v2.4.16

Use uglify source map token names if missing

.travis.yml

@@ -1,6 +1,6 @@
 language: node_js
+before_install: "npm install -g npm"
 node_js:
-    - "0.4"
     - "0.8"
     - "0.10"
     - "0.11"

README.md

@@ -256,6 +256,10 @@ to set `true`; it's effectively a shortcut for `foo=true`).
 - `drop_console` -- default `false`.  Pass `true` to discard calls to
   `console.*` functions.
 
+- `keep_fargs` -- default `false`.  Pass `true` to prevent the
+  compressor from discarding unused function arguments.  You need this
+  for code which relies on `Function.length`.
+
 ### The `unsafe` option
 
 It enables some transformations that *might* break code logic in certain
@@ -400,6 +404,38 @@ Acorn is really fast (e.g. 250ms instead of 380ms on some 650K code), but
 converting the SpiderMonkey tree that Acorn produces takes another 150ms so
 in total it's a bit more than just using UglifyJS's own parser.
 
+### Using UglifyJS to transform SpiderMonkey AST
+
+Now you can use UglifyJS as any other intermediate tool for transforming
+JavaScript ASTs in SpiderMonkey format.
+
+Example:
+
+```javascript
+function uglify(ast, options, mangle) {
+  // Conversion from SpiderMonkey AST to internal format
+  var uAST = UglifyJS.AST_Node.from_mozilla_ast(ast);
+
+  // Compression
+  uAST.figure_out_scope();
+  uAST = uAST.transform(UglifyJS.Compressor(options));
+
+  // Mangling (optional)
+  if (mangle) {
+    uAST.figure_out_scope();
+    uAST.compute_char_frequency();
+    uAST.mangle_names();
+  }
+
+  // Back-conversion to SpiderMonkey AST
+  return uAST.to_mozilla_ast();
+}
+```
+
+Check out
+[original blog post](http://rreverser.com/using-mozilla-ast-with-uglifyjs/)
+for details.
+
 API Reference
 -------------
 

bin/uglifyjs

@@ -64,6 +64,7 @@ You need to pass an argument to this option to specify the name that your module
     .describe("v", "Verbose")
     .describe("V", "Print version number and exit.")
     .describe("noerr", "Don't throw an error for unknown options in -c, -b or -m.")
+    .describe("bare-returns", "Allow return outside of functions.  Useful when minifying CommonJS modules.")
 
     .alias("p", "prefix")
     .alias("o", "output")
@@ -100,6 +101,7 @@ You need to pass an argument to this option to specify the name that your module
     .boolean("lint")
     .boolean("V")
     .boolean("noerr")
+    .boolean("bare-returns")
 
     .wrap(80)
 
@@ -275,9 +277,10 @@ async.eachLimit(files, 1, function (file, cb) {
             else {
                 try {
                     TOPLEVEL = UglifyJS.parse(code, {
-                        filename   : file,
-                        toplevel   : TOPLEVEL,
-                        expression : ARGS.expr,
+                        filename     : file,
+                        toplevel     : TOPLEVEL,
+                        expression   : ARGS.expr,
+                        bare_returns : ARGS.bare_returns,
                     });
                 } catch(ex) {
                     if (ex instanceof UglifyJS.JS_Parse_Error) {

lib/ast.js

@@ -295,10 +295,10 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
         var parameters = [];
 
         arg_parameter_pairs.forEach(function(pair) {
-            var split = pair.split(":");
+            var splitAt = pair.lastIndexOf(":");
 
-            args.push(split[0]);
-            parameters.push(split[1]);
+            args.push(pair.substr(0, splitAt));
+            parameters.push(pair.substr(splitAt + 1));
         });
 
         var wrapped_tl = "(function(" + parameters.join(",") + "){ '$ORIG'; })(" + args.join(",") + ")";

lib/compress.js

@@ -775,6 +775,14 @@ merge(Compressor.prototype, {
             if (d && d.constant && d.init) return ev(d.init, compressor);
             throw def;
         });
+        def(AST_Dot, function(compressor){
+            if (compressor.option("unsafe") && this.property == "length") {
+                var str = ev(this.expression, compressor);
+                if (typeof str == "string")
+                    return str.length;
+            }
+            throw def;
+        });
     })(function(node, func){
         node.DEFMETHOD("_eval", func);
     });
@@ -889,7 +897,9 @@ merge(Compressor.prototype, {
                 || this.operator == "--"
                 || this.expression.has_side_effects(compressor);
         });
-        def(AST_SymbolRef, function(compressor){ return false });
+        def(AST_SymbolRef, function(compressor){
+            return this.global() && this.undeclared();
+        });
         def(AST_Object, function(compressor){
             for (var i = this.properties.length; --i >= 0;)
                 if (this.properties[i].has_side_effects(compressor))
@@ -1737,6 +1747,7 @@ merge(Compressor.prototype, {
                             } catch(ex) {
                                 if (ex !== ast) throw ex;
                             };
+                            if (!fun) return self;
                             var args = fun.argnames.map(function(arg, i){
                                 return make_node(AST_String, self.args[i], {
                                     value: arg.print_to_string()
@@ -2312,6 +2323,17 @@ merge(Compressor.prototype, {
                 alternative: alternative
             });
         }
+        // x=y?1:1 --> x=1
+        if (consequent instanceof AST_Constant
+            && alternative instanceof AST_Constant
+            && consequent.equivalent_to(alternative)) {
+            if (self.condition.has_side_effects(compressor)) {
+                return AST_Seq.from_array([self.condition, make_node_from_constant(compressor, consequent.value, self)]);
+            } else {
+                return make_node_from_constant(compressor, consequent.value, self);
+
+            }
+        }
         return self;
     });
 
@@ -2349,7 +2371,7 @@ merge(Compressor.prototype, {
                 return make_node(AST_Dot, self, {
                     expression : self.expression,
                     property   : prop
-                });
+                }).optimize(compressor);
             }
             var v = parseFloat(prop);
             if (!isNaN(v) && v.toString() == prop) {
@@ -2361,6 +2383,19 @@ merge(Compressor.prototype, {
         return self;
     });
 
+    OPT(AST_Dot, function(self, compressor){
+        var prop = self.property;
+        if (RESERVED_WORDS(prop) && !compressor.option("screw_ie8")) {
+            return make_node(AST_Sub, self, {
+                expression : self.expression,
+                property   : make_node(AST_String, self, {
+                    value: prop
+                })
+            }).optimize(compressor);
+        }
+        return self.evaluate(compressor)[0];
+    });
+
     function literals_in_boolean_context(self, compressor) {
         if (compressor.option("booleans") && compressor.in_boolean_context()) {
             return make_node(AST_True, self);

lib/mozilla-ast.js

@@ -46,53 +46,68 @@
 (function(){
 
     var MOZ_TO_ME = {
-        TryStatement : function(M) {
+        ExpressionStatement: function(M) {
+            var expr = M.expression;
+            if (expr.type === "Literal" && typeof expr.value === "string") {
+                return new AST_Directive({
+                    start: my_start_token(M),
+                    end: my_end_token(M),
+                    value: expr.value
+                });
+            }
+            return new AST_SimpleStatement({
+                start: my_start_token(M),
+                end: my_end_token(M),
+                body: from_moz(expr)
+            });
+        },
+        TryStatement: function(M) {
+            var handlers = M.handlers || [M.handler];
+            if (handlers.length > 1 || M.guardedHandlers && M.guardedHandlers.length) {
+                throw new Error("Multiple catch clauses are not supported.");
+            }
             return new AST_Try({
                 start    : my_start_token(M),
                 end      : my_end_token(M),
                 body     : from_moz(M.block).body,
-                bcatch   : from_moz(M.handlers[0]),
+                bcatch   : from_moz(handlers[0]),
                 bfinally : M.finalizer ? new AST_Finally(from_moz(M.finalizer)) : null
             });
         },
-        CatchClause : function(M) {
-            return new AST_Catch({
-                start   : my_start_token(M),
-                end     : my_end_token(M),
-                argname : from_moz(M.param),
-                body    : from_moz(M.body).body
-            });
+        Property: function(M) {
+            var key = M.key;
+            var name = key.type == "Identifier" ? key.name : key.value;
+            var args = {
+                start    : my_start_token(key),
+                end      : my_end_token(M.value),
+                key      : name,
+                value    : from_moz(M.value)
+            };
+            switch (M.kind) {
+              case "init":
+                return new AST_ObjectKeyVal(args);
+              case "set":
+                args.value.name = from_moz(key);
+                return new AST_ObjectSetter(args);
+              case "get":
+                args.value.name = from_moz(key);
+                return new AST_ObjectGetter(args);
+            }
         },
-        ObjectExpression : function(M) {
+        ObjectExpression: function(M) {
             return new AST_Object({
                 start      : my_start_token(M),
                 end        : my_end_token(M),
                 properties : M.properties.map(function(prop){
-                    var key = prop.key;
-                    var name = key.type == "Identifier" ? key.name : key.value;
-                    var args = {
-                        start    : my_start_token(key),
-                        end      : my_end_token(prop.value),
-                        key      : name,
-                        value    : from_moz(prop.value)
-                    };
-                    switch (prop.kind) {
-                      case "init":
-                        return new AST_ObjectKeyVal(args);
-                      case "set":
-                        args.value.name = from_moz(key);
-                        return new AST_ObjectSetter(args);
-                      case "get":
-                        args.value.name = from_moz(key);
-                        return new AST_ObjectGetter(args);
-                    }
+                    prop.type = "Property";
+                    return from_moz(prop)
                 })
             });
         },
-        SequenceExpression : function(M) {
+        SequenceExpression: function(M) {
             return AST_Seq.from_array(M.expressions.map(from_moz));
         },
-        MemberExpression : function(M) {
+        MemberExpression: function(M) {
             return new (M.computed ? AST_Sub : AST_Dot)({
                 start      : my_start_token(M),
                 end        : my_end_token(M),
@@ -100,7 +115,7 @@
                 expression : from_moz(M.object)
             });
         },
-        SwitchCase : function(M) {
+        SwitchCase: function(M) {
             return new (M.test ? AST_Case : AST_Default)({
                 start      : my_start_token(M),
                 end        : my_end_token(M),
@@ -108,7 +123,14 @@
                 body       : M.consequent.map(from_moz)
             });
         },
-        Literal : function(M) {
+        VariableDeclaration: function(M) {
+            return new (M.kind === "const" ? AST_Const : AST_Var)({
+                start       : my_start_token(M),
+                end         : my_end_token(M),
+                definitions : M.declarations.map(from_moz)
+            });
+        },
+        Literal: function(M) {
             var val = M.value, args = {
                 start  : my_start_token(M),
                 end    : my_end_token(M)
@@ -128,12 +150,9 @@
                 return new AST_RegExp(args);
             }
         },
-        UnaryExpression: From_Moz_Unary,
-        UpdateExpression: From_Moz_Unary,
         Identifier: function(M) {
             var p = FROM_MOZ_STACK[FROM_MOZ_STACK.length - 2];
-            return new (M.name == "this" ? AST_This
-                        : p.type == "LabeledStatement" ? AST_Label
+            return new (  p.type == "LabeledStatement" ? AST_Label
                         : p.type == "VariableDeclarator" && p.id === M ? (p.kind == "const" ? AST_SymbolConst : AST_SymbolVar)
                         : p.type == "FunctionExpression" ? (p.id === M ? AST_SymbolLambda : AST_SymbolFunarg)
                         : p.type == "FunctionDeclaration" ? (p.id === M ? AST_SymbolDefun : AST_SymbolFunarg)
@@ -147,7 +166,8 @@
         }
     };
 
-    function From_Moz_Unary(M) {
+    MOZ_TO_ME.UpdateExpression =
+    MOZ_TO_ME.UnaryExpression = function To_Moz_Unary(M) {
         var prefix = "prefix" in M ? M.prefix
             : M.type == "UnaryExpression" ? true : false;
         return new (prefix ? AST_UnaryPrefix : AST_UnaryPostfix)({
@@ -158,14 +178,9 @@
         });
     };
 
-    var ME_TO_MOZ = {};
-
-    map("Node", AST_Node);
     map("Program", AST_Toplevel, "body@body");
-    map("Function", AST_Function, "id>name, params@argnames, body%body");
     map("EmptyStatement", AST_EmptyStatement);
     map("BlockStatement", AST_BlockStatement, "body@body");
-    map("ExpressionStatement", AST_SimpleStatement, "expression>body");
     map("IfStatement", AST_If, "test>condition, consequent>body, alternate>alternative");
     map("LabeledStatement", AST_LabeledStatement, "label>label, body>body");
     map("BreakStatement", AST_Break, "label>label");
@@ -180,71 +195,257 @@
     map("ForInStatement", AST_ForIn, "left>init, right>object, body>body");
     map("DebuggerStatement", AST_Debugger);
     map("FunctionDeclaration", AST_Defun, "id>name, params@argnames, body%body");
-    map("VariableDeclaration", AST_Var, "declarations@definitions");
     map("VariableDeclarator", AST_VarDef, "id>name, init>value");
+    map("CatchClause", AST_Catch, "param>argname, body%body");
 
     map("ThisExpression", AST_This);
     map("ArrayExpression", AST_Array, "elements@elements");
     map("FunctionExpression", AST_Function, "id>name, params@argnames, body%body");
     map("BinaryExpression", AST_Binary, "operator=operator, left>left, right>right");
-    map("AssignmentExpression", AST_Assign, "operator=operator, left>left, right>right");
     map("LogicalExpression", AST_Binary, "operator=operator, left>left, right>right");
+    map("AssignmentExpression", AST_Assign, "operator=operator, left>left, right>right");
     map("ConditionalExpression", AST_Conditional, "test>condition, consequent>consequent, alternate>alternative");
     map("NewExpression", AST_New, "callee>expression, arguments@args");
     map("CallExpression", AST_Call, "callee>expression, arguments@args");
 
+    def_to_moz(AST_Directive, function To_Moz_Directive(M) {
+        return {
+            type: "ExpressionStatement",
+            expression: {
+                type: "Literal",
+                value: M.value
+            }
+        };
+    });
+
+    def_to_moz(AST_SimpleStatement, function To_Moz_ExpressionStatement(M) {
+        return {
+            type: "ExpressionStatement",
+            expression: to_moz(M.body)
+        };
+    });
+
+    def_to_moz(AST_SwitchBranch, function To_Moz_SwitchCase(M) {
+        return {
+            type: "SwitchCase",
+            test: to_moz(M.expression),
+            consequent: M.body.map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_Try, function To_Moz_TryStatement(M) {
+        return {
+            type: "TryStatement",
+            block: to_moz_block(M),
+            handler: to_moz(M.bcatch),
+            guardedHandlers: [],
+            finalizer: to_moz(M.bfinally)
+        };
+    });
+
+    def_to_moz(AST_Catch, function To_Moz_CatchClause(M) {
+        return {
+            type: "CatchClause",
+            param: to_moz(M.argname),
+            guard: null,
+            body: to_moz_block(M)
+        };
+    });
+
+    def_to_moz(AST_Definitions, function To_Moz_VariableDeclaration(M) {
+        return {
+            type: "VariableDeclaration",
+            kind: M instanceof AST_Const ? "const" : "var",
+            declarations: M.definitions.map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_Seq, function To_Moz_SequenceExpression(M) {
+        return {
+            type: "SequenceExpression",
+            expressions: M.to_array().map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_PropAccess, function To_Moz_MemberExpression(M) {
+        var isComputed = M instanceof AST_Sub;
+        return {
+            type: "MemberExpression",
+            object: to_moz(M.expression),
+            computed: isComputed,
+            property: isComputed ? to_moz(M.property) : {type: "Identifier", name: M.property}
+        };
+    });
+
+    def_to_moz(AST_Unary, function To_Moz_Unary(M) {
+        return {
+            type: M.operator == "++" || M.operator == "--" ? "UpdateExpression" : "UnaryExpression",
+            operator: M.operator,
+            prefix: M instanceof AST_UnaryPrefix,
+            argument: to_moz(M.expression)
+        };
+    });
+
+    def_to_moz(AST_Binary, function To_Moz_BinaryExpression(M) {
+        return {
+            type: M.operator == "&&" || M.operator == "||" ? "LogicalExpression" : "BinaryExpression",
+            left: to_moz(M.left),
+            operator: M.operator,
+            right: to_moz(M.right)
+        };
+    });
+
+    def_to_moz(AST_Object, function To_Moz_ObjectExpression(M) {
+        return {
+            type: "ObjectExpression",
+            properties: M.properties.map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_ObjectProperty, function To_Moz_Property(M) {
+        var key = (
+            is_identifier(M.key)
+            ? {type: "Identifier", name: M.key}
+            : {type: "Literal", value: M.key}
+        );
+        var kind;
+        if (M instanceof AST_ObjectKeyVal) {
+            kind = "init";
+        } else
+        if (M instanceof AST_ObjectGetter) {
+            kind = "get";
+        } else
+        if (M instanceof AST_ObjectSetter) {
+            kind = "set";
+        }
+        return {
+            type: "Property",
+            kind: kind,
+            key: key,
+            value: to_moz(M.value)
+        };
+    });
+
+    def_to_moz(AST_Symbol, function To_Moz_Identifier(M) {
+        var def = M.definition();
+        return {
+            type: "Identifier",
+            name: def ? def.mangled_name || def.name : M.name
+        };
+    });
+
+    def_to_moz(AST_Constant, function To_Moz_Literal(M) {
+        var value = M.value;
+        if (typeof value === 'number' && (value < 0 || (value === 0 && 1 / value < 0))) {
+            return {
+                type: "UnaryExpression",
+                operator: "-",
+                prefix: true,
+                argument: {
+                    type: "Literal",
+                    value: -value
+                }
+            };
+        }
+        return {
+            type: "Literal",
+            value: value
+        };
+    });
+
+    def_to_moz(AST_Atom, function To_Moz_Atom(M) {
+        return {
+            type: "Identifier",
+            name: String(M.value)
+        };
+    });
+
+    AST_Boolean.DEFMETHOD("to_mozilla_ast", AST_Constant.prototype.to_mozilla_ast);
+    AST_Null.DEFMETHOD("to_mozilla_ast", AST_Constant.prototype.to_mozilla_ast);
+    AST_Hole.DEFMETHOD("to_mozilla_ast", function To_Moz_ArrayHole() { return null });
+
+    AST_Block.DEFMETHOD("to_mozilla_ast", AST_BlockStatement.prototype.to_mozilla_ast);
+    AST_Lambda.DEFMETHOD("to_mozilla_ast", AST_Function.prototype.to_mozilla_ast);
+
     /* -----[ tools ]----- */
 
     function my_start_token(moznode) {
+        var loc = moznode.loc;
+        var range = moznode.range;
         return new AST_Token({
-            file   : moznode.loc && moznode.loc.source,
-            line   : moznode.loc && moznode.loc.start.line,
-            col    : moznode.loc && moznode.loc.start.column,
-            pos    : moznode.start,
-            endpos : moznode.start
+            file   : loc && loc.source,
+            line   : loc && loc.start.line,
+            col    : loc && loc.start.column,
+            pos    : range ? range[0] : moznode.start,
+            endpos : range ? range[0] : moznode.start
         });
     };
 
     function my_end_token(moznode) {
+        var loc = moznode.loc;
+        var range = moznode.range;
         return new AST_Token({
-            file   : moznode.loc && moznode.loc.source,
-            line   : moznode.loc && moznode.loc.end.line,
-            col    : moznode.loc && moznode.loc.end.column,
-            pos    : moznode.end,
-            endpos : moznode.end
+            file   : loc && loc.source,
+            line   : loc && loc.end.line,
+            col    : loc && loc.end.column,
+            pos    : range ? range[1] : moznode.end,
+            endpos : range ? range[1] : moznode.end
         });
     };
 
     function map(moztype, mytype, propmap) {
         var moz_to_me = "function From_Moz_" + moztype + "(M){\n";
-        moz_to_me += "return new mytype({\n" +
+        moz_to_me += "return new " + mytype.name + "({\n" +
             "start: my_start_token(M),\n" +
             "end: my_end_token(M)";
 
+        var me_to_moz = "function To_Moz_" + moztype + "(M){\n";
+        me_to_moz += "return {\n" +
+            "type: " + JSON.stringify(moztype);
+
         if (propmap) propmap.split(/\s*,\s*/).forEach(function(prop){
             var m = /([a-z0-9$_]+)(=|@|>|%)([a-z0-9$_]+)/i.exec(prop);
             if (!m) throw new Error("Can't understand property map: " + prop);
-            var moz = "M." + m[1], how = m[2], my = m[3];
+            var moz = m[1], how = m[2], my = m[3];
             moz_to_me += ",\n" + my + ": ";
-            if (how == "@") {
-                moz_to_me += moz + ".map(from_moz)";
-            } else if (how == ">") {
-                moz_to_me += "from_moz(" + moz + ")";
-            } else if (how == "=") {
-                moz_to_me += moz;
-            } else if (how == "%") {
-                moz_to_me += "from_moz(" + moz + ").body";
-            } else throw new Error("Can't understand operator in propmap: " + prop);
+            me_to_moz += ",\n" + moz + ": ";
+            switch (how) {
+                case "@":
+                    moz_to_me += "M." + moz + ".map(from_moz)";
+                    me_to_moz += "M." +  my + ".map(to_moz)";
+                    break;
+                case ">":
+                    moz_to_me += "from_moz(M." + moz + ")";
+                    me_to_moz += "to_moz(M." + my + ")";
+                    break;
+                case "=":
+                    moz_to_me += "M." + moz;
+                    me_to_moz += "M." + my;
+                    break;
+                case "%":
+                    moz_to_me += "from_moz(M." + moz + ").body";
+                    me_to_moz += "to_moz_block(M)";
+                    break;
+                default:
+                    throw new Error("Can't understand operator in propmap: " + prop);
+            }
         });
-        moz_to_me += "\n})}";
 
-        // moz_to_me = parse(moz_to_me).print_to_string({ beautify: true });
-        // console.log(moz_to_me);
+        moz_to_me += "\n})\n}";
+        me_to_moz += "\n}\n}";
 
-        moz_to_me = new Function("mytype", "my_start_token", "my_end_token", "from_moz", "return(" + moz_to_me + ")")(
-            mytype, my_start_token, my_end_token, from_moz
+        //moz_to_me = parse(moz_to_me).print_to_string({ beautify: true });
+        //me_to_moz = parse(me_to_moz).print_to_string({ beautify: true });
+        //console.log(moz_to_me);
+
+        moz_to_me = new Function("my_start_token", "my_end_token", "from_moz", "return(" + moz_to_me + ")")(
+            my_start_token, my_end_token, from_moz
         );
-        return MOZ_TO_ME[moztype] = moz_to_me;
+        me_to_moz = new Function("to_moz", "to_moz_block", "return(" + me_to_moz + ")")(
+            to_moz, to_moz_block
+        );
+        MOZ_TO_ME[moztype] = moz_to_me;
+        def_to_moz(mytype, me_to_moz);
     };
 
     var FROM_MOZ_STACK = null;
@@ -264,4 +465,46 @@
         return ast;
     };
 
+    function moz_sub_loc(token) {
+        return token.line ? {
+            line: token.line,
+            column: token.col
+        } : null;
+    };
+
+    function set_moz_loc(mynode, moznode) {
+        var start = mynode.start;
+        var end = mynode.end;
+        if (start.pos != null && end.pos != null) {
+            moznode.range = [start.pos, end.pos];
+        }
+        if (start.line) {
+            moznode.loc = {
+                start: moz_sub_loc(start),
+                end: moz_sub_loc(end)
+            };
+            if (start.file) {
+                moznode.loc.source = start.file;
+            }
+        }
+        return moznode;
+    };
+
+    function def_to_moz(mytype, handler) {
+        mytype.DEFMETHOD("to_mozilla_ast", function() {
+            return set_moz_loc(this, handler(this));
+        });
+    };
+
+    function to_moz(node) {
+        return node != null ? node.to_mozilla_ast() : null;
+    };
+
+    function to_moz_block(node) {
+        return {
+            type: "BlockStatement",
+            body: node.body.map(to_moz)
+        };
+    };
+
 })();

lib/output.js

@@ -434,7 +434,13 @@ function OutputStream(options) {
     /* -----[ PARENTHESES ]----- */
 
     function PARENS(nodetype, func) {
-        nodetype.DEFMETHOD("needs_parens", func);
+        if (Array.isArray(nodetype)) {
+            nodetype.forEach(function(nodetype){
+                PARENS(nodetype, func);
+            });
+        } else {
+            nodetype.DEFMETHOD("needs_parens", func);
+        }
     };
 
     PARENS(AST_Node, function(){
@@ -453,7 +459,7 @@ function OutputStream(options) {
         return first_in_statement(output);
     });
 
-    PARENS(AST_Unary, function(output){
+    PARENS([ AST_Unary, AST_Undefined ], function(output){
         var p = output.parent();
         return p instanceof AST_PropAccess && p.expression === this;
     });
@@ -549,7 +555,7 @@ function OutputStream(options) {
             return true;
     });
 
-    function assign_and_conditional_paren_rules(output) {
+    PARENS([ AST_Assign, AST_Conditional ], function (output){
         var p = output.parent();
         // !(a = false) → true
         if (p instanceof AST_Unary)
@@ -566,10 +572,7 @@ function OutputStream(options) {
         // (a = foo)["prop"] —or— (a = foo).prop
         if (p instanceof AST_PropAccess && p.expression === this)
             return true;
-    };
-
-    PARENS(AST_Assign, assign_and_conditional_paren_rules);
-    PARENS(AST_Conditional, assign_and_conditional_paren_rules);
+    });
 
     /* -----[ PRINTERS ]----- */
 
@@ -656,7 +659,7 @@ function OutputStream(options) {
         output.print("for");
         output.space();
         output.with_parens(function(){
-            if (self.init) {
+            if (self.init && !(self.init instanceof AST_EmptyStatement)) {
                 if (self.init instanceof AST_Definitions) {
                     self.init.print(output);
                 } else {
@@ -996,8 +999,12 @@ function OutputStream(options) {
     DEFPRINT(AST_UnaryPrefix, function(self, output){
         var op = self.operator;
         output.print(op);
-        if (/^[a-z]/i.test(op))
+        if (/^[a-z]/i.test(op)
+            || (/[+-]$/.test(op)
+                && self.expression instanceof AST_UnaryPrefix
+                && /^[+-]/.test(self.expression.operator))) {
             output.space();
+        }
         self.expression.print(output);
     });
     DEFPRINT(AST_UnaryPostfix, function(self, output){

lib/parse.js

@@ -168,14 +168,7 @@ function is_identifier_char(ch) {
 };
 
 function is_identifier_string(str){
-    var i = str.length;
-    if (i == 0) return false;
-    if (!is_identifier_start(str.charCodeAt(0))) return false;
-    while (--i >= 0) {
-        if (!is_identifier_char(str.charAt(i)))
-            return false;
-    }
-    return true;
+    return /^[a-z_$][a-z0-9_$]*$/i.test(str);
 };
 
 function parse_js_number(num) {
@@ -616,6 +609,7 @@ function parse($TEXT, options) {
         toplevel       : null,
         expression     : false,
         html5_comments : true,
+        bare_returns   : false,
     });
 
     var S = {
@@ -795,7 +789,7 @@ function parse($TEXT, options) {
                 return if_();
 
               case "return":
-                if (S.in_function == 0)
+                if (S.in_function == 0 && !options.bare_returns)
                     croak("'return' outside of function");
                 return new AST_Return({
                     value: ( is("punc", ";")

lib/scope.js

@@ -532,6 +532,7 @@ AST_Toplevel.DEFMETHOD("scope_warnings", function(options){
         }
         if (options.unreferenced
             && (node instanceof AST_SymbolDeclaration || node instanceof AST_Label)
+            && !(node instanceof AST_SymbolCatch)
             && node.unreferenced()) {
             AST_Node.warn("{type} {name} is declared but not referenced [{file}:{line},{col}]", {
                 type: node instanceof AST_Label ? "Label" : "Symbol",

lib/sourcemap.js

@@ -70,7 +70,7 @@ function SourceMap(options) {
             source = info.source;
             orig_line = info.line;
             orig_col = info.column;
-            name = info.name;
+            name = info.name || name;
         }
         generator.addMapping({
             generated : { line: gen_line + options.dest_line_diff, column: gen_col },

package.json

@@ -1,9 +1,9 @@
 {
-    "name": "uglify-js",
-    "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
+  "name": "uglify-js",
+  "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
     "homepage": "http://lisperator.net/uglifyjs",
     "main": "tools/node.js",
-    "version": "2.4.13",
+    "version": "2.4.16",
     "engines": { "node" : ">=0.4.0" },
     "maintainers": [{
         "name": "Mihai Bazon",
@@ -16,15 +16,22 @@
     },
     "dependencies": {
         "async"      : "~0.2.6",
-        "source-map" : "~0.1.33",
-        "optimist"   : "~0.3.5",
+        "source-map" : "0.1.34",
+        "optimist": "~0.3.5",
         "uglify-to-browserify": "~1.0.0"
     },
+    "devDependencies": {
+        "acorn": "~0.6.0",
+        "escodegen": "~1.3.3",
+        "esfuzz": "~0.3.1",
+        "estraverse": "~1.5.1"
+    },
     "browserify": {
         "transform": [ "uglify-to-browserify" ]
     },
     "bin": {
         "uglifyjs" : "bin/uglifyjs"
     },
+    "license": "BSD",
     "scripts": {"test": "node test/run-tests.js"}
 }

test/compress/conditionals.js

@@ -232,3 +232,83 @@ cond_5: {
         some_condition() && some_other_condition() && do_something();
     }
 }
+
+cond_7: {
+    options = {
+        conditionals: true,
+        evaluate    : true
+    };
+    input: {
+        var x, y, z, a, b;
+        // compress these
+        if (y) {
+            x = 1+1;
+        } else {
+            x = 2;
+        }
+
+        if (y) {
+            x = 1+1;
+        } else if (z) {
+            x = 2;
+        } else {
+            x = 3-1;
+        }
+
+        x = y ? 'foo' : 'fo'+'o';
+
+        x = y ? 'foo' : y ? 'foo' : 'fo'+'o';
+
+        // Compress conditions that have side effects
+        if (condition()) {
+            x = 10+10;
+        } else {
+            x = 20;
+        }
+
+        if (z) {
+            x = 'fuji';
+        } else if (condition()) {
+            x = 'fu'+'ji';
+        } else {
+            x = 'fuji';
+        }
+
+        x = condition() ? 'foobar' : 'foo'+'bar';
+
+        // don't compress these
+        x = y ? a : b;
+
+        x = y ? 'foo' : 'fo';
+    }
+    expect: {
+        var x, y, z, a, b;
+        x = 2;
+        x = 2;
+        x = 'foo';
+        x = 'foo';
+        x = (condition(), 20);
+        x = z ? 'fuji' : (condition(), 'fuji');
+        x = (condition(), 'foobar');
+        x = y ? a : b;
+        x = y ? 'foo' : 'fo';
+    }
+}
+
+cond_7_1: {
+    options = {
+        conditionals: true,
+        evaluate    : true
+    };
+    input: {
+        // access to global should be assumed to have side effects
+        if (y) {
+            x = 1+1;
+        } else {
+            x = 2;
+        }
+    }
+    expect: {
+        x = (y, 2);
+    }
+}

test/compress/properties.js

@@ -26,7 +26,7 @@ dot_properties: {
         a.foo = "bar";
         a["if"] = "if";
         a["*"] = "asterisk";
-        a.\u0EB3 = "unicode";
+        a["\u0EB3"] = "unicode";
         a[""] = "whitespace";
         a["1_1"] = "foo";
     }
@@ -48,7 +48,27 @@ dot_properties_es5: {
         a.foo = "bar";
         a.if = "if";
         a["*"] = "asterisk";
-        a.\u0EB3 = "unicode";
+        a["\u0EB3"] = "unicode";
         a[""] = "whitespace";
     }
 }
+
+evaluate_length: {
+    options = {
+        properties: true,
+        unsafe: true,
+        evaluate: true
+    };
+    input: {
+        a = "foo".length;
+        a = ("foo" + "bar")["len" + "gth"];
+        a = b.length;
+        a = ("foo" + b).length;
+    }
+    expect: {
+        a = 3;
+        a = 6;
+        a = b.length;
+        a = ("foo" + b).length;
+    }
+}

test/compress/sequences.js

@@ -91,9 +91,11 @@ make_sequences_4: {
 lift_sequences_1: {
     options = { sequences: true };
     input: {
+        var foo, x, y, bar;
         foo = !(x(), y(), bar());
     }
     expect: {
+        var foo, x, y, bar;
         x(), y(), foo = !bar();
     }
 }
@@ -101,10 +103,12 @@ lift_sequences_1: {
 lift_sequences_2: {
     options = { sequences: true, evaluate: true };
     input: {
+        var foo, bar;
         foo.x = (foo = {}, 10);
         bar = (bar = {}, 10);
     }
     expect: {
+        var foo, bar;
         foo.x = (foo = {}, 10),
         bar = {}, bar = 10;
     }
@@ -113,9 +117,11 @@ lift_sequences_2: {
 lift_sequences_3: {
     options = { sequences: true, conditionals: true };
     input: {
+        var x, foo, bar, baz;
         x = (foo(), bar(), baz()) ? 10 : 20;
     }
     expect: {
+        var x, foo, bar, baz;
         foo(), bar(), x = baz() ? 10 : 20;
     }
 }
@@ -123,9 +129,11 @@ lift_sequences_3: {
 lift_sequences_4: {
     options = { side_effects: true };
     input: {
+        var x, foo, bar, baz;
         x = (foo, bar, baz);
     }
     expect: {
+        var x, foo, bar, baz;
         x = baz;
     }
 }

test/mozilla-ast.js

@@ -0,0 +1,103 @@
+// Testing UglifyJS <-> SpiderMonkey AST conversion
+// through generative testing.
+
+var UglifyJS = require(".."),
+    escodegen = require("escodegen"),
+    esfuzz = require("esfuzz"),
+    estraverse = require("estraverse"),
+    prefix = Array(20).join("\b") + "    ";
+
+// Normalizes input AST for UglifyJS in order to get correct comparison.
+
+function normalizeInput(ast) {
+    return estraverse.replace(ast, {
+        enter: function(node, parent) {
+            switch (node.type) {
+                // Internally mark all the properties with semi-standard type "Property".
+                case "ObjectExpression":
+                    node.properties.forEach(function (property) {
+                        property.type = "Property";
+                    });
+                    break;
+
+                // Since UglifyJS doesn"t recognize different types of property keys,
+                // decision on SpiderMonkey node type is based on check whether key
+                // can be valid identifier or not - so we do in input AST.
+                case "Property":
+                    var key = node.key;
+                    if (key.type === "Literal" && typeof key.value === "string" && UglifyJS.is_identifier(key.value)) {
+                        node.key = {
+                            type: "Identifier",
+                            name: key.value
+                        };
+                    } else if (key.type === "Identifier" && !UglifyJS.is_identifier(key.name)) {
+                        node.key = {
+                            type: "Literal",
+                            value: key.name
+                        };
+                    }
+                    break;
+
+                // UglifyJS internally flattens all the expression sequences - either
+                // to one element (if sequence contains only one element) or flat list.
+                case "SequenceExpression":
+                    node.expressions = node.expressions.reduce(function flatten(list, expr) {
+                        return list.concat(expr.type === "SequenceExpression" ? expr.expressions.reduce(flatten, []) : [expr]);
+                    }, []);
+                    if (node.expressions.length === 1) {
+                        return node.expressions[0];
+                    }
+                    break;
+            }
+        }
+    });
+}
+
+module.exports = function(options) {
+    console.log("--- UglifyJS <-> Mozilla AST conversion");
+
+    for (var counter = 0; counter < options.iterations; counter++) {
+        process.stdout.write(prefix + counter + "/" + options.iterations);
+
+        var ast1 = normalizeInput(esfuzz.generate({
+            maxDepth: options.maxDepth
+        }));
+        
+        var ast2 =
+            UglifyJS
+            .AST_Node
+            .from_mozilla_ast(ast1)
+            .to_mozilla_ast();
+
+        var astPair = [
+            {name: 'expected', value: ast1},
+            {name: 'actual', value: ast2}
+        ];
+
+        var jsPair = astPair.map(function(item) {
+            return {
+                name: item.name,
+                value: escodegen.generate(item.value)
+            }
+        });
+
+        if (jsPair[0].value !== jsPair[1].value) {
+            var fs = require("fs");
+            var acorn = require("acorn");
+
+            fs.existsSync("tmp") || fs.mkdirSync("tmp");
+
+            jsPair.forEach(function (item) {
+                var fileName = "tmp/dump_" + item.name;
+                var ast = acorn.parse(item.value);
+                fs.writeFileSync(fileName + ".js", item.value);
+                fs.writeFileSync(fileName + ".json", JSON.stringify(ast, null, 2));
+            });
+
+            process.stdout.write("\n");
+            throw new Error("Got different outputs, check out tmp/dump_*.{js,json} for codes and ASTs.");
+        }
+    }
+
+    process.stdout.write(prefix + "Probability of error is less than " + (100 / options.iterations) + "%, stopping.\n");
+};

test/run-tests.js

@@ -17,6 +17,12 @@ if (failures) {
     process.exit(1);
 }
 
+var run_ast_conversion_tests = require("./mozilla-ast");
+
+run_ast_conversion_tests({
+    iterations: 1000
+});
+
 /* -----[ utils ]----- */
 
 function tmpl() {

tools/node.js

@@ -115,7 +115,7 @@ exports.minify = function(files, options) {
         if (options.sourceMapIncludeSources) {
             for (var file in sourcesContent) {
                 if (sourcesContent.hasOwnProperty(file)) {
-                    options.source_map.get().setSourceContent(file, sourcesContent[file]);
+                    output.source_map.get().setSourceContent(file, sourcesContent[file]);
                 }
             }
         }
@@ -126,6 +126,11 @@ exports.minify = function(files, options) {
     }
     var stream = UglifyJS.OutputStream(output);
     toplevel.print(stream);
+
+    if(options.outSourceMap){
+        stream += "\n//# sourceMappingURL=" + options.outSourceMap;
+    }
+
     return {
         code : stream + "",
         map  : output.source_map + ""