v3.3.17

fixes #3035

README.md

@@ -6,9 +6,8 @@ UglifyJS is a JavaScript parser, minifier, compressor and beautifier toolkit.
 #### Note:
 - **`uglify-js@3` has a simplified [API](#api-reference) and [CLI](#command-line-usage) that is not backwards compatible with [`uglify-js@2`](https://github.com/mishoo/UglifyJS2/tree/v2.x)**.
 - **Documentation for UglifyJS `2.x` releases can be found [here](https://github.com/mishoo/UglifyJS2/tree/v2.x)**.
-- `uglify-js` only supports ECMAScript 5 (ES5).
-- Those wishing to minify
-ES2015+ (ES6+) should use the `npm` package [**uglify-es**](https://github.com/mishoo/UglifyJS2/tree/harmony).
+- `uglify-js` only supports JavaScript (ECMAScript 5).
+- To minify ECMAScript 2015 or above, transpile using tools like [Babel](https://babeljs.io/).
 
 Install
 -------
@@ -598,6 +597,9 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 ## Compress options
 
+- `arguments` (default: `true`) -- replace `arguments[index]` with function
+  parameter name whenever possible.
+
 - `booleans` (default: `true`) -- various optimizations for boolean context,
   for example `!!a ? b : c → a ? b : c`
 
@@ -605,8 +607,8 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   side effects permitting.
 
 - `comparisons` (default: `true`) -- apply certain optimizations to binary nodes,
-  e.g. `!(a <= b) → a > b` (only when `unsafe_comps`), attempts to negate binary
-  nodes, e.g. `a = !b && !c && !d && !e → a=!(b||c||d||e)` etc.
+  e.g. `!(a <= b) → a > b`, attempts to negate binary nodes, e.g.
+  `a = !b && !c && !d && !e → a=!(b||c||d||e)` etc.
 
 - `conditionals` (default: `true`) -- apply optimizations for `if`-s and conditional
   expressions
@@ -730,12 +732,8 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 - `unsafe` (default: `false`) -- apply "unsafe" transformations (discussion below)
 
-- `unsafe_comps` (default: `false`) -- Reverse `<` and `<=` to `>` and `>=` to
-  allow improved compression. This might be unsafe when an at least one of two
-  operands is an object with computed values due the use of methods like `get`,
-  or `valueOf`. This could cause change in execution order after operands in the
-  comparison are switching. Compression only works if both `comparisons` and
-  `unsafe_comps` are both set to true.
+- `unsafe_comps` (default: `false`) -- compress expressions like `a <= b` assuming
+  none of the operands can be (coerced to) `NaN`.
 
 - `unsafe_Function` (default: `false`) -- compress and mangle `Function(args, code)`
   when both `args` and `code` are string literals.
@@ -826,7 +824,7 @@ can pass additional arguments that control the code output:
   when you want to generate minified code, in order to specify additional
   arguments, so you can use `-b beautify=false` to override it.
 
-- `bracketize` (default `false`) -- always insert brackets in `if`, `for`,
+- `braces` (default `false`) -- always insert braces in `if`, `for`,
   `do`, `while` or `with` statements, even if their body is a single
   statement.
 
@@ -838,8 +836,8 @@ can pass additional arguments that control the code output:
 
 - `indent_start` (default `0`) -- prefix all lines by that many spaces
 
-- `inline_script` (default `false`) -- escape the slash in occurrences of
-  `</script` in strings
+- `inline_script` (default `true`) -- escape HTML comments and the slash in
+  occurrences of `</script>` in strings
 
 - `keep_quoted_props` (default `false`) -- when turned on, prevents stripping
   quotes from property names in object literals.

lib/ast.js

@@ -165,7 +165,7 @@ function walk_body(node, visitor) {
 };
 
 var AST_Block = DEFNODE("Block", "body", {
-    $documentation: "A body of statements (usually bracketed)",
+    $documentation: "A body of statements (usually braced)",
     $propdoc: {
         body: "[AST_Statement*] an array of statements"
     },
@@ -916,5 +916,25 @@ TreeWalker.prototype = {
                 || node instanceof AST_Break && x instanceof AST_Switch)
                 return x;
         }
+    },
+    in_boolean_context: function() {
+        var self = this.self();
+        for (var i = 0, p; p = this.parent(i); i++) {
+            if (p instanceof AST_SimpleStatement
+                || p instanceof AST_Conditional && p.condition === self
+                || p instanceof AST_DWLoop && p.condition === self
+                || p instanceof AST_For && p.condition === self
+                || p instanceof AST_If && p.condition === self
+                || p instanceof AST_UnaryPrefix && p.operator == "!" && p.expression === self) {
+                return true;
+            }
+            if (p instanceof AST_Binary && (p.operator == "&&" || p.operator == "||")
+                || p instanceof AST_Conditional
+                || p.tail_node() === self) {
+                self = p;
+            } else {
+                return false;
+            }
+        }
     }
 };

lib/compress.js

@@ -48,6 +48,7 @@ function Compressor(options, false_by_default) {
         return new Compressor(options, false_by_default);
     TreeTransformer.call(this, this.before, this.after);
     this.options = defaults(options, {
+        arguments     : !false_by_default,
         booleans      : !false_by_default,
         collapse_vars : !false_by_default,
         comparisons   : !false_by_default,
@@ -146,27 +147,6 @@ merge(Compressor.prototype, {
                 return true;
         return false;
     },
-    in_boolean_context: function() {
-        if (!this.option("booleans")) return false;
-        var self = this.self();
-        for (var i = 0, p; p = this.parent(i); i++) {
-            if (p instanceof AST_SimpleStatement
-                || p instanceof AST_Conditional && p.condition === self
-                || p instanceof AST_DWLoop && p.condition === self
-                || p instanceof AST_For && p.condition === self
-                || p instanceof AST_If && p.condition === self
-                || p instanceof AST_UnaryPrefix && p.operator == "!" && p.expression === self) {
-                return true;
-            }
-            if (p instanceof AST_Binary && (p.operator == "&&" || p.operator == "||")
-                || p instanceof AST_Conditional
-                || p.tail_node() === self) {
-                self = p;
-            } else {
-                return false;
-            }
-        }
-    },
     compress: function(node) {
         if (this.option("expression")) {
             node.process_expression(true);
@@ -516,6 +496,15 @@ merge(Compressor.prototype, {
             pop(tw);
             return true;
         });
+        def(AST_Case, function(tw) {
+            push(tw);
+            this.expression.walk(tw);
+            pop(tw);
+            push(tw);
+            walk_body(this, tw);
+            pop(tw);
+            return true;
+        });
         def(AST_Conditional, function(tw) {
             this.condition.walk(tw);
             push(tw);
@@ -526,6 +515,12 @@ merge(Compressor.prototype, {
             pop(tw);
             return true;
         });
+        def(AST_Default, function(tw, descend) {
+            push(tw);
+            descend();
+            pop(tw);
+            return true;
+        });
         def(AST_Defun, function(tw, descend, compressor) {
             this.inlined = false;
             var save_ids = tw.safe_ids;
@@ -623,12 +618,6 @@ merge(Compressor.prototype, {
             pop(tw);
             return true;
         });
-        def(AST_SwitchBranch, function(tw, descend) {
-            push(tw);
-            descend();
-            pop(tw);
-            return true;
-        });
         def(AST_SymbolCatch, function() {
             this.definition().fixed = false;
         });
@@ -777,8 +766,7 @@ merge(Compressor.prototype, {
                 lhs = lhs.fixed_value();
             }
             if (!lhs) return true;
-            if (lhs instanceof AST_RegExp) return false;
-            if (lhs instanceof AST_Constant) return true;
+            if (lhs.is_constant()) return true;
             return is_lhs_read_only(lhs);
         }
         return false;
@@ -890,6 +878,11 @@ merge(Compressor.prototype, {
         return x;
     };
 
+    function root_expr(prop) {
+        while (prop instanceof AST_PropAccess) prop = prop.expression;
+        return prop;
+    }
+
     function is_iife_call(node) {
         if (node.TYPE != "Call") return false;
         return node.expression instanceof AST_Function || is_iife_call(node.expression);
@@ -913,8 +906,8 @@ merge(Compressor.prototype, {
     }
 
     function tighten_body(statements, compressor) {
-        var scope = compressor.find_parent(AST_Scope);
-        var in_loop = is_in_loop();
+        var in_loop, in_try, scope;
+        find_loop_scope_try();
         var CHANGED, max_iter = 10;
         do {
             CHANGED = false;
@@ -937,12 +930,20 @@ merge(Compressor.prototype, {
             }
         } while (CHANGED && max_iter-- > 0);
 
-        function is_in_loop() {
-            for (var node, level = 0; node = compressor.parent(level); level++) {
-                if (node instanceof AST_IterationStatement) return true;
-                if (node instanceof AST_Scope) break;
-            }
-            return false;
+        function find_loop_scope_try() {
+            var node = compressor.self(), level = 0;
+            do {
+                if (node instanceof AST_Catch || node instanceof AST_Finally) {
+                    level++;
+                } else if (node instanceof AST_IterationStatement) {
+                    in_loop = true;
+                } else if (node instanceof AST_Scope) {
+                    scope = node;
+                    break;
+                } else if (node instanceof AST_Try) {
+                    in_try = true;
+                }
+            } while (node = compressor.parent(level++));
         }
 
         // Search from right to left for assignment-like expressions:
@@ -957,9 +958,8 @@ merge(Compressor.prototype, {
             if (scope.uses_eval || scope.uses_with) return statements;
             var args;
             var candidates = [];
-            var in_try = compressor.self() instanceof AST_Try;
             var stat_index = statements.length;
-            var scanner = new TreeTransformer(function(node, descend) {
+            var scanner = new TreeTransformer(function(node) {
                 if (abort) return node;
                 // Skip nodes before `candidate` as quickly as possible
                 if (!hit) {
@@ -987,17 +987,19 @@ merge(Compressor.prototype, {
                     return node;
                 }
                 // Stop only if candidate is found within conditional branches
-                if (!stop_if_hit && (!lhs_local || !replace_all)
+                if (!stop_if_hit
                     && (parent instanceof AST_Binary && lazy_op(parent.operator) && parent.left !== node
                         || parent instanceof AST_Conditional && parent.condition !== node
                         || parent instanceof AST_If && parent.condition !== node)) {
                     stop_if_hit = parent;
                 }
                 // Replace variable with assignment when found
+                var hit_lhs, hit_rhs;
                 if (can_replace
                     && !(node instanceof AST_SymbolDeclaration)
-                    && lhs.equivalent_to(node)) {
-                    if (stop_if_hit) {
+                    && (scan_lhs && (hit_lhs = lhs.equivalent_to(node))
+                        || scan_rhs && (hit_rhs = scan_rhs(node, this)))) {
+                    if (stop_if_hit && (hit_rhs || !lhs_local || !replace_all)) {
                         abort = true;
                         return node;
                     }
@@ -1049,7 +1051,8 @@ merge(Compressor.prototype, {
                     || node instanceof AST_PropAccess
                         && (side_effects || node.expression.may_throw_on_access(compressor))
                     || node instanceof AST_SymbolRef
-                        && (lvalues[node.name] || side_effects && may_modify(node))
+                        && (symbol_in_lvalues(node) || side_effects && may_modify(node))
+                    || node instanceof AST_This && symbol_in_lvalues(node)
                     || node instanceof AST_VarDef && node.value
                         && (node.name.name in lvalues || side_effects && may_modify(node.name))
                     || (sym = is_lhs(node.left, node))
@@ -1104,12 +1107,15 @@ merge(Compressor.prototype, {
                     var stop_after = null;
                     var stop_if_hit = null;
                     var lhs = get_lhs(candidate);
-                    if (!lhs || is_lhs_read_only(lhs) || lhs.has_side_effects(compressor)) continue;
+                    var rhs = get_rhs(candidate);
+                    var side_effects = lhs && lhs.has_side_effects(compressor);
+                    var scan_lhs = lhs && !side_effects && !is_lhs_read_only(lhs);
+                    var scan_rhs = rhs && foldable(rhs);
+                    if (!scan_lhs && !scan_rhs) continue;
                     // Locate symbols which may execute code outside of scanning range
                     var lvalues = get_lvalues(candidate);
                     var lhs_local = is_lhs_local(lhs);
-                    if (lhs instanceof AST_SymbolRef) lvalues[lhs.name] = false;
-                    var side_effects = value_has_side_effects(candidate);
+                    if (!side_effects) side_effects = value_has_side_effects(candidate);
                     var replace_all = replace_all_symbols();
                     var may_throw = candidate.may_throw(compressor);
                     var funarg = candidate.name instanceof AST_SymbolFunarg;
@@ -1214,9 +1220,7 @@ merge(Compressor.prototype, {
             function extract_candidates(expr) {
                 hit_stack.push(expr);
                 if (expr instanceof AST_Assign) {
-                    if (!expr.left.has_side_effects(compressor)) {
-                        candidates.push(hit_stack.slice());
-                    }
+                    candidates.push(hit_stack.slice());
                     extract_candidates(expr.right);
                 } else if (expr instanceof AST_Binary) {
                     extract_candidates(expr.left);
@@ -1354,21 +1358,69 @@ merge(Compressor.prototype, {
                 }
             }
 
+            function get_rhs(expr) {
+                if (!(candidate instanceof AST_Assign && candidate.operator == "=")) return;
+                return candidate.right;
+            }
+
             function get_rvalue(expr) {
                 return expr[expr instanceof AST_Assign ? "right" : "value"];
             }
 
+            function foldable(expr) {
+                if (expr instanceof AST_SymbolRef) {
+                    var value = expr.evaluate(compressor);
+                    if (value === expr) return rhs_exact_match;
+                    return rhs_fuzzy_match(value, rhs_exact_match);
+                }
+                if (expr instanceof AST_This) return rhs_exact_match;
+                if (expr.is_truthy()) return rhs_fuzzy_match(true, return_false);
+                if (expr.is_constant()) {
+                    return rhs_fuzzy_match(expr.evaluate(compressor), rhs_exact_match);
+                }
+                if (!(lhs instanceof AST_SymbolRef)) return false;
+                if (expr.has_side_effects(compressor)) return false;
+                var circular;
+                var def = lhs.definition();
+                expr.walk(new TreeWalker(function(node) {
+                    if (circular) return true;
+                    if (node instanceof AST_SymbolRef && node.definition() === def) {
+                        circular = true;
+                    }
+                }));
+                return !circular && rhs_exact_match;
+            }
+
+            function rhs_exact_match(node) {
+                return rhs.equivalent_to(node);
+            }
+
+            function rhs_fuzzy_match(value, fallback) {
+                return function(node, tw) {
+                    if (tw.in_boolean_context()) {
+                        if (value && node.is_truthy() && !node.has_side_effects(compressor)) {
+                            return true;
+                        }
+                        if (node.is_constant()) {
+                            return !node.evaluate(compressor) == !value;
+                        }
+                    }
+                    return fallback(node);
+                };
+            }
+
             function get_lvalues(expr) {
                 var lvalues = Object.create(null);
-                if (expr instanceof AST_Unary) return lvalues;
-                var tw = new TreeWalker(function(node, descend) {
-                    var sym = node;
-                    while (sym instanceof AST_PropAccess) sym = sym.expression;
+                if (candidate instanceof AST_VarDef) {
+                    lvalues[candidate.name.name] = lhs;
+                }
+                var tw = new TreeWalker(function(node) {
+                    var sym = root_expr(node);
                     if (sym instanceof AST_SymbolRef || sym instanceof AST_This) {
                         lvalues[sym.name] = lvalues[sym.name] || is_lhs(node, tw.parent());
                     }
                 });
-                get_rvalue(expr).walk(tw);
+                expr.walk(tw);
                 return lvalues;
             }
 
@@ -1401,11 +1453,11 @@ merge(Compressor.prototype, {
             }
 
             function is_lhs_local(lhs) {
-                while (lhs instanceof AST_PropAccess) lhs = lhs.expression;
-                return lhs instanceof AST_SymbolRef
-                    && lhs.definition().scope === scope
+                var sym = root_expr(lhs);
+                return sym instanceof AST_SymbolRef
+                    && sym.definition().scope === scope
                     && !(in_loop
-                        && (lhs.name in lvalues
+                        && (sym.name in lvalues && lvalues[sym.name] !== lhs
                             || candidate instanceof AST_Unary
                             || candidate instanceof AST_Assign && candidate.operator != "="));
             }
@@ -1427,12 +1479,22 @@ merge(Compressor.prototype, {
                 return false;
             }
 
+            function symbol_in_lvalues(sym) {
+                var lvalue = lvalues[sym.name];
+                if (!lvalue) return;
+                if (lvalue !== lhs) return true;
+                scan_rhs = false;
+            }
+
             function may_modify(sym) {
                 var def = sym.definition();
                 if (def.orig.length == 1 && def.orig[0] instanceof AST_SymbolDefun) return false;
                 if (def.scope !== scope) return true;
                 return !all(def.references, function(ref) {
-                    return ref.scope === scope;
+                    var s = ref.scope;
+                    // "block" scope within AST_Catch
+                    if (s.TYPE == "Scope") s = s.parent_scope;
+                    return s === scope;
                 });
             }
 
@@ -1981,6 +2043,28 @@ merge(Compressor.prototype, {
                 && !node.expression.has_side_effects(compressor);
     }
 
+    // is_truthy()
+    // return true if `!!node === true`
+    (function(def) {
+        def(AST_Node, return_false);
+        def(AST_Array, return_true);
+        def(AST_Assign, function() {
+            return this.operator == "=" && this.right.is_truthy();
+        });
+        def(AST_Lambda, return_true);
+        def(AST_Object, return_true);
+        def(AST_RegExp, return_true);
+        def(AST_Sequence, function() {
+            return this.tail_node().is_truthy();
+        });
+        def(AST_SymbolRef, function() {
+            var fixed = this.fixed_value();
+            return fixed && fixed.is_truthy();
+        });
+    })(function(node, func) {
+        node.DEFMETHOD("is_truthy", func);
+    });
+
     // may_throw_on_access()
     // returns true if this node may be null, undefined or contain `AST_Accessor`
     (function(def) {
@@ -2314,7 +2398,11 @@ merge(Compressor.prototype, {
         // descendant of AST_Node.
         AST_Node.DEFMETHOD("evaluate", function(compressor){
             if (!compressor.option("evaluate")) return this;
-            var val = this._eval(compressor, 1);
+            var cached = [];
+            var val = this._eval(compressor, cached, 1);
+            cached.forEach(function(node) {
+                delete node._eval;
+            });
             if (!val || val instanceof RegExp) return val;
             if (typeof val == "function" || typeof val == "object") return this;
             return val;
@@ -2350,12 +2438,12 @@ merge(Compressor.prototype, {
             }
             return this;
         });
-        def(AST_Array, function(compressor, depth) {
+        def(AST_Array, function(compressor, cached, depth) {
             if (compressor.option("unsafe")) {
                 var elements = [];
                 for (var i = 0, len = this.elements.length; i < len; i++) {
                     var element = this.elements[i];
-                    var value = element._eval(compressor, depth);
+                    var value = element._eval(compressor, cached, depth);
                     if (element === value) return this;
                     elements.push(value);
                 }
@@ -2363,7 +2451,7 @@ merge(Compressor.prototype, {
             }
             return this;
         });
-        def(AST_Object, function(compressor, depth) {
+        def(AST_Object, function(compressor, cached, depth) {
             if (compressor.option("unsafe")) {
                 var val = {};
                 for (var i = 0, len = this.properties.length; i < len; i++) {
@@ -2372,14 +2460,14 @@ merge(Compressor.prototype, {
                     if (key instanceof AST_Symbol) {
                         key = key.name;
                     } else if (key instanceof AST_Node) {
-                        key = key._eval(compressor, depth);
+                        key = key._eval(compressor, cached, depth);
                         if (key === prop.key) return this;
                     }
                     if (typeof Object.prototype[key] === 'function') {
                         return this;
                     }
                     if (prop.value instanceof AST_Function) continue;
-                    val[key] = prop.value._eval(compressor, depth);
+                    val[key] = prop.value._eval(compressor, cached, depth);
                     if (val[key] === prop.value) return this;
                 }
                 return val;
@@ -2387,7 +2475,7 @@ merge(Compressor.prototype, {
             return this;
         });
         var non_converting_unary = makePredicate("! typeof void");
-        def(AST_UnaryPrefix, function(compressor, depth) {
+        def(AST_UnaryPrefix, function(compressor, cached, depth) {
             var e = this.expression;
             // Function would be evaluated to an array and so typeof would
             // incorrectly return 'object'. Hence making is a special case.
@@ -2399,7 +2487,7 @@ merge(Compressor.prototype, {
                 return typeof function(){};
             }
             if (!non_converting_unary(this.operator)) depth++;
-            e = e._eval(compressor, depth);
+            e = e._eval(compressor, cached, depth);
             if (e === this.expression) return this;
             switch (this.operator) {
               case "!": return !e;
@@ -2416,11 +2504,11 @@ merge(Compressor.prototype, {
             return this;
         });
         var non_converting_binary = makePredicate("&& || === !==");
-        def(AST_Binary, function(compressor, depth) {
+        def(AST_Binary, function(compressor, cached, depth) {
             if (!non_converting_binary(this.operator)) depth++;
-            var left = this.left._eval(compressor, depth);
+            var left = this.left._eval(compressor, cached, depth);
             if (left === this.left) return this;
-            var right = this.right._eval(compressor, depth);
+            var right = this.right._eval(compressor, cached, depth);
             if (right === this.right) return this;
             var result;
             switch (this.operator) {
@@ -2454,27 +2542,28 @@ merge(Compressor.prototype, {
             }
             return result;
         });
-        def(AST_Conditional, function(compressor, depth) {
-            var condition = this.condition._eval(compressor, depth);
+        def(AST_Conditional, function(compressor, cached, depth) {
+            var condition = this.condition._eval(compressor, cached, depth);
             if (condition === this.condition) return this;
             var node = condition ? this.consequent : this.alternative;
-            var value = node._eval(compressor, depth);
+            var value = node._eval(compressor, cached, depth);
             return value === node ? this : value;
         });
-        def(AST_SymbolRef, function(compressor, depth) {
+        def(AST_SymbolRef, function(compressor, cached, depth) {
             var fixed = this.fixed_value();
             if (!fixed) return this;
             var value;
-            if (HOP(fixed, "_eval")) {
+            if (cached.indexOf(fixed) >= 0) {
                 value = fixed._eval();
             } else {
                 this._eval = return_this;
-                value = fixed._eval(compressor, depth);
+                value = fixed._eval(compressor, cached, depth);
                 delete this._eval;
                 if (value === fixed) return this;
                 fixed._eval = function() {
                     return value;
                 };
+                cached.push(fixed);
             }
             if (value && typeof value == "object") {
                 var escaped = this.definition().escaped;
@@ -2509,11 +2598,11 @@ merge(Compressor.prototype, {
             ],
         };
         convert_to_predicate(static_values);
-        def(AST_PropAccess, function(compressor, depth) {
+        def(AST_PropAccess, function(compressor, cached, depth) {
             if (compressor.option("unsafe")) {
                 var key = this.property;
                 if (key instanceof AST_Node) {
-                    key = key._eval(compressor, depth);
+                    key = key._eval(compressor, cached, depth);
                     if (key === this.property) return this;
                 }
                 var exp = this.expression;
@@ -2522,7 +2611,7 @@ merge(Compressor.prototype, {
                     if (!(static_values[exp.name] || return_false)(key)) return this;
                     val = global_objs[exp.name];
                 } else {
-                    val = exp._eval(compressor, depth + 1);
+                    val = exp._eval(compressor, cached, depth + 1);
                     if (!val || val === exp || !HOP(val, key)) return this;
                     if (typeof val == "function") switch (key) {
                       case "name":
@@ -2537,12 +2626,12 @@ merge(Compressor.prototype, {
             }
             return this;
         });
-        def(AST_Call, function(compressor, depth) {
+        def(AST_Call, function(compressor, cached, depth) {
             var exp = this.expression;
             if (compressor.option("unsafe") && exp instanceof AST_PropAccess) {
                 var key = exp.property;
                 if (key instanceof AST_Node) {
-                    key = key._eval(compressor, depth);
+                    key = key._eval(compressor, cached, depth);
                     if (key === exp.property) return this;
                 }
                 var val;
@@ -2551,13 +2640,13 @@ merge(Compressor.prototype, {
                     if (!(static_fns[e.name] || return_false)(key)) return this;
                     val = global_objs[e.name];
                 } else {
-                    val = e._eval(compressor, depth + 1);
+                    val = e._eval(compressor, cached, depth + 1);
                     if (val === e || !(val && native_fns[val.constructor.name] || return_false)(key)) return this;
                 }
                 var args = [];
                 for (var i = 0, len = this.args.length; i < len; i++) {
                     var arg = this.args[i];
-                    var value = arg._eval(compressor, depth);
+                    var value = arg._eval(compressor, cached, depth);
                     if (arg === value) return this;
                     args.push(value);
                 }
@@ -3014,6 +3103,16 @@ merge(Compressor.prototype, {
         return self;
     });
 
+    OPT(AST_Lambda, function(self, compressor){
+        tighten_body(self.body, compressor);
+        if (compressor.option("side_effects")
+            && self.body.length == 1
+            && self.body[0] === compressor.has_directive("use strict")) {
+            self.body.length = 0;
+        }
+        return self;
+    });
+
     AST_Scope.DEFMETHOD("drop_unused", function(compressor){
         if (!compressor.option("unused")) return;
         if (compressor.has_directive("use asm")) return;
@@ -3039,6 +3138,8 @@ merge(Compressor.prototype, {
         var in_use = [];
         var in_use_ids = Object.create(null); // avoid expensive linear scans of in_use
         var fixed_ids = Object.create(null);
+        var value_read = Object.create(null);
+        var value_modified = Object.create(null);
         if (self instanceof AST_Toplevel && compressor.top_retain) {
             self.variables.each(function(def) {
                 if (compressor.top_retain(def) && !(def.id in in_use_ids)) {
@@ -3306,6 +3407,17 @@ merge(Compressor.prototype, {
         );
         self.transform(tt);
 
+        function verify_safe_usage(def, read, modified) {
+            if (def.id in in_use_ids) return;
+            if (read && modified) {
+                in_use_ids[def.id] = true;
+                in_use.push(def);
+            } else {
+                value_read[def.id] = read;
+                value_modified[def.id] = modified;
+            }
+        }
+
         function scan_ref_scoped(node, descend) {
             var node_def, props = [], sym = assign_as_unused(node, props);
             if (sym instanceof AST_SymbolRef
@@ -3315,8 +3427,18 @@ merge(Compressor.prototype, {
                 });
                 if (node instanceof AST_Assign) {
                     node.right.walk(tw);
-                    if (node.left === sym && !node_def.chained && sym.fixed_value() === node.right) {
-                        fixed_ids[node_def.id] = node;
+                    if (node.left === sym) {
+                        if (!node_def.chained && sym.fixed_value() === node.right) {
+                            fixed_ids[node_def.id] = node;
+                        }
+                        if (!node.write_only) {
+                            verify_safe_usage(node_def, true, value_modified[node_def.id]);
+                        }
+                    } else {
+                        var fixed = sym.fixed_value();
+                        if (!fixed || !fixed.is_constant()) {
+                            verify_safe_usage(node_def, value_read[node_def.id], true);
+                        }
                     }
                 }
                 return true;
@@ -3404,8 +3526,9 @@ merge(Compressor.prototype, {
                 var defs = [];
                 vars.each(function(def, name){
                     if (self instanceof AST_Lambda
-                        && find_if(function(x){ return x.name == def.name.name },
-                                   self.argnames)) {
+                        && !all(self.argnames, function(argname) {
+                            return argname.name != name;
+                        })) {
                         vars.del(name);
                     } else {
                         def = def.clone();
@@ -3485,7 +3608,7 @@ merge(Compressor.prototype, {
 
     AST_Scope.DEFMETHOD("make_var_name", function(prefix) {
         var var_names = this.var_names();
-        prefix = prefix.replace(/[^a-z_$]+/ig, "_");
+        prefix = prefix.replace(/(?:^[^a-z_$]|[^a-z0-9_$])/ig, "_");
         var name = prefix;
         for (var i = 0; var_names[name]; i++) name = prefix + "$" + i;
         var_names[name] = true;
@@ -3502,8 +3625,9 @@ merge(Compressor.prototype, {
                 var sym = node.name, def, value;
                 if (sym.scope === self
                     && (def = sym.definition()).escaped != 1
-                    && !def.single_use
+                    && !def.assignments
                     && !def.direct_access
+                    && !def.single_use
                     && !top_retain(def)
                     && (value = sym.fixed_value()) === node.value
                     && value instanceof AST_Object) {
@@ -3583,7 +3707,15 @@ merge(Compressor.prototype, {
                 if (this.expression instanceof AST_Function
                     && (!this.expression.name || !this.expression.name.definition().references.length)) {
                     var node = this.clone();
-                    node.expression.process_expression(false, compressor);
+                    var exp = node.expression;
+                    exp.process_expression(false, compressor);
+                    exp.walk(new TreeWalker(function(node) {
+                        if (node instanceof AST_Return && node.value) {
+                            node.value = node.value.drop_side_effect_free(compressor);
+                            return true;
+                        }
+                        if (node instanceof AST_Scope && node !== exp) return true;
+                    }));
                     return node;
                 }
                 return this;
@@ -3619,10 +3751,7 @@ merge(Compressor.prototype, {
                 return this;
             }
             this.write_only = true;
-            while (left instanceof AST_PropAccess) {
-                left = left.expression;
-            }
-            if (left.is_constant_expression(compressor.find_parent(AST_Scope))) {
+            if (root_expr(left).is_constant_expression(compressor.find_parent(AST_Scope))) {
                 return this.right.drop_side_effect_free(compressor);
             }
             return this;
@@ -3718,7 +3847,7 @@ merge(Compressor.prototype, {
 
     OPT(AST_Do, function(self, compressor){
         if (!compressor.option("loops")) return self;
-        var cond = self.condition.tail_node().evaluate(compressor);
+        var cond = self.condition.is_truthy() || self.condition.tail_node().evaluate(compressor);
         if (!(cond instanceof AST_Node)) {
             if (cond) return make_node(AST_For, self, {
                 body: make_node(AST_BlockStatement, self.body, {
@@ -3840,9 +3969,11 @@ merge(Compressor.prototype, {
                     self.condition = best_of_expression(self.condition.transform(compressor), orig);
                 }
             }
-            if (compressor.option("dead_code")) {
-                if (cond instanceof AST_Node) cond = self.condition.tail_node().evaluate(compressor);
-                if (!cond) {
+            if (cond instanceof AST_Node) {
+                cond = self.condition.is_truthy() || self.condition.tail_node().evaluate(compressor);
+            }
+            if (!cond) {
+                if (compressor.option("dead_code")) {
                     var body = [];
                     extract_declarations_from_unreachable_code(compressor, self.body, body);
                     if (self.init instanceof AST_Statement) {
@@ -3857,6 +3988,16 @@ merge(Compressor.prototype, {
                     }));
                     return make_node(AST_BlockStatement, self, { body: body }).optimize(compressor);
                 }
+            } else if (self.condition && !(cond instanceof AST_Node)) {
+                self.body = make_node(AST_BlockStatement, self.body, {
+                    body: [
+                        make_node(AST_SimpleStatement, self.condition, {
+                            body: self.condition
+                        }),
+                        self.body
+                    ]
+                });
+                self.condition = null;
             }
         }
         return if_break_in_loop(self, compressor);
@@ -3877,7 +4018,9 @@ merge(Compressor.prototype, {
             self.condition = best_of_expression(self.condition.transform(compressor), orig);
         }
         if (compressor.option("dead_code")) {
-            if (cond instanceof AST_Node) cond = self.condition.tail_node().evaluate(compressor);
+            if (cond instanceof AST_Node) {
+                cond = self.condition.is_truthy() || self.condition.tail_node().evaluate(compressor);
+            }
             if (!cond) {
                 compressor.warn("Condition always false [{file}:{line},{col}]", self.condition.start);
                 var body = [];
@@ -4404,7 +4547,6 @@ merge(Compressor.prototype, {
                     var comp = new Compressor(compressor.options);
                     ast = ast.transform(comp);
                     ast.figure_out_scope(mangle);
-                    base54.reset();
                     ast.compute_char_frequency(mangle);
                     ast.mangle_names(mangle);
                     var fun;
@@ -4634,8 +4776,10 @@ merge(Compressor.prototype, {
                     var var_def = stat.definitions[j];
                     var name = var_def.name;
                     append_var(decls, expressions, name, var_def.value);
-                    if (in_loop) {
-                        var def = name.definition();
+                    if (in_loop && all(fn.argnames, function(argname) {
+                        return argname.name != name.name;
+                    })) {
+                        var def = fn.variables.get(name.name);
                         var sym = make_node(AST_SymbolRef, name, name);
                         def.references.push(sym);
                         expressions.splice(pos++, 0, make_node(AST_Assign, var_def, {
@@ -4762,8 +4906,10 @@ merge(Compressor.prototype, {
                 return make_node(AST_Undefined, self).optimize(compressor);
             }
         }
-        if (compressor.in_boolean_context()) {
-            switch (self.operator) {
+        if (compressor.option("booleans")) {
+            if (self.operator == "!" && e.is_truthy()) {
+                return make_sequence(self, [ e, make_node(AST_False, self) ]).optimize(compressor);
+            } else if (compressor.in_boolean_context()) switch (self.operator) {
               case "!":
                 if (e instanceof AST_UnaryPrefix && e.operator == "!") {
                     // !!foo ==> foo, if we're in boolean context
@@ -4949,7 +5095,7 @@ merge(Compressor.prototype, {
             }
             break;
         }
-        if (self.operator == "+" && compressor.in_boolean_context()) {
+        if (compressor.option("booleans") && self.operator == "+" && compressor.in_boolean_context()) {
             var ll = self.left.evaluate(compressor);
             var rr = self.right.evaluate(compressor);
             if (ll && typeof ll == "string") {
@@ -4976,11 +5122,9 @@ merge(Compressor.prototype, {
                 });
                 self = best_of(compressor, self, negated);
             }
-            if (compressor.option("unsafe_comps")) {
-                switch (self.operator) {
-                  case "<": reverse(">"); break;
-                  case "<=": reverse(">="); break;
-                }
+            switch (self.operator) {
+              case ">": reverse("<"); break;
+              case ">=": reverse("<="); break;
             }
         }
         if (self.operator == "+") {
@@ -5006,7 +5150,7 @@ merge(Compressor.prototype, {
         if (compressor.option("evaluate")) {
             switch (self.operator) {
               case "&&":
-                var ll = self.left.truthy ? true : self.left.falsy ? false : self.left.evaluate(compressor);
+                var ll = fuzzy_eval(self.left);
                 if (!ll) {
                     compressor.warn("Condition left of && always false [{file}:{line},{col}]", self.start);
                     return maintain_this_binding(compressor.parent(), compressor.self(), self.left).optimize(compressor);
@@ -5016,7 +5160,7 @@ merge(Compressor.prototype, {
                 }
                 var rr = self.right.evaluate(compressor);
                 if (!rr) {
-                    if (compressor.in_boolean_context()) {
+                    if (compressor.option("booleans") && compressor.in_boolean_context()) {
                         compressor.warn("Boolean && always false [{file}:{line},{col}]", self.start);
                         return make_sequence(self, [
                             self.left,
@@ -5025,7 +5169,8 @@ merge(Compressor.prototype, {
                     } else self.falsy = true;
                 } else if (!(rr instanceof AST_Node)) {
                     var parent = compressor.parent();
-                    if (parent.operator == "&&" && parent.left === compressor.self() || compressor.in_boolean_context()) {
+                    if (parent.operator == "&&" && parent.left === compressor.self()
+                        || compressor.option("booleans") && compressor.in_boolean_context()) {
                         compressor.warn("Dropping side-effect-free && [{file}:{line},{col}]", self.start);
                         return self.left.optimize(compressor);
                     }
@@ -5041,7 +5186,7 @@ merge(Compressor.prototype, {
                 }
                 break;
               case "||":
-                var ll = self.left.truthy ? true : self.left.falsy ? false : self.left.evaluate(compressor);
+                var ll = fuzzy_eval(self.left);
                 if (!ll) {
                     compressor.warn("Condition left of || always false [{file}:{line},{col}]", self.start);
                     return make_sequence(self, [ self.left, self.right ]).optimize(compressor);
@@ -5052,12 +5197,13 @@ merge(Compressor.prototype, {
                 var rr = self.right.evaluate(compressor);
                 if (!rr) {
                     var parent = compressor.parent();
-                    if (parent.operator == "||" && parent.left === compressor.self() || compressor.in_boolean_context()) {
+                    if (parent.operator == "||" && parent.left === compressor.self()
+                        || compressor.option("booleans") && compressor.in_boolean_context()) {
                         compressor.warn("Dropping side-effect-free || [{file}:{line},{col}]", self.start);
                         return self.left.optimize(compressor);
                     }
                 } else if (!(rr instanceof AST_Node)) {
-                    if (compressor.in_boolean_context()) {
+                    if (compressor.option("booleans") && compressor.in_boolean_context()) {
                         compressor.warn("Boolean || always true [{file}:{line},{col}]", self.start);
                         return make_sequence(self, [
                             self.left,
@@ -5279,6 +5425,13 @@ merge(Compressor.prototype, {
             return best_of(compressor, ev, self);
         }
         return self;
+
+        function fuzzy_eval(node) {
+            if (node.truthy) return true;
+            if (node.falsy) return false;
+            if (node.is_truthy()) return true;
+            return node.evaluate(compressor);
+        }
     });
 
     function recursive_ref(compressor, def) {
@@ -5574,15 +5727,13 @@ merge(Compressor.prototype, {
             expressions.push(self);
             return make_sequence(self, expressions);
         }
-        var cond = self.condition.evaluate(compressor);
-        if (cond !== self.condition) {
-            if (cond) {
-                compressor.warn("Condition always true [{file}:{line},{col}]", self.start);
-                return maintain_this_binding(compressor.parent(), compressor.self(), self.consequent);
-            } else {
-                compressor.warn("Condition always false [{file}:{line},{col}]", self.start);
-                return maintain_this_binding(compressor.parent(), compressor.self(), self.alternative);
-            }
+        var cond = self.condition.is_truthy() || self.condition.tail_node().evaluate(compressor);
+        if (!cond) {
+            compressor.warn("Condition always false [{file}:{line},{col}]", self.start);
+            return make_sequence(self, [ self.condition, self.alternative ]).optimize(compressor);
+        } else if (!(cond instanceof AST_Node)) {
+            compressor.warn("Condition always true [{file}:{line},{col}]", self.start);
+            return make_sequence(self, [ self.condition, self.consequent ]).optimize(compressor);
         }
         var negated = cond.negate(compressor, first_in_statement(compressor));
         if (best_of(compressor, cond, negated) === negated) {
@@ -5664,6 +5815,18 @@ merge(Compressor.prototype, {
                 consequent
             ]).optimize(compressor);
         }
+        // x ? (y, w) : (z, w) --> x ? y : z, w
+        if ((consequent instanceof AST_Sequence || alternative instanceof AST_Sequence)
+            && consequent.tail_node().equivalent_to(alternative.tail_node())) {
+            return make_sequence(self, [
+                make_node(AST_Conditional, self, {
+                    condition: self.condition,
+                    consequent: pop_seq(consequent),
+                    alternative: pop_seq(alternative)
+                }),
+                consequent.tail_node()
+            ]).optimize(compressor);
+        }
         // x ? y || z : z --> x && y || z
         if (consequent instanceof AST_Binary
             && consequent.operator == "||"
@@ -5678,7 +5841,7 @@ merge(Compressor.prototype, {
                 right: alternative
             }).optimize(compressor);
         }
-        var in_bool = compressor.in_boolean_context();
+        var in_bool = compressor.option("booleans") && compressor.in_boolean_context();
         if (is_true(self.consequent)) {
             if (is_false(self.alternative)) {
                 // c ? true : false ---> !!c
@@ -5766,35 +5929,39 @@ merge(Compressor.prototype, {
                 }
             }
         }
+
+        function pop_seq(node) {
+            if (!(node instanceof AST_Sequence)) return make_node(AST_Number, node, {
+                value: 0
+            });
+            return make_sequence(node, node.expressions.slice(0, -1));
+        }
     });
 
     OPT(AST_Boolean, function(self, compressor){
+        if (!compressor.option("booleans")) return self;
         if (compressor.in_boolean_context()) return make_node(AST_Number, self, {
             value: +self.value
         });
-        if (compressor.option("booleans")) {
-            var p = compressor.parent();
-            if (p instanceof AST_Binary && (p.operator == "=="
-                                            || p.operator == "!=")) {
-                compressor.warn("Non-strict equality against boolean: {operator} {value} [{file}:{line},{col}]", {
-                    operator : p.operator,
-                    value    : self.value,
-                    file     : p.start.file,
-                    line     : p.start.line,
-                    col      : p.start.col,
-                });
-                return make_node(AST_Number, self, {
-                    value: +self.value
-                });
-            }
-            return make_node(AST_UnaryPrefix, self, {
-                operator: "!",
-                expression: make_node(AST_Number, self, {
-                    value: 1 - self.value
-                })
+        var p = compressor.parent();
+        if (p instanceof AST_Binary && (p.operator == "==" || p.operator == "!=")) {
+            compressor.warn("Non-strict equality against boolean: {operator} {value} [{file}:{line},{col}]", {
+                operator : p.operator,
+                value    : self.value,
+                file     : p.start.file,
+                line     : p.start.line,
+                col      : p.start.col,
+            });
+            return make_node(AST_Number, self, {
+                value: +self.value
             });
         }
-        return self;
+        return make_node(AST_UnaryPrefix, self, {
+            operator: "!",
+            expression: make_node(AST_Number, self, {
+                value: 1 - self.value
+            })
+        });
     });
 
     OPT(AST_Sub, function(self, compressor){
@@ -5867,6 +6034,31 @@ merge(Compressor.prototype, {
                 });
             }
         }
+        var fn;
+        if (compressor.option("arguments")
+            && expr instanceof AST_SymbolRef
+            && expr.name == "arguments"
+            && expr.definition().orig.length == 1
+            && (fn = expr.scope) instanceof AST_Lambda
+            && prop instanceof AST_Number) {
+            var index = prop.getValue();
+            var argname = fn.argnames[index];
+            if (!argname && !compressor.option("keep_fargs")) {
+                while (index >= fn.argnames.length) {
+                    argname = make_node(AST_SymbolFunarg, fn, {
+                        name: fn.make_var_name("argument_" + fn.argnames.length),
+                        scope: fn
+                    });
+                    fn.argnames.push(argname);
+                    fn.enclosed.push(fn.def_variable(argname));
+                }
+            }
+            if (argname) {
+                var sym = make_node(AST_SymbolRef, self, argname);
+                sym.reference({});
+                return sym;
+            }
+        }
         var ev = self.evaluate(compressor);
         if (ev !== self) {
             ev = make_node_from_constant(ev, self).optimize(compressor);
@@ -5978,19 +6170,6 @@ merge(Compressor.prototype, {
         return self;
     });
 
-    function literals_in_boolean_context(self, compressor) {
-        if (compressor.in_boolean_context()) {
-            return best_of(compressor, self, make_sequence(self, [
-                self,
-                make_node(AST_True, self)
-            ]).optimize(compressor));
-        }
-        return self;
-    };
-    OPT(AST_Array, literals_in_boolean_context);
-    OPT(AST_Object, literals_in_boolean_context);
-    OPT(AST_RegExp, literals_in_boolean_context);
-
     OPT(AST_Return, function(self, compressor){
         if (self.value && is_undefined(self.value, compressor)) {
             self.value = null;

lib/minify.js

@@ -150,7 +150,6 @@ function minify(files, options) {
         if (options.mangle) toplevel.figure_out_scope(options.mangle);
         if (timings) timings.mangle = Date.now();
         if (options.mangle) {
-            base54.reset();
             toplevel.compute_char_frequency(options.mangle);
             toplevel.mangle_names(options.mangle);
         }

lib/mozilla-ast.js

@@ -180,6 +180,17 @@
                 end    : my_end_token(M)
             };
             if (val === null) return new AST_Null(args);
+            var rx = M.regex;
+            if (rx && rx.pattern) {
+                // RegExpLiteral as per ESTree AST spec
+                args.value = new RegExp(rx.pattern, rx.flags);
+                args.value.raw_source = rx.pattern;
+                return new AST_RegExp(args);
+            } else if (rx) {
+                // support legacy RegExp
+                args.value = M.regex && M.raw ? M.raw : val;
+                return new AST_RegExp(args);
+            }
             switch (typeof val) {
               case "string":
                 args.value = val;
@@ -189,16 +200,6 @@
                 return new AST_Number(args);
               case "boolean":
                 return new (val ? AST_True : AST_False)(args);
-              default:
-                var rx = M.regex;
-                if (rx && rx.pattern) {
-                    // RegExpLiteral as per ESTree AST spec
-                    args.value = new RegExp(rx.pattern, rx.flags).toString();
-                } else {
-                    // support legacy RegExp
-                    args.value = M.regex && M.raw ? M.raw : val;
-                }
-                return new AST_RegExp(args);
             }
         },
         Identifier: function(M) {
@@ -410,14 +411,15 @@
     });
 
     def_to_moz(AST_RegExp, function To_Moz_RegExpLiteral(M) {
-        var value = M.value;
+        var flags = M.value.toString().match(/[gimuy]*$/)[0];
+        var value = "/" + M.value.raw_source + "/" + flags;
         return {
             type: "Literal",
             value: value,
-            raw: value.toString(),
+            raw: value,
             regex: {
-                pattern: value.source,
-                flags: value.toString().match(/[gimuy]*$/)[0]
+                pattern: M.value.raw_source,
+                flags: flags
             }
         };
     });
@@ -564,6 +566,21 @@
         FROM_MOZ_STACK = [];
         var ast = from_moz(node);
         FROM_MOZ_STACK = save_stack;
+        ast.walk(new TreeWalker(function(node) {
+            if (node instanceof AST_LabelRef) {
+                for (var level = 0, parent; parent = this.parent(level); level++) {
+                    if (parent instanceof AST_Scope) break;
+                    if (parent instanceof AST_LabeledStatement && parent.label.name == node.name) {
+                        node.thedef = parent.label;
+                        break;
+                    }
+                }
+                if (!node.thedef) {
+                    var s = node.start;
+                    js_error("Undefined label " + node.name, s.file, s.line, s.col, s.pos);
+                }
+            }
+        }));
         return ast;
     };
 

lib/output.js

@@ -56,7 +56,7 @@ function OutputStream(options) {
     options = defaults(options, {
         ascii_only       : false,
         beautify         : false,
-        bracketize       : false,
+        braces           : false,
         comments         : false,
         ie8              : false,
         indent_level     : 4,
@@ -178,7 +178,7 @@ function OutputStream(options) {
     function encode_string(str, quote) {
         var ret = make_string(str, quote);
         if (options.inline_script) {
-            ret = ret.replace(/<\x2fscript([>\/\t\n\f\r ])/gi, "<\\/script$1");
+            ret = ret.replace(/<\x2f(script)([>\/\t\n\f\r ])/gi, "<\\/$1$2");
             ret = ret.replace(/\x3c!--/g, "\\x3c!--");
             ret = ret.replace(/--\x3e/g, "--\\x3e");
         }
@@ -576,6 +576,7 @@ function OutputStream(options) {
         indentation     : function() { return indentation },
         current_width   : function() { return current_col - indentation },
         should_break    : function() { return options.width && this.current_width() >= options.width },
+        has_parens      : function() { return OUTPUT[OUTPUT.length - 1] == "(" },
         newline         : newline,
         print           : print,
         space           : space,
@@ -683,7 +684,7 @@ function OutputStream(options) {
     // a function expression needs parens around it when it's provably
     // the first token to appear in a statement.
     PARENS(AST_Function, function(output){
-        if (first_in_statement(output)) {
+        if (!output.has_parens() && first_in_statement(output)) {
             return true;
         }
 
@@ -704,7 +705,9 @@ function OutputStream(options) {
 
     // same goes for an object literal, because otherwise it would be
     // interpreted as a block of code.
-    PARENS(AST_Object, first_in_statement);
+    PARENS(AST_Object, function(output){
+        return !output.has_parens() && first_in_statement(output);
+    });
 
     PARENS(AST_Unary, function(output){
         var p = output.parent();
@@ -883,21 +886,22 @@ function OutputStream(options) {
         self.body.print(output);
         output.semicolon();
     });
-    function print_bracketed(self, output, allow_directives) {
+    function print_braced_empty(self, output) {
+        output.print("{");
+        output.with_indent(output.next_indent(), function() {
+            output.append_comments(self, true);
+        });
+        output.print("}");
+    }
+    function print_braced(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("}");
-        }
+        } else print_braced_empty(self, output);
     };
     DEFPRINT(AST_BlockStatement, function(self, output){
-        print_bracketed(self, output);
+        print_braced(self, output);
     });
     DEFPRINT(AST_EmptyStatement, function(self, output){
         output.semicolon();
@@ -992,7 +996,7 @@ function OutputStream(options) {
             });
         });
         output.space();
-        print_bracketed(self, output, true);
+        print_braced(self, output, true);
     });
     DEFPRINT(AST_Lambda, function(self, output){
         self._do_print(output);
@@ -1033,7 +1037,7 @@ function OutputStream(options) {
     /* -----[ if ]----- */
     function make_then(self, output) {
         var b = self.body;
-        if (output.option("bracketize")
+        if (output.option("braces")
             || output.option("ie8") && b instanceof AST_Do)
             return make_block(b, output);
         // The squeezer replaces "block"-s that contain only a single
@@ -1042,7 +1046,7 @@ function OutputStream(options) {
         // IF having an ELSE clause where the THEN clause ends in an
         // IF *without* an ELSE block (then the outer ELSE would refer
         // to the inner IF).  This function checks for this case and
-        // adds the block brackets if needed.
+        // adds the block braces if needed.
         if (!b) return output.force_semicolon();
         while (true) {
             if (b instanceof AST_If) {
@@ -1089,7 +1093,7 @@ function OutputStream(options) {
         });
         output.space();
         var last = self.body.length - 1;
-        if (last < 0) output.print("{}");
+        if (last < 0) print_braced_empty(self, output);
         else output.with_block(function(){
             self.body.forEach(function(branch, i){
                 output.indent(true);
@@ -1123,7 +1127,7 @@ function OutputStream(options) {
     DEFPRINT(AST_Try, function(self, output){
         output.print("try");
         output.space();
-        print_bracketed(self, output);
+        print_braced(self, output);
         if (self.bcatch) {
             output.space();
             self.bcatch.print(output);
@@ -1140,12 +1144,12 @@ function OutputStream(options) {
             self.argname.print(output);
         });
         output.space();
-        print_bracketed(self, output);
+        print_braced(self, output);
     });
     DEFPRINT(AST_Finally, function(self, output){
         output.print("finally");
         output.space();
-        print_bracketed(self, output);
+        print_braced(self, output);
     });
 
     /* -----[ var/const ]----- */
@@ -1344,7 +1348,7 @@ function OutputStream(options) {
             });
             output.newline();
         });
-        else output.print("{}");
+        else print_braced_empty(self, output);
     });
 
     function print_property_name(key, quote, output) {
@@ -1416,7 +1420,7 @@ function OutputStream(options) {
     });
 
     function force_statement(stat, output) {
-        if (output.option("bracketize")) {
+        if (output.option("braces")) {
             make_block(stat, output);
         } else {
             if (!stat || stat instanceof AST_EmptyStatement)
@@ -1480,47 +1484,52 @@ function OutputStream(options) {
     /* -----[ source map generators ]----- */
 
     function DEFMAP(nodetype, generator) {
-        nodetype.DEFMETHOD("add_source_map", function(stream){
-            generator(this, stream);
+        nodetype.forEach(function(nodetype) {
+            nodetype.DEFMETHOD("add_source_map", generator);
         });
-    };
+    }
 
-    // We could easily add info for ALL nodes, but it seems to me that
-    // would be quite wasteful, hence this noop in the base class.
-    DEFMAP(AST_Node, noop);
-
-    function basic_sourcemap_gen(self, output) {
-        output.add_mapping(self.start);
-    };
+    DEFMAP([
+        // We could easily add info for ALL nodes, but it seems to me that
+        // would be quite wasteful, hence this noop in the base class.
+        AST_Node,
+        // since the label symbol will mark it
+        AST_LabeledStatement,
+        AST_Toplevel,
+    ], noop);
 
     // XXX: I'm not exactly sure if we need it for all of these nodes,
     // or if we should add even more.
-
-    DEFMAP(AST_Directive, basic_sourcemap_gen);
-    DEFMAP(AST_Debugger, basic_sourcemap_gen);
-    DEFMAP(AST_Symbol, basic_sourcemap_gen);
-    DEFMAP(AST_Jump, basic_sourcemap_gen);
-    DEFMAP(AST_StatementWithBody, basic_sourcemap_gen);
-    DEFMAP(AST_LabeledStatement, noop); // since the label symbol will mark it
-    DEFMAP(AST_Lambda, basic_sourcemap_gen);
-    DEFMAP(AST_Switch, basic_sourcemap_gen);
-    DEFMAP(AST_SwitchBranch, basic_sourcemap_gen);
-    DEFMAP(AST_BlockStatement, basic_sourcemap_gen);
-    DEFMAP(AST_Toplevel, noop);
-    DEFMAP(AST_New, basic_sourcemap_gen);
-    DEFMAP(AST_Try, basic_sourcemap_gen);
-    DEFMAP(AST_Catch, basic_sourcemap_gen);
-    DEFMAP(AST_Finally, basic_sourcemap_gen);
-    DEFMAP(AST_Definitions, basic_sourcemap_gen);
-    DEFMAP(AST_Constant, basic_sourcemap_gen);
-    DEFMAP(AST_ObjectSetter, function(self, output){
-        output.add_mapping(self.start, self.key.name);
-    });
-    DEFMAP(AST_ObjectGetter, function(self, output){
-        output.add_mapping(self.start, self.key.name);
-    });
-    DEFMAP(AST_ObjectProperty, function(self, output){
-        output.add_mapping(self.start, self.key);
+    DEFMAP([
+        AST_Array,
+        AST_BlockStatement,
+        AST_Catch,
+        AST_Constant,
+        AST_Debugger,
+        AST_Definitions,
+        AST_Directive,
+        AST_Finally,
+        AST_Jump,
+        AST_Lambda,
+        AST_New,
+        AST_Object,
+        AST_StatementWithBody,
+        AST_Symbol,
+        AST_Switch,
+        AST_SwitchBranch,
+        AST_Try,
+    ], function(output) {
+        output.add_mapping(this.start);
     });
 
+    DEFMAP([
+        AST_ObjectGetter,
+        AST_ObjectSetter,
+     ], function(output) {
+        output.add_mapping(this.start, this.key.name);
+    });
+
+    DEFMAP([ AST_ObjectProperty ], function(output) {
+        output.add_mapping(this.start, this.key);
+    });
 })();

lib/parse.js

@@ -969,7 +969,9 @@ function parse($TEXT, options) {
 
     function labeled_statement() {
         var label = as_symbol(AST_Label);
-        if (find_if(function(l){ return l.name == label.name }, S.labels)) {
+        if (!all(S.labels, function(l) {
+            return l.name != label.name;
+        })) {
             // ECMA-262, 12.12: An ECMAScript program is considered
             // syntactically incorrect if it contains a
             // LabelledStatement that is enclosed by a

lib/scope.js

@@ -74,17 +74,13 @@ SymbolDef.prototype = {
         var cache = options.cache && options.cache.props;
         if (this.global && cache && cache.has(this.name)) {
             this.mangled_name = cache.get(this.name);
-        }
-        else if (!this.mangled_name && !this.unmangleable(options)) {
-            var s = this.scope;
-            var sym = this.orig[0];
-            if (options.ie8 && sym instanceof AST_SymbolLambda)
-                s = s.parent_scope;
+        } else if (!this.mangled_name && !this.unmangleable(options)) {
             var def;
             if (def = this.redefined()) {
                 this.mangled_name = def.mangled_name || def.name;
-            } else
-                this.mangled_name = s.next_mangled(options, this);
+            } else {
+                this.mangled_name = next_mangled_name(this.scope, options, this);
+            }
             if (this.global && cache) {
                 cache.set(this.name, this.mangled_name);
             }
@@ -104,7 +100,6 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
     // pass 1: setup scope chaining and handle definitions
     var self = this;
     var scope = self.parent_scope = null;
-    var labels = new Dictionary();
     var defun = null;
     var tw = new TreeWalker(function(node, descend){
         if (node instanceof AST_Catch) {
@@ -119,25 +114,12 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             node.init_scope_vars(scope);
             var save_scope = scope;
             var save_defun = defun;
-            var save_labels = labels;
             defun = scope = node;
-            labels = new Dictionary();
             descend();
             scope = save_scope;
             defun = save_defun;
-            labels = save_labels;
             return true;        // don't descend again in TreeWalker
         }
-        if (node instanceof AST_LabeledStatement) {
-            var l = node.label;
-            if (labels.has(l.name)) {
-                throw new Error(string_template("Label {name} defined twice", l));
-            }
-            labels.set(l.name, l);
-            descend();
-            labels.del(l.name);
-            return true;        // no descend again
-        }
         if (node instanceof AST_With) {
             for (var s = scope; s; s = s.parent_scope)
                 s.uses_with = true;
@@ -168,22 +150,13 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
                 var def = scope.find_variable(node);
                 if (node.thedef !== def) {
                     node.thedef = def;
-                    node.reference(options);
                 }
+                node.reference(options);
             }
         }
         else if (node instanceof AST_SymbolCatch) {
             scope.def_variable(node).defun = defun;
         }
-        else if (node instanceof AST_LabelRef) {
-            var sym = labels.get(node.name);
-            if (!sym) throw new Error(string_template("Undefined label {name} [{line},{col}]", {
-                name: node.name,
-                line: node.start.line,
-                col: node.start.col
-            }));
-            node.thedef = sym;
-        }
     });
     self.walk(tw);
 
@@ -325,56 +298,62 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol, init){
     return symbol.thedef = def;
 });
 
-function next_mangled(scope, options) {
-    var ext = scope.enclosed;
-    out: while (true) {
-        var m = base54(++scope.cname);
-        if (!is_identifier(m)) continue; // skip over "do"
-
-        // https://github.com/mishoo/UglifyJS2/issues/242 -- do not
-        // shadow a name reserved from mangling.
-        if (member(m, options.reserved)) continue;
-
-        // we must ensure that the mangled name does not shadow a name
-        // from some parent scope that is referenced in this or in
-        // inner scopes.
-        for (var i = ext.length; --i >= 0;) {
-            var sym = ext[i];
-            var name = sym.mangled_name || (sym.unmangleable(options) && sym.name);
-            if (m == name) continue out;
-        }
-        return m;
+function names_in_use(scope, options) {
+    var names = scope.names_in_use;
+    if (!names) {
+        scope.names_in_use = names = Object.create(scope.mangled_names || null);
+        scope.cname_holes = [];
+        scope.enclosed.forEach(function(def) {
+            if (def.unmangleable(options)) names[def.name] = true;
+        });
     }
+    return names;
 }
 
-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){
+function next_mangled_name(scope, options, def) {
+    var in_use = names_in_use(scope, options);
+    var holes = scope.cname_holes;
+    var names = Object.create(null);
     // #179, #326
     // in Safari strict mode, something like (function x(x){...}) is a syntax error;
     // a function expression's argument cannot shadow the function expression's name
-
-    var tricky_def = def.orig[0] instanceof AST_SymbolFunarg && this.name && this.name.definition();
-
-    // the function's mangled_name is null when keep_fnames is true
-    var tricky_name = tricky_def ? tricky_def.mangled_name || tricky_def.name : null;
-
-    while (true) {
-        var name = next_mangled(this, options);
-        if (!tricky_name || tricky_name != name)
-            return name;
+    if (scope instanceof AST_Function && scope.name && def.orig[0] instanceof AST_SymbolFunarg) {
+        var tricky_def = scope.name.definition();
+        // the function's mangled_name is null when keep_fnames is true
+        names[tricky_def.mangled_name || tricky_def.name] = true;
     }
-});
+    var scopes = [ scope ];
+    def.references.forEach(function(sym) {
+        var scope = sym.scope;
+        do {
+            if (scopes.indexOf(scope) < 0) {
+                for (var name in names_in_use(scope, options)) {
+                    names[name] = true;
+                }
+                scopes.push(scope);
+            } else break;
+        } while (scope = scope.parent_scope);
+    });
+    var name;
+    for (var i = 0, len = holes.length; i < len; i++) {
+        name = base54(holes[i]);
+        if (names[name]) continue;
+        holes.splice(i, 1);
+        scope.names_in_use[name] = true;
+        return name;
+    }
+    while (true) {
+        name = base54(++scope.cname);
+        if (in_use[name] || !is_identifier(name) || member(name, options.reserved)) continue;
+        if (!names[name]) break;
+        holes.push(scope.cname);
+    }
+    scope.names_in_use[name] = true;
+    if (options.ie8 && def.orig[0] instanceof AST_SymbolLambda) {
+        names_in_use(scope.parent_scope, options)[name] = true;
+    }
+    return name;
+}
 
 AST_Symbol.DEFMETHOD("unmangleable", function(options){
     var def = this.definition();
@@ -397,7 +376,7 @@ AST_Symbol.DEFMETHOD("global", function(){
     return this.definition().global;
 });
 
-AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options) {
+function _default_mangler_options(options) {
     options = defaults(options, {
         eval        : false,
         ie8         : false,
@@ -409,28 +388,25 @@ AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options) {
     // Never mangle arguments
     push_uniq(options.reserved, "arguments");
     return options;
-});
+}
 
 AST_Toplevel.DEFMETHOD("mangle_names", function(options){
-    options = this._default_mangler_options(options);
+    options = _default_mangler_options(options);
 
     // We only need to mangle declaration nodes.  Special logic wired
     // into the code generator will display the mangled name if it's
     // present (and for AST_SymbolRef-s it'll use the mangled name of
     // the AST_SymbolDeclaration that it points to).
     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);
-            });
-        }
+    if (options.cache && options.cache.props) {
+        var mangled_names = this.mangled_names = Object.create(null);
+        options.cache.props.each(function(mangled_name) {
+            mangled_names[mangled_name] = true;
+        });
     }
 
+    var redefined = [];
     var tw = new TreeWalker(function(node, descend){
         if (node instanceof AST_LabeledStatement) {
             // lname is incremented when we get to the AST_Label
@@ -440,8 +416,12 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             return true;        // don't descend again in TreeWalker
         }
         if (node instanceof AST_Scope) {
-            node.variables.each(collect);
-            return;
+            descend();
+            if (options.cache && node instanceof AST_Toplevel) {
+                node.globals.each(mangle);
+            }
+            node.variables.each(mangle);
+            return true;
         }
         if (node instanceof AST_Label) {
             var name;
@@ -449,17 +429,31 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             node.mangled_name = name;
             return true;
         }
-        if (!options.ie8 && node instanceof AST_SymbolCatch) {
-            to_mangle.push(node.definition());
-            return;
+        if (!options.ie8 && node instanceof AST_Catch) {
+            var def = node.argname.definition();
+            var redef = def.redefined();
+            if (redef) {
+                redefined.push(def);
+                reference(node.argname);
+                def.references.forEach(reference);
+            }
+            descend();
+            if (!redef) mangle(def);
+            return true;
+        }
+
+        function reference(sym) {
+            sym.thedef = redef;
+            sym.reference(options);
+            sym.thedef = def;
         }
     });
     this.walk(tw);
-    to_mangle.forEach(function(def){ def.mangle(options) });
+    redefined.forEach(mangle);
 
-    function collect(symbol) {
-        if (!member(symbol.name, options.reserved)) {
-            to_mangle.push(symbol);
+    function mangle(def) {
+        if (!member(def.name, options.reserved)) {
+            def.mangle(options);
         }
     }
 });
@@ -490,7 +484,7 @@ AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
 AST_Toplevel.DEFMETHOD("expand_names", function(options) {
     base54.reset();
     base54.sort();
-    options = this._default_mangler_options(options);
+    options = _default_mangler_options(options);
     var avoid = this.find_colliding_names(options);
     var cname = 0;
     this.globals.each(rename);
@@ -528,7 +522,8 @@ AST_Sequence.DEFMETHOD("tail_node", function() {
 });
 
 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
-    options = this._default_mangler_options(options);
+    options = _default_mangler_options(options);
+    base54.reset();
     try {
         AST_Node.prototype.print = function(stream, force_parens) {
             this._print(stream, force_parens);

package.json

@@ -1,10 +1,9 @@
 {
   "name": "uglify-js",
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
-  "homepage": "http://lisperator.net/uglifyjs",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.3.12",
+  "version": "3.3.17",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -24,16 +23,39 @@
     "LICENSE"
   ],
   "dependencies": {
-    "commander": "~2.14.1",
+    "commander": "~2.15.0",
     "source-map": "~0.6.1"
   },
   "devDependencies": {
-    "acorn": "~5.4.1",
+    "acorn": "~5.5.3",
     "mocha": "~3.5.1",
     "semver": "~5.5.0"
   },
   "scripts": {
     "test": "node test/run-tests.js"
   },
-  "keywords": ["uglify", "uglify-js", "minify", "minifier", "es5"]
+  "keywords": [
+    "cli",
+    "compress",
+    "compressor",
+    "ecma",
+    "ecmascript",
+    "es",
+    "es5",
+    "javascript",
+    "js",
+    "jsmin",
+    "min",
+    "minification",
+    "minifier",
+    "minify",
+    "optimize",
+    "optimizer",
+    "pack",
+    "packer",
+    "parse",
+    "parser",
+    "uglifier",
+    "uglify"
+  ]
 }

test/benchmark.js

@@ -28,6 +28,7 @@ var remaining = 2 * urls.length;
 function done() {
     if (!--remaining) {
         var failures = [];
+        var sum = { input: 0, output: 0, gzip: 0 };
         urls.forEach(function(url) {
             var info = results[url];
             console.log();
@@ -40,6 +41,9 @@ function done() {
             if (info.code) {
                 failures.push(url);
             }
+            sum.input += info.input;
+            sum.output += info.output;
+            sum.gzip += info.gzip;
         });
         if (failures.length) {
             console.error("Benchmark failed:");
@@ -47,6 +51,13 @@ function done() {
                 console.error(url);
             });
             process.exit(1);
+        } else {
+            console.log();
+            console.log("Subtotal");
+            console.log();
+            console.log("Original:", sum.input, "bytes");
+            console.log("Uglified:", sum.output, "bytes");
+            console.log("GZipped: ", sum.gzip, "bytes");
         }
     }
 }

test/compress/arguments.js

@@ -0,0 +1,119 @@
+replace_index: {
+    options = {
+        arguments: true,
+        evaluate: true,
+        properties: true,
+    }
+    input: {
+        console.log(arguments && arguments[0]);
+        (function() {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function(a, b) {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function(arguments) {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function() {
+            var arguments;
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+    }
+    expect: {
+        console.log(arguments && arguments[0]);
+        (function() {
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+        (function(a, b) {
+            console.log(b, b, arguments.foo);
+        })("bar", 42);
+        (function(arguments) {
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+        (function() {
+            var arguments;
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+    }
+    expect_stdout: [
+        "undefined",
+        "42 42 undefined",
+        "42 42 undefined",
+        "a a undefined",
+        "42 42 undefined",
+    ]
+}
+
+replace_index_keep_fargs: {
+    options = {
+        arguments: true,
+        evaluate: true,
+        keep_fargs: false,
+        properties: true,
+    }
+    input: {
+        console.log(arguments && arguments[0]);
+        (function() {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function(a, b) {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function(arguments) {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function() {
+            var arguments;
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+    }
+    expect: {
+        console.log(arguments && arguments[0]);
+        (function(argument_0, argument_1) {
+            console.log(argument_1, argument_1, arguments.foo);
+        })("bar", 42);
+        (function(a, b) {
+            console.log(b, b, arguments.foo);
+        })("bar", 42);
+        (function(arguments) {
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+        (function() {
+            var arguments;
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+    }
+    expect_stdout: [
+        "undefined",
+        "42 42 undefined",
+        "42 42 undefined",
+        "a a undefined",
+        "42 42 undefined",
+    ]
+}
+
+modified: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        (function(a, b) {
+            var c = arguments[0];
+            var d = arguments[1];
+            a = "foo";
+            b++;
+            console.log(a, b, c, d, arguments[0], arguments[1]);
+        })("bar", 42);
+    }
+    expect: {
+        (function(a, b) {
+            var c = a;
+            var d = b;
+            a = "foo";
+            b++;
+            console.log(a, b, c, d, a, b);
+        })("bar", 42);
+    }
+    expect_stdout: "foo 43 bar 42 foo 43"
+}

test/compress/collapse_vars.js

@@ -913,15 +913,15 @@ collapse_vars_unary: {
             return delete x;
         }
         function f1(n) {
-            return n > +!!n
+            return +!!n < n;
         }
         function f2(n) {
             var k = 7;
-            return k--
+            return k--;
         }
         function f3(n) {
             var k = 7;
-            return ++k
+            return ++k;
         }
         function f4(n) {
             var k = 8 - n;
@@ -2219,8 +2219,8 @@ unused_orig: {
         console.log(function(b) {
             var c = b;
             for (var d in c) {
-                var a = c[0];
-                return --b + a;
+                var a;
+                return --b + c[0];
             }
             a && a.NaN;
         }([2]), a);
@@ -3124,7 +3124,57 @@ issue_2425_3: {
     expect_stdout: "15"
 }
 
-issue_2437: {
+issue_2437_1: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        inline: true,
+        join_vars: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        side_effects: true,
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            return bar();
+        }
+        function bar() {
+            if (xhrDesc) {
+                var req = new XMLHttpRequest();
+                var result = !!req.onreadystatechange;
+                Object.defineProperty(XMLHttpRequest.prototype, 'onreadystatechange', xhrDesc || {});
+                return result;
+            } else {
+                var req = new XMLHttpRequest();
+                var detectFunc = function () {};
+                req.onreadystatechange = detectFunc;
+                var result = req[SYMBOL_FAKE_ONREADYSTATECHANGE_1] === detectFunc;
+                req.onreadystatechange = null;
+                return result;
+            }
+        }
+        console.log(foo());
+    }
+    expect: {
+        console.log(function() {
+            if (xhrDesc) {
+                var result = !!(req = new XMLHttpRequest()).onreadystatechange;
+                return Object.defineProperty(XMLHttpRequest.prototype, "onreadystatechange", xhrDesc || {}),
+                    result;
+            }
+            var req, detectFunc = function() {};
+            (req = new XMLHttpRequest()).onreadystatechange = detectFunc;
+            result = req[SYMBOL_FAKE_ONREADYSTATECHANGE_1] === detectFunc;
+            return req.onreadystatechange = null, result;
+        }());
+    }
+}
+
+issue_2437_2: {
     options = {
         collapse_vars: true,
         conditionals: true,
@@ -3161,14 +3211,12 @@ issue_2437: {
     }
     expect: {
         !function() {
-            if (xhrDesc) {
-                var result = !!(req = new XMLHttpRequest()).onreadystatechange;
-                return Object.defineProperty(XMLHttpRequest.prototype, "onreadystatechange", xhrDesc || {}),
-                    result;
-            }
-            var req, detectFunc = function() {};
-            (req = new XMLHttpRequest()).onreadystatechange = detectFunc;
-            result = req[SYMBOL_FAKE_ONREADYSTATECHANGE_1] === detectFunc;
+            if (xhrDesc)
+                return (req = new XMLHttpRequest()).onreadystatechange,
+                    Object.defineProperty(XMLHttpRequest.prototype, "onreadystatechange", xhrDesc || {});
+            var req;
+            (req = new XMLHttpRequest).onreadystatechange = function(){},
+            req[SYMBOL_FAKE_ONREADYSTATECHANGE_1],
             req.onreadystatechange = null;
         }();
     }
@@ -4665,3 +4713,617 @@ issue_2931: {
     }
     expect_stdout: "undefined"
 }
+
+issue_2954_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "PASS", b;
+        try {
+            do {
+                b = function() {
+                    throw 0;
+                }();
+                a = "FAIL";
+                b && b.c;
+            } while (0);
+        } catch (e) {
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS", b;
+        try {
+            do {
+                b = function() {
+                    throw 0;
+                }();
+                a = "FAIL";
+                b && b.c;
+            } while (0);
+        } catch (e) {
+        }
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2954_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "FAIL_1", b;
+        try {
+            throw 0;
+        } catch (e) {
+            do {
+                b = function() {
+                    throw new Error("PASS");
+                }();
+                a = "FAIL_2";
+                b && b.c;
+            } while (0);
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL_1", b;
+        try {
+            throw 0;
+        } catch (e) {
+            do {
+                a = "FAIL_2";
+                (b = function() {
+                    throw new Error("PASS");
+                }()) && b.c;
+            } while (0);
+        }
+        console.log(a);
+    }
+    expect_stdout: Error("PASS")
+}
+
+issue_2954_3: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "FAIL_1", b;
+        try {
+        } finally {
+            do {
+                b = function() {
+                    throw new Error("PASS");
+                }();
+                a = "FAIL_2";
+                b && b.c;
+            } while (0);
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL_1", b;
+        try {
+        } finally {
+            do {
+                a = "FAIL_2";
+                (b = function() {
+                    throw new Error("PASS");
+                }()) && b.c;
+            } while (0);
+        }
+        console.log(a);
+    }
+    expect_stdout: Error("PASS")
+}
+
+collapse_rhs_conditional_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "PASS", b = "FAIL";
+        b = a;
+        "function" == typeof f && f(a);
+        console.log(a, b);
+    }
+    expect: {
+        var a = "PASS", b = "FAIL";
+        b = a;
+        "function" == typeof f && f(a);
+        console.log(a, b);
+    }
+    expect_stdout: "PASS PASS"
+}
+
+collapse_rhs_conditional_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "FAIL", b;
+        while ((a = "PASS", --b) && "PASS" == b);
+        console.log(a, b);
+    }
+    expect: {
+        var a = "FAIL", b;
+        while ((a = "PASS", --b) && "PASS" == b);
+        console.log(a, b);
+    }
+    expect_stdout: "PASS NaN"
+}
+
+collapse_rhs_lhs_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var c = 0;
+        new function() {
+            this[c++] = 1;
+            c += 1;
+        }();
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        new function() {
+            this[c++] = 1;
+            c += 1;
+        }();
+        console.log(c);
+    }
+    expect_stdout: "2"
+}
+
+collapse_rhs_lhs_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var b = 1;
+        (function f(f) {
+            f = b;
+            f[b] = 0;
+        })();
+        console.log("PASS");
+    }
+    expect: {
+        var b = 1;
+        (function f(f) {
+            f = b;
+            f[b] = 0;
+        })();
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+collapse_rhs_side_effects: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 1, c = 0;
+        new function f() {
+            this[a-- && f()] = 1;
+            c += 1;
+        }();
+        console.log(c);
+    }
+    expect: {
+        var a = 1, c = 0;
+        new function f() {
+            this[a-- && f()] = 1;
+            c += 1;
+        }();
+        console.log(c);
+    }
+    expect_stdout: "2"
+}
+
+collapse_rhs_vardef: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b = 1;
+        a = --b + function c() {
+            var b;
+            c[--b] = 1;
+        }();
+        b |= a;
+        console.log(a, b);
+    }
+    expect: {
+        var a, b = 1;
+        a = --b + function c() {
+            var b;
+            c[--b] = 1;
+        }();
+        b |= a;
+        console.log(a, b);
+    }
+    expect_stdout: "NaN 0"
+}
+
+collapse_rhs_array: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = [];
+            b = [];
+            return [];
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            a = [];
+            b = [];
+            return [];
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "false false false"
+}
+
+collapse_rhs_boolean_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = !0;
+            b = !0;
+            return !0;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            return b = a = !0;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "true true true"
+}
+
+collapse_rhs_boolean_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a;
+        (function f1() {
+            a = function() {};
+            if (/foo/)
+                console.log(typeof a);
+        })();
+        console.log(function f2() {
+            a = [];
+            return !1;
+        }());
+    }
+    expect: {
+        var a;
+        (function f1() {
+            if (a = function() {})
+                console.log(typeof a);
+        })();
+        console.log(function f2() {
+            return !(a = []);
+        }());
+    }
+    expect_stdout: [
+        "function",
+        "false",
+    ]
+}
+
+collapse_rhs_boolean_3: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        conditionals: true,
+    }
+    input: {
+        var a, f, g, h, i, n, s, t, x, y;
+        if (x()) {
+            n = a;
+        } else if (y()) {
+            n = f();
+        } else if (s) {
+            i = false;
+            n = g(true);
+        } else if (t) {
+            i = false;
+            n = h(true);
+        } else {
+            n = [];
+        }
+    }
+    expect: {
+        var a, f, g, h, i, n, s, t, x, y;
+        n = x() ? a : y() ? f() : s ? g(!(i = !1)) : t ? h(!(i = !1)) : [];
+    }
+}
+
+collapse_rhs_function: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = function() {};
+            b = function() {};
+            return function() {};
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            a = function() {};
+            b = function() {};
+            return function() {};
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "false false false"
+}
+
+collapse_rhs_number: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = 42;
+            b = 42;
+            return 42;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            return b = a = 42;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "true true true"
+}
+
+collapse_rhs_object: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = {};
+            b = {};
+            return {};
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            a = {};
+            b = {};
+            return {};
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "false false false"
+}
+
+collapse_rhs_regexp: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = /bar/;
+            b = /bar/;
+            return /bar/;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            a = /bar/;
+            b = /bar/;
+            return /bar/;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "false false false"
+}
+
+collapse_rhs_string: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = "foo";
+            b = "foo";
+            return "foo";
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            return b = a = "foo";
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "true true true"
+}
+
+collapse_rhs_var: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = f;
+            b = f;
+            return f;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            return b = a = f;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "true true true"
+}
+
+collapse_rhs_this: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = this;
+            b = this;
+            return this;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            return b = a = this;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "true true true"
+}
+
+collapse_rhs_undefined: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a, b;
+        function f() {
+            a = void 0;
+            b = void 0;
+            return void 0;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect: {
+        var a, b;
+        function f() {
+            b = a = void 0;
+            return;
+        }
+        var c = f();
+        console.log(a === b, b === c, c === a);
+    }
+    expect_stdout: "true true true"
+}
+
+issue_2974: {
+    options = {
+        booleans: true,
+        collapse_vars: true,
+        evaluate: true,
+        loops: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        (function f(b) {
+            var a = 2;
+            do {
+                b && b[b];
+                b && (b.null = -4);
+                c++;
+            } while (b.null && --a > 0);
+        })(true);
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        (function(b) {
+            var a = 2;
+            for (; b.null = -4, c++, b.null && --a > 0;);
+        })(!0),
+        console.log(c);
+    }
+    expect_stdout: "1"
+}
+
+issue_3032: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        console.log({
+            f: function() {
+                this.a = 42;
+                return [ this.a, !1 ];
+            }
+        }.f()[0]);
+    }
+    expect: {
+        console.log({
+            f: function() {
+                this.a = 42;
+                return [ this.a, !1 ];
+            }
+        }.f()[0]);
+    }
+    expect_stdout: "42"
+}

test/compress/comparing.js

@@ -1,62 +1,42 @@
-keep_comparisons: {
+comparisons: {
     options = {
         comparisons: true,
-        unsafe_comps: false
     }
     input: {
-        var obj1 = {
-            valueOf: function() {triggeredFirst();}
-        }
-        var obj2 = {
-            valueOf: function() {triggeredSecond();}
-        }
+        var obj1, obj2;
         var result1 = obj1 <= obj2;
         var result2 = obj1 <  obj2;
         var result3 = obj1 >= obj2;
         var result4 = obj1 >  obj2;
     }
     expect: {
-        var obj1 = {
-            valueOf: function() {triggeredFirst();}
-        }
-        var obj2 = {
-            valueOf: function() {triggeredSecond();}
-        }
+        var obj1, obj2;
         var result1 = obj1 <= obj2;
         var result2 = obj1 <  obj2;
-        var result3 = obj1 >= obj2;
-        var result4 = obj1 >  obj2;
+        var result3 = obj2 <= obj1;
+        var result4 = obj2 <  obj1;
     }
 }
 
-keep_comparisons_with_unsafe_comps: {
+unsafe_comps: {
     options = {
         comparisons: true,
-        unsafe_comps: true
+        conditionals: true,
+        unsafe_comps: true,
     }
     input: {
-        var obj1 = {
-            valueOf: function() {triggeredFirst();}
-        }
-        var obj2 = {
-            valueOf: function() {triggeredSecond();}
-        }
-        var result1 = obj1 <= obj2;
-        var result2 = obj1 <  obj2;
-        var result3 = obj1 >= obj2;
-        var result4 = obj1 >  obj2;
+        var obj1, obj2;
+        obj1 <= obj2 ? f1() : g1();
+        obj1 <  obj2 ? f2() : g2();
+        obj1 >= obj2 ? f3() : g3();
+        obj1 >  obj2 ? f4() : g4();
     }
     expect: {
-        var obj1 = {
-            valueOf: function() {triggeredFirst();}
-        }
-        var obj2 = {
-            valueOf: function() {triggeredSecond();}
-        }
-        var result1 = obj2 >= obj1;
-        var result2 = obj2 >  obj1;
-        var result3 = obj1 >= obj2;
-        var result4 = obj1 >  obj2;
+        var obj1, obj2;
+        obj2 <  obj1 ? g1() : f1();
+        obj1 <  obj2 ? f2() : g2();
+        obj1 <  obj2 ? g3() : f3();
+        obj2 <  obj1 ? f4() : g4();
     }
 }
 

test/compress/conditionals.js

@@ -332,7 +332,7 @@ cond_7: {
         x = 'foo';
         x = 'foo';
         x = (condition(), 20);
-        x = z ? 'fuji' : (condition(), 'fuji');
+        x = (z || condition(), 'fuji');
         x = (condition(), 'foobar');
         x = y ? a : b;
         x = y ? 'foo' : 'fo';
@@ -703,10 +703,11 @@ ternary_boolean_alternative: {
 
 trivial_boolean_ternary_expressions : {
     options = {
+        booleans: true,
         conditionals: true,
-        evaluate    : true,
-        booleans    : true
-    };
+        evaluate: true,
+        side_effects: true,
+    }
     input: {
         f('foo' in m ? true  : false);
         f('foo' in m ? false : true);

test/compress/drop-unused.js

@@ -1785,3 +1785,32 @@ issue_805_2: {
         "bar",
     ]
 }
+
+issue_2995: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var b;
+            a.b = b = function() {};
+            b.c = "PASS";
+        }
+        var o = {};
+        f(o);
+        console.log(o.b.c);
+    }
+    expect: {
+        function f(a) {
+            var b;
+            a.b = b = function() {};
+            b.c = "PASS";
+        }
+        var o = {};
+        f(o);
+        console.log(o.b.c);
+    }
+    expect_stdout: "PASS"
+}

test/compress/evaluate.js

@@ -745,7 +745,7 @@ in_boolean_context: {
             !b("foo"),
             !b([1, 2]),
             !b(/foo/),
-            ![1, foo()],
+            (foo(), !1),
             (foo(), !1)
         );
     }
@@ -1535,3 +1535,74 @@ issue_2926_2: {
     }
     expect_stdout: "function"
 }
+
+issue_2968: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var c = "FAIL";
+        (function() {
+            (function(a, b) {
+                a <<= 0;
+                a && (a[(c = "PASS", 0 >>> (b += 1))] = 0);
+            })(42, -42);
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = "FAIL";
+        (function() {
+            b = -(a = 42),
+            void ((a <<= 0) && (a[(c = "PASS", 0 >>> (b += 1))] = 0));
+            var a, b;
+        })();
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
+truthy_conditionals: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+    }
+    input: {
+        if (a = {}) x();
+        (b = /foo/) && y();
+        (c = function() {}) || z();
+    }
+    expect: {
+        a = {}, x();
+        b = /foo/, y();
+        c = function() {};
+    }
+}
+
+truthy_loops: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        while ([]) x();
+        do {
+            y();
+        } while(a = {});
+    }
+    expect: {
+        for (;;) {
+            [];
+            x();
+        }
+        for (;;) {
+            y();
+            a = {};
+        }
+    }
+}

test/compress/functions.js

@@ -2012,3 +2012,228 @@ issue_2898: {
     }
     expect_stdout: "2"
 }
+
+deduplicate_parenthesis: {
+    input: {
+        ({}).a = b;
+        (({}).a = b)();
+        (function() {}).a = b;
+        ((function() {}).a = b)();
+    }
+    expect_exact: "({}).a=b;({}.a=b)();(function(){}).a=b;(function(){}.a=b)();"
+}
+
+drop_lone_use_strict: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        function f1() {
+            "use strict";
+        }
+        function f2() {
+            "use strict";
+            function f3() {
+                "use strict";
+            }
+        }
+        (function f4() {
+            "use strict";
+        })();
+    }
+    expect: {
+        function f1() {
+        }
+        function f2() {
+            "use strict";
+            function f3() {
+            }
+        }
+    }
+}
+
+issue_3016_1: {
+    options = {
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        var b = 1;
+        do {
+            (function(a) {
+                return a[b];
+                var a;
+            })(3);
+        } while (0);
+        console.log(b);
+    }
+    expect: {
+        var b = 1;
+        do {
+            a = 3,
+            a[b];
+        } while(0);
+        var a;
+        console.log(b);
+    }
+    expect_stdout: "1"
+}
+
+issue_3016_2: {
+    options = {
+        dead_code: true,
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        var b = 1;
+        do {
+            (function(a) {
+                return a[b];
+                try {
+                    a = 2;
+                } catch (a) {
+                    var a;
+                }
+            })(3);
+        } while (0);
+        console.log(b);
+    }
+    expect: {
+        var b = 1;
+        do {
+            a = 3,
+            a[b];
+        } while(0);
+        var a;
+        console.log(b);
+    }
+    expect_stdout: "1"
+}
+
+issue_3016_2_ie8: {
+    options = {
+        dead_code: true,
+        ie8: true,
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        var b = 1;
+        do {
+            (function(a) {
+                return a[b];
+                try {
+                    a = 2;
+                } catch (a) {
+                    var a;
+                }
+            })(3);
+        } while (0);
+        console.log(b);
+    }
+    expect: {
+        var b = 1;
+        do {
+            a = 3,
+            a[b];
+        } while(0);
+        var a;
+        console.log(b);
+    }
+    expect_stdout: "1"
+}
+
+issue_3016_3: {
+    options = {
+        dead_code: true,
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        var b = 1;
+        do {
+            console.log(function() {
+                return a ? "FAIL" : a = "PASS";
+                try {
+                    a = 2;
+                } catch (a) {
+                    var a;
+                }
+            }());
+        } while (b--);
+    }
+    expect: {
+        var b = 1;
+        do {
+            console.log((a = void 0, a ? "FAIL" : a = "PASS"));
+        } while(b--);
+        var a;
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+    ]
+}
+
+issue_3016_3_ie8: {
+    options = {
+        dead_code: true,
+        ie8: true,
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        var b = 1;
+        do {
+            console.log(function() {
+                return a ? "FAIL" : a = "PASS";
+                try {
+                    a = 2;
+                } catch (a) {
+                    var a;
+                }
+            }());
+        } while (b--);
+    }
+    expect: {
+        var b = 1;
+        do {
+            console.log((a = void 0, a ? "FAIL" : a = "PASS"));
+        } while(b--);
+        var a;
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+    ]
+}
+
+issue_3018: {
+    options = {
+        inline: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var b = 1, c = "PASS";
+        do {
+            (function() {
+                (function(a) {
+                    a = 0 != (a && (c = "FAIL"));
+                })();
+            })();
+        } while (b--);
+        console.log(c);
+    }
+    expect: {
+        var b = 1, c = "PASS";
+        do {
+            a = void 0,
+            a = 0 != (a && (c = "FAIL"));
+        } while (b--);
+        var a;
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}

test/compress/hoist_props.js

@@ -239,14 +239,14 @@ name_collision_2: {
     input: {
         var o = {
             p: 1,
-            0: function(x) {
+            "+": function(x) {
                 return x;
             },
-            1: function(x) {
+            "-": function(x) {
                 return x + 1;
             }
         }, o__$0 = 2, o__$1 = 3;
-        console.log(o.p === o.p, o[0](4), o[1](5), o__$0, o__$1);
+        console.log(o.p === o.p, o["+"](4), o["-"](5), o__$0, o__$1);
     }
     expect: {
         var o_p = 1,
@@ -273,14 +273,14 @@ name_collision_3: {
     input: {
         var o = {
             p: 1,
-            0: function(x) {
+            "+": function(x) {
                 return x;
             },
-            1: function(x) {
+            "-": function(x) {
                 return x + 1;
             }
         }, o__$0 = 2, o__$1 = 3;
-        console.log(o.p === o.p, o[0](4), o[1](5));
+        console.log(o.p === o.p, o["+"](4), o["-"](5));
     }
     expect: {
         var o_p = 1,
@@ -686,3 +686,33 @@ undefined_key: {
     }
     expect_stdout: "3"
 }
+
+issue_3021: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+    }
+    input: {
+        var a = 1, b = 2;
+        (function() {
+            b = a;
+            if (a++ + b--)
+                return 1;
+            return;
+            var b = {};
+        })();
+        console.log(a, b);
+    }
+    expect: {
+        var a = 1, b = 2;
+        (function() {
+            b = a;
+            if (a++ + b--)
+                return 1;
+            return;
+            var b = {};
+        })();
+        console.log(a, b);
+    }
+    expect_stdout: "2 2"
+}

test/compress/ie8.js

@@ -102,12 +102,12 @@ dont_screw_try_catch: {
         };
     }
     expect: {
-        bad = function(n){
-            return function(t){
+        bad = function(t){
+            return function(n){
                 try{
-                    n()
-                } catch(n) {
-                    t(n)
+                    t()
+                } catch(t) {
+                    n(t)
                 }
             }
         };
@@ -349,11 +349,11 @@ issue_2254_1: {
         try {
             console.log(f("PASS"));
         } catch (e) {}
-        function f(e) {
+        function f(t) {
             try {
                 throw "FAIL";
-            } catch (t) {
-                return e;
+            } catch (e) {
+                return t;
             }
         }
     }
@@ -392,3 +392,149 @@ issue_2254_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_24_1: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        (function(a) {
+            console.log(typeof function f(){} === typeof a ? "FAIL" : "PASS");
+        })();
+    }
+    expect: {
+        (function(o) {
+            console.log(typeof function o(){} === typeof o ? "FAIL" : "PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_24_2: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        (function(a) {
+            console.log(typeof function f(){} === typeof a ? "FAIL" : "PASS");
+        })();
+    }
+    expect: {
+        (function(n) {
+            console.log(typeof function o(){} === typeof n ? "FAIL" : "PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2976_1: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        console.log(function f() {
+            var a;
+            return a === f ? "FAIL" : "PASS";
+        }());
+    }
+    expect: {
+        console.log(function n() {
+            var o;
+            return o === n ? "FAIL" : "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2976_2: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        console.log(function f() {
+            var a;
+            return a === f ? "FAIL" : "PASS";
+        }());
+    }
+    expect: {
+        console.log(function n() {
+            var o;
+            return o === n ? "FAIL" : "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3035: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        var c = "FAIL";
+        (function(a) {
+            try {
+                throw 1;
+            } catch (b) {
+                try {
+                    throw 0;
+                } catch (a) {
+                    b && (c = "PASS");
+                }
+            }
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = "FAIL";
+        (function(o) {
+            try {
+                throw 1;
+            } catch (t) {
+                try {
+                    throw 0;
+                } catch (o) {
+                    t && (c = "PASS");
+                }
+            }
+        })();
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3035_ie8: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        var c = "FAIL";
+        (function(a) {
+            try {
+                throw 1;
+            } catch (b) {
+                try {
+                    throw 0;
+                } catch (a) {
+                    b && (c = "PASS");
+                }
+            }
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = "FAIL";
+        (function(t) {
+            try {
+                throw 1;
+            } catch (o) {
+                try {
+                    throw 0;
+                } catch (t) {
+                    o && (c = "PASS");
+                }
+            }
+        })();
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}

test/compress/if_return.js

@@ -243,7 +243,7 @@ issue_1089: {
     expect: {
         function x() {
             var f = document.getElementById("fname");
-            if (f.files[0].size > 12345)
+            if (12345 < f.files[0].size)
                 return alert("alert"), f.focus(), !1;
         }
     }

test/compress/issue-1261.js

@@ -175,8 +175,8 @@ should_warn: {
         "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:141,31]",
         "WARN: Condition always true [test/compress/issue-1261.js:141,8]",
         "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:142,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:143,24]",
         "WARN: Condition always true [test/compress/issue-1261.js:143,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:143,24]",
         "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-1704.js

@@ -104,7 +104,7 @@ mangle_catch_toplevel: {
         }
         console.log(a);
     }
-    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_exact: 'var c="FAIL";try{throw 1}catch(o){c="PASS"}console.log(c);'
     expect_stdout: "PASS"
 }
 
@@ -148,7 +148,7 @@ mangle_catch_var_toplevel: {
         }
         console.log(a);
     }
-    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_exact: 'var r="FAIL";try{throw 1}catch(o){var r="PASS"}console.log(r);'
     expect_stdout: "PASS"
 }
 
@@ -345,3 +345,95 @@ mangle_catch_redef_2_ie8_toplevel: {
     expect_exact: 'try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
     expect_stdout: "undefined"
 }
+
+mangle_catch_redef_3: {
+    mangle = {
+        ie8: false,
+        toplevel: false,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    expect_exact: 'var o="PASS";try{throw 0}catch(o){(function(){function c(){o="FAIL"}c(),c()})()}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_3_toplevel: {
+    mangle = {
+        ie8: false,
+        toplevel: true,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    expect_exact: 'var c="PASS";try{throw 0}catch(c){(function(){function o(){c="FAIL"}o(),o()})()}console.log(c);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_ie8_3: {
+    mangle = {
+        ie8: true,
+        toplevel: false,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    expect_exact: 'var o="PASS";try{throw 0}catch(o){(function(){function c(){o="FAIL"}c(),c()})()}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_3_ie8_toplevel: {
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    expect_exact: 'var c="PASS";try{throw 0}catch(c){(function(){function o(){c="FAIL"}o(),o()})()}console.log(c);'
+    expect_stdout: "PASS"
+}

test/compress/issue-1733.js

@@ -15,7 +15,7 @@ function_iife_catch: {
         }
         f();
     }
-    expect_exact: "function f(o){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
+    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
     expect_stdout: "0 1"
 }
 
@@ -36,7 +36,7 @@ function_iife_catch_ie8: {
         }
         f();
     }
-    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
+    expect_exact: "function f(c){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
     expect_stdout: "0 1"
 }
 
@@ -61,7 +61,7 @@ function_catch_catch: {
         }
         f();
     }
-    expect_exact: "var o=0;function f(){try{throw 1}catch(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_exact: "var o=0;function f(){try{throw 1}catch(o){try{throw 2}catch(c){var c=3;console.log(c)}}console.log(c)}f();"
     expect_stdout: [
         "3",
         "undefined",

test/compress/issue-2989.js

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

test/compress/loops.js

@@ -294,10 +294,10 @@ issue_186_beautify_ie8: {
     ]
 }
 
-issue_186_bracketize: {
+issue_186_braces: {
     beautify = {
         beautify: false,
-        bracketize: true,
+        braces: true,
         ie8: false,
     }
     input: {
@@ -314,10 +314,10 @@ issue_186_bracketize: {
     expect_exact: 'var x=3;if(foo()){do{do{alert(x)}while(--x)}while(x)}else{bar()}'
 }
 
-issue_186_bracketize_ie8: {
+issue_186_braces_ie8: {
     beautify = {
         beautify: false,
-        bracketize: true,
+        braces: true,
         ie8: true,
     }
     input: {
@@ -334,10 +334,10 @@ issue_186_bracketize_ie8: {
     expect_exact: 'var x=3;if(foo()){do{do{alert(x)}while(--x)}while(x)}else{bar()}'
 }
 
-issue_186_beautify_bracketize: {
+issue_186_beautify_braces: {
     beautify = {
         beautify: true,
-        bracketize: true,
+        braces: true,
         ie8: false,
     }
     input: {
@@ -366,10 +366,10 @@ issue_186_beautify_bracketize: {
     ]
 }
 
-issue_186_beautify_bracketize_ie8: {
+issue_186_beautify_braces_ie8: {
     beautify = {
         beautify: true,
-        bracketize: true,
+        braces: true,
         ie8: true,
     }
     input: {

test/compress/negate-iife.js

@@ -67,7 +67,7 @@ negate_iife_3_evaluate: {
         (function(){ return true })() ? console.log(true) : console.log(false);
     }
     expect: {
-        console.log(true);
+        true, console.log(true);
     }
     expect_stdout: true
 }
@@ -110,7 +110,7 @@ negate_iife_3_off_evaluate: {
         (function(){ return true })() ? console.log(true) : console.log(false);
     }
     expect: {
-        console.log(true);
+        true, console.log(true);
     }
     expect_stdout: true
 }

test/compress/pure_getters.js

@@ -830,3 +830,334 @@ issue_2938_4: {
     }
     expect_stdout: "PASS"
 }
+
+collapse_vars_1_true: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+    expect: {
+        function f(a, b) {
+            for (;;) {
+                if (a.g() || b.p) break;
+            }
+        }
+    }
+}
+
+collapse_vars_1_false: {
+    options = {
+        collapse_vars: true,
+        pure_getters: false,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+    expect: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+}
+
+collapse_vars_1_strict: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+    expect: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+}
+
+collapse_vars_2_true: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+        reduce_vars: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            g.a = function() {};
+            g.b = g.a;
+            return g;
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            g.b = g.a = function() {};
+            return g;
+        }
+    }
+}
+
+collapse_vars_2_false: {
+    options = {
+        collapse_vars: true,
+        pure_getters: false,
+        reduce_vars: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            g.a = function() {};
+            g.b = g.a;
+            return g;
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            g.a = function() {};
+            g.b = g.a;
+            return g;
+        }
+    }
+}
+
+collapse_vars_2_strict: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            g.a = function() {};
+            g.b = g.a;
+            return g;
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            g.b = g.a = function() {};
+            return g;
+        }
+    }
+}
+
+collapse_rhs_true: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        console.log((42..length = "PASS", "PASS"));
+        console.log(("foo".length = "PASS", "PASS"));
+        console.log((false.length = "PASS", "PASS"));
+        console.log((function() {}.length = "PASS", "PASS"));
+        console.log(({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS", "PASS"));
+    }
+    expect: {
+        console.log(42..length = "PASS");
+        console.log("foo".length = "PASS");
+        console.log(false.length = "PASS");
+        console.log(function() {}.length = "PASS");
+        console.log({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+}
+
+collapse_rhs_false: {
+    options = {
+        collapse_vars: true,
+        pure_getters: false,
+    }
+    input: {
+        console.log((42..length = "PASS", "PASS"));
+        console.log(("foo".length = "PASS", "PASS"));
+        console.log((false.length = "PASS", "PASS"));
+        console.log((function() {}.length = "PASS", "PASS"));
+        console.log(({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS", "PASS"));
+    }
+    expect: {
+        console.log(42..length = "PASS");
+        console.log("foo".length = "PASS");
+        console.log(false.length = "PASS");
+        console.log(function() {}.length = "PASS");
+        console.log({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+}
+
+collapse_rhs_strict: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+    }
+    input: {
+        console.log((42..length = "PASS", "PASS"));
+        console.log(("foo".length = "PASS", "PASS"));
+        console.log((false.length = "PASS", "PASS"));
+        console.log((function() {}.length = "PASS", "PASS"));
+        console.log(({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS", "PASS"));
+    }
+    expect: {
+        console.log(42..length = "PASS");
+        console.log("foo".length = "PASS");
+        console.log(false.length = "PASS");
+        console.log(function() {}.length = "PASS");
+        console.log({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+}
+
+collapse_rhs_setter: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+    }
+    input: {
+        try {
+            console.log(({
+                set length(v) {
+                    throw "PASS";
+                }
+            }.length = "FAIL", "FAIL"));
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        try {
+            console.log({
+                set length(v) {
+                    throw "PASS";
+                }
+            }.length = "FAIL");
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+collapse_rhs_call: {
+    options = {
+        collapse_vars: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {};
+        function f() {
+            console.log("PASS");
+        }
+        o.f = f;
+        f();
+    }
+    expect: {
+        ({}.f = function() {
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+collapse_rhs_lhs: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b) {
+            a.b = b, b += 2;
+            console.log(a.b, b);
+        }
+        f({}, 1);
+    }
+    expect: {
+        function f(a, b) {
+            a.b = b, b += 2;
+            console.log(a.b, b);
+        }
+        f({}, 1);
+    }
+    expect_stdout: "1 3"
+}

test/compress/reduce_vars.js

@@ -55,7 +55,7 @@ reduce_vars: {
             console.log(a - 5);
             eval("console.log(a);");
         })(eval);
-        "yes";
+        true, "yes";
         console.log(A + 1);
     }
     expect_stdout: true
@@ -147,7 +147,7 @@ modified: {
         }
         function f4() {
             var b = 2, c = 3;
-            b = c;
+            1, b = c;
             console.log(1 + b);
             console.log(b + c);
             console.log(1 + c);
@@ -715,10 +715,12 @@ passes: {
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
+        sequences: true,
+        side_effects: true,
         unused: true,
     }
     input: {
-        function f() {
+        (function() {
             var a = 1, b = 2, c = 3;
             if (a) {
                 b = c;
@@ -729,17 +731,22 @@ passes: {
             console.log(b + c);
             console.log(a + c);
             console.log(a + b + c);
-        }
+        })();
     }
     expect: {
-        function f() {
-            3;
-            console.log(4);
-            console.log(6);
-            console.log(4);
+        (function() {
+            console.log(4),
+            console.log(6),
+            console.log(4),
             console.log(7);
-        }
+        })();
     }
+    expect_stdout: [
+        "4",
+        "6",
+        "4",
+        "7",
+    ]
 }
 
 iife: {
@@ -5545,3 +5552,33 @@ issue_2919: {
     }
     expect_stdout: "function"
 }
+
+issue_2992: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        var c = "PASS";
+        (function f(b) {
+            switch (0) {
+            case 0:
+            case b = 1:
+                b && (c = "FAIL");
+            }
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = "PASS";
+        (function f(b) {
+            switch (0) {
+            case 0:
+            case b = 1:
+                b && (c = "FAIL");
+            }
+        })();
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}

test/compress/rename.js

@@ -109,7 +109,7 @@ mangle_catch_toplevel: {
         }
         console.log(a);
     }
-    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_exact: 'var c="FAIL";try{throw 1}catch(o){c="PASS"}console.log(c);'
     expect_stdout: "PASS"
 }
 
@@ -155,7 +155,7 @@ mangle_catch_var_toplevel: {
         }
         console.log(a);
     }
-    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_exact: 'var r="FAIL";try{throw 1}catch(o){var r="PASS"}console.log(r);'
     expect_stdout: "PASS"
 }
 
@@ -451,7 +451,7 @@ function_iife_catch: {
         }
         f();
     }
-    expect_exact: "function f(o){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
+    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
     expect_stdout: "0 1"
 }
 
@@ -473,7 +473,7 @@ function_iife_catch_ie8: {
         }
         f();
     }
-    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
+    expect_exact: "function f(c){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
     expect_stdout: "0 1"
 }
 
@@ -499,7 +499,7 @@ function_catch_catch: {
         }
         f();
     }
-    expect_exact: "var o=0;function f(){try{throw 1}catch(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_exact: "var o=0;function f(){try{throw 1}catch(o){try{throw 2}catch(c){var c=3;console.log(c)}}console.log(c)}f();"
     expect_stdout: [
         "3",
         "undefined",

test/compress/sequences.js

@@ -668,8 +668,7 @@ side_effects_cascade_2: {
     }
     expect: {
         function f(a, b) {
-            b = a,
-            !a + (b += a) || (b += a),
+            !(b = a) + (b += a) || (b += a),
             b = a;
         }
     }

test/compress/transform.js

@@ -59,7 +59,7 @@ if_else_empty: {
         if ({} ? a : b); else {}
     }
     expect: {
-        !{} ? b : a;
+        ({}), a;
     }
 }
 
@@ -104,6 +104,7 @@ if_return: {
         conditionals: true,
         if_return: true,
         sequences: true,
+        side_effects: true,
     }
     input: {
         function f(w, x, y, z) {
@@ -124,7 +125,7 @@ if_return: {
                 if (w) {
                     if (y) return;
                 } else if (z) return;
-                return x == y || (x && w(), y && z(), !0);
+                return x == y || (x && w(), y && z()), !0;
             }
         }
     }

test/mocha/cli.js

@@ -164,13 +164,13 @@ describe("bin/uglifyjs", function () {
             done();
         });
     });
-    it("Should work with `--beautify bracketize`", function (done) {
-        var command = uglifyjscmd + ' test/input/issue-1482/input.js -b bracketize';
+    it("Should work with `--beautify braces`", function (done) {
+        var command = uglifyjscmd + ' test/input/issue-1482/input.js -b braces';
 
         exec(command, function (err, stdout) {
             if (err) throw err;
 
-            assert.strictEqual(stdout, read("test/input/issue-1482/bracketize.js"));
+            assert.strictEqual(stdout, read("test/input/issue-1482/braces.js"));
             done();
         });
     });

test/mocha/comment.js

@@ -139,6 +139,26 @@ describe("Comment", function() {
         assert.strictEqual(result.code, code);
     });
 
+    it("Should retain comments within braces", function() {
+        var code = [
+            "{/* foo */}",
+            "a({/* foo */});",
+            "while (a) {/* foo */}",
+            "switch (a) {/* foo */}",
+            "if (a) {/* foo */} else {/* bar */}",
+        ].join("\n\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 = [
             [

test/mocha/minify.js

@@ -46,10 +46,10 @@ describe("minify", function() {
         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 c=console.log.bind(console);",
+            'function o(o){c("Foo:",2*o)}',
             "var a=n(3),b=r(12);",
-            'o("qux",a,b),c(11);',
+            'c("qux",a,b),o(11);',
         ].join(""));
         assert.strictEqual(run_code(compressed), run_code(original));
     });
@@ -79,10 +79,10 @@ describe("minify", function() {
         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 c=console.log.bind(console);",
+            'function o(o){c("Foo:",2*o)}',
             "var a=n(3),b=r(12);",
-            'o("qux",a,b),c(11);',
+            'c("qux",a,b),o(11);',
         ].join(""));
         assert.strictEqual(run_code(compressed), run_code(original));
     });
@@ -186,99 +186,6 @@ describe("minify", function() {
         });
     });
 
-    describe("inSourceMap", function() {
-        it("Should read the given string filename correctly when sourceMapIncludeSources is enabled (#1236)", function() {
-            var result = Uglify.minify(read("./test/input/issue-1236/simple.js"), {
-                sourceMap: {
-                    content: read("./test/input/issue-1236/simple.js.map"),
-                    filename: "simple.min.js",
-                    includeSources: true
-                }
-            });
-
-            var map = JSON.parse(result.map);
-
-            assert.equal(map.file, 'simple.min.js');
-            assert.equal(map.sourcesContent.length, 1);
-            assert.equal(map.sourcesContent[0],
-                'let foo = x => "foo " + x;\nconsole.log(foo("bar"));');
-        });
-        it("Should process inline source map", function() {
-            var code = Uglify.minify(read("./test/input/issue-520/input.js"), {
-                compress: { toplevel: true },
-                sourceMap: {
-                    content: "inline",
-                    url: "inline"
-                }
-            }).code + "\n";
-            assert.strictEqual(code, readFileSync("test/input/issue-520/output.js", "utf8"));
-        });
-        it("Should warn for missing inline source map", function() {
-            var warn_function = Uglify.AST_Node.warn_function;
-            var warnings = [];
-            Uglify.AST_Node.warn_function = function(txt) {
-                warnings.push(txt);
-            };
-            try {
-                var result = Uglify.minify(read("./test/input/issue-1323/sample.js"), {
-                    mangle: false,
-                    sourceMap: {
-                        content: "inline"
-                    }
-                });
-                assert.strictEqual(result.code, "var bar=function(bar){return bar};");
-                assert.strictEqual(warnings.length, 1);
-                assert.strictEqual(warnings[0], "inline source map not found");
-            } finally {
-                Uglify.AST_Node.warn_function = warn_function;
-            }
-        });
-        it("Should fail with multiple input and inline source map", function() {
-            var result = Uglify.minify([
-                read("./test/input/issue-520/input.js"),
-                read("./test/input/issue-520/output.js")
-            ], {
-                sourceMap: {
-                    content: "inline",
-                    url: "inline"
-                }
-            });
-            var err = result.error;
-            assert.ok(err instanceof Error);
-            assert.strictEqual(err.stack.split(/\n/)[0], "Error: inline source map only works with singular input");
-        });
-    });
-
-    describe("sourceMapInline", function() {
-        it("should append source map to output js when sourceMapInline is enabled", function() {
-            var result = Uglify.minify('var a = function(foo) { return foo; };', {
-                sourceMap: {
-                    url: "inline"
-                }
-            });
-            var code = result.code;
-            assert.strictEqual(code, "var a=function(n){return n};\n" +
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsiYSIsImZvbyJdLCJtYXBwaW5ncyI6IkFBQUEsSUFBSUEsRUFBSSxTQUFTQyxHQUFPLE9BQU9BIn0=");
-        });
-        it("should not append source map to output js when sourceMapInline is not enabled", function() {
-            var result = Uglify.minify('var a = function(foo) { return foo; };');
-            var code = result.code;
-            assert.strictEqual(code, "var a=function(n){return n};");
-        });
-        it("should work with max_line_len", function() {
-            var result = Uglify.minify(read("./test/input/issue-505/input.js"), {
-                output: {
-                    max_line_len: 20
-                },
-                sourceMap: {
-                    url: "inline"
-                }
-            });
-            assert.strictEqual(result.error, undefined);
-            assert.strictEqual(result.code, read("./test/input/issue-505/output.js"));
-        });
-    });
-
     describe("#__PURE__", function() {
         it("should drop #__PURE__ hint after use", function() {
             var result = Uglify.minify('//@__PURE__ comment1 #__PURE__ comment2\n foo(), bar();', {
@@ -312,6 +219,15 @@ describe("minify", function() {
             assert.strictEqual(err.line, 1);
             assert.strictEqual(err.col, 12);
         });
+        it("should reject duplicated label name", function() {
+            var result = Uglify.minify("L:{L:{}}");
+            var err = result.error;
+            assert.ok(err instanceof Error);
+            assert.strictEqual(err.stack.split(/\n/)[0], "SyntaxError: Label L defined twice");
+            assert.strictEqual(err.filename, "0");
+            assert.strictEqual(err.line, 1);
+            assert.strictEqual(err.col, 4);
+        });
     });
 
     describe("global_defs", function() {

test/mocha/release.js

@@ -17,7 +17,7 @@ describe("test/benchmark.js", function() {
     this.timeout(10 * 60 * 1000);
     [
         "-b",
-        "-b bracketize",
+        "-b braces",
         "-m",
         "-mc passes=3",
         "-mc passes=3,toplevel",

test/mocha/sourcemaps.js

@@ -0,0 +1,143 @@
+var assert = require("assert");
+var readFileSync = require("fs").readFileSync;
+var Uglify = require("../../");
+
+function read(path) {
+    return readFileSync(path, "utf8");
+}
+
+function source_map(code) {
+    return JSON.parse(Uglify.minify(code, {
+        compress: false,
+        mangle: false,
+        sourceMap: true,
+    }).map);
+}
+
+describe("sourcemaps", function() {
+    it("Should give correct version", function() {
+        var map = source_map("var x = 1 + 1;");
+        assert.strictEqual(map.version, 3);
+        assert.deepEqual(map.names, [ "x" ]);
+    });
+
+    it("Should give correct names", function() {
+        var map = source_map([
+            "({",
+            "    get enabled() {",
+            "        return 3;",
+            "    },",
+            "    set enabled(x) {",
+            "        ;",
+            "    }",
+            "});",
+        ].join("\n"));
+        assert.deepEqual(map.names, [ "enabled", "x" ]);
+    });
+
+    it("Should mark array/object literals", function() {
+        var result = Uglify.minify([
+            "var obj = {};",
+            "obj.wat([]);",
+        ].join("\n"), {
+            sourceMap: true,
+            toplevel: true,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, "({}).wat([]);");
+        assert.strictEqual(result.map, '{"version":3,"sources":["0"],"names":["wat"],"mappings":"CAAU,IACNA,IAAI"}');
+    });
+
+    describe("inSourceMap", function() {
+        it("Should read the given string filename correctly when sourceMapIncludeSources is enabled (#1236)", function() {
+            var result = Uglify.minify(read("./test/input/issue-1236/simple.js"), {
+                sourceMap: {
+                    content: read("./test/input/issue-1236/simple.js.map"),
+                    filename: "simple.min.js",
+                    includeSources: true
+                }
+            });
+
+            var map = JSON.parse(result.map);
+
+            assert.equal(map.file, 'simple.min.js');
+            assert.equal(map.sourcesContent.length, 1);
+            assert.equal(map.sourcesContent[0],
+                'let foo = x => "foo " + x;\nconsole.log(foo("bar"));');
+        });
+        it("Should process inline source map", function() {
+            var code = Uglify.minify(read("./test/input/issue-520/input.js"), {
+                compress: { toplevel: true },
+                sourceMap: {
+                    content: "inline",
+                    url: "inline"
+                }
+            }).code + "\n";
+            assert.strictEqual(code, readFileSync("test/input/issue-520/output.js", "utf8"));
+        });
+        it("Should warn for missing inline source map", function() {
+            var warn_function = Uglify.AST_Node.warn_function;
+            var warnings = [];
+            Uglify.AST_Node.warn_function = function(txt) {
+                warnings.push(txt);
+            };
+            try {
+                var result = Uglify.minify(read("./test/input/issue-1323/sample.js"), {
+                    mangle: false,
+                    sourceMap: {
+                        content: "inline"
+                    }
+                });
+                assert.strictEqual(result.code, "var bar=function(bar){return bar};");
+                assert.strictEqual(warnings.length, 1);
+                assert.strictEqual(warnings[0], "inline source map not found");
+            } finally {
+                Uglify.AST_Node.warn_function = warn_function;
+            }
+        });
+        it("Should fail with multiple input and inline source map", function() {
+            var result = Uglify.minify([
+                read("./test/input/issue-520/input.js"),
+                read("./test/input/issue-520/output.js")
+            ], {
+                sourceMap: {
+                    content: "inline",
+                    url: "inline"
+                }
+            });
+            var err = result.error;
+            assert.ok(err instanceof Error);
+            assert.strictEqual(err.stack.split(/\n/)[0], "Error: inline source map only works with singular input");
+        });
+    });
+
+    describe("sourceMapInline", function() {
+        it("should append source map to output js when sourceMapInline is enabled", function() {
+            var result = Uglify.minify('var a = function(foo) { return foo; };', {
+                sourceMap: {
+                    url: "inline"
+                }
+            });
+            var code = result.code;
+            assert.strictEqual(code, "var a=function(n){return n};\n" +
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsiYSIsImZvbyJdLCJtYXBwaW5ncyI6IkFBQUEsSUFBSUEsRUFBSSxTQUFTQyxHQUFPLE9BQU9BIn0=");
+        });
+        it("should not append source map to output js when sourceMapInline is not enabled", function() {
+            var result = Uglify.minify('var a = function(foo) { return foo; };');
+            var code = result.code;
+            assert.strictEqual(code, "var a=function(n){return n};");
+        });
+        it("should work with max_line_len", function() {
+            var result = Uglify.minify(read("./test/input/issue-505/input.js"), {
+                output: {
+                    max_line_len: 20
+                },
+                sourceMap: {
+                    url: "inline"
+                }
+            });
+            assert.strictEqual(result.error, undefined);
+            assert.strictEqual(result.code, read("./test/input/issue-505/output.js"));
+        });
+    });
+});

test/mocha/spidermonkey.js

@@ -23,6 +23,15 @@ describe("spidermonkey export/import sanity test", function() {
         });
     });
 
+    it("should not add unnecessary escape slashes to regexps", function() {
+        var input = "/[\\\\/]/;";
+        var ast = uglify.parse(input).to_mozilla_ast();
+        assert.equal(
+            uglify.AST_Node.from_mozilla_ast(ast).print_to_string(),
+            input
+        );
+    });
+
     it("Should judge between directives and strings correctly on import", function() {
         var tests = [
             {

test/mozilla-ast.js

@@ -11,7 +11,7 @@ function try_beautify(code) {
         mangle: false,
         output: {
             beautify: true,
-            bracketize: true
+            braces: true
         }
     });
     if (beautified.error) {

test/run-tests.js

@@ -22,9 +22,6 @@ if (failures) {
 var mocha_tests = require("./mocha.js");
 mocha_tests();
 
-var run_sourcemaps_tests = require('./sourcemaps');
-run_sourcemaps_tests();
-
 /* -----[ utils ]----- */
 
 function tmpl() {
@@ -49,16 +46,9 @@ function log_test(name) {
 }
 
 function find_test_files(dir) {
-    var files = fs.readdirSync(dir).filter(function(name){
+    return fs.readdirSync(dir).filter(function(name) {
         return /\.js$/i.test(name);
     });
-    if (process.argv.length > 2) {
-        var x = process.argv.slice(2);
-        files = files.filter(function(f){
-            return x.indexOf(f) >= 0;
-        });
-    }
-    return files;
 }
 
 function test_directory(dir) {
@@ -135,7 +125,6 @@ function run_compress_tests() {
             var output = cmp.compress(input);
             output.figure_out_scope(test.mangle);
             if (test.mangle) {
-                U.base54.reset();
                 output.compute_char_frequency(test.mangle);
                 output.mangle_names(test.mangle);
                 if (test.mangle.properties) {
@@ -183,7 +172,7 @@ function run_compress_tests() {
             }
             if (test.expect_stdout
                 && (!test.node_version || semver.satisfies(process.version, test.node_version))) {
-                var stdout = sandbox.run_code(input_code);
+                var stdout = sandbox.run_code(input_code, true);
                 if (test.expect_stdout === true) {
                     test.expect_stdout = stdout;
                 }
@@ -197,7 +186,7 @@ function run_compress_tests() {
                     });
                     return false;
                 }
-                stdout = sandbox.run_code(output);
+                stdout = sandbox.run_code(output, true);
                 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,
@@ -344,7 +333,6 @@ function parse_test(file) {
 }
 
 function make_code(ast, options) {
-    options.inline_script = true;
     var stream = U.OutputStream(options);
     ast.print(stream);
     return stream.get();
@@ -379,7 +367,7 @@ function reminify(orig_options, input_code, input_formatted, expect_stdout) {
             });
             return false;
         } else {
-            var stdout = sandbox.run_code(result.code);
+            var stdout = sandbox.run_code(result.code, true);
             if (typeof expect_stdout != "string" && typeof stdout != "string" && expect_stdout.name == stdout.name) {
                 stdout = expect_stdout;
             }

test/sandbox.js

@@ -1,6 +1,27 @@
 var semver = require("semver");
 var vm = require("vm");
 
+function createContext() {
+    var context = Object.create(null);
+    Object.defineProperty(context, "console", {
+        value: function() {
+            var con = Object.create(null);
+            Object.defineProperty(con, "log", {
+                value: function(msg) {
+                    if (arguments.length == 1 && typeof msg == "string") {
+                        return console.log("%s", msg);
+                    }
+                    return console.log.apply(console, [].map.call(arguments, function(arg) {
+                        return safe_log(arg, 3);
+                    }));
+                }
+            });
+            return con;
+        }()
+    });
+    return vm.createContext(context);
+}
+
 function safe_log(arg, level) {
     if (arg) switch (typeof arg) {
       case "function":
@@ -9,7 +30,8 @@ function safe_log(arg, level) {
         if (/Error$/.test(arg.name)) return arg.toString();
         arg.constructor.toString();
         if (level--) for (var key in arg) {
-            if (!Object.getOwnPropertyDescriptor(arg, key).get) {
+            var desc = Object.getOwnPropertyDescriptor(arg, key);
+            if (!desc || !desc.get) {
                 arg[key] = safe_log(arg[key], level);
             }
         }
@@ -21,6 +43,7 @@ function strip_func_ids(text) {
     return text.toString().replace(/F[0-9]{6}N/g, "<F<>N>");
 }
 
+var context;
 var FUNC_TOSTRING = [
     "[ Array, Boolean, Error, Function, Number, Object, RegExp, String].forEach(function(f) {",
     "    f.toString = Function.prototype.toString;",
@@ -43,35 +66,30 @@ var FUNC_TOSTRING = [
     "    };",
     "}();",
 ]).join("\n");
-exports.run_code = function(code) {
+exports.run_code = function(code, reuse) {
     var stdout = "";
     var original_write = process.stdout.write;
     process.stdout.write = function(chunk) {
         stdout += chunk;
     };
     try {
-        vm.runInNewContext([
+        if (!reuse || !context) context = createContext();
+        vm.runInContext([
             FUNC_TOSTRING,
             "!function() {",
             code,
             "}();",
-        ].join("\n"), {
-            console: {
-                log: function(msg) {
-                    if (arguments.length == 1 && typeof msg == "string") {
-                        return console.log("%s", msg);
-                    }
-                    return console.log.apply(console, [].map.call(arguments, function(arg) {
-                        return safe_log(arg, 3);
-                    }));
-                }
-            }
-        }, { timeout: 5000 });
+        ].join("\n"), context, { timeout: 5000 });
         return stdout;
     } catch (ex) {
         return ex;
     } finally {
         process.stdout.write = original_write;
+        if (!reuse || /prototype/.test(code)) {
+            context = null;
+        } else for (var key in context) {
+            delete context[key];
+        }
     }
 };
 exports.same_stdout = semver.satisfies(process.version, "0.12") ? function(expected, actual) {

test/sourcemaps.js

@@ -1,40 +0,0 @@
-var UglifyJS = require("..");
-var ok = require("assert");
-
-module.exports = function () {
-    console.log("--- Sourcemaps tests");
-
-    var basic = source_map([
-        'var x = 1 + 1;'
-    ].join('\n'));
-
-    ok.equal(basic.version, 3);
-    ok.deepEqual(basic.names, ['x']);
-
-    var issue836 = source_map([
-        "({",
-        "    get enabled() {",
-        "        return 3;",
-        "    },",
-        "    set enabled(x) {",
-        "        ;",
-        "    }",
-        "});",
-    ].join("\n"));
-
-    ok.deepEqual(issue836.names, ['enabled', 'x']);
-}
-
-function source_map(js) {
-    return JSON.parse(UglifyJS.minify(js, {
-        compress: false,
-        mangle: false,
-        sourceMap: true
-    }).map);
-}
-
-// Run standalone
-if (module.parent === null) {
-    module.exports();
-}
-

test/ufuzz.js

@@ -975,7 +975,7 @@ function try_beautify(code, result, printfn) {
         mangle: false,
         output: {
             beautify: true,
-            bracketize: true,
+            braces: true,
         },
     });
     if (beautified.error) {

test/ufuzz.json

@@ -4,7 +4,7 @@
         "mangle": false,
         "output": {
             "beautify": true,
-            "bracketize": true
+            "braces": true
         },
         "rename": true
     },