(e.message) >= 0;
         }
+
+        function test(input) {
+            return function() {
+                UglifyJS.parse(input);
+            }
+        }
+
+        identifiers.map(function(code) {
+            return "function* f() { " + code + " }";
+        }).concat([
+            // Fail in as_symbol
+            "function* f(yield) {}",
+        ]).forEach(function(code) {
+            assert.throws(test(code), fail, code);
+        });
     });
 
     it("Should allow yield to be used as class/object property name", function() {

test/run-tests.js

@@ -10,6 +10,7 @@ var semver = require("semver");
 var tests_dir = path.dirname(module.filename);
 var failures = 0;
 var failed_files = {};
+var minify_options = require("./ufuzz.json").map(JSON.stringify);
 
 run_compress_tests();
 if (failures) {
@@ -100,6 +101,15 @@ function run_compress_tests() {
                 quote_style: 3,
                 keep_quoted_props: true
             });
+            try {
+                U.parse(input_code);
+            } catch (ex) {
+                log("!!! Cannot parse input\n---INPUT---\n{input}\n--PARSE ERROR--\n{error}\n\n", {
+                    input: input_formatted,
+                    error: ex,
+                });
+                return false;
+            }
             var options = U.defaults(test.options, {
                 warnings: false
             });
@@ -139,78 +149,77 @@ function run_compress_tests() {
                     output: output,
                     expected: expect
                 });
-                failures++;
-                failed_files[file] = 1;
+                return false;
             }
-            else {
-                // expect == output
-                try {
-                    var reparsed_ast = U.parse(output);
-                } catch (ex) {
-                    log("!!! Test matched expected result but cannot parse output\n---INPUT---\n{input}\n---OUTPUT---\n{output}\n--REPARSE ERROR--\n{error}\n\n", {
+            // expect == output
+            try {
+                U.parse(output);
+            } catch (ex) {
+                log("!!! Test matched expected result but cannot parse output\n---INPUT---\n{input}\n---OUTPUT---\n{output}\n--REPARSE ERROR--\n{error}\n\n", {
+                    input: input_formatted,
+                    output: output,
+                    error: ex,
+                });
+                return false;
+            }
+            if (test.expect_warnings) {
+                U.AST_Node.warn_function = original_warn_function;
+                var expected_warnings = make_code(test.expect_warnings, {
+                    beautify: false,
+                    quote_style: 2, // force double quote to match JSON
+                });
+                warnings_emitted = warnings_emitted.map(function(input) {
+                    return input.split(process.cwd() + path.sep).join("").split(path.sep).join("/");
+                });
+                var actual_warnings = JSON.stringify(warnings_emitted);
+                if (expected_warnings != actual_warnings) {
+                    log("!!! failed\n---INPUT---\n{input}\n---EXPECTED WARNINGS---\n{expected_warnings}\n---ACTUAL WARNINGS---\n{actual_warnings}\n\n", {
                         input: input_formatted,
-                        output: output,
-                        error: ex.toString(),
+                        expected_warnings: expected_warnings,
+                        actual_warnings: actual_warnings,
                     });
-                    failures++;
-                    failed_files[file] = 1;
-                }
-                if (test.expect_warnings) {
-                    U.AST_Node.warn_function = original_warn_function;
-                    var expected_warnings = make_code(test.expect_warnings, {
-                        beautify: false,
-                        quote_style: 2, // force double quote to match JSON
-                    });
-                    warnings_emitted = warnings_emitted.map(function(input) {
-                      return input.split(process.cwd() + path.sep).join("").split(path.sep).join("/");
-                    });
-                    var actual_warnings = JSON.stringify(warnings_emitted);
-                    if (expected_warnings != actual_warnings) {
-                        log("!!! failed\n---INPUT---\n{input}\n---EXPECTED WARNINGS---\n{expected_warnings}\n---ACTUAL WARNINGS---\n{actual_warnings}\n\n", {
-                            input: input_formatted,
-                            expected_warnings: expected_warnings,
-                            actual_warnings: actual_warnings,
-                        });
-                        failures++;
-                        failed_files[file] = 1;
-                    }
-                }
-                if (test.expect_stdout
-                    && (!test.node_version || semver.satisfies(process.version, test.node_version))) {
-                    var stdout = sandbox.run_code(input_code);
-                    if (test.expect_stdout === true) {
-                        test.expect_stdout = stdout;
-                    }
-                    if (!sandbox.same_stdout(test.expect_stdout, stdout)) {
-                        log("!!! Invalid input or expected stdout\n---INPUT---\n{input}\n---EXPECTED {expected_type}---\n{expected}\n---ACTUAL {actual_type}---\n{actual}\n\n", {
-                            input: input_formatted,
-                            expected_type: typeof test.expect_stdout == "string" ? "STDOUT" : "ERROR",
-                            expected: test.expect_stdout,
-                            actual_type: typeof stdout == "string" ? "STDOUT" : "ERROR",
-                            actual: stdout,
-                        });
-                        failures++;
-                        failed_files[file] = 1;
-                    } else {
-                        stdout = sandbox.run_code(output);
-                        if (!sandbox.same_stdout(test.expect_stdout, stdout)) {
-                            log("!!! failed\n---INPUT---\n{input}\n---EXPECTED {expected_type}---\n{expected}\n---ACTUAL {actual_type}---\n{actual}\n\n", {
-                                input: input_formatted,
-                                expected_type: typeof test.expect_stdout == "string" ? "STDOUT" : "ERROR",
-                                expected: test.expect_stdout,
-                                actual_type: typeof stdout == "string" ? "STDOUT" : "ERROR",
-                                actual: stdout,
-                            });
-                            failures++;
-                            failed_files[file] = 1;
-                        }
-                    }
+                    return false;
                 }
             }
+            if (test.expect_stdout
+                && (!test.node_version || semver.satisfies(process.version, test.node_version))) {
+                var stdout = sandbox.run_code(input_code);
+                if (test.expect_stdout === true) {
+                    test.expect_stdout = stdout;
+                }
+                if (!sandbox.same_stdout(test.expect_stdout, stdout)) {
+                    log("!!! Invalid input or expected stdout\n---INPUT---\n{input}\n---EXPECTED {expected_type}---\n{expected}\n---ACTUAL {actual_type}---\n{actual}\n\n", {
+                        input: input_formatted,
+                        expected_type: typeof test.expect_stdout == "string" ? "STDOUT" : "ERROR",
+                        expected: test.expect_stdout,
+                        actual_type: typeof stdout == "string" ? "STDOUT" : "ERROR",
+                        actual: stdout,
+                    });
+                    return false;
+                }
+                stdout = sandbox.run_code(output);
+                if (!sandbox.same_stdout(test.expect_stdout, stdout)) {
+                    log("!!! failed\n---INPUT---\n{input}\n---EXPECTED {expected_type}---\n{expected}\n---ACTUAL {actual_type}---\n{actual}\n\n", {
+                        input: input_formatted,
+                        expected_type: typeof test.expect_stdout == "string" ? "STDOUT" : "ERROR",
+                        expected: test.expect_stdout,
+                        actual_type: typeof stdout == "string" ? "STDOUT" : "ERROR",
+                        actual: stdout,
+                    });
+                    return false;
+                }
+                if (test.reminify && !reminify(test.options, input_code, input_formatted, test.expect_stdout)) {
+                    return false;
+                }
+            }
+            return true;
         }
         var tests = parse_test(path.resolve(dir, file));
         for (var i in tests) if (tests.hasOwnProperty(i)) {
-            test_case(tests[i]);
+            if (!test_case(tests[i])) {
+                failures++;
+                failed_files[file] = 1;
+            }
         }
     }
     files.forEach(function(file){
@@ -255,6 +264,16 @@ function parse_test(file) {
         }));
     }
 
+    function read_boolean(stat) {
+        if (stat.TYPE == "SimpleStatement") {
+            var body = stat.body;
+            if (body instanceof U.AST_Boolean) {
+                return body.value;
+            }
+        }
+        throw new Error("Should be boolean");
+    }
+
     function read_string(stat) {
         if (stat.TYPE == "SimpleStatement") {
             var body = stat.body;
@@ -273,7 +292,11 @@ function parse_test(file) {
     }
 
     function get_one_test(name, block) {
-        var test = { name: name, options: {} };
+        var test = {
+            name: name,
+            options: {},
+            reminify: true,
+        };
         var tw = new U.TreeWalker(function(node, descend){
             if (node instanceof U.AST_Assign) {
                 if (!(node.left instanceof U.AST_SymbolRef)) {
@@ -293,6 +316,7 @@ function parse_test(file) {
                         "expect_warnings",
                         "expect_stdout",
                         "node_version",
+                        "reminify",
                     ].indexOf(label.name) >= 0,
                     tmpl("Unsupported label {name} [{line},{col}]", {
                         name: label.name,
@@ -303,6 +327,9 @@ function parse_test(file) {
                 var stat = node.body;
                 if (label.name == "expect_exact" || label.name == "node_version") {
                     test[label.name] = read_string(stat);
+                } else if (label.name == "reminify") {
+                    var value = read_boolean(stat);
+                    test.reminify = value == null || value;
                 } else if (label.name == "expect_stdout") {
                     var body = stat.body;
                     if (body instanceof U.AST_Boolean) {
@@ -346,3 +373,49 @@ function evaluate(code) {
         code = make_code(code, { beautify: true });
     return new Function("return(" + code + ")")();
 }
+
+// Try to reminify original input with standard options
+// to see if it matches expect_stdout.
+function reminify(orig_options, input_code, input_formatted, expect_stdout) {
+    for (var i = 0; i < minify_options.length; i++) {
+        var options = JSON.parse(minify_options[i]);
+        options.keep_fnames = orig_options.keep_fnames;
+        options.keep_classnames = orig_options.keep_classnames;
+        if (orig_options.compress) {
+            options.compress.keep_classnames = orig_options.compress.keep_classnames;
+            options.compress.keep_fargs = orig_options.compress.keep_fargs;
+            options.compress.keep_fnames = orig_options.compress.keep_fnames;
+        }
+        if (orig_options.mangle) {
+            options.mangle.keep_classnames = orig_options.mangle.keep_classnames;
+            options.mangle.keep_fnames = orig_options.mangle.keep_fnames;
+        }
+        var options_formatted = JSON.stringify(options, null, 4);
+        var result = U.minify(input_code, options);
+        if (result.error) {
+            log("!!! failed input reminify\n---INPUT---\n{input}\n--ERROR---\n{error}\n\n", {
+                input: input_formatted,
+                error: result.error,
+            });
+            return false;
+        } else {
+            var stdout = sandbox.run_code(result.code);
+            if (typeof expect_stdout != "string" && typeof stdout != "string" && expect_stdout.name == stdout.name) {
+                stdout = expect_stdout;
+            }
+            if (!sandbox.same_stdout(expect_stdout, stdout)) {
+                log("!!! failed running reminified input\n---INPUT---\n{input}\n---OPTIONS---\n{options}\n---OUTPUT---\n{output}\n---EXPECTED {expected_type}---\n{expected}\n---ACTUAL {actual_type}---\n{actual}\n\n", {
+                    input: input_formatted,
+                    options: options_formatted,
+                    output: result.code,
+                    expected_type: typeof expect_stdout == "string" ? "STDOUT" : "ERROR",
+                    expected: expect_stdout,
+                    actual_type: typeof stdout == "string" ? "STDOUT" : "ERROR",
+                    actual: stdout,
+                });
+                return false;
+            }
+        }
+    }
+    return true;
+}

test/sandbox.js

@@ -17,26 +17,33 @@ function safe_log(arg, level) {
     return arg;
 }
 
+function strip_func_ids(text) {
+    return text.toString().replace(/F[0-9]{6}N/g, "<F<>N>");
+}
+
 var FUNC_TOSTRING = [
+    "[ Array, Boolean, Error, Function, Number, Object, RegExp, String].forEach(function(f) {",
+    "    f.toString = Function.prototype.toString;",
+    "    f.valueOf = Function.prototype.valueOf;",
+    "});",
     "Function.prototype.toString = Function.prototype.valueOf = function() {",
     "    var id = 100000;",
     "    return function() {",
-    '        if (this === Array) return "[Function: Array]";',
-    '        if (this === Object) return "[Function: Object]";',
-    "        var i = this.name;",
-    '        if (typeof i != "number") {',
-    "            i = ++id;",
+    "        var n = this.name;",
+    '        if (!/^F[0-9]{6}N$/.test(n)) {',
+    '            n = "F" + ++id + "N";',
 ].concat(Object.getOwnPropertyDescriptor(Function.prototype, "name").configurable ? [
     '            Object.defineProperty(this, "name", {',
     "                get: function() {",
-    "                    return i;",
+    "                    return n;",
     "                }",
     "            });",
 ] : [], [
     "        }",
-    '        return "[Function: " + i + "]";',
+    '        return "[Function: " + n + "]";',
     "    }",
     "}();",
+    'Object.defineProperty(Function.prototype, "valueOf", { enumerable: false });',
 ]).join("\n");
 exports.run_code = function(code) {
     var stdout = "";
@@ -76,7 +83,7 @@ exports.same_stdout = semver.satisfies(process.version, "0.12") ? function(expec
         expected = expected.message.slice(expected.message.lastIndexOf("\n") + 1);
         actual = actual.message.slice(actual.message.lastIndexOf("\n") + 1);
     }
-    return expected == actual;
+    return strip_func_ids(expected) == strip_func_ids(actual);
 } : function(expected, actual) {
-    return typeof expected == typeof actual && expected.toString() == actual.toString();
+    return typeof expected == typeof actual && strip_func_ids(expected) == strip_func_ids(actual);
 };

test/travis-ufuzz.js

@@ -0,0 +1,82 @@
+"use strict";
+
+var child_process = require("child_process");
+var https = require("https");
+var url = require("url");
+
+var period = 45 * 60 * 1000;
+var wait = 2 * 60 * 1000;
+var ping = 5 * 60 * 1000;
+if (process.argv[2] == "run") {
+    var endTime = Date.now() + period;
+    for (var i = 0; i < 2; i++) spawn(endTime);
+} else if (process.argv.length > 2) {
+    var token = process.argv[2];
+    var branch = process.argv[3] || "v" + require("../package.json").version;
+    var repository = encodeURIComponent(process.argv[4] || "mishoo/UglifyJS2");
+    var concurrency = process.argv[5] || 1;
+    (function request() {
+        setTimeout(request, (period + wait) / concurrency);
+        var options = url.parse("https://api.travis-ci.org/repo/" + repository + "/requests");
+        options.method = "POST";
+        options.headers = {
+            "Content-Type": "application/json",
+            "Travis-API-Version": 3,
+            "Authorization": "token " + token
+        };
+        https.request(options, function(res) {
+            console.log("HTTP", res.statusCode);
+            console.log(JSON.stringify(res.headers, null, 2));
+            console.log();
+            res.setEncoding("utf8");
+            res.on("data", console.log);
+        }).on("error", console.error).end(JSON.stringify({
+            request: {
+                message: "ufuzz testing (when idle)",
+                branch: branch,
+                config: {
+                    merge_mode: "replace",
+                    language: "node_js",
+                    node_js: "9",
+                    sudo: false,
+                    script: "node test/travis-ufuzz run"
+                }
+            }
+        }));
+    })();
+} else {
+    console.log("Usage: test/travis-ufuzz.js <token> [branch] [repository] [concurrency]");
+}
+
+function spawn(endTime) {
+    var child = child_process.spawn("node", [
+        "--max-old-space-size=2048",
+        "test/ufuzz"
+    ], {
+        stdio: [ "ignore", "pipe", "pipe" ]
+    }).on("exit", respawn);
+    var line = "";
+    child.stdout.on("data", function(data) {
+        line += data;
+    });
+    child.stderr.on("data", function() {
+        process.exitCode = 1;
+    }).pipe(process.stdout);
+    var keepAlive = setInterval(function() {
+        var end = line.lastIndexOf("\r");
+        console.log(line.slice(line.lastIndexOf("\r", end - 1) + 1, end));
+        line = line.slice(end + 1);
+    }, ping);
+    var timer = setTimeout(function() {
+        clearInterval(keepAlive);
+        child.removeListener("exit", respawn);
+        child.kill();
+    }, endTime - Date.now());
+
+    function respawn() {
+        console.log(line);
+        clearInterval(keepAlive);
+        clearTimeout(timer);
+        spawn(endTime);
+    }
+}

test/ufuzz.js

@@ -6,11 +6,7 @@
 // bin/uglifyjs s.js -c && bin/uglifyjs s.js -c passes=3 && bin/uglifyjs s.js -c passes=3 -m
 // cat s.js | node && node s.js && bin/uglifyjs s.js -c | node && bin/uglifyjs s.js -c passes=3 | node && bin/uglifyjs s.js -c passes=3 -m | node
 
-// workaround for tty output truncation upon process.exit()
-[process.stdout, process.stderr].forEach(function(stream){
-    if (stream._handle && stream._handle.setBlocking)
-        stream._handle.setBlocking(true);
-});
+require("../tools/exit");
 
 var UglifyJS = require("..");
 var randomBytes = require("crypto").randomBytes;
@@ -127,6 +123,9 @@ for (var i = 2; i < process.argv.length; ++i) {
 }
 
 var VALUES = [
+    '"a"',
+    '"b"',
+    '"c"',
     '""',
     'true',
     'false',
@@ -263,10 +262,8 @@ var CAN_CONTINUE = true;
 var CANNOT_CONTINUE = false;
 var CAN_RETURN = false;
 var CANNOT_RETURN = true;
-var NOT_GLOBAL = true;
-var IN_GLOBAL = true;
-var ANY_TYPE = false;
-var NO_DECL = true;
+var NO_DEFUN = false;
+var DEFUN_OK = true;
 var DONT_STORE = true;
 
 var VAR_NAMES = [
@@ -307,6 +304,7 @@ var TYPEOF_OUTCOMES = [
 var unique_vars = [];
 var loops = 0;
 var funcs = 0;
+var called = Object.create(null);
 var labels = 10000;
 
 function rng(max) {
@@ -323,21 +321,23 @@ function createTopLevelCode() {
     unique_vars.length = 0;
     loops = 0;
     funcs = 0;
+    called = Object.create(null);
     return [
         strictMode(),
-        'var a = 100, b = 10, c = 0;',
+        'var _calls_ = 10, a = 100, b = 10, c = 0;',
         rng(2) == 0
         ? createStatements(3, MAX_GENERATION_RECURSION_DEPTH, CANNOT_THROW, CANNOT_BREAK, CANNOT_CONTINUE, CANNOT_RETURN, 0)
-        : createFunctions(rng(MAX_GENERATED_TOPLEVELS_PER_RUN) + 1, MAX_GENERATION_RECURSION_DEPTH, IN_GLOBAL, ANY_TYPE, CANNOT_THROW, 0),
-        'console.log(null, a, b, c);' // preceding `null` makes for a cleaner output (empty string still shows up etc)
+        : createFunctions(rng(MAX_GENERATED_TOPLEVELS_PER_RUN) + 1, MAX_GENERATION_RECURSION_DEPTH, DEFUN_OK, CANNOT_THROW, 0),
+        // preceding `null` makes for a cleaner output (empty string still shows up etc)
+        'console.log(null, a, b, c, Infinity, NaN, undefined);'
     ].join('\n');
 }
 
-function createFunctions(n, recurmax, inGlobal, noDecl, canThrow, stmtDepth) {
+function createFunctions(n, recurmax, allowDefun, canThrow, stmtDepth) {
     if (--recurmax < 0) { return ';'; }
     var s = '';
     while (n-- > 0) {
-        s += createFunction(recurmax, inGlobal, noDecl, canThrow, stmtDepth) + '\n';
+        s += createFunction(recurmax, allowDefun, canThrow, stmtDepth) + '\n';
     }
     return s;
 }
@@ -363,16 +363,16 @@ function filterDirective(s) {
     return s;
 }
 
-function createFunction(recurmax, inGlobal, noDecl, canThrow, stmtDepth) {
+function createFunction(recurmax, allowDefun, canThrow, stmtDepth) {
     if (--recurmax < 0) { return ';'; }
     if (!STMT_COUNT_FROM_GLOBAL) stmtDepth = 0;
-    var func = funcs++;
     var namesLenBefore = VAR_NAMES.length;
     var name;
-    if (inGlobal || rng(5) > 0) name = 'f' + func;
-    else {
+    if (allowDefun || rng(5) > 0) {
+        name = 'f' + funcs++;
+    } else {
         unique_vars.push('a', 'b', 'c');
-        name = createVarName(MANDATORY, noDecl);
+        name = createVarName(MANDATORY, !allowDefun);
         unique_vars.length -= 3;
     }
     var s = [
@@ -381,7 +381,7 @@ function createFunction(recurmax, inGlobal, noDecl, canThrow, stmtDepth) {
     ];
     if (rng(5) === 0) {
         // functions with functions. lower the recursion to prevent a mess.
-        s.push(createFunctions(rng(5) + 1, Math.ceil(recurmax * 0.7), NOT_GLOBAL, ANY_TYPE, canThrow, stmtDepth));
+        s.push(createFunctions(rng(5) + 1, Math.ceil(recurmax * 0.7), DEFUN_OK, canThrow, stmtDepth));
     } else {
         // functions with statements
         s.push(createStatements(3, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth));
@@ -391,12 +391,16 @@ function createFunction(recurmax, inGlobal, noDecl, canThrow, stmtDepth) {
 
     VAR_NAMES.length = namesLenBefore;
 
-    if (noDecl) s = 'var ' + createVarName(MANDATORY) + ' = ' + s;
-    // avoid "function statements" (decl inside statements)
-    else if (inGlobal || rng(10) > 0) s += 'var ' + createVarName(MANDATORY) + ' = ' + name;
-    s += '(' + createArgs(recurmax, stmtDepth, canThrow) + ');';
+    if (!allowDefun) {
+        // avoid "function statements" (decl inside statements)
+        s = 'var ' + createVarName(MANDATORY) + ' = ' + s;
+        s += '(' + createArgs(recurmax, stmtDepth, canThrow) + ')';
+    } else if (!(name in called) || rng(3) > 0) {
+        s += 'var ' + createVarName(MANDATORY) + ' = ' + name;
+        s += '(' + createArgs(recurmax, stmtDepth, canThrow) + ')';
+    }
 
-    return s;
+    return s + ';';
 }
 
 function createStatements(n, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) {
@@ -541,7 +545,7 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
       case STMT_FUNC_EXPR:
         // "In non-strict mode code, functions can only be declared at top level, inside a block, or ..."
         // (dont both with func decls in `if`; it's only a parser thing because you cant call them without a block)
-        return '{' + createFunction(recurmax, NOT_GLOBAL, NO_DECL, canThrow, stmtDepth) + '}';
+        return '{' + createFunction(recurmax, NO_DEFUN, canThrow, stmtDepth) + '}';
       case STMT_TRY:
         // catch var could cause some problems
         // note: the "blocks" are syntactically mandatory for try/catch/finally
@@ -631,6 +635,8 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
       case p++:
       case p++:
         return getVarName();
+      case p++:
+        return getVarName() + createAssignment() + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow);
       case p++:
         return createExpression(recurmax, COMMA_OK, stmtDepth, canThrow);
       case p++:
@@ -648,7 +654,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
                 '(function ' + name + '(){',
                 strictMode(),
                 createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
-                '})()'
+                rng(2) == 0 ? '})' : '})()'
             );
             break;
           case 1:
@@ -687,7 +693,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
             }
             s.push(
                 createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
-                '}'
+                rng(2) == 0 ? '}' : '}()'
             );
             break;
         }
@@ -754,6 +760,13 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
       case p++:
         var name = getVarName();
         return name + ' && ' + name + '.' + getDotKey();
+      case p++:
+      case p++:
+      case p++:
+      case p++:
+        var name = rng(3) == 0 ? getVarName() : 'f' + rng(funcs + 2);
+        called[name] = true;
+        return 'typeof ' + name + ' == "function" && --_calls_ >= 0 && ' + name + '(' + createArgs(recurmax, stmtDepth, canThrow) + ')';
     }
     _createExpression.N = p;
     return _createExpression(recurmax, noComma, stmtDepth, canThrow);
@@ -985,10 +998,11 @@ function log_suspects(minify_options, component) {
     if (typeof options != "object") options = {};
     var defs = default_options[component];
     var suspects = Object.keys(defs).filter(function(name) {
-        if ((name in options ? options : defs)[name]) {
+        var flip = name == "keep_fargs";
+        if (flip ? name in options : (name in options ? options : defs)[name]) {
             var m = JSON.parse(JSON.stringify(minify_options));
             var o = JSON.parse(JSON.stringify(options));
-            o[name] = false;
+            o[name] = flip;
             m[component] = o;
             var result = UglifyJS.minify(original_code, m);
             if (result.error) {
@@ -1009,6 +1023,23 @@ function log_suspects(minify_options, component) {
     }
 }
 
+function log_rename(options) {
+    var m = JSON.parse(JSON.stringify(options));
+    m.rename = false;
+    var result = UglifyJS.minify(original_code, m);
+    if (result.error) {
+        errorln("Error testing options.rename");
+        errorln(result.error.stack);
+    } else {
+        var r = sandbox.run_code(result.code);
+        if (sandbox.same_stdout(original_result, r)) {
+            errorln("Suspicious options:");
+            errorln("  rename");
+            errorln();
+        }
+    }
+}
+
 function log(options) {
     if (!ok) errorln('\n\n\n\n\n\n!!!!!!!!!!\n\n\n');
     errorln("//=============================================================");
@@ -1043,6 +1074,7 @@ function log(options) {
     errorln();
     if (!ok && typeof uglify_code == "string") {
         Object.keys(default_options).forEach(log_suspects.bind(null, options));
+        log_rename(options);
         errorln("!!!!!! Failed... round " + round);
     }
 }

test/ufuzz.json

@@ -5,7 +5,8 @@
         "output": {
             "beautify": true,
             "bracketize": true
-        }
+        },
+        "rename": true
     },
     {
         "compress": false
@@ -15,15 +16,18 @@
     },
     {},
     {
-        "compress": {
-            "hoist_props": true
-        },
         "toplevel": true
     },
     {
         "compress": {
             "keep_fargs": false,
-            "passes": 3
+            "passes": 1e6,
+            "sequences": 1e6,
+            "unsafe": true,
+            "unsafe_Function": true,
+            "unsafe_math": true,
+            "unsafe_proto": true,
+            "unsafe_regexp": true
         }
     }
 ]

tools/exit.js

@@ -0,0 +1,15 @@
+// workaround for tty output truncation upon process.exit()
+var exit = process.exit;
+process.exit = function() {
+    var args = [].slice.call(arguments);
+    process.once("uncaughtException", function() {
+        (function callback() {
+            if (process.stdout.bufferSize || process.stderr.bufferSize) {
+                setImmediate(callback);
+            } else {
+                exit.apply(process, args);
+            }
+        })();
+    });
+    throw exit;
+};

tools/exports.js

@@ -2,4 +2,5 @@ exports["Dictionary"] = Dictionary;
 exports["TreeWalker"] = TreeWalker;
 exports["TreeTransformer"] = TreeTransformer;
 exports["minify"] = minify;
+exports["parse"] = parse;
 exports["_push_uniq"] = push_uniq;