v3.11.6

fixes #4274

.github/workflows/ufuzz.yml

@@ -6,6 +6,7 @@ on:
 env:
   BASE_URL: https://api.github.com/repos/${{ github.repository }}
   CAUSE: ${{ github.event_name }}
+  RUN_NUM: ${{ github.run_number }}
   TOKEN: ${{ github.token }}
 jobs:
   ufuzz:
@@ -36,12 +37,8 @@ jobs:
           npm config set update-notifier false
           npm --version
           while !(npm install); do echo "'npm install' failed - retrying..."; done
-          PERIOD=1800000
           if [[ $CAUSE == "schedule" ]]; then
-            PERIOD=`node test/ufuzz/actions $BASE_URL $TOKEN`
-          fi
-          if (( $PERIOD == 0 )); then
-            echo "too many jobs in queue - skipping..."
+            node test/ufuzz/job $BASE_URL $TOKEN $RUN_NUM
           else
-            node test/ufuzz/job $PERIOD
+            node test/ufuzz/job 5000
           fi

README.md

@@ -688,6 +688,8 @@ to be `false` and all symbol names will be omitted.
 - `loops` (default: `true`) -- optimizations for `do`, `while` and `for` loops
   when we can statically determine the condition.
 
+- `merge_vars` (default: `true`) -- combine and reuse variables.
+
 - `negate_iife` (default: `true`) -- negate "Immediately-Called Function Expressions"
   where the return value is discarded, to avoid the parens that the
   code generator would insert.
@@ -782,6 +784,9 @@ to be `false` and all symbol names will be omitted.
 - `unused` (default: `true`) -- drop unreferenced functions and variables (simple
   direct variable assignments do not count as references unless set to `"keep_assign"`)
 
+- `varify` (default: `true`) -- convert block-scoped declaractions into `var`
+  whenever safe to do so
+
 ## Mangle options
 
 - `eval` (default `false`) -- Pass `true` to mangle names visible in scopes

bin/uglifyjs

@@ -276,7 +276,9 @@ function convert_ast(fn) {
 function run() {
     var content = options.sourceMap && options.sourceMap.content;
     if (content && content != "inline") {
-        UglifyJS.AST_Node.info("Using input source map: " + content);
+        UglifyJS.AST_Node.info("Using input source map: {content}", {
+            content : content,
+        });
         options.sourceMap.content = read_file(content, content);
     }
     try {
@@ -342,7 +344,18 @@ function run() {
         }
         fatal(ex);
     } else if (output == "ast") {
-        if (!options.compress && !options.mangle) result.ast.figure_out_scope({});
+        if (!options.compress && !options.mangle) {
+            var toplevel = result.ast;
+            if (!(toplevel instanceof UglifyJS.AST_Toplevel)) {
+                if (!(toplevel instanceof UglifyJS.AST_Statement)) toplevel = new UglifyJS.AST_SimpleStatement({
+                    body: toplevel,
+                });
+                toplevel = new UglifyJS.AST_Toplevel({
+                    body: [ toplevel ],
+                });
+            }
+            toplevel.figure_out_scope({});
+        }
         print(JSON.stringify(result.ast, function(key, value) {
             if (value) switch (key) {
               case "thedef":

lib/ast.js

@@ -137,17 +137,17 @@ var AST_Node = DEFNODE("Node", "start end", {
 }, null);
 
 (AST_Node.log_function = function(fn, verbose) {
-    var printed = Object.create(null);
-    if (fn) {
-        AST_Node.info = verbose ? function(text, props) {
-            log("INFO: " + string_template(text, props));
-        } : noop;
-        AST_Node.warn = function(text, props) {
-            log("WARN: " + string_template(text, props));
-        };
-    } else {
+    if (!fn) {
         AST_Node.info = AST_Node.warn = noop;
+        return;
     }
+    var printed = Object.create(null);
+    AST_Node.info = verbose ? function(text, props) {
+        log("INFO: " + string_template(text, props));
+    } : noop;
+    AST_Node.warn = function(text, props) {
+        log("WARN: " + string_template(text, props));
+    };
 
     function log(msg) {
         if (printed[msg]) return;
@@ -203,6 +203,10 @@ var AST_Directive = DEFNODE("Directive", "value quote", {
     },
 }, AST_Statement);
 
+var AST_EmptyStatement = DEFNODE("EmptyStatement", null, {
+    $documentation: "The empty statement (empty block or simply a semicolon)"
+}, AST_Statement);
+
 function must_be_expression(node, prop) {
     if (!(node[prop] instanceof AST_Node)) throw new Error(prop + " must be AST_Node");
     if (node[prop] instanceof AST_Statement && !(node[prop] instanceof AST_Function)) {
@@ -226,6 +230,34 @@ var AST_SimpleStatement = DEFNODE("SimpleStatement", "body", {
     },
 }, AST_Statement);
 
+var AST_BlockScope = DEFNODE("BlockScope", "enclosed functions make_def parent_scope variables", {
+    $documentation: "Base class for all statements introducing a lexical scope",
+    $propdoc: {
+        enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any subscopes",
+        functions: "[Object/S] like `variables`, but only lists function declarations",
+        parent_scope: "[AST_Scope?/S] link to the parent scope",
+        variables: "[Object/S] a map of name -> SymbolDef for all variables/functions defined in this scope",
+    },
+    clone: function(deep) {
+        var node = this._clone(deep);
+        if (this.enclosed) node.enclosed = this.enclosed.slice();
+        if (this.functions) node.functions = this.functions.clone();
+        if (this.variables) node.variables = this.variables.clone();
+        return node;
+    },
+    pinned: function() {
+        return this.resolve().pinned();
+    },
+    resolve: function() {
+        return this.parent_scope.resolve();
+    },
+    _validate: function() {
+        if (this.parent_scope == null) return;
+        if (!(this.parent_scope instanceof AST_BlockScope)) throw new Error("parent_scope must be AST_BlockScope");
+        if (!(this.resolve() instanceof AST_Scope)) throw new Error("must be contained within AST_Scope");
+    },
+}, AST_Statement);
+
 function walk_body(node, visitor) {
     node.body.forEach(function(node) {
         node.walk(visitor);
@@ -249,16 +281,12 @@ var AST_Block = DEFNODE("Block", "body", {
             if (node instanceof AST_Function) throw new Error("body cannot contain AST_Function");
         });
     },
-}, AST_Statement);
+}, AST_BlockScope);
 
 var AST_BlockStatement = DEFNODE("BlockStatement", null, {
     $documentation: "A block statement",
 }, AST_Block);
 
-var AST_EmptyStatement = DEFNODE("EmptyStatement", null, {
-    $documentation: "The empty statement (empty block or simply a semicolon)"
-}, AST_Statement);
-
 var AST_StatementWithBody = DEFNODE("StatementWithBody", "body", {
     $documentation: "Base class for all statements that contain one nested body: `For`, `ForIn`, `Do`, `While`, `With`",
     $propdoc: {
@@ -268,7 +296,7 @@ var AST_StatementWithBody = DEFNODE("StatementWithBody", "body", {
         if (!(this.body instanceof AST_Statement)) throw new Error("body must be AST_Statement");
         if (this.body instanceof AST_Function) throw new Error("body cannot be AST_Function");
     },
-}, AST_Statement);
+}, AST_BlockScope);
 
 var AST_LabeledStatement = DEFNODE("LabeledStatement", "label", {
     $documentation: "Statement with a label",
@@ -288,10 +316,13 @@ var AST_LabeledStatement = DEFNODE("LabeledStatement", "label", {
             var label = node.label;
             var def = this.label;
             node.walk(new TreeWalker(function(node) {
-                if (node instanceof AST_LoopControl && node.label && node.label.thedef === def) {
+                if (node instanceof AST_LoopControl) {
+                    if (!node.label || node.label.thedef !== def) return;
                     node.label.thedef = label;
                     label.references.push(node);
+                    return true;
                 }
+                if (node instanceof AST_Scope) return true;
             }));
         }
         return node;
@@ -409,32 +440,16 @@ var AST_With = DEFNODE("With", "expression", {
 
 /* -----[ scope and functions ]----- */
 
-var AST_Scope = DEFNODE("Scope", "variables functions uses_with uses_eval parent_scope enclosed cname", {
+var AST_Scope = DEFNODE("Scope", "uses_eval uses_with", {
     $documentation: "Base class for all statements introducing a lexical scope",
     $propdoc: {
-        variables: "[Object/S] a map of name -> SymbolDef for all variables/functions defined in this scope",
-        functions: "[Object/S] like `variables`, but only lists function declarations",
-        uses_with: "[boolean/S] tells whether this scope uses the `with` statement",
         uses_eval: "[boolean/S] tells whether this scope contains a direct call to the global `eval`",
-        parent_scope: "[AST_Scope?/S] link to the parent scope",
-        enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any subscopes",
-        cname: "[integer/S] current index for mangling variables (used internally by the mangler)",
-    },
-    clone: function(deep) {
-        var node = this._clone(deep);
-        if (this.variables) node.variables = this.variables.clone();
-        if (this.functions) node.functions = this.functions.clone();
-        if (this.enclosed) node.enclosed = this.enclosed.slice();
-        return node;
+        uses_with: "[boolean/S] tells whether this scope uses the `with` statement",
     },
     pinned: function() {
         return this.uses_eval || this.uses_with;
     },
-    _validate: function() {
-        if (this.parent_scope != null) {
-            if (!(this.parent_scope instanceof AST_Scope)) throw new Error("parent_scope must be AST_Scope");
-        }
-    },
+    resolve: return_this,
 }, AST_Block);
 
 var AST_Toplevel = DEFNODE("Toplevel", "globals", {
@@ -628,6 +643,9 @@ var AST_Switch = DEFNODE("Switch", "expression", {
     },
     _validate: function() {
         must_be_expression(this, "expression");
+        this.body.forEach(function(node) {
+            if (!(node instanceof AST_SwitchBranch)) throw new Error("body must be AST_SwitchBranch[]");
+        });
     },
 }, AST_Block);
 
@@ -685,17 +703,19 @@ var AST_Try = DEFNODE("Try", "bcatch bfinally", {
 var AST_Catch = DEFNODE("Catch", "argname", {
     $documentation: "A `catch` node; only makes sense as part of a `try` statement",
     $propdoc: {
-        argname: "[AST_SymbolCatch] symbol for the exception"
+        argname: "[AST_SymbolCatch?] symbol for the exception, or null if not present",
     },
     walk: function(visitor) {
         var node = this;
         visitor.visit(node, function() {
-            node.argname.walk(visitor);
+            if (node.argname) node.argname.walk(visitor);
             walk_body(node, visitor);
         });
     },
     _validate: function() {
-        if (!(this.argname instanceof AST_SymbolCatch)) throw new Error("argname must be AST_SymbolCatch");
+        if (this.argname != null) {
+            if (!(this.argname instanceof AST_SymbolCatch)) throw new Error("argname must be AST_SymbolCatch");
+        }
     },
 }, AST_Block);
 
@@ -717,14 +737,41 @@ var AST_Definitions = DEFNODE("Definitions", "definitions", {
                 defn.walk(visitor);
             });
         });
-    }
+    },
+    _validate: function() {
+        if (this.definitions.length < 1) throw new Error("must have at least one definition");
+    },
 }, AST_Statement);
 
+var AST_Const = DEFNODE("Const", null, {
+    $documentation: "A `const` statement",
+    _validate: function() {
+        this.definitions.forEach(function(node) {
+            if (!(node instanceof AST_VarDef)) throw new Error("definitions must be AST_VarDef[]");
+            if (!(node.name instanceof AST_SymbolConst)) throw new Error("name must be AST_SymbolConst");
+            must_be_expression(node, "value");
+        });
+    },
+}, AST_Definitions);
+
+var AST_Let = DEFNODE("Let", null, {
+    $documentation: "A `let` statement",
+    _validate: function() {
+        this.definitions.forEach(function(node) {
+            if (!(node instanceof AST_VarDef)) throw new Error("definitions must be AST_VarDef[]");
+            if (!(node.name instanceof AST_SymbolLet)) throw new Error("name must be AST_SymbolLet");
+            if (node.value != null) must_be_expression(node, "value");
+        });
+    },
+}, AST_Definitions);
+
 var AST_Var = DEFNODE("Var", null, {
     $documentation: "A `var` statement",
     _validate: function() {
         this.definitions.forEach(function(node) {
             if (!(node instanceof AST_VarDef)) throw new Error("definitions must be AST_VarDef[]");
+            if (!(node.name instanceof AST_SymbolVar)) throw new Error("name must be AST_SymbolVar");
+            if (node.value != null) must_be_expression(node, "value");
         });
     },
 }, AST_Definitions);
@@ -742,10 +789,6 @@ var AST_VarDef = DEFNODE("VarDef", "name value", {
             if (node.value) node.value.walk(visitor);
         });
     },
-    _validate: function() {
-        if (!(this.name instanceof AST_SymbolVar)) throw new Error("name must be AST_SymbolVar");
-        if (this.value != null) must_be_expression(this, "value");
-    },
 });
 
 /* -----[ OTHER ]----- */
@@ -972,24 +1015,28 @@ var AST_Object = DEFNODE("Object", "properties", {
 var AST_ObjectProperty = DEFNODE("ObjectProperty", "key value", {
     $documentation: "Base class for literal object properties",
     $propdoc: {
-        key: "[string|AST_SymbolAccessor] property name. For ObjectKeyVal this is a string. For getters and setters this is an AST_SymbolAccessor.",
-        value: "[AST_Node] property value.  For getters and setters this is an AST_Accessor."
+        key: "[string|AST_Node] property name.  For computed property this is an AST_Node.",
+        value: "[AST_Node] property value.  For getters and setters this is an AST_Accessor.",
     },
     walk: function(visitor) {
         var node = this;
         visitor.visit(node, function() {
+            if (node.key instanceof AST_Node) node.key.walk(visitor);
             node.value.walk(visitor);
         });
-    }
-});
-
-var AST_ObjectKeyVal = DEFNODE("ObjectKeyVal", "quote", {
-    $documentation: "A key: value object property",
-    $propdoc: {
-        quote: "[string] the original quote character"
     },
     _validate: function() {
-        if (typeof this.key != "string") throw new Error("key must be string");
+        if (typeof this.key != "string") {
+            if (!(this.key instanceof AST_Node)) throw new Error("key must be string or AST_Node");
+            must_be_expression(this, "key");
+        }
+        if (!(this.value instanceof AST_Node)) throw new Error("value must be AST_Node");
+    },
+});
+
+var AST_ObjectKeyVal = DEFNODE("ObjectKeyVal", null, {
+    $documentation: "A key: value object property",
+    _validate: function() {
         must_be_expression(this, "value");
     },
 }, AST_ObjectProperty);
@@ -997,7 +1044,6 @@ var AST_ObjectKeyVal = DEFNODE("ObjectKeyVal", "quote", {
 var AST_ObjectSetter = DEFNODE("ObjectSetter", null, {
     $documentation: "An object setter property",
     _validate: function() {
-        if (!(this.key instanceof AST_SymbolAccessor)) throw new Error("key must be AST_SymbolAccessor");
         if (!(this.value instanceof AST_Accessor)) throw new Error("value must be AST_Accessor");
     },
 }, AST_ObjectProperty);
@@ -1005,31 +1051,34 @@ var AST_ObjectSetter = DEFNODE("ObjectSetter", null, {
 var AST_ObjectGetter = DEFNODE("ObjectGetter", null, {
     $documentation: "An object getter property",
     _validate: function() {
-        if (!(this.key instanceof AST_SymbolAccessor)) throw new Error("key must be AST_SymbolAccessor");
         if (!(this.value instanceof AST_Accessor)) throw new Error("value must be AST_Accessor");
     },
 }, AST_ObjectProperty);
 
 var AST_Symbol = DEFNODE("Symbol", "scope name thedef", {
+    $documentation: "Base class for all symbols",
     $propdoc: {
         name: "[string] name of this symbol",
         scope: "[AST_Scope/S] the current scope (not necessarily the definition scope)",
         thedef: "[SymbolDef/S] the definition of this symbol"
     },
-    $documentation: "Base class for all symbols",
     _validate: function() {
         if (typeof this.name != "string") throw new Error("name must be string");
     },
 });
 
-var AST_SymbolAccessor = DEFNODE("SymbolAccessor", null, {
-    $documentation: "The name of a property accessor (setter/getter function)"
-}, AST_Symbol);
-
 var AST_SymbolDeclaration = DEFNODE("SymbolDeclaration", "init", {
     $documentation: "A declaration symbol (symbol in var, function name or argument, symbol in catch)",
 }, AST_Symbol);
 
+var AST_SymbolConst = DEFNODE("SymbolConst", null, {
+    $documentation: "Symbol defining a constant",
+}, AST_SymbolDeclaration);
+
+var AST_SymbolLet = DEFNODE("SymbolLet", null, {
+    $documentation: "Symbol defining a lexical-scoped variable",
+}, AST_SymbolDeclaration);
+
 var AST_SymbolVar = DEFNODE("SymbolVar", null, {
     $documentation: "Symbol defining a variable",
 }, AST_SymbolDeclaration);

lib/minify.js

@@ -33,7 +33,9 @@ function read_source_map(name, toplevel) {
             return to_ascii(match[2]);
         }
     }
-    AST_Node.warn("inline source map not found: " + name);
+    AST_Node.warn("inline source map not found: {name}", {
+        name: name,
+    });
 }
 
 function parse_source_map(content) {
@@ -258,6 +260,7 @@ function minify(files, options) {
     } catch (ex) {
         return { error: ex };
     } finally {
+        AST_Node.log_function();
         AST_Node.disable_validation();
     }
 }

lib/mozilla-ast.js

@@ -115,9 +115,6 @@
                 value    : from_moz(M.value)
             };
             if (M.kind == "init") return new AST_ObjectKeyVal(args);
-            args.key = new AST_SymbolAccessor({
-                name: args.key
-            });
             args.value = new AST_Accessor(args.value);
             if (M.kind == "get") return new AST_ObjectGetter(args);
             if (M.kind == "set") return new AST_ObjectSetter(args);
@@ -385,7 +382,7 @@
     def_to_moz(AST_ObjectProperty, function To_Moz_Property(M) {
         var key = {
             type: "Literal",
-            value: M.key instanceof AST_SymbolAccessor ? M.key.name : M.key
+            value: M.key
         };
         var kind;
         if (M instanceof AST_ObjectKeyVal) {

lib/output.js

@@ -100,13 +100,16 @@ function OutputStream(options) {
         }
     }
 
-    var indentation = 0;
+    var indentation = options.indent_start;
     var current_col = 0;
     var current_line = 1;
     var current_pos = 0;
     var OUTPUT = "";
 
     var to_utf8 = options.ascii_only ? function(str, identifier) {
+        if (identifier) str = str.replace(/[\ud800-\udbff][\udc00-\udfff]/g, function(ch) {
+            return "\\u{" + (ch.charCodeAt(0) - 0xd7c0 << 10 | ch.charCodeAt(1) - 0xdc00).toString(16) + "}";
+        });
         return str.replace(/[\u0000-\u001f\u007f-\uffff]/g, function(ch) {
             var code = ch.charCodeAt(0).toString(16);
             if (code.length <= 2 && !identifier) {
@@ -191,10 +194,6 @@ function OutputStream(options) {
         return name;
     }
 
-    function make_indent(back) {
-        return repeat_string(" ", options.indent_start + indentation - back * options.indent_level);
-    }
-
     /* -----[ beautification/minification ]----- */
 
     var has_parens = false;
@@ -345,9 +344,7 @@ function OutputStream(options) {
     };
 
     var indent = options.beautify ? function(half) {
-        if (options.beautify) {
-            print(make_indent(half ? 0.5 : 0));
-        }
+        print(repeat_string(" ", half ? indentation - (options.indent_level >> 1) : indentation));
     } : noop;
 
     var with_indent = options.beautify ? function(col, cont) {
@@ -575,9 +572,9 @@ function OutputStream(options) {
         get             : get,
         toString        : get,
         indent          : indent,
-        indentation     : function() { return indentation },
-        current_width   : function() { return current_col - indentation },
-        should_break    : function() { return options.width && this.current_width() >= options.width },
+        should_break    : readonly ? noop : function() {
+            return options.width && current_col - indentation >= options.width;
+        },
         has_parens      : function() { return has_parens },
         newline         : newline,
         print           : print,
@@ -630,13 +627,7 @@ function OutputStream(options) {
     var use_asm = false;
 
     AST_Node.DEFMETHOD("print", function(stream, force_parens) {
-        var self = this, generator = self._codegen;
-        function doit() {
-            stream.prepend_comments(self);
-            self.add_source_map(stream);
-            generator(self, stream);
-            stream.append_comments(self);
-        }
+        var self = this;
         stream.push_node(self);
         if (force_parens || self.needs_parens(stream)) {
             stream.with_parens(doit);
@@ -644,9 +635,14 @@ function OutputStream(options) {
             doit();
         }
         stream.pop_node();
-    });
-    AST_Node.DEFMETHOD("_print", AST_Node.prototype.print);
 
+        function doit() {
+            stream.prepend_comments(self);
+            self.add_source_map(stream);
+            self._codegen(stream);
+            stream.append_comments(self);
+        }
+    });
     AST_Node.DEFMETHOD("print_to_string", function(options) {
         var s = OutputStream(options);
         this.print(s);
@@ -689,78 +685,67 @@ function OutputStream(options) {
 
     PARENS(AST_Unary, function(output) {
         var p = output.parent();
-        return p instanceof AST_PropAccess && p.expression === this
-            || p instanceof AST_Call && p.expression === this;
+        return (p instanceof AST_Call || p instanceof AST_PropAccess) && p.expression === this;
     });
 
     PARENS(AST_Sequence, function(output) {
         var p = output.parent();
-            // (foo, bar)() or foo(1, (2, 3), 4)
-        return p instanceof AST_Call
-            // !(foo, bar, baz)
-            || p instanceof AST_Unary
+            // [ 1, (2, 3), 4 ] ==> [ 1, 3, 4 ]
+        return p instanceof AST_Array
             // 1 + (2, 3) + 4 ==> 8
             || p instanceof AST_Binary
-            // var a = (1, 2), b = a + a; ==> b == 4
-            || p instanceof AST_VarDef
-            // (1, {foo:2}).foo or (1, {foo:2})["foo"] ==> 2
-            || p instanceof AST_PropAccess && p.expression === this
-            // [ 1, (2, 3), 4 ] ==> [ 1, 3, 4 ]
-            || p instanceof AST_Array
-            // { foo: (1, 2) }.foo ==> 2
-            || p instanceof AST_ObjectProperty
+            // new (foo, bar) or foo(1, (2, 3), 4)
+            || p instanceof AST_Call
             // (false, true) ? (a = 10, b = 20) : (c = 30)
             // ==> 20 (side effect, set a := 10 and b := 20)
-            || p instanceof AST_Conditional;
+            || p instanceof AST_Conditional
+            // { [(1, 2)]: 3 }[2] ==> 3
+            // { foo: (1, 2) }.foo ==> 2
+            || p instanceof AST_ObjectProperty
+            // (1, {foo:2}).foo or (1, {foo:2})["foo"] ==> 2
+            || p instanceof AST_PropAccess && p.expression === this
+            // !(foo, bar, baz)
+            || p instanceof AST_Unary
+            // var a = (1, 2), b = a + a; ==> b == 4
+            || p instanceof AST_VarDef;
     });
 
     PARENS(AST_Binary, function(output) {
         var p = output.parent();
-        // (foo && bar)()
-        if (p instanceof AST_Call && p.expression === this)
-            return true;
-        // typeof (foo && bar)
-        if (p instanceof AST_Unary)
-            return true;
-        // (foo && bar)["prop"], (foo && bar).prop
-        if (p instanceof AST_PropAccess && p.expression === this)
-            return true;
         // this deals with precedence: 3 * (2 + 1)
         if (p instanceof AST_Binary) {
             var po = p.operator, pp = PRECEDENCE[po];
             var so = this.operator, sp = PRECEDENCE[so];
-            if (pp > sp
-                || (pp == sp
-                    && this === p.right)) {
-                return true;
-            }
+            return pp > sp || (pp == sp && this === p.right);
         }
+        // (foo && bar)()
+        if (p instanceof AST_Call) return p.expression === this;
+        // (foo && bar)["prop"], (foo && bar).prop
+        if (p instanceof AST_PropAccess) return p.expression === this;
+        // typeof (foo && bar)
+        if (p instanceof AST_Unary) return true;
     });
 
     PARENS(AST_PropAccess, function(output) {
+        var node = this;
         var p = output.parent();
-        if (p instanceof AST_New && p.expression === this) {
-            // i.e. new (foo.bar().baz)
+        if (p instanceof AST_New && p.expression === node) {
+            // i.e. new (foo().bar)
             //
             // if there's one call into this subtree, then we need
             // parens around it too, otherwise the call will be
             // interpreted as passing the arguments to the upper New
             // expression.
-            var parens = false;
-            this.walk(new TreeWalker(function(node) {
-                if (parens || node instanceof AST_Scope) return true;
-                if (node instanceof AST_Call) {
-                    parens = true;
-                    return true;
-                }
-            }));
-            return parens;
+            do {
+                node = node.expression;
+            } while (node instanceof AST_PropAccess);
+            return node.TYPE == "Call";
         }
     });
 
     PARENS(AST_Call, function(output) {
         var p = output.parent();
-        if (p instanceof AST_New && p.expression === this) return true;
+        if (p instanceof AST_New) return p.expression === this;
         // https://bugs.webkit.org/show_bug.cgi?id=123506
         if (output.option('webkit')) {
             var g = output.parent(1);
@@ -773,11 +758,12 @@ function OutputStream(options) {
     });
 
     PARENS(AST_New, function(output) {
+        if (need_constructor_parens(this, output)) return false;
         var p = output.parent();
-        if (!need_constructor_parens(this, output)
-            && (p instanceof AST_PropAccess // (new Date).getTime(), (new Date)["getTime"]()
-                || p instanceof AST_Call && p.expression === this)) // (new foo)(bar)
-            return true;
+        // (new foo)(bar)
+        if (p instanceof AST_Call) return p.expression === this;
+        // (new Date).getTime(), (new Date)["getTime"]()
+        return p instanceof AST_PropAccess;
     });
 
     PARENS(AST_Number, function(output) {
@@ -786,36 +772,29 @@ function OutputStream(options) {
             var value = this.value;
             // https://github.com/mishoo/UglifyJS/issues/115
             // https://github.com/mishoo/UglifyJS/pull/1009
-            if (value < 0 || /^0/.test(make_num(value))) {
-                return true;
-            }
+            return value < 0 || /^0/.test(make_num(value));
         }
     });
 
     PARENS([ AST_Assign, AST_Conditional ], function(output) {
         var p = output.parent();
-        // !(a = false) → true
-        if (p instanceof AST_Unary)
-            return true;
         // 1 + (a = 2) + 3 → 6, side effect setting a = 2
-        if (p instanceof AST_Binary && !(p instanceof AST_Assign))
-            return true;
+        if (p instanceof AST_Binary) return !(p instanceof AST_Assign);
         // (a = func)() —or— new (a = Object)()
-        if (p instanceof AST_Call && p.expression === this)
-            return true;
+        if (p instanceof AST_Call) return p.expression === this;
         // (a = foo) ? bar : baz
-        if (p instanceof AST_Conditional && p.condition === this)
-            return true;
+        if (p instanceof AST_Conditional) return p.condition === this;
         // (a = foo)["prop"] —or— (a = foo).prop
-        if (p instanceof AST_PropAccess && p.expression === this)
-            return true;
+        if (p instanceof AST_PropAccess) return p.expression === this;
+        // !(a = false) → true
+        if (p instanceof AST_Unary) return true;
     });
 
     /* -----[ PRINTERS ]----- */
 
-    DEFPRINT(AST_Directive, function(self, output) {
-        var quote = self.quote;
-        var value = self.value;
+    DEFPRINT(AST_Directive, function(output) {
+        var quote = this.quote;
+        var value = this.value;
         switch (output.option("quote_style")) {
           case 0:
           case 2:
@@ -828,7 +807,7 @@ function OutputStream(options) {
         output.print(quote + value + quote);
         output.semicolon();
     });
-    DEFPRINT(AST_Debugger, function(self, output) {
+    DEFPRINT(AST_Debugger, function(output) {
         output.print("debugger");
         output.semicolon();
     });
@@ -860,25 +839,21 @@ function OutputStream(options) {
         use_asm = was_asm;
     }
 
-    AST_StatementWithBody.DEFMETHOD("_do_print_body", function(output) {
-        force_statement(this.body, output);
-    });
-
-    DEFPRINT(AST_Statement, function(self, output) {
-        self.body.print(output);
+    DEFPRINT(AST_Statement, function(output) {
+        this.body.print(output);
         output.semicolon();
     });
-    DEFPRINT(AST_Toplevel, function(self, output) {
-        display_body(self.body, true, output, true);
+    DEFPRINT(AST_Toplevel, function(output) {
+        display_body(this.body, true, output, true);
         output.print("");
     });
-    DEFPRINT(AST_LabeledStatement, function(self, output) {
-        self.label.print(output);
+    DEFPRINT(AST_LabeledStatement, function(output) {
+        this.label.print(output);
         output.colon();
-        self.body.print(output);
+        this.body.print(output);
     });
-    DEFPRINT(AST_SimpleStatement, function(self, output) {
-        self.body.print(output);
+    DEFPRINT(AST_SimpleStatement, function(output) {
+        this.body.print(output);
         output.semicolon();
     });
     function print_braced_empty(self, output) {
@@ -895,13 +870,14 @@ function OutputStream(options) {
             });
         } else print_braced_empty(self, output);
     }
-    DEFPRINT(AST_BlockStatement, function(self, output) {
-        print_braced(self, output);
+    DEFPRINT(AST_BlockStatement, function(output) {
+        print_braced(this, output);
     });
-    DEFPRINT(AST_EmptyStatement, function(self, output) {
+    DEFPRINT(AST_EmptyStatement, function(output) {
         output.semicolon();
     });
-    DEFPRINT(AST_Do, function(self, output) {
+    DEFPRINT(AST_Do, function(output) {
+        var self = this;
         output.print("do");
         output.space();
         make_block(self.body, output);
@@ -913,16 +889,18 @@ function OutputStream(options) {
         });
         output.semicolon();
     });
-    DEFPRINT(AST_While, function(self, output) {
+    DEFPRINT(AST_While, function(output) {
+        var self = this;
         output.print("while");
         output.space();
         output.with_parens(function() {
             self.condition.print(output);
         });
         output.space();
-        self._do_print_body(output);
+        force_statement(self.body, output);
     });
-    DEFPRINT(AST_For, function(self, output) {
+    DEFPRINT(AST_For, function(output) {
+        var self = this;
         output.print("for");
         output.space();
         output.with_parens(function() {
@@ -949,9 +927,10 @@ function OutputStream(options) {
             }
         });
         output.space();
-        self._do_print_body(output);
+        force_statement(self.body, output);
     });
-    DEFPRINT(AST_ForIn, function(self, output) {
+    DEFPRINT(AST_ForIn, function(output) {
+        var self = this;
         output.print("for");
         output.space();
         output.with_parens(function() {
@@ -962,20 +941,21 @@ function OutputStream(options) {
             self.object.print(output);
         });
         output.space();
-        self._do_print_body(output);
+        force_statement(self.body, output);
     });
-    DEFPRINT(AST_With, function(self, output) {
+    DEFPRINT(AST_With, function(output) {
+        var self = this;
         output.print("with");
         output.space();
         output.with_parens(function() {
             self.expression.print(output);
         });
         output.space();
-        self._do_print_body(output);
+        force_statement(self.body, output);
     });
 
     /* -----[ functions ]----- */
-    AST_Lambda.DEFMETHOD("_do_print", function(output, nokeyword) {
+    DEFPRINT(AST_Lambda, function(output, nokeyword) {
         var self = this;
         if (!nokeyword) {
             output.print("function");
@@ -993,37 +973,28 @@ function OutputStream(options) {
         output.space();
         print_braced(self, output, true);
     });
-    DEFPRINT(AST_Lambda, function(self, output) {
-        self._do_print(output);
-    });
 
     /* -----[ jumps ]----- */
-    function print_jump(output, kind, target) {
-        output.print(kind);
-        if (target) {
-            output.space();
-            target.print(output);
-        }
-        output.semicolon();
+    function print_jump(kind, prop) {
+        return function(output) {
+            output.print(kind);
+            var target = this[prop];
+            if (target) {
+                output.space();
+                target.print(output);
+            }
+            output.semicolon();
+        };
     }
-
-    DEFPRINT(AST_Return, function(self, output) {
-        print_jump(output, "return", self.value);
-    });
-    DEFPRINT(AST_Throw, function(self, output) {
-        print_jump(output, "throw", self.value);
-    });
-    DEFPRINT(AST_Break, function(self, output) {
-        print_jump(output, "break", self.label);
-    });
-    DEFPRINT(AST_Continue, function(self, output) {
-        print_jump(output, "continue", self.label);
-    });
+    DEFPRINT(AST_Return, print_jump("return", "value"));
+    DEFPRINT(AST_Throw, print_jump("throw", "value"));
+    DEFPRINT(AST_Break, print_jump("break", "label"));
+    DEFPRINT(AST_Continue, print_jump("continue", "label"));
 
     /* -----[ if ]----- */
     function make_then(self, output) {
         var b = self.body;
-        if (output.option("braces")
+        if (output.option("braces") && !(b instanceof AST_Const || b instanceof AST_Let)
             || output.option("ie8") && b instanceof AST_Do)
             return make_block(b, output);
         // The squeezer replaces "block"-s that contain only a single
@@ -1047,7 +1018,8 @@ function OutputStream(options) {
         }
         force_statement(self.body, output);
     }
-    DEFPRINT(AST_If, function(self, output) {
+    DEFPRINT(AST_If, function(output) {
+        var self = this;
         output.print("if");
         output.space();
         output.with_parens(function() {
@@ -1064,12 +1036,13 @@ function OutputStream(options) {
             else
                 force_statement(self.alternative, output);
         } else {
-            self._do_print_body(output);
+            force_statement(self.body, output);
         }
     });
 
     /* -----[ switch ]----- */
-    DEFPRINT(AST_Switch, function(self, output) {
+    DEFPRINT(AST_Switch, function(output) {
+        var self = this;
         output.print("switch");
         output.space();
         output.with_parens(function() {
@@ -1087,28 +1060,30 @@ function OutputStream(options) {
             });
         });
     });
-    AST_SwitchBranch.DEFMETHOD("_do_print_body", function(output) {
+    function print_branch_body(self, output) {
         output.newline();
-        this.body.forEach(function(stmt) {
+        self.body.forEach(function(stmt) {
             output.indent();
             stmt.print(output);
             output.newline();
         });
-    });
-    DEFPRINT(AST_Default, function(self, output) {
+    }
+    DEFPRINT(AST_Default, function(output) {
         output.print("default:");
-        self._do_print_body(output);
+        print_branch_body(this, output);
     });
-    DEFPRINT(AST_Case, function(self, output) {
+    DEFPRINT(AST_Case, function(output) {
+        var self = this;
         output.print("case");
         output.space();
         self.expression.print(output);
         output.print(":");
-        self._do_print_body(output);
+        print_branch_body(self, output);
     });
 
     /* -----[ exceptions ]----- */
-    DEFPRINT(AST_Try, function(self, output) {
+    DEFPRINT(AST_Try, function(output) {
+        var self = this;
         output.print("try");
         output.space();
         print_braced(self, output);
@@ -1121,31 +1096,40 @@ function OutputStream(options) {
             self.bfinally.print(output);
         }
     });
-    DEFPRINT(AST_Catch, function(self, output) {
+    DEFPRINT(AST_Catch, function(output) {
+        var self = this;
         output.print("catch");
-        output.space();
-        output.with_parens(function() {
-            self.argname.print(output);
-        });
+        if (self.argname) {
+            output.space();
+            output.with_parens(function() {
+                self.argname.print(output);
+            });
+        }
         output.space();
         print_braced(self, output);
     });
-    DEFPRINT(AST_Finally, function(self, output) {
+    DEFPRINT(AST_Finally, function(output) {
         output.print("finally");
         output.space();
-        print_braced(self, output);
+        print_braced(this, output);
     });
 
-    DEFPRINT(AST_Var, function(self, output) {
-        output.print("var");
-        output.space();
-        self.definitions.forEach(function(def, i) {
-            if (i) output.comma();
-            def.print(output);
-        });
-        var p = output.parent();
-        if (p && p.init !== self || !(p instanceof AST_For || p instanceof AST_ForIn)) output.semicolon();
-    });
+    function print_definitinos(type) {
+        return function(output) {
+            var self = this;
+            output.print(type);
+            output.space();
+            self.definitions.forEach(function(def, i) {
+                if (i) output.comma();
+                def.print(output);
+            });
+            var p = output.parent();
+            if (p && p.init !== self || !(p instanceof AST_For || p instanceof AST_ForIn)) output.semicolon();
+        };
+    }
+    DEFPRINT(AST_Const, print_definitinos("const"));
+    DEFPRINT(AST_Let, print_definitinos("let"));
+    DEFPRINT(AST_Var, print_definitinos("var"));
 
     function parenthesize_for_noin(node, output, noin) {
         var parens = false;
@@ -1161,7 +1145,8 @@ function OutputStream(options) {
         node.print(output, parens);
     }
 
-    DEFPRINT(AST_VarDef, function(self, output) {
+    DEFPRINT(AST_VarDef, function(output) {
+        var self = this;
         self.name.print(output);
         if (self.value) {
             output.space();
@@ -1185,18 +1170,19 @@ function OutputStream(options) {
             });
         });
     }
-    DEFPRINT(AST_Call, function(self, output) {
-        self.expression.print(output);
-        print_call_args(self, output);
+    DEFPRINT(AST_Call, function(output) {
+        this.expression.print(output);
+        print_call_args(this, output);
     });
-    DEFPRINT(AST_New, function(self, output) {
+    DEFPRINT(AST_New, function(output) {
+        var self = this;
         output.print("new");
         output.space();
         self.expression.print(output);
         if (need_constructor_parens(self, output)) print_call_args(self, output);
     });
-    DEFPRINT(AST_Sequence, function(self, output) {
-        self.expressions.forEach(function(node, index) {
+    DEFPRINT(AST_Sequence, function(output) {
+        this.expressions.forEach(function(node, index) {
             if (index > 0) {
                 output.comma();
                 if (output.should_break()) {
@@ -1207,7 +1193,8 @@ function OutputStream(options) {
             node.print(output);
         });
     });
-    DEFPRINT(AST_Dot, function(self, output) {
+    DEFPRINT(AST_Dot, function(output) {
+        var self = this;
         var expr = self.expression;
         expr.print(output);
         var prop = self.property;
@@ -1228,35 +1215,38 @@ function OutputStream(options) {
             output.print_name(prop);
         }
     });
-    DEFPRINT(AST_Sub, function(self, output) {
-        self.expression.print(output);
+    DEFPRINT(AST_Sub, function(output) {
+        this.expression.print(output);
         output.print("[");
-        self.property.print(output);
+        this.property.print(output);
         output.print("]");
     });
-    DEFPRINT(AST_UnaryPrefix, function(self, output) {
-        var op = self.operator;
+    DEFPRINT(AST_UnaryPrefix, function(output) {
+        var op = this.operator;
+        var exp = this.expression;
         output.print(op);
         if (/^[a-z]/i.test(op)
             || (/[+-]$/.test(op)
-                && self.expression instanceof AST_UnaryPrefix
-                && /^[+-]/.test(self.expression.operator))) {
+                && exp instanceof AST_UnaryPrefix
+                && /^[+-]/.test(exp.operator))) {
             output.space();
         }
-        self.expression.print(output);
+        exp.print(output);
     });
-    DEFPRINT(AST_UnaryPostfix, function(self, output) {
-        self.expression.print(output);
-        output.print(self.operator);
+    DEFPRINT(AST_UnaryPostfix, function(output) {
+        this.expression.print(output);
+        output.print(this.operator);
     });
-    DEFPRINT(AST_Binary, function(self, output) {
+    DEFPRINT(AST_Binary, function(output) {
+        var self = this;
         self.left.print(output);
         output.space();
         output.print(self.operator);
         output.space();
         self.right.print(output);
     });
-    DEFPRINT(AST_Conditional, function(self, output) {
+    DEFPRINT(AST_Conditional, function(output) {
+        var self = this;
         self.condition.print(output);
         output.space();
         output.print("?");
@@ -1268,10 +1258,10 @@ function OutputStream(options) {
     });
 
     /* -----[ literals ]----- */
-    DEFPRINT(AST_Array, function(self, output) {
-        output.with_square(function() {
-            var a = self.elements, len = a.length;
-            if (len > 0) output.space();
+    DEFPRINT(AST_Array, function(output) {
+        var a = this.elements, len = a.length;
+        output.with_square(len > 0 ? function() {
+            output.space();
             a.forEach(function(exp, i) {
                 if (i) output.comma();
                 exp.print(output);
@@ -1281,12 +1271,13 @@ function OutputStream(options) {
                 if (i === len - 1 && exp instanceof AST_Hole)
                   output.comma();
             });
-            if (len > 0) output.space();
-        });
+            output.space();
+        } : noop);
     });
-    DEFPRINT(AST_Object, function(self, output) {
-        if (self.properties.length > 0) output.with_block(function() {
-            self.properties.forEach(function(prop, i) {
+    DEFPRINT(AST_Object, function(output) {
+        var props = this.properties;
+        if (props.length > 0) output.with_block(function() {
+            props.forEach(function(prop, i) {
                 if (i) {
                     output.print(",");
                     output.newline();
@@ -1296,66 +1287,75 @@ function OutputStream(options) {
             });
             output.newline();
         });
-        else print_braced_empty(self, output);
+        else print_braced_empty(this, output);
     });
 
-    function print_property_name(key, quote, output) {
-        if (output.option("quote_keys")) {
+    function print_property_key(self, output) {
+        var key = self.key;
+        if (key instanceof AST_Node) {
+            output.with_square(function() {
+                key.print(output);
+            });
+        } else if (output.option("quote_keys")) {
             output.print_string(key);
         } else if ("" + +key == key && key >= 0) {
             output.print(make_num(key));
-        } else if (RESERVED_WORDS[key] ? !output.option("ie8") : is_identifier_string(key)) {
-            if (quote && output.option("keep_quoted_props")) {
-                output.print_string(key, quote);
-            } else {
-                output.print_name(key);
-            }
         } else {
-            output.print_string(key, quote);
+            var quote = self.start && self.start.quote;
+            if (RESERVED_WORDS[key] ? !output.option("ie8") : is_identifier_string(key)) {
+                if (quote && output.option("keep_quoted_props")) {
+                    output.print_string(key, quote);
+                } else {
+                    output.print_name(key);
+                }
+            } else {
+                output.print_string(key, quote);
+            }
         }
     }
 
-    DEFPRINT(AST_ObjectKeyVal, function(self, output) {
-        print_property_name(self.key, self.quote, output);
+    DEFPRINT(AST_ObjectKeyVal, function(output) {
+        var self = this;
+        print_property_key(self, output);
         output.colon();
         self.value.print(output);
     });
-    AST_ObjectProperty.DEFMETHOD("_print_getter_setter", function(type, output) {
-        output.print(type);
-        output.space();
-        print_property_name(this.key.name, this.quote, output);
-        this.value._do_print(output, true);
-    });
-    DEFPRINT(AST_ObjectSetter, function(self, output) {
-        self._print_getter_setter("set", output);
-    });
-    DEFPRINT(AST_ObjectGetter, function(self, output) {
-        self._print_getter_setter("get", output);
-    });
-    DEFPRINT(AST_Symbol, function(self, output) {
-        var def = self.definition();
-        output.print_name(def && def.mangled_name || self.name);
+    function print_accessor(type) {
+        return function(output) {
+            var self = this;
+            output.print(type);
+            output.space();
+            print_property_key(self, output);
+            self.value._codegen(output, true);
+        };
+    }
+    DEFPRINT(AST_ObjectGetter, print_accessor("get"));
+    DEFPRINT(AST_ObjectSetter, print_accessor("set"));
+    DEFPRINT(AST_Symbol, function(output) {
+        var def = this.definition();
+        output.print_name(def && def.mangled_name || this.name);
     });
     DEFPRINT(AST_Hole, noop);
-    DEFPRINT(AST_This, function(self, output) {
+    DEFPRINT(AST_This, function(output) {
         output.print("this");
     });
-    DEFPRINT(AST_Constant, function(self, output) {
-        output.print(self.value);
+    DEFPRINT(AST_Constant, function(output) {
+        output.print(this.value);
     });
-    DEFPRINT(AST_String, function(self, output) {
-        output.print_string(self.value, self.quote);
+    DEFPRINT(AST_String, function(output) {
+        output.print_string(this.value, this.quote);
     });
-    DEFPRINT(AST_Number, function(self, output) {
-        if (use_asm && self.start && self.start.raw != null) {
-            output.print(self.start.raw);
+    DEFPRINT(AST_Number, function(output) {
+        var start = this.start;
+        if (use_asm && start && start.raw != null) {
+            output.print(start.raw);
         } else {
-            output.print(make_num(self.value));
+            output.print(make_num(this.value));
         }
     });
 
-    DEFPRINT(AST_RegExp, function(self, output) {
-        var regexp = self.value;
+    DEFPRINT(AST_RegExp, function(output) {
+        var regexp = this.value;
         var str = regexp.toString();
         var end = str.lastIndexOf("/");
         if (regexp.raw_source) {
@@ -1389,18 +1389,17 @@ function OutputStream(options) {
             }
         }));
         var p = output.parent();
-        if (p instanceof AST_Binary && /^in/.test(p.operator) && p.left === self)
+        if (p instanceof AST_Binary && /^in/.test(p.operator) && p.left === this)
             output.print(" ");
     });
 
     function force_statement(stat, output) {
-        if (output.option("braces")) {
+        if (output.option("braces") && !(stat instanceof AST_Const || stat instanceof AST_Let)) {
             make_block(stat, output);
+        } else if (!stat || stat instanceof AST_EmptyStatement) {
+            output.force_semicolon();
         } else {
-            if (!stat || stat instanceof AST_EmptyStatement)
-                output.force_semicolon();
-            else
-                stat.print(output);
+            stat.print(output);
         }
     }
 
@@ -1498,14 +1497,7 @@ function OutputStream(options) {
         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);
+        if (typeof this.key == "string") output.add_mapping(this.start, this.key);
     });
 })();

lib/parse.js

@@ -44,21 +44,23 @@
 
 "use strict";
 
-var KEYWORDS = 'break case catch const continue debugger default delete do else finally for function if in instanceof new return switch throw try typeof var void while with';
-var KEYWORDS_ATOM = 'false null true';
-var RESERVED_WORDS = 'abstract boolean byte char class double enum export extends final float goto implements import int interface let long native package private protected public short static super synchronized this throws transient volatile yield'
-    + " " + KEYWORDS_ATOM + " " + KEYWORDS;
-var KEYWORDS_BEFORE_EXPRESSION = 'return new delete throw else case';
+var KEYWORDS = "break case catch const continue debugger default delete do else finally for function if in instanceof let new return switch throw try typeof var void while with";
+var KEYWORDS_ATOM = "false null true";
+var RESERVED_WORDS = [
+    "abstract boolean byte char class double enum export extends final float goto implements import int interface let long native package private protected public short static super synchronized this throws transient volatile yield",
+    KEYWORDS_ATOM,
+    KEYWORDS,
+].join(" ");
+var KEYWORDS_BEFORE_EXPRESSION = "return new delete throw else case";
 
 KEYWORDS = makePredicate(KEYWORDS);
 RESERVED_WORDS = makePredicate(RESERVED_WORDS);
 KEYWORDS_BEFORE_EXPRESSION = makePredicate(KEYWORDS_BEFORE_EXPRESSION);
 KEYWORDS_ATOM = makePredicate(KEYWORDS_ATOM);
 
-var OPERATOR_CHARS = makePredicate(characters("+-*&%=<>!?|~^"));
-
-var RE_HEX_NUMBER = /^0x[0-9a-f]+$/i;
-var RE_OCT_NUMBER = /^0[0-7]+$/;
+var RE_BIN_NUMBER = /^0b([01]+)$/i;
+var RE_HEX_NUMBER = /^0x([0-9a-f]+)$/i;
+var RE_OCT_NUMBER = /^0o?([0-7]+)$/i;
 
 var OPERATORS = makePredicate([
     "in",
@@ -107,31 +109,21 @@ var OPERATORS = makePredicate([
     "||"
 ]);
 
-var WHITESPACE_CHARS = makePredicate(characters(" \u00a0\n\r\t\f\u000b\u200b\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u2028\u2029\u202f\u205f\u3000\uFEFF"));
+var NEWLINE_CHARS = "\n\r\u2028\u2029";
+var OPERATOR_CHARS = "+-*&%=<>!?|~^";
+var PUNC_BEFORE_EXPRESSION = "[{(,;:";
+var PUNC_CHARS = PUNC_BEFORE_EXPRESSION + ")}]";
+var WHITESPACE_CHARS = NEWLINE_CHARS + " \u00a0\t\f\u000b\u200b\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u202f\u205f\u3000\uFEFF";
+var NON_IDENTIFIER_CHARS = makePredicate(characters("./'\"" + OPERATOR_CHARS + PUNC_CHARS + WHITESPACE_CHARS));
 
-var NEWLINE_CHARS = makePredicate(characters("\n\r\u2028\u2029"));
-
-var PUNC_BEFORE_EXPRESSION = makePredicate(characters("[{(,;:"));
-
-var PUNC_CHARS = makePredicate(characters("[]{}(),;:"));
+NEWLINE_CHARS = makePredicate(characters(NEWLINE_CHARS));
+OPERATOR_CHARS = makePredicate(characters(OPERATOR_CHARS));
+PUNC_BEFORE_EXPRESSION = makePredicate(characters(PUNC_BEFORE_EXPRESSION));
+PUNC_CHARS = makePredicate(characters(PUNC_CHARS));
+WHITESPACE_CHARS = makePredicate(characters(WHITESPACE_CHARS));
 
 /* -----[ Tokenizer ]----- */
 
-// regexps adapted from http://xregexp.com/plugins/#unicode
-var UNICODE = {
-    letter: new RegExp("[\\u0041-\\u005A\\u0061-\\u007A\\u00AA\\u00B5\\u00BA\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u02C1\\u02C6-\\u02D1\\u02E0-\\u02E4\\u02EC\\u02EE\\u0370-\\u0374\\u0376\\u0377\\u037A-\\u037D\\u037F\\u0386\\u0388-\\u038A\\u038C\\u038E-\\u03A1\\u03A3-\\u03F5\\u03F7-\\u0481\\u048A-\\u052F\\u0531-\\u0556\\u0559\\u0561-\\u0587\\u05D0-\\u05EA\\u05F0-\\u05F2\\u0620-\\u064A\\u066E\\u066F\\u0671-\\u06D3\\u06D5\\u06E5\\u06E6\\u06EE\\u06EF\\u06FA-\\u06FC\\u06FF\\u0710\\u0712-\\u072F\\u074D-\\u07A5\\u07B1\\u07CA-\\u07EA\\u07F4\\u07F5\\u07FA\\u0800-\\u0815\\u081A\\u0824\\u0828\\u0840-\\u0858\\u08A0-\\u08B2\\u0904-\\u0939\\u093D\\u0950\\u0958-\\u0961\\u0971-\\u0980\\u0985-\\u098C\\u098F\\u0990\\u0993-\\u09A8\\u09AA-\\u09B0\\u09B2\\u09B6-\\u09B9\\u09BD\\u09CE\\u09DC\\u09DD\\u09DF-\\u09E1\\u09F0\\u09F1\\u0A05-\\u0A0A\\u0A0F\\u0A10\\u0A13-\\u0A28\\u0A2A-\\u0A30\\u0A32\\u0A33\\u0A35\\u0A36\\u0A38\\u0A39\\u0A59-\\u0A5C\\u0A5E\\u0A72-\\u0A74\\u0A85-\\u0A8D\\u0A8F-\\u0A91\\u0A93-\\u0AA8\\u0AAA-\\u0AB0\\u0AB2\\u0AB3\\u0AB5-\\u0AB9\\u0ABD\\u0AD0\\u0AE0\\u0AE1\\u0B05-\\u0B0C\\u0B0F\\u0B10\\u0B13-\\u0B28\\u0B2A-\\u0B30\\u0B32\\u0B33\\u0B35-\\u0B39\\u0B3D\\u0B5C\\u0B5D\\u0B5F-\\u0B61\\u0B71\\u0B83\\u0B85-\\u0B8A\\u0B8E-\\u0B90\\u0B92-\\u0B95\\u0B99\\u0B9A\\u0B9C\\u0B9E\\u0B9F\\u0BA3\\u0BA4\\u0BA8-\\u0BAA\\u0BAE-\\u0BB9\\u0BD0\\u0C05-\\u0C0C\\u0C0E-\\u0C10\\u0C12-\\u0C28\\u0C2A-\\u0C39\\u0C3D\\u0C58\\u0C59\\u0C60\\u0C61\\u0C85-\\u0C8C\\u0C8E-\\u0C90\\u0C92-\\u0CA8\\u0CAA-\\u0CB3\\u0CB5-\\u0CB9\\u0CBD\\u0CDE\\u0CE0\\u0CE1\\u0CF1\\u0CF2\\u0D05-\\u0D0C\\u0D0E-\\u0D10\\u0D12-\\u0D3A\\u0D3D\\u0D4E\\u0D60\\u0D61\\u0D7A-\\u0D7F\\u0D85-\\u0D96\\u0D9A-\\u0DB1\\u0DB3-\\u0DBB\\u0DBD\\u0DC0-\\u0DC6\\u0E01-\\u0E30\\u0E32\\u0E33\\u0E40-\\u0E46\\u0E81\\u0E82\\u0E84\\u0E87\\u0E88\\u0E8A\\u0E8D\\u0E94-\\u0E97\\u0E99-\\u0E9F\\u0EA1-\\u0EA3\\u0EA5\\u0EA7\\u0EAA\\u0EAB\\u0EAD-\\u0EB0\\u0EB2\\u0EB3\\u0EBD\\u0EC0-\\u0EC4\\u0EC6\\u0EDC-\\u0EDF\\u0F00\\u0F40-\\u0F47\\u0F49-\\u0F6C\\u0F88-\\u0F8C\\u1000-\\u102A\\u103F\\u1050-\\u1055\\u105A-\\u105D\\u1061\\u1065\\u1066\\u106E-\\u1070\\u1075-\\u1081\\u108E\\u10A0-\\u10C5\\u10C7\\u10CD\\u10D0-\\u10FA\\u10FC-\\u1248\\u124A-\\u124D\\u1250-\\u1256\\u1258\\u125A-\\u125D\\u1260-\\u1288\\u128A-\\u128D\\u1290-\\u12B0\\u12B2-\\u12B5\\u12B8-\\u12BE\\u12C0\\u12C2-\\u12C5\\u12C8-\\u12D6\\u12D8-\\u1310\\u1312-\\u1315\\u1318-\\u135A\\u1380-\\u138F\\u13A0-\\u13F4\\u1401-\\u166C\\u166F-\\u167F\\u1681-\\u169A\\u16A0-\\u16EA\\u16EE-\\u16F8\\u1700-\\u170C\\u170E-\\u1711\\u1720-\\u1731\\u1740-\\u1751\\u1760-\\u176C\\u176E-\\u1770\\u1780-\\u17B3\\u17D7\\u17DC\\u1820-\\u1877\\u1880-\\u18A8\\u18AA\\u18B0-\\u18F5\\u1900-\\u191E\\u1950-\\u196D\\u1970-\\u1974\\u1980-\\u19AB\\u19C1-\\u19C7\\u1A00-\\u1A16\\u1A20-\\u1A54\\u1AA7\\u1B05-\\u1B33\\u1B45-\\u1B4B\\u1B83-\\u1BA0\\u1BAE\\u1BAF\\u1BBA-\\u1BE5\\u1C00-\\u1C23\\u1C4D-\\u1C4F\\u1C5A-\\u1C7D\\u1CE9-\\u1CEC\\u1CEE-\\u1CF1\\u1CF5\\u1CF6\\u1D00-\\u1DBF\\u1E00-\\u1F15\\u1F18-\\u1F1D\\u1F20-\\u1F45\\u1F48-\\u1F4D\\u1F50-\\u1F57\\u1F59\\u1F5B\\u1F5D\\u1F5F-\\u1F7D\\u1F80-\\u1FB4\\u1FB6-\\u1FBC\\u1FBE\\u1FC2-\\u1FC4\\u1FC6-\\u1FCC\\u1FD0-\\u1FD3\\u1FD6-\\u1FDB\\u1FE0-\\u1FEC\\u1FF2-\\u1FF4\\u1FF6-\\u1FFC\\u2071\\u207F\\u2090-\\u209C\\u2102\\u2107\\u210A-\\u2113\\u2115\\u2119-\\u211D\\u2124\\u2126\\u2128\\u212A-\\u212D\\u212F-\\u2139\\u213C-\\u213F\\u2145-\\u2149\\u214E\\u2160-\\u2188\\u2C00-\\u2C2E\\u2C30-\\u2C5E\\u2C60-\\u2CE4\\u2CEB-\\u2CEE\\u2CF2\\u2CF3\\u2D00-\\u2D25\\u2D27\\u2D2D\\u2D30-\\u2D67\\u2D6F\\u2D80-\\u2D96\\u2DA0-\\u2DA6\\u2DA8-\\u2DAE\\u2DB0-\\u2DB6\\u2DB8-\\u2DBE\\u2DC0-\\u2DC6\\u2DC8-\\u2DCE\\u2DD0-\\u2DD6\\u2DD8-\\u2DDE\\u2E2F\\u3005-\\u3007\\u3021-\\u3029\\u3031-\\u3035\\u3038-\\u303C\\u3041-\\u3096\\u309D-\\u309F\\u30A1-\\u30FA\\u30FC-\\u30FF\\u3105-\\u312D\\u3131-\\u318E\\u31A0-\\u31BA\\u31F0-\\u31FF\\u3400-\\u4DB5\\u4E00-\\u9FCC\\uA000-\\uA48C\\uA4D0-\\uA4FD\\uA500-\\uA60C\\uA610-\\uA61F\\uA62A\\uA62B\\uA640-\\uA66E\\uA67F-\\uA69D\\uA6A0-\\uA6EF\\uA717-\\uA71F\\uA722-\\uA788\\uA78B-\\uA78E\\uA790-\\uA7AD\\uA7B0\\uA7B1\\uA7F7-\\uA801\\uA803-\\uA805\\uA807-\\uA80A\\uA80C-\\uA822\\uA840-\\uA873\\uA882-\\uA8B3\\uA8F2-\\uA8F7\\uA8FB\\uA90A-\\uA925\\uA930-\\uA946\\uA960-\\uA97C\\uA984-\\uA9B2\\uA9CF\\uA9E0-\\uA9E4\\uA9E6-\\uA9EF\\uA9FA-\\uA9FE\\uAA00-\\uAA28\\uAA40-\\uAA42\\uAA44-\\uAA4B\\uAA60-\\uAA76\\uAA7A\\uAA7E-\\uAAAF\\uAAB1\\uAAB5\\uAAB6\\uAAB9-\\uAABD\\uAAC0\\uAAC2\\uAADB-\\uAADD\\uAAE0-\\uAAEA\\uAAF2-\\uAAF4\\uAB01-\\uAB06\\uAB09-\\uAB0E\\uAB11-\\uAB16\\uAB20-\\uAB26\\uAB28-\\uAB2E\\uAB30-\\uAB5A\\uAB5C-\\uAB5F\\uAB64\\uAB65\\uABC0-\\uABE2\\uAC00-\\uD7A3\\uD7B0-\\uD7C6\\uD7CB-\\uD7FB\\uF900-\\uFA6D\\uFA70-\\uFAD9\\uFB00-\\uFB06\\uFB13-\\uFB17\\uFB1D\\uFB1F-\\uFB28\\uFB2A-\\uFB36\\uFB38-\\uFB3C\\uFB3E\\uFB40\\uFB41\\uFB43\\uFB44\\uFB46-\\uFBB1\\uFBD3-\\uFD3D\\uFD50-\\uFD8F\\uFD92-\\uFDC7\\uFDF0-\\uFDFB\\uFE70-\\uFE74\\uFE76-\\uFEFC\\uFF21-\\uFF3A\\uFF41-\\uFF5A\\uFF66-\\uFFBE\\uFFC2-\\uFFC7\\uFFCA-\\uFFCF\\uFFD2-\\uFFD7\\uFFDA-\\uFFDC]"),
-    digit: new RegExp("[\\u0030-\\u0039\\u0660-\\u0669\\u06F0-\\u06F9\\u07C0-\\u07C9\\u0966-\\u096F\\u09E6-\\u09EF\\u0A66-\\u0A6F\\u0AE6-\\u0AEF\\u0B66-\\u0B6F\\u0BE6-\\u0BEF\\u0C66-\\u0C6F\\u0CE6-\\u0CEF\\u0D66-\\u0D6F\\u0DE6-\\u0DEF\\u0E50-\\u0E59\\u0ED0-\\u0ED9\\u0F20-\\u0F29\\u1040-\\u1049\\u1090-\\u1099\\u17E0-\\u17E9\\u1810-\\u1819\\u1946-\\u194F\\u19D0-\\u19D9\\u1A80-\\u1A89\\u1A90-\\u1A99\\u1B50-\\u1B59\\u1BB0-\\u1BB9\\u1C40-\\u1C49\\u1C50-\\u1C59\\uA620-\\uA629\\uA8D0-\\uA8D9\\uA900-\\uA909\\uA9D0-\\uA9D9\\uA9F0-\\uA9F9\\uAA50-\\uAA59\\uABF0-\\uABF9\\uFF10-\\uFF19]"),
-    non_spacing_mark: new RegExp("[\\u0300-\\u036F\\u0483-\\u0487\\u0591-\\u05BD\\u05BF\\u05C1\\u05C2\\u05C4\\u05C5\\u05C7\\u0610-\\u061A\\u064B-\\u065E\\u0670\\u06D6-\\u06DC\\u06DF-\\u06E4\\u06E7\\u06E8\\u06EA-\\u06ED\\u0711\\u0730-\\u074A\\u07A6-\\u07B0\\u07EB-\\u07F3\\u0816-\\u0819\\u081B-\\u0823\\u0825-\\u0827\\u0829-\\u082D\\u0900-\\u0902\\u093C\\u0941-\\u0948\\u094D\\u0951-\\u0955\\u0962\\u0963\\u0981\\u09BC\\u09C1-\\u09C4\\u09CD\\u09E2\\u09E3\\u0A01\\u0A02\\u0A3C\\u0A41\\u0A42\\u0A47\\u0A48\\u0A4B-\\u0A4D\\u0A51\\u0A70\\u0A71\\u0A75\\u0A81\\u0A82\\u0ABC\\u0AC1-\\u0AC5\\u0AC7\\u0AC8\\u0ACD\\u0AE2\\u0AE3\\u0B01\\u0B3C\\u0B3F\\u0B41-\\u0B44\\u0B4D\\u0B56\\u0B62\\u0B63\\u0B82\\u0BC0\\u0BCD\\u0C3E-\\u0C40\\u0C46-\\u0C48\\u0C4A-\\u0C4D\\u0C55\\u0C56\\u0C62\\u0C63\\u0CBC\\u0CBF\\u0CC6\\u0CCC\\u0CCD\\u0CE2\\u0CE3\\u0D41-\\u0D44\\u0D4D\\u0D62\\u0D63\\u0DCA\\u0DD2-\\u0DD4\\u0DD6\\u0E31\\u0E34-\\u0E3A\\u0E47-\\u0E4E\\u0EB1\\u0EB4-\\u0EB9\\u0EBB\\u0EBC\\u0EC8-\\u0ECD\\u0F18\\u0F19\\u0F35\\u0F37\\u0F39\\u0F71-\\u0F7E\\u0F80-\\u0F84\\u0F86\\u0F87\\u0F90-\\u0F97\\u0F99-\\u0FBC\\u0FC6\\u102D-\\u1030\\u1032-\\u1037\\u1039\\u103A\\u103D\\u103E\\u1058\\u1059\\u105E-\\u1060\\u1071-\\u1074\\u1082\\u1085\\u1086\\u108D\\u109D\\u135F\\u1712-\\u1714\\u1732-\\u1734\\u1752\\u1753\\u1772\\u1773\\u17B7-\\u17BD\\u17C6\\u17C9-\\u17D3\\u17DD\\u180B-\\u180D\\u18A9\\u1920-\\u1922\\u1927\\u1928\\u1932\\u1939-\\u193B\\u1A17\\u1A18\\u1A56\\u1A58-\\u1A5E\\u1A60\\u1A62\\u1A65-\\u1A6C\\u1A73-\\u1A7C\\u1A7F\\u1B00-\\u1B03\\u1B34\\u1B36-\\u1B3A\\u1B3C\\u1B42\\u1B6B-\\u1B73\\u1B80\\u1B81\\u1BA2-\\u1BA5\\u1BA8\\u1BA9\\u1C2C-\\u1C33\\u1C36\\u1C37\\u1CD0-\\u1CD2\\u1CD4-\\u1CE0\\u1CE2-\\u1CE8\\u1CED\\u1DC0-\\u1DE6\\u1DFD-\\u1DFF\\u20D0-\\u20DC\\u20E1\\u20E5-\\u20F0\\u2CEF-\\u2CF1\\u2DE0-\\u2DFF\\u302A-\\u302F\\u3099\\u309A\\uA66F\\uA67C\\uA67D\\uA6F0\\uA6F1\\uA802\\uA806\\uA80B\\uA825\\uA826\\uA8C4\\uA8E0-\\uA8F1\\uA926-\\uA92D\\uA947-\\uA951\\uA980-\\uA982\\uA9B3\\uA9B6-\\uA9B9\\uA9BC\\uAA29-\\uAA2E\\uAA31\\uAA32\\uAA35\\uAA36\\uAA43\\uAA4C\\uAAB0\\uAAB2-\\uAAB4\\uAAB7\\uAAB8\\uAABE\\uAABF\\uAAC1\\uABE5\\uABE8\\uABED\\uFB1E\\uFE00-\\uFE0F\\uFE20-\\uFE26]"),
-    space_combining_mark: new RegExp("[\\u0903\\u093E-\\u0940\\u0949-\\u094C\\u094E\\u0982\\u0983\\u09BE-\\u09C0\\u09C7\\u09C8\\u09CB\\u09CC\\u09D7\\u0A03\\u0A3E-\\u0A40\\u0A83\\u0ABE-\\u0AC0\\u0AC9\\u0ACB\\u0ACC\\u0B02\\u0B03\\u0B3E\\u0B40\\u0B47\\u0B48\\u0B4B\\u0B4C\\u0B57\\u0BBE\\u0BBF\\u0BC1\\u0BC2\\u0BC6-\\u0BC8\\u0BCA-\\u0BCC\\u0BD7\\u0C01-\\u0C03\\u0C41-\\u0C44\\u0C82\\u0C83\\u0CBE\\u0CC0-\\u0CC4\\u0CC7\\u0CC8\\u0CCA\\u0CCB\\u0CD5\\u0CD6\\u0D02\\u0D03\\u0D3E-\\u0D40\\u0D46-\\u0D48\\u0D4A-\\u0D4C\\u0D57\\u0D82\\u0D83\\u0DCF-\\u0DD1\\u0DD8-\\u0DDF\\u0DF2\\u0DF3\\u0F3E\\u0F3F\\u0F7F\\u102B\\u102C\\u1031\\u1038\\u103B\\u103C\\u1056\\u1057\\u1062-\\u1064\\u1067-\\u106D\\u1083\\u1084\\u1087-\\u108C\\u108F\\u109A-\\u109C\\u17B6\\u17BE-\\u17C5\\u17C7\\u17C8\\u1923-\\u1926\\u1929-\\u192B\\u1930\\u1931\\u1933-\\u1938\\u19B0-\\u19C0\\u19C8\\u19C9\\u1A19-\\u1A1B\\u1A55\\u1A57\\u1A61\\u1A63\\u1A64\\u1A6D-\\u1A72\\u1B04\\u1B35\\u1B3B\\u1B3D-\\u1B41\\u1B43\\u1B44\\u1B82\\u1BA1\\u1BA6\\u1BA7\\u1BAA\\u1C24-\\u1C2B\\u1C34\\u1C35\\u1CE1\\u1CF2\\uA823\\uA824\\uA827\\uA880\\uA881\\uA8B4-\\uA8C3\\uA952\\uA953\\uA983\\uA9B4\\uA9B5\\uA9BA\\uA9BB\\uA9BD-\\uA9C0\\uAA2F\\uAA30\\uAA33\\uAA34\\uAA4D\\uAA7B\\uABE3\\uABE4\\uABE6\\uABE7\\uABE9\\uABEA\\uABEC]"),
-    connector_punctuation: new RegExp("[\\u005F\\u203F\\u2040\\u2054\\uFE33\\uFE34\\uFE4D-\\uFE4F\\uFF3F]")
-};
-
-function is_letter(code) {
-    return (code >= 97 && code <= 122)
-        || (code >= 65 && code <= 90)
-        || (code >= 0xaa && UNICODE.letter.test(String.fromCharCode(code)));
-}
-
 function is_surrogate_pair_head(code) {
     return code >= 0xd800 && code <= 0xdbff;
 }
@@ -144,36 +136,8 @@ function is_digit(code) {
     return code >= 48 && code <= 57;
 }
 
-function is_alphanumeric_char(code) {
-    return is_digit(code) || is_letter(code);
-}
-
-function is_unicode_digit(code) {
-    return UNICODE.digit.test(String.fromCharCode(code));
-}
-
-function is_unicode_combining_mark(ch) {
-    return UNICODE.non_spacing_mark.test(ch) || UNICODE.space_combining_mark.test(ch);
-}
-
-function is_unicode_connector_punctuation(ch) {
-    return UNICODE.connector_punctuation.test(ch);
-}
-
-function is_identifier_start(code) {
-    return code == 36 || code == 95 || is_letter(code);
-}
-
 function is_identifier_char(ch) {
-    var code = ch.charCodeAt(0);
-    return is_identifier_start(code)
-        || is_digit(code)
-        || code == 8204 // \u200c: zero-width non-joiner <ZWNJ>
-        || code == 8205 // \u200d: zero-width joiner <ZWJ> (in my ECMA-262 PDF, this is also 200c)
-        || is_unicode_combining_mark(ch)
-        || is_unicode_connector_punctuation(ch)
-        || is_unicode_digit(code)
-    ;
+    return !NON_IDENTIFIER_CHARS[ch];
 }
 
 function is_identifier_string(str) {
@@ -181,14 +145,12 @@ function is_identifier_string(str) {
 }
 
 function parse_js_number(num) {
-    if (RE_HEX_NUMBER.test(num)) {
-        return parseInt(num.substr(2), 16);
-    } else if (RE_OCT_NUMBER.test(num)) {
-        return parseInt(num.substr(1), 8);
-    } else {
-        var val = parseFloat(num);
-        if (val == num) return val;
-    }
+    var match;
+    if (match = RE_BIN_NUMBER.exec(num)) return parseInt(match[1], 2);
+    if (match = RE_HEX_NUMBER.exec(num)) return parseInt(match[1], 16);
+    if (match = RE_OCT_NUMBER.exec(num)) return parseInt(match[1], 8);
+    var val = parseFloat(num);
+    if (val == num) return val;
 }
 
 function JS_Parse_Error(message, filename, line, col, pos) {
@@ -344,11 +306,13 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
               case (after_e = false, 46): // .
                 return (!has_dot && !has_x && !has_e) ? (has_dot = true) : false;
             }
-            return is_alphanumeric_char(code);
+            return is_digit(code) || /[_0-9a-fo]/i.test(ch);
         });
         if (prefix) num = prefix + num;
-        if (RE_OCT_NUMBER.test(num) && next_token.has_directive("use strict")) {
-            parse_error("Legacy octal literals are not allowed in strict mode");
+        if (/^0[0-7_]+$/.test(num)) {
+            if (next_token.has_directive("use strict")) parse_error("Legacy octal literals are not allowed in strict mode");
+        } else {
+            num = num.replace(has_x ? /([1-9a-f]|.0)_(?=[0-9a-f])/gi : /([1-9]|.0)_(?=[0-9])/gi, "$1");
         }
         var valid = parse_js_number(num);
         if (!isNaN(valid)) return token("num", valid);
@@ -358,20 +322,30 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
     function read_escaped_char(in_string) {
         var ch = next(true, in_string);
         switch (ch.charCodeAt(0)) {
-          case 110 : return "\n";
-          case 114 : return "\r";
-          case 116 : return "\t";
-          case 98  : return "\b";
-          case 118 : return "\u000b"; // \v
-          case 102 : return "\f";
-          case 120 : return String.fromCharCode(hex_bytes(2)); // \x
-          case 117 : return String.fromCharCode(hex_bytes(4)); // \u
-          case 10  : return ""; // newline
-          case 13  :            // \r
-            if (peek() == "\n") { // DOS newline
-                next(true, in_string);
-                return "";
-            }
+          case 110: return "\n";
+          case 114: return "\r";
+          case 116: return "\t";
+          case 98:  return "\b";
+          case 118: return "\u000b";                            // \v
+          case 102: return "\f";
+          case 120: return String.fromCharCode(hex_bytes(2));   // \x
+          case 117:                                             // \u
+            if (peek() != "{") return String.fromCharCode(hex_bytes(4));
+            next();
+            var num = 0;
+            do {
+                var digit = parseInt(next(true), 16);
+                if (isNaN(digit)) parse_error("Invalid hex-character pattern in string");
+                num = num * 16 + digit;
+            } while (peek() != "}");
+            next();
+            if (num < 0x10000) return String.fromCharCode(num);
+            if (num > 0x10ffff) parse_error("Invalid character code: " + num);
+            return String.fromCharCode((num >> 10) + 0xd7c0) + String.fromCharCode((num & 0x03ff) + 0xdc00);
+          case 13:                                              // \r
+            // DOS newline
+            if (peek() == "\n") next(true, in_string);
+          case 10:  return "";                                  // \n
         }
         if (ch >= "0" && ch <= "7")
             return read_octal_escape_sequence(ch);
@@ -438,7 +412,7 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
     var skip_multiline_comment = with_eof_error("Unterminated multiline comment", function() {
         var regex_allowed = S.regex_allowed;
         var i = find("*/", true);
-        var text = S.text.substring(S.pos, i).replace(/\r\n|\r|\u2028|\u2029/g, '\n');
+        var text = S.text.substring(S.pos, i).replace(/\r\n|\r|\u2028|\u2029/g, "\n");
         // update stream position
         forward(text.length /* doesn't count \r\n as 2 char while S.pos - i does */ + 2);
         S.comments_before.push(token("comment2", text, true));
@@ -448,7 +422,7 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
 
     function read_name() {
         var backslash = false, name = "", ch, escaped = false, hex;
-        while ((ch = peek()) != null) {
+        while (ch = peek()) {
             if (!backslash) {
                 if (ch == "\\") escaped = backslash = true, next();
                 else if (is_identifier_char(ch)) name += next();
@@ -587,7 +561,7 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
             if (is_digit(code)) return read_num();
             if (PUNC_CHARS[ch]) return token("punc", next());
             if (OPERATOR_CHARS[ch]) return read_operator();
-            if (code == 92 || is_identifier_start(code)) return read_word();
+            if (code == 92 || !NON_IDENTIFIER_CHARS[ch]) return read_word();
             break;
         }
         parse_error("Unexpected character '" + ch + "'");
@@ -779,7 +753,7 @@ function parse($TEXT, options) {
         }
     }
 
-    var statement = embed_tokens(function(strict_defun) {
+    var statement = embed_tokens(function() {
         handle_regexp();
         switch (S.token.type) {
           case "string":
@@ -832,6 +806,12 @@ function parse($TEXT, options) {
                 next();
                 return break_cont(AST_Break);
 
+              case "const":
+                next();
+                var node = const_();
+                semicolon();
+                return node;
+
               case "continue":
                 next();
                 return break_cont(AST_Continue);
@@ -864,9 +844,6 @@ function parse($TEXT, options) {
                 return for_();
 
               case "function":
-                if (!strict_defun && S.input.has_directive("use strict")) {
-                    croak("In strict mode code, functions can only be declared at top level or immediately within another function.");
-                }
                 next();
                 return function_(AST_Defun);
 
@@ -874,6 +851,12 @@ function parse($TEXT, options) {
                 next();
                 return if_();
 
+              case "let":
+                next();
+                var node = let_();
+                semicolon();
+                return node;
+
               case "return":
                 if (S.in_function == 0 && !options.bare_returns)
                     croak("'return' outside of function");
@@ -988,7 +971,9 @@ function parse($TEXT, options) {
         expect("(");
         var init = null;
         if (!is("punc", ";")) {
-            init = is("keyword", "var")
+            init = is("keyword", "const")
+                ? (next(), const_(true))
+                : is("keyword", "var")
                 ? (next(), var_(true))
                 : expression(true, true);
             if (is("operator", "in")) {
@@ -1050,7 +1035,7 @@ function parse($TEXT, options) {
         S.input.push_directives_stack();
         S.in_loop = 0;
         S.labels = [];
-        var body = block_(true);
+        var body = block_();
         if (S.input.has_directive("use strict")) {
             if (name) strict_verify_symbol(name);
             argnames.forEach(strict_verify_symbol);
@@ -1079,12 +1064,12 @@ function parse($TEXT, options) {
         });
     }
 
-    function block_(strict_defun) {
+    function block_() {
         expect("{");
         var a = [];
         while (!is("punc", "}")) {
             if (is("eof")) expect_token("punc", "}");
-            a.push(statement(strict_defun));
+            a.push(statement());
         }
         next();
         return a;
@@ -1130,9 +1115,12 @@ function parse($TEXT, options) {
         if (is("keyword", "catch")) {
             var start = S.token;
             next();
-            expect("(");
-            var name = as_symbol(AST_SymbolCatch);
-            expect(")");
+            var name = null;
+            if (is("punc", "(")) {
+                next();
+                name = as_symbol(AST_SymbolCatch);
+                expect(")");
+            }
             bcatch = new AST_Catch({
                 start   : start,
                 argname : name,
@@ -1158,13 +1146,22 @@ function parse($TEXT, options) {
         });
     }
 
-    function vardefs(no_in) {
+    function vardefs(type, no_in, must_init) {
         var a = [];
         for (;;) {
+            var start = S.token;
+            var name = as_symbol(type);
+            var value = null;
+            if (is("operator", "=")) {
+                next();
+                value = expression(false, no_in);
+            } else if (must_init) {
+                croak("Missing initializer in declaration");
+            }
             a.push(new AST_VarDef({
-                start : S.token,
-                name  : as_symbol(AST_SymbolVar),
-                value : is("operator", "=") ? (next(), expression(false, no_in)) : null,
+                start : start,
+                name  : name,
+                value : value,
                 end   : prev()
             }));
             if (!is("punc", ","))
@@ -1174,10 +1171,26 @@ function parse($TEXT, options) {
         return a;
     }
 
+    var const_ = function(no_in) {
+        return new AST_Const({
+            start       : prev(),
+            definitions : vardefs(AST_SymbolConst, no_in, true),
+            end         : prev()
+        });
+    };
+
+    var let_ = function(no_in) {
+        return new AST_Let({
+            start       : prev(),
+            definitions : vardefs(AST_SymbolLet, no_in),
+            end         : prev()
+        });
+    };
+
     var var_ = function(no_in) {
         return new AST_Var({
             start       : prev(),
-            definitions : vardefs(no_in),
+            definitions : vardefs(AST_SymbolVar, no_in),
             end         : prev()
         });
     };
@@ -1206,7 +1219,7 @@ function parse($TEXT, options) {
         var tok = S.token, ret;
         switch (tok.type) {
           case "name":
-            ret = _make_symbol(AST_SymbolRef);
+            ret = _make_symbol(AST_SymbolRef, tok);
             break;
           case "num":
             ret = new AST_Number({ start: tok, end: tok, value: tok.value });
@@ -1324,51 +1337,62 @@ function parse($TEXT, options) {
         var first = true, a = [];
         while (!is("punc", "}")) {
             if (first) first = false; else expect(",");
-            if (!options.strict && is("punc", "}"))
-                // allow trailing comma
-                break;
+            // allow trailing comma
+            if (!options.strict && is("punc", "}")) break;
             var start = S.token;
-            var type = start.type;
-            var name = as_property_name();
-            if (type == "name" && !is("punc", ":")) {
-                var key = new AST_SymbolAccessor({
-                    start: S.token,
-                    name: "" + as_property_name(),
-                    end: prev()
-                });
-                if (name == "get") {
-                    a.push(new AST_ObjectGetter({
-                        start : start,
-                        key   : key,
-                        value : create_accessor(),
-                        end   : prev()
-                    }));
-                    continue;
-                }
-                if (name == "set") {
-                    a.push(new AST_ObjectSetter({
-                        start : start,
-                        key   : key,
-                        value : create_accessor(),
-                        end   : prev()
-                    }));
-                    continue;
-                }
+            var key = as_property_key();
+            if (is("punc", "(")) {
+                var func_start = S.token;
+                var func = function_(AST_Function);
+                func.start = func_start;
+                func.end = prev();
+                a.push(new AST_ObjectKeyVal({
+                    start: start,
+                    key: key,
+                    value: func,
+                    end: prev(),
+                }));
+                continue;
+            }
+            if (!is("punc", ":") && start.type == "name") switch (key) {
+              case "get":
+                a.push(new AST_ObjectGetter({
+                    start: start,
+                    key: as_property_key(),
+                    value: create_accessor(),
+                    end: prev(),
+                }));
+                continue;
+              case "set":
+                a.push(new AST_ObjectSetter({
+                    start: start,
+                    key: as_property_key(),
+                    value: create_accessor(),
+                    end: prev(),
+                }));
+                continue;
+              default:
+                a.push(new AST_ObjectKeyVal({
+                    start: start,
+                    key: key,
+                    value: _make_symbol(AST_SymbolRef, start),
+                    end: prev(),
+                }));
+                continue;
             }
             expect(":");
             a.push(new AST_ObjectKeyVal({
-                start : start,
-                quote : start.quote,
-                key   : "" + name,
-                value : expression(false),
-                end   : prev()
+                start: start,
+                key: key,
+                value: expression(false),
+                end: prev(),
             }));
         }
         next();
         return new AST_Object({ properties: a });
     });
 
-    function as_property_name() {
+    function as_property_key() {
         var tmp = S.token;
         switch (tmp.type) {
           case "operator":
@@ -1379,7 +1403,13 @@ function parse($TEXT, options) {
           case "keyword":
           case "atom":
             next();
-            return tmp.value;
+            return "" + tmp.value;
+          case "punc":
+            if (tmp.value != "[") unexpected();
+            next();
+            var key = expression(false);
+            expect("]");
+            return key;
           default:
             unexpected();
         }
@@ -1392,12 +1422,12 @@ function parse($TEXT, options) {
         return name;
     }
 
-    function _make_symbol(type) {
-        var name = S.token.value;
-        return new (name == "this" ? AST_This : type)({
-            name  : String(name),
-            start : S.token,
-            end   : S.token
+    function _make_symbol(type, token) {
+        var name = token.value;
+        return new (name === "this" ? AST_This : type)({
+            name: "" + name,
+            start: token,
+            end: token,
         });
     }
 
@@ -1411,7 +1441,7 @@ function parse($TEXT, options) {
             if (!noerror) croak("Name expected");
             return null;
         }
-        var sym = _make_symbol(type);
+        var sym = _make_symbol(type, S.token);
         if (S.input.has_directive("use strict") && sym instanceof AST_SymbolDeclaration) {
             strict_verify_symbol(sym);
         }
@@ -1600,7 +1630,7 @@ function parse($TEXT, options) {
         var body = [];
         S.input.push_directives_stack();
         while (!is("eof"))
-            body.push(statement(true));
+            body.push(statement());
         S.input.pop_directives_stack();
         var end = prev();
         var toplevel = options.toplevel;

lib/propmangle.js

@@ -81,8 +81,8 @@ var builtins = function() {
 
 function reserve_quoted_keys(ast, reserved) {
     ast.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_ObjectKeyVal) {
-            if (node.quote) add(node.key);
+        if (node instanceof AST_ObjectProperty) {
+            if (node.start && node.start.quote) add(node.key);
         } else if (node instanceof AST_Sub) {
             addStrings(node.property, add);
         }
@@ -110,7 +110,6 @@ function mangle_properties(ast, options) {
         cache: null,
         debug: false,
         keep_quoted: false,
-        only_cache: false,
         regex: null,
         reserved: null,
     }, true);
@@ -166,11 +165,8 @@ function mangle_properties(ast, options) {
             }
         } else if (node instanceof AST_Dot) {
             add(node.property);
-        } else if (node instanceof AST_ObjectKeyVal) {
-            add(node.key);
         } else if (node instanceof AST_ObjectProperty) {
-            // setter or getter, since KeyVal is handled above
-            add(node.key.name);
+            if (typeof node.key == "string") add(node.key);
         } else if (node instanceof AST_Sub) {
             addStrings(node.property, add);
         }
@@ -199,11 +195,8 @@ function mangle_properties(ast, options) {
             }
         } else if (node instanceof AST_Dot) {
             node.property = mangle(node.property);
-        } else if (node instanceof AST_ObjectKeyVal) {
-            node.key = mangle(node.key);
         } else if (node instanceof AST_ObjectProperty) {
-            // setter or getter
-            node.key.name = mangle(node.key.name);
+            if (typeof node.key == "string") node.key = mangle(node.key);
         } else if (node instanceof AST_Sub) {
             if (!options.keep_quoted) mangleStrings(node.property);
         }
@@ -213,7 +206,6 @@ function mangle_properties(ast, options) {
 
     function can_mangle(name) {
         if (unmangleable[name]) return false;
-        if (options.only_cache) return cache.has(name);
         if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
         return true;
     }

lib/scope.js

@@ -59,21 +59,17 @@ function SymbolDef(id, scope, orig, init) {
 }
 
 SymbolDef.prototype = {
-    unmangleable: function(options) {
-        return this.global && !options.toplevel
-            || this.undeclared
-            || !options.eval && this.scope.pinned()
-            || options.keep_fnames
-                && (this.orig[0] instanceof AST_SymbolLambda
-                    || this.orig[0] instanceof AST_SymbolDefun);
+    forEach: function(fn) {
+        this.orig.forEach(fn);
+        this.references.forEach(fn);
     },
     mangle: function(options) {
         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 def;
-            if (def = this.redefined()) {
+            var def = this.redefined();
+            if (def) {
                 this.mangled_name = def.mangled_name || def.name;
             } else {
                 this.mangled_name = next_mangled_name(this.scope, options, this);
@@ -84,8 +80,24 @@ SymbolDef.prototype = {
         }
     },
     redefined: function() {
-        return this.defun && this.defun.variables.get(this.name);
-    }
+        var scope = this.defun;
+        if (!scope) return;
+        var name = this.name;
+        var def = scope.variables.get(name)
+            || scope instanceof AST_Toplevel && scope.globals.get(name)
+            || this.orig[0] instanceof AST_SymbolConst && find_if(function(def) {
+                return def.name == name;
+            }, scope.enclosed);
+        if (def && def !== this) return def.redefined() || def;
+    },
+    unmangleable: function(options) {
+        return this.global && !options.toplevel
+            || this.undeclared
+            || !options.eval && this.scope.pinned()
+            || options.keep_fnames
+                && (this.orig[0] instanceof AST_SymbolLambda
+                    || this.orig[0] instanceof AST_SymbolDefun);
+    },
 };
 
 AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
@@ -96,30 +108,46 @@ 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 defun = null;
+    var next_def_id = 0;
+    var scope = self.parent_scope = null;
     var tw = new TreeWalker(function(node, descend) {
-        if (node instanceof AST_Catch) {
-            var save_scope = scope;
-            scope = new AST_Scope(node);
-            scope.init_scope_vars(save_scope);
-            descend();
-            scope = save_scope;
+        if (node instanceof AST_Defun) {
+            node.name.walk(tw);
+            walk_scope(function() {
+                node.argnames.forEach(function(argname) {
+                    argname.walk(tw);
+                });
+                walk_body(node, tw);
+            });
             return true;
         }
-        if (node instanceof AST_Scope) {
-            node.init_scope_vars(scope);
-            var save_scope = scope;
-            var save_defun = defun;
-            defun = scope = node;
+        if (node instanceof AST_SwitchBranch) {
+            node.init_vars(scope);
             descend();
-            scope = save_scope;
-            defun = save_defun;
+            return true;
+        }
+        if (node instanceof AST_Try) {
+            walk_scope(function() {
+                walk_body(node, tw);
+            });
+            if (node.bcatch) node.bcatch.walk(tw);
+            if (node.bfinally) node.bfinally.walk(tw);
             return true;
         }
         if (node instanceof AST_With) {
-            for (var s = scope; s; s = s.parent_scope) s.uses_with = true;
-            return;
+            var s = scope;
+            do {
+                s = s.resolve();
+                if (s.uses_with) break;
+                s.uses_with = true;
+            } while (s = s.parent_scope);
+            walk_scope(descend);
+            return true;
+        }
+        if (node instanceof AST_BlockScope) {
+            walk_scope(descend);
+            return true;
         }
         if (node instanceof AST_Symbol) {
             node.scope = scope;
@@ -128,28 +156,50 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             node.thedef = node;
             node.references = [];
         }
-        if (node instanceof AST_SymbolDefun) {
-            // This should be defined in the parent scope, as we encounter the
-            // AST_Defun node before getting to its AST_Symbol.
-            (node.scope = defun.parent_scope.resolve()).def_function(node, defun);
+        if (node instanceof AST_SymbolCatch) {
+            scope.def_variable(node).defun = defun;
+        } else if (node instanceof AST_SymbolConst) {
+            scope.def_variable(node).defun = defun;
+        } else if (node instanceof AST_SymbolDefun) {
+            defun.def_function(node, tw.parent());
+            entangle(defun, scope);
+        } else if (node instanceof AST_SymbolFunarg) {
+            defun.def_variable(node);
+            entangle(defun, scope);
         } else if (node instanceof AST_SymbolLambda) {
             var def = defun.def_function(node, node.name == "arguments" ? undefined : defun);
             if (options.ie8) def.defun = defun.parent_scope.resolve();
+        } else if (node instanceof AST_SymbolLet) {
+            scope.def_variable(node);
         } else if (node instanceof AST_SymbolVar) {
-            defun.def_variable(node, node.TYPE == "SymbolVar" ? null : undefined);
-            if (defun !== scope) {
-                node.mark_enclosed(options);
-                var def = scope.find_variable(node);
-                if (node.thedef !== def) {
-                    node.thedef = def;
-                }
-                node.reference(options);
-            }
-        } else if (node instanceof AST_SymbolCatch) {
-            scope.def_variable(node).defun = defun;
+            defun.def_variable(node, null);
+            entangle(defun, scope);
+        }
+
+        function walk_scope(descend) {
+            node.init_vars(scope);
+            var save_defun = defun;
+            var save_scope = scope;
+            if (node instanceof AST_Scope) defun = node;
+            scope = node;
+            descend();
+            scope = save_scope;
+            defun = save_defun;
+        }
+
+        function entangle(defun, scope) {
+            if (defun === scope) return;
+            node.mark_enclosed(options);
+            var def = scope.find_variable(node);
+            if (node.thedef === def) return;
+            node.thedef = def;
+            def.orig.push(node);
+            node.mark_enclosed(options);
         }
     });
-    self.next_def_id = 0;
+    self.make_def = function(orig, init) {
+        return new SymbolDef(++next_def_id, this, orig, init);
+    };
     self.walk(tw);
 
     // pass 2: find back references and eval
@@ -164,15 +214,18 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             var sym = node.scope.find_variable(name);
             if (!sym) {
                 sym = self.def_global(node);
-            } else if (sym.scope instanceof AST_Lambda && name == "arguments") {
+            } else if (name == "arguments" && sym.scope instanceof AST_Lambda) {
                 sym.scope.uses_arguments = true;
             }
             if (name == "eval") {
                 var parent = tw.parent();
                 if (parent.TYPE == "Call" && parent.expression === node) {
-                    for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) {
+                    var s = node.scope;
+                    do {
+                        s = s.resolve();
+                        if (s.uses_eval) break;
                         s.uses_eval = true;
-                    }
+                    } while (s = s.parent_scope);
                 } else if (sym.undeclared) {
                     self.uses_eval = true;
                 }
@@ -181,7 +234,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             node.reference(options);
             return true;
         }
-        // ensure mangling works if catch reuses a scope variable
+        // ensure mangling works if `catch` reuses a scope variable
         if (node instanceof AST_SymbolCatch) {
             var def = node.definition().redefined();
             if (def) for (var s = node.scope; s; s = s.parent_scope) {
@@ -190,6 +243,12 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             }
             return true;
         }
+        // ensure compression works if `const` reuses a scope variable
+        if (node instanceof AST_SymbolConst) {
+            var redef = node.definition().redefined();
+            if (redef) redef.const_redefs = true;
+            return true;
+        }
     });
     self.walk(tw);
 
@@ -218,10 +277,13 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     function redefine(node, scope) {
         var name = node.name;
         var old_def = node.thedef;
+        if (!all(old_def.orig, function(sym) {
+            return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
+        })) return;
         var new_def = scope.find_variable(name);
         if (new_def) {
-            var redef;
-            while (redef = new_def.redefined()) new_def = redef;
+            var redef = new_def.redefined();
+            if (redef) new_def = redef;
         } else {
             new_def = self.globals.get(name);
         }
@@ -231,7 +293,8 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             new_def = scope.def_variable(node);
         }
         old_def.defun = new_def.scope;
-        old_def.orig.concat(old_def.references).forEach(function(node) {
+        old_def.forEach(function(node) {
+            node.redef = true;
             node.thedef = new_def;
             node.reference(options);
         });
@@ -240,12 +303,6 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     }
 });
 
-AST_Scope.DEFMETHOD("make_def", function(orig, init) {
-    var top = this;
-    while (top.parent_scope) top = top.parent_scope;
-    return new SymbolDef(++top.next_def_id, this, orig, init);
-});
-
 AST_Toplevel.DEFMETHOD("def_global", function(node) {
     var globals = this.globals, name = node.name;
     if (globals.has(name)) {
@@ -259,24 +316,35 @@ AST_Toplevel.DEFMETHOD("def_global", function(node) {
     }
 });
 
-AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope) {
-    this.variables = new Dictionary();  // map name to AST_SymbolVar (variables defined in this scope; includes functions)
-    this.functions = new Dictionary();  // map name to AST_SymbolDefun (functions defined in this scope)
-    this.uses_with = false;             // will be set to true if this or some nested scope uses the `with` statement
-    this.uses_eval = false;             // will be set to true if this or nested scope uses the global `eval`
-    this.parent_scope = parent_scope;   // the parent scope
-    this.enclosed = [];                 // a list of variables from this or outer scope(s) that are referenced from this or inner scopes
-    this.cname = -1;                    // the current index for mangling functions/variables
-});
+function init_block_vars(scope, parent) {
+    scope.enclosed = [];                            // variables from this or outer scope(s) that are referenced from this or inner scopes
+    scope.parent_scope = parent;                    // the parent scope (null if this is the top level)
+    scope.functions = new Dictionary();             // map name to AST_SymbolDefun (functions defined in this scope)
+    scope.variables = new Dictionary();             // map name to AST_SymbolVar (variables defined in this scope; includes functions)
+    if (parent) scope.make_def = parent.make_def;   // top-level tracking of SymbolDef instances
+}
 
-AST_Lambda.DEFMETHOD("init_scope_vars", function() {
-    AST_Scope.prototype.init_scope_vars.apply(this, arguments);
+function init_scope_vars(scope, parent) {
+    init_block_vars(scope, parent);
+    scope.uses_eval = false;                        // will be set to true if this or nested scope uses the global `eval`
+    scope.uses_with = false;                        // will be set to true if this or some nested scope uses the `with` statement
+}
+
+AST_BlockScope.DEFMETHOD("init_vars", function(parent_scope) {
+    init_block_vars(this, parent_scope);
+});
+AST_Scope.DEFMETHOD("init_vars", function(parent_scope) {
+    init_scope_vars(this, parent_scope);
+});
+AST_Lambda.DEFMETHOD("init_vars", function(parent_scope) {
+    init_scope_vars(this, parent_scope);
     this.uses_arguments = false;
     this.def_variable(new AST_SymbolFunarg({
         name: "arguments",
         start: this.start,
-        end: this.end
+        end: this.end,
     }));
+    return this;
 });
 
 AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
@@ -297,20 +365,20 @@ AST_Symbol.DEFMETHOD("reference", function(options) {
     this.mark_enclosed(options);
 });
 
-AST_Scope.DEFMETHOD("find_variable", function(name) {
+AST_BlockScope.DEFMETHOD("find_variable", function(name) {
     if (name instanceof AST_Symbol) name = name.name;
     return this.variables.get(name)
         || (this.parent_scope && this.parent_scope.find_variable(name));
 });
 
-AST_Scope.DEFMETHOD("def_function", function(symbol, init) {
+AST_BlockScope.DEFMETHOD("def_function", function(symbol, init) {
     var def = this.def_variable(symbol, init);
     if (!def.init || def.init instanceof AST_Defun) def.init = init;
     this.functions.set(symbol.name, def);
     return def;
 });
 
-AST_Scope.DEFMETHOD("def_variable", function(symbol, init) {
+AST_BlockScope.DEFMETHOD("def_variable", function(symbol, init) {
     var def = this.variables.get(symbol.name);
     if (def) {
         def.orig.push(symbol);
@@ -323,17 +391,12 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol, init) {
     return symbol.thedef = def;
 });
 
-AST_Lambda.DEFMETHOD("resolve", return_this);
-AST_Scope.DEFMETHOD("resolve", function() {
-    return this.parent_scope.resolve();
-});
-AST_Toplevel.DEFMETHOD("resolve", return_this);
-
 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 = -1;
         scope.cname_holes = [];
+        scope.names_in_use = names = Object.create(null);
         var cache = options.cache && options.cache.props;
         scope.enclosed.forEach(function(def) {
             if (def.unmangleable(options)) names[def.name] = true;
@@ -350,7 +413,7 @@ function next_mangled_name(scope, options, def) {
     var holes = scope.cname_holes;
     var names = Object.create(null);
     var scopes = [ scope ];
-    def.references.forEach(function(sym) {
+    def.forEach(function(sym) {
         var scope = sym.scope;
         do {
             if (scopes.indexOf(scope) < 0) {
@@ -366,7 +429,7 @@ function next_mangled_name(scope, options, def) {
         name = base54(holes[i]);
         if (names[name]) continue;
         holes.splice(i, 1);
-        scope.names_in_use[name] = true;
+        in_use[name] = true;
         return name;
     }
     while (true) {
@@ -375,7 +438,7 @@ function next_mangled_name(scope, options, def) {
         if (!names[name]) break;
         holes.push(scope.cname);
     }
-    scope.names_in_use[name] = true;
+    in_use[name] = true;
     return name;
 }
 
@@ -387,18 +450,10 @@ AST_Symbol.DEFMETHOD("unmangleable", function(options) {
 // labels are always mangleable
 AST_Label.DEFMETHOD("unmangleable", return_false);
 
-AST_Symbol.DEFMETHOD("unreferenced", function() {
-    return !this.definition().references.length && !this.scope.pinned();
-});
-
 AST_Symbol.DEFMETHOD("definition", function() {
     return this.thedef;
 });
 
-AST_Symbol.DEFMETHOD("global", function() {
-    return this.definition().global;
-});
-
 function _default_mangler_options(options) {
     options = defaults(options, {
         eval        : false,
@@ -424,7 +479,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
     var lname = -1;
 
     if (options.cache && options.cache.props) {
-        var mangled_names = this.mangled_names = Object.create(null);
+        var mangled_names = names_in_use(this, options);
         options.cache.props.each(function(mangled_name) {
             mangled_names[mangled_name] = true;
         });
@@ -439,7 +494,11 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             lname = save_nesting;
             return true;
         }
-        if (node instanceof AST_Scope) {
+        if (node instanceof AST_BlockScope) {
+            var to_mangle = [];
+            node.variables.each(function(def) {
+                if (!defer_redef(def)) to_mangle.push(def);
+            });
             descend();
             if (options.cache && node instanceof AST_Toplevel) {
                 node.globals.each(mangle);
@@ -449,9 +508,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
                 sym.scope = node;
                 sym.reference(options);
             }
-            node.variables.each(function(def) {
-                if (!defer_redef(def)) mangle(def);
-            });
+            to_mangle.forEach(mangle);
             return true;
         }
         if (node instanceof AST_Label) {
@@ -462,13 +519,6 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             node.mangled_name = name;
             return true;
         }
-        if (!options.ie8 && node instanceof AST_Catch) {
-            var def = node.argname.definition();
-            var redef = defer_redef(def, node.argname);
-            descend();
-            if (!redef) mangle(def);
-            return true;
-        }
     });
     this.walk(tw);
     redefined.forEach(mangle);
@@ -483,7 +533,8 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
         if (!redef) return false;
         redefined.push(def);
         def.references.forEach(reference);
-        if (node) reference(node);
+        var node = def.orig[0];
+        if (node instanceof AST_SymbolCatch || node instanceof AST_SymbolConst) reference(node);
         return true;
 
         function reference(sym) {
@@ -496,12 +547,11 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
 
 AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
     var cache = options.cache && options.cache.props;
-    var avoid = Object.create(null);
+    var avoid = Object.create(RESERVED_WORDS);
     options.reserved.forEach(to_avoid);
     this.globals.each(add_def);
     this.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_Scope) node.variables.each(add_def);
-        if (node instanceof AST_SymbolCatch) add_def(node.definition());
+        if (node instanceof AST_BlockScope) node.variables.each(add_def);
     }));
     return avoid;
 
@@ -525,15 +575,14 @@ AST_Toplevel.DEFMETHOD("expand_names", function(options) {
     var cname = 0;
     this.globals.each(rename);
     this.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_Scope) node.variables.each(rename);
-        if (node instanceof AST_SymbolCatch) rename(node.definition());
+        if (node instanceof AST_BlockScope) node.variables.each(rename);
     }));
 
     function next_name() {
         var name;
         do {
             name = base54(cname++);
-        } while (avoid[name] || RESERVED_WORDS[name]);
+        } while (avoid[name]);
         return name;
     }
 
@@ -544,7 +593,7 @@ AST_Toplevel.DEFMETHOD("expand_names", function(options) {
         var redef = def.redefined();
         var name = redef ? redef.rename || redef.name : next_name();
         def.rename = name;
-        def.orig.concat(def.references).forEach(function(sym) {
+        def.forEach(function(sym) {
             if (sym.definition() === def) sym.name = name;
         });
     }
@@ -558,8 +607,8 @@ AST_Sequence.DEFMETHOD("tail_node", function() {
 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options) {
     options = _default_mangler_options(options);
     base54.reset();
+    var fn = AST_Symbol.prototype.add_source_map;
     try {
-        var fn = AST_Symbol.prototype.add_source_map;
         AST_Symbol.prototype.add_source_map = function() {
             if (!this.unmangleable(options)) base54.consider(this.name, -1);
         };

lib/transform.js

@@ -116,7 +116,7 @@ TreeTransformer.prototype = new TreeWalker;
         if (self.bfinally) self.bfinally = self.bfinally.transform(tw);
     });
     DEF(AST_Catch, function(self, tw) {
-        self.argname = self.argname.transform(tw);
+        if (self.argname) self.argname = self.argname.transform(tw);
         self.body = do_list(self.body, tw);
     });
     DEF(AST_Definitions, function(self, tw) {
@@ -164,6 +164,7 @@ TreeTransformer.prototype = new TreeWalker;
         self.properties = do_list(self.properties, tw);
     });
     DEF(AST_ObjectProperty, function(self, tw) {
+        if (self.key instanceof AST_Node) self.key = self.key.transform(tw);
         self.value = self.value.transform(tw);
     });
 })(function(node, descend) {

lib/utils.js

@@ -112,51 +112,29 @@ function return_this() { return this; }
 function return_null() { return null; }
 
 var List = (function() {
-    function List(a, f, backwards) {
-        var ret = [], top = [], i;
-        function doit() {
+    function List(a, f) {
+        var ret = [];
+        for (var i = 0; i < a.length; i++) {
             var val = f(a[i], i);
-            var is_last = val instanceof Last;
-            if (is_last) val = val.v;
-            if (val instanceof AtTop) {
-                val = val.v;
-                if (val instanceof Splice) {
-                    top.push.apply(top, backwards ? val.v.slice().reverse() : val.v);
-                } else {
-                    top.push(val);
-                }
-            } else if (val !== skip) {
-                if (val instanceof Splice) {
-                    ret.push.apply(ret, backwards ? val.v.slice().reverse() : val.v);
-                } else {
-                    ret.push(val);
-                }
-            }
-            return is_last;
-        }
-        if (Array.isArray(a)) {
-            if (backwards) {
-                for (i = a.length; --i >= 0;) if (doit()) break;
-                ret.reverse();
-                top.reverse();
+            if (val === skip) continue;
+            if (val instanceof Splice) {
+                ret.push.apply(ret, val.v);
             } else {
-                for (i = 0; i < a.length; ++i) if (doit()) break;
+                ret.push(val);
             }
-        } else {
-            for (i in a) if (HOP(a, i)) if (doit()) break;
         }
-        return top.concat(ret);
+        return ret;
     }
     List.is_op = function(val) {
-        return val === skip || val instanceof AtTop || val instanceof Last || val instanceof Splice;
+        return val === skip || val instanceof Splice;
+    };
+    List.splice = function(val) {
+        return new Splice(val);
     };
-    List.at_top = function(val) { return new AtTop(val); };
-    List.splice = function(val) { return new Splice(val); };
-    List.last = function(val) { return new Last(val); };
     var skip = List.skip = {};
-    function AtTop(val) { this.v = val; }
-    function Splice(val) { this.v = val; }
-    function Last(val) { this.v = val; }
+    function Splice(val) {
+        this.v = val;
+    }
     return List;
 })();
 
@@ -165,8 +143,9 @@ function push_uniq(array, el) {
 }
 
 function string_template(text, props) {
-    return text.replace(/\{(.+?)\}/g, function(str, p) {
-        return props && props[p];
+    return text.replace(/\{([^}]+)\}/g, function(str, p) {
+        var value = props[p];
+        return value instanceof AST_Node ? value.print_to_string() : value;
     });
 }
 

package.json

@@ -3,7 +3,7 @@
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.10.2",
+  "version": "3.11.6",
   "engines": {
     "node": ">=0.8.0"
   },

test/compress.js

@@ -315,6 +315,7 @@ function test_case(test) {
         if (test.mangle.properties) U.mangle_properties(output, test.mangle.properties);
     }
     var output_code = make_code(output, output_options);
+    U.AST_Node.log_function();
     if (expect != output_code) {
         log([
             "!!! failed",
@@ -386,7 +387,7 @@ function test_case(test) {
             mangle: test.mangle
         });
         var actual = stdout[toplevel ? 1 : 0];
-        if (test.expect_stdout === true) {
+        if (test.expect_stdout === true || test.expect_stdout instanceof Error && test.expect_stdout.name === actual.name) {
             test.expect_stdout = actual;
         }
         if (!sandbox.same_stdout(test.expect_stdout, actual)) {

test/compress/arguments.js

@@ -783,3 +783,27 @@ issue_3420_7: {
     }
     expect_stdout: "true"
 }
+
+issue_4200: {
+    options = {
+        arguments: true,
+        keep_fargs: false,
+    }
+    input: {
+        var o = {
+            get p() {
+                return arguments[0];
+            },
+        };
+        console.log(o.p);
+    }
+    expect: {
+        var o = {
+            get p() {
+                return arguments[0];
+            },
+        };
+        console.log(o.p);
+    }
+    expect_stdout: "undefined"
+}

test/compress/ascii.js

@@ -1,35 +0,0 @@
-ascii_only_true: {
-    options = {}
-    beautify = {
-        ascii_only : true,
-        ie8        : false,
-        beautify   : false,
-    }
-    input: {
-        function f() {
-            return "\x000\x001\x007\x008\x00" +
-                   "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
-                   "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
-                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
-        }
-    }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\x008\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\f\\r\\x0e\\x0f"+"\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f"+\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\'}'
-}
-
-ascii_only_false: {
-    options = {}
-    beautify = {
-        ascii_only : false,
-        ie8        : false,
-        beautify   : false,
-    }
-    input: {
-        function f() {
-            return "\x000\x001\x007\x008\x00" +
-                   "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
-                   "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
-                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
-        }
-    }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\x008\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\f\\r\x0e\x0f"+"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"+\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
-}

test/compress/asm.js

@@ -76,9 +76,8 @@ asm_mixed: {
                 start = start | 0;
                 end = end | 0;
                 var sum = 0.0, p = 0, q = 0;
-                for (p = start << 3, q = end << 3; (p | 0) < (q | 0); p = p + 8 | 0) {
+                for (p = start << 3, q = end << 3; (p | 0) < (q | 0); p = p + 8 | 0)
                     sum = sum + +log(values[p >> 3]);
-                }
                 return +sum;
             }
             function geometricMean(start, end) {
@@ -91,11 +90,12 @@ asm_mixed: {
         function no_asm_GeometricMean(stdlib, foreign, buffer) {
             function logSum(start, end) {
                 start |= 0, end |= 0;
-                for (var sum = 0, p = 0, q = 0, p = start << 3, q = end << 3; (0 | p) < (0 | q); p = p + 8 | 0) sum += +log(values[p >> 3]);
+                for (var sum = 0, p = 0, q = 0, p = start << 3, q = end << 3; (0 | p) < (0 | q); p = p + 8 | 0)
+                    sum += +log(values[p >> 3]);
                 return +sum;
             }
             function geometricMean(start, end) {
-                return start |= 0, end |= 0, +exp(logSum(start, end) / (end - start | 0));
+                return start |= 0, end |= 0, +exp(+logSum(start, end) / (end - start | 0));
             }
             var exp = stdlib.Math.exp, log = stdlib.Math.log, values = new stdlib.Float64Array(buffer);
             return { geometricMean: geometricMean };

test/compress/collapse_vars.js

@@ -62,18 +62,18 @@ collapse_vars_side_effects_1: {
     expect: {
         function f1() {
             var s = "abcdef", i = 2;
-            console.log.bind(console)(s.charAt(i++), s.charAt(i++), s.charAt(4), 7);
+            console.log.bind(console)(s.charAt(i++), s.charAt(+i), s.charAt(4), 7);
         }
         function f2() {
             var s = "abcdef", i = 2;
-            console.log.bind(console)(s.charAt(i++), 5, s.charAt(i++), s.charAt(i++), 7);
+            console.log.bind(console)(s.charAt(i++), 5, s.charAt(i++), s.charAt(+i), 7);
         }
         function f3() {
             var s = "abcdef",
                 i = 2,
                 log = console.log.bind(console),
                 x = s.charAt(i++),
-                y = s.charAt(i++);
+                y = s.charAt(+i);
             log(x, s.charAt(4), y, 7);
         }
         function f4() {
@@ -346,9 +346,8 @@ collapse_vars_if: {
             return "x" != "Bar" + x / 4 ? g9 : g5;
         }
         function f3(x) {
-            if (x) {
+            if (x)
                 return 1;
-            }
             return 2;
         }
     }
@@ -3073,7 +3072,6 @@ issue_2298: {
     expect: {
         !function() {
             (function() {
-                0;
                 try {
                     !function(b) {
                         (void 0)[1] = "foo";
@@ -4193,9 +4191,8 @@ issue_2436_11: {
             if (isCollection(arg1)) {
                 var size = arg1, max = arg2, min = 0, res = _randomDataForMatrix(size.valueOf(), min, max, _randomInt);
                 return size && true === size.isMatrix ? matrix(res) : res;
-            } else {
+            } else
                 return _randomInt(min = arg1, max = arg2);
-            }
         }
     }
 }
@@ -4311,9 +4308,8 @@ issue_2497: {
         function sample() {
             if (true)
                 for (var i = 0; i < 1; ++i)
-                    for (var k = 0; k < 1; ++k) {
+                    for (var k = 0; k < 1; ++k)
                         value = (value = 1) ? value + 1 : 0;
-                    }
             else
                 for (i = 0; i < 1; ++i)
                     for (k = 0; k < 1; ++k)
@@ -8538,3 +8534,71 @@ issue_4051: {
     }
     expect_stdout: "undefined"
 }
+
+issue_4070: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function f() {
+            function g() {}
+            g.p++;
+            return f.p = g.p;
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            function g() {}
+            return f.p = ++g.p;
+        }());
+    }
+    expect_stdout: "NaN"
+}
+
+issue_4242: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            if (console)
+                var a = function(){}, b = (!1 === console || a)();
+        }());
+    }
+    expect: {
+        console.log(function() {
+            console && (!1 === console || function(){})();
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4248: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 0;
+        try {
+            a = 1;
+            b[1];
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect: {
+        var a = 0;
+        try {
+            a = 1;
+            b[1];
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect_stdout: "1"
+}

test/compress/concat-strings.js

@@ -238,6 +238,41 @@ concat_8: {
     expect_stdout: true
 }
 
+concat_9: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        reduce_vars: true,
+        strings: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "foo";
+        console.log(
+            12 + (34 + a),
+            null + (34 + a),
+            12 + (null + a),
+            false + (34 + a),
+            12 + (false + a),
+            "bar" + (34 + a),
+            12 + ("bar" + a)
+        );
+    }
+    expect: {
+        var a = "foo";
+        console.log(
+            "1234" + a,
+            "null34" + a,
+            "12null" + a,
+            !1 + (34 + a),
+            12 + (!1 + a),
+            "bar34" + a,
+            "12bar" + a
+        );
+    }
+    expect_stdout: true
+}
+
 issue_3689: {
     options = {
         strings: true,

test/compress/conditionals.js

@@ -55,14 +55,15 @@ ifs_3_should_warn: {
     }
     input: {
         var x, y;
-        if (x && !(x + "1") && y) { // 1
+        // 1
+        if (x && !(x + "1") && y) {
             var qq;
             foo();
         } else {
             bar();
         }
-
-        if (x || !!(x + "1") || y) { // 2
+        // 2
+        if (x || !!(x + "1") || y) {
             foo();
         } else {
             var jj;
@@ -71,9 +72,25 @@ ifs_3_should_warn: {
     }
     expect: {
         var x, y;
-        var qq; bar();          // 1
-        var jj; foo();          // 2
+        // 1
+        var qq; bar();
+        // 2
+        foo(); var jj;
     }
+    expect_warnings: [
+        "WARN: + in boolean context always true [test/compress/conditionals.js:3,18]",
+        "WARN: Boolean && always false [test/compress/conditionals.js:3,12]",
+        "WARN: Condition left of && always false [test/compress/conditionals.js:3,12]",
+        "WARN: Condition always false [test/compress/conditionals.js:3,12]",
+        "WARN: Dropping unreachable code [test/compress/conditionals.js:3,34]",
+        "WARN: + in boolean context always true [test/compress/conditionals.js:10,19]",
+        "WARN: Boolean || always true [test/compress/conditionals.js:10,12]",
+        "WARN: Condition left of || always true [test/compress/conditionals.js:10,12]",
+        "WARN: Condition always true [test/compress/conditionals.js:10,12]",
+        "WARN: Dropping unreachable code [test/compress/conditionals.js:12,15]",
+        "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:3,12]",
+        "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:10,12]",
+    ]
 }
 
 ifs_4: {
@@ -783,6 +800,28 @@ cond_12: {
     }
 }
 
+cond_13: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        x ? y(a) : z(a);
+        x ? y.f(a) : z.f(a);
+        x ? y.f(a) : z.g(a);
+        x ? y.f()(a) : z.g()(a);
+        x ? y.f.u(a) : z.g.u(a);
+        x ? y.f().u(a) : z.g().u(a);
+    }
+    expect: {
+        (x ? y : z)(a);
+        (x ? y : z).f(a);
+        x ? y.f(a) : z.g(a);
+        (x ? y.f() : z.g())(a);
+        (x ? y.f : z.g).u(a);
+        (x ? y.f() : z.g()).u(a);
+    }
+}
+
 ternary_boolean_consequent: {
     options = {
         booleans: true,
@@ -1137,7 +1176,7 @@ issue_1645_2: {
     expect_stdout: true
 }
 
-condition_symbol_matches_consequent: {
+condition_matches_consequent: {
     options = {
         conditionals: true,
     }
@@ -1166,6 +1205,35 @@ condition_symbol_matches_consequent: {
     expect_stdout: "3 7 true 4"
 }
 
+condition_matches_alternative: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function foo(x, y) {
+            return x.p ? y[0] : x.p;
+        }
+        function bar() {
+            return g ? h : g;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo({ p: 3 }, [ null ]), foo({ p: 0 }, [ 7 ]), foo({ p: true } , [ false ]), bar());
+    }
+    expect: {
+        function foo(x, y) {
+            return x.p && y[0];
+        }
+        function bar() {
+            return g && h;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo({ p: 3 }, [ null ]), foo({ p: 0 }, [ 7 ]), foo({ p: true } , [ false ]), bar());
+    }
+    expect_stdout: "null 0 false 5"
+}
+
 delete_conditional_1: {
     options = {
         booleans: true,

test/compress/dead-code.js

@@ -59,6 +59,9 @@ dead_code_2_should_warn: {
         f();
     }
     expect_stdout: true
+    expect_warnings: [
+        "WARN: Dropping unreachable code [test/compress/dead-code.js:8,12]",
+    ]
     node_version: "<=4"
 }
 
@@ -89,11 +92,21 @@ dead_code_constant_boolean_should_warn_more: {
         function bar() {}
         // nothing for the while
         // as for the for, it should keep:
-        var moo;
         var x = 10, y;
+        var moo;
         bar();
     }
     expect_stdout: true
+    expect_warnings: [
+        "WARN: + in boolean context always true [test/compress/dead-code.js:1,33]",
+        "WARN: Boolean || always true [test/compress/dead-code.js:1,16]",
+        "WARN: Dropping unreachable code [test/compress/dead-code.js:1,45]",
+        "WARN: Boolean expression always true [test/compress/dead-code.js:6,47]",
+        "WARN: Boolean && always false [test/compress/dead-code.js:6,28]",
+        "WARN: Dropping unreachable code [test/compress/dead-code.js:6,63]",
+        "WARN: Dropping side-effect-free statement [test/compress/dead-code.js:1,15]",
+        "WARN: Dropping side-effect-free statement [test/compress/dead-code.js:6,28]",
+    ]
     node_version: "<=4"
 }
 

test/compress/drop-unused.js

@@ -1730,7 +1730,7 @@ chained_3: {
     expect: {
         console.log(function(a, b) {
             var c = b;
-            b++;
+            +b;
             return c;
         }(0, 2));
     }
@@ -1997,7 +1997,7 @@ issue_3146_4: {
     expect_stdout: "PASS"
 }
 
-issue_3192: {
+issue_3192_1: {
     options = {
         unused: true,
     }
@@ -2025,6 +2025,26 @@ issue_3192: {
     ]
 }
 
+issue_3192_2: {
+    options = {
+        keep_fargs: "strict",
+        unused: true,
+    }
+    input: {
+        "use strict";
+        (function(a) {
+            console.log(a = "foo", arguments[0]);
+        })("bar");
+    }
+    expect: {
+        "use strict";
+        (function() {
+            console.log("foo", arguments[0]);
+        })("bar");
+    }
+    expect_stdout: "foo bar"
+}
+
 issue_3233: {
     options = {
         pure_getters: "strict",
@@ -2161,8 +2181,7 @@ issue_3515_1: {
     expect: {
         var c = 0;
         (function() {
-            this[c++] = 0;
-            for (var key20 in !0);
+            for (var key20 in !(this[c++] = 0));
         })();
         console.log(c);
     }
@@ -2718,7 +2737,7 @@ issue_3962_1: {
                 0..toString();
             } while (0);
             if (c) console.log("PASS");
-        }((a--, 1)), 0);
+        }(1), 0);
         void 0;
     }
     expect_stdout: "PASS"
@@ -2751,7 +2770,7 @@ issue_3962_2: {
                 0..toString();
             } while (0);
             if (c) console.log("PASS");
-        }((a--, 1)), 0);
+        }(1), 0);
     }
     expect_stdout: "PASS"
 }
@@ -2834,11 +2853,11 @@ issue_4025: {
         console.log(a, b, d);
     }
     expect: {
-        var d, c = 0;
+        var c = 0;
         try {
             console.log(c);
         } finally {
-            d = c + 1;
+            var d = c + 1;
             c = 0;
         }
         console.log(1, 1, d);
@@ -2848,3 +2867,248 @@ issue_4025: {
         "1 1 1",
     ]
 }
+
+forin_var_1: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var k;
+        for (k in [ 1, 2 ])
+            console.log(k);
+        for (k in { PASS: 3 })
+            console.log(k);
+        console.log(k);
+    }
+    expect: {
+        for (var k in [ 1, 2 ])
+            console.log(k);
+        for (k in { PASS: 3 })
+            console.log(k);
+        console.log(k);
+    }
+    expect_stdout: [
+        "0",
+        "1",
+        "PASS",
+        "PASS",
+    ]
+}
+
+forin_var_2: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            switch (0) {
+              case function() {
+                    for (a in 0);
+                }:
+                var b = 0;
+            }
+            for (var c = 0; a;);
+            var a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            switch (0) {
+              case function() {
+                    for (a in 0);
+                }:
+            }
+            for (; a;);
+            var a;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4133: {
+    options = {
+        evaluate: true,
+        merge_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        var b = [ a-- ], c = b && b[c];
+        console.log(a);
+    }
+    expect: {
+        var b = 1;
+        console.log(0);
+    }
+    expect_stdout: "0"
+}
+
+issue_4144: {
+    options = {
+        keep_fargs: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a, b) {
+            var b = console, c = ++b;
+        })(console.log("PASS"), 0);
+    }
+    expect: {
+        (function(b) {
+            b = console,
+            ++b;
+        })(console.log("PASS"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4146: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            function g() {}
+            var a = g;
+            var c = b;
+            c.p;
+            console.log(typeof a);
+        }
+        f("FAIL", 42);
+    }
+    expect: {
+        (function(a, b) {
+            a = function () {};
+            var c = b;
+            c.p;
+            console.log(typeof a);
+        })(0, 42);
+    }
+    expect_stdout: "function"
+}
+
+var_catch_redefined: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw "PASS";
+        } catch (a) {
+            function f() {
+                return a;
+            }
+            console.log(a);
+        }
+        f();
+    }
+    expect: {
+        var a = "FAIL";
+        try {
+            throw "PASS";
+        } catch (a) {
+            function f() {
+                return a;
+            }
+            console.log(a);
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+single_use_catch_redefined: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect_stdout: true
+}
+
+issue_4184: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = function() {}, b = [ a, 1 && b, a = {} ];
+            try {
+                throw 42;
+            } catch (a) {
+                {
+                    console.log(a);
+                }
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            var b = [ function() {}, 1 && b, {} ];
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(a);
+            }
+        })();
+    }
+    expect_stdout: "42"
+}
+
+issue_4235: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        (function() {
+            {
+                const f = 0;
+            }
+            (function f() {
+                var f = console.log(f);
+            })();
+        })();
+    }
+    expect: {
+        (function() {
+            f = console.log(f),
+            void 0;
+            var f;
+        })();
+    }
+    expect_stdout: "undefined"
+}

test/compress/evaluate.js

@@ -2869,3 +2869,208 @@ issue_4035: {
         "true",
     ]
 }
+
+issue_4067: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        (function(a) {
+            (function(b) {
+                b[0] += 0;
+                console.log(+a);
+            })(a);
+        })([]);
+    }
+    expect: {
+        (function(a) {
+            (function(b) {
+                b[0] += 0;
+                console.log(+a);
+            })(a);
+        })([]);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_4077: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log((a = []) - (a[0]++, 1) || "PASS");
+    }
+    expect: {
+        console.log((a = []) - (a[0]++, 1) || "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4119_1: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var a, b;
+        b = a = [];
+        a[0] += 0;
+        if (+b + 1) {
+            console.log("FAIL");
+        } else {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        var a, b;
+        b = a = [];
+        a[0] += 0;
+        +b + 1 ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4119_2: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        var a;
+        (function(b) {
+            a[0] += 0;
+            console.log(+b + 1 ? "FAIL" : "PASS");
+        })(a = []);
+    }
+    expect: {
+        var a;
+        (function(b) {
+            a[0] += 0;
+            console.log(+b + 1 ? "FAIL" : "PASS");
+        })(a = []);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4119_3: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var a, b;
+        b = a = {
+            p: 42,
+        };
+        delete a.p;
+        console.log(b.p ? "FAIL" : "PASS");
+    }
+    expect: {
+        var a, b;
+        b = a = {
+            p: 42,
+        };
+        delete a.p;
+        console.log(b.p ? "FAIL" : "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4119_4: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a, b;
+        b = a = {
+            p: 42,
+        };
+        delete a.p;
+        console.log(!b ? "FAIL" : "PASS");
+    }
+    expect: {
+        var a, b;
+        b = a = {
+            p: 42,
+        };
+        delete a.p;
+        console.log((b, 0, "PASS"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4214: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            return function() {
+                try {
+                    return a;
+                } finally {
+                    var b = 0;
+                }
+            }(a++ && this());
+        }
+        var c = f();
+        console.log(c);
+    }
+    expect: {
+        var c = function(a) {
+            return function() {
+                try {
+                    return a;
+                } finally {}
+            }(a++ && this());
+        }();
+        console.log(c);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_4271: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        ({
+            p: null,
+            q: (console.log("foo"), 42),
+            p: function() {}
+        })[console.log("bar"), "p"] && console.log("PASS");
+    }
+    expect: {
+        ({
+            p: null,
+            q: (console.log("foo"), 42),
+            p: function() {}
+        })[console.log("bar"), "p"],
+        console.log("PASS");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "PASS",
+    ]
+}

test/compress/functions.js

@@ -1483,8 +1483,7 @@ issue_2663_2: {
     }
     expect: {
         (function() {
-            var i;
-            for (i in { a: 1, b: 2, c: 3 })
+            for (var i in { a: 1, b: 2, c: 3 })
                 j = i, console.log(j);
             var j;
         })();
@@ -2082,7 +2081,7 @@ issue_3016_1: {
         var b = 1;
         do {
             3[b];
-        } while(0);
+        } while (0);
         console.log(b);
     }
     expect_stdout: "1"
@@ -2113,7 +2112,7 @@ issue_3016_2: {
         do {
             a = 3,
             a[b];
-        } while(0);
+        } while (0);
         var a;
         console.log(b);
     }
@@ -2146,7 +2145,7 @@ issue_3016_2_ie8: {
         do {
             a = 3,
             a[b];
-        } while(0);
+        } while (0);
         var a;
         console.log(b);
     }
@@ -2176,7 +2175,7 @@ issue_3016_3: {
         var b = 1;
         do {
             console.log((a = void 0, a ? "FAIL" : a = "PASS"));
-        } while(b--);
+        } while (b--);
         var a;
     }
     expect_stdout: [
@@ -2209,7 +2208,7 @@ issue_3016_3_ie8: {
         var b = 1;
         do {
             console.log((a = void 0, a ? "FAIL" : a = "PASS"));
-        } while(b--);
+        } while (b--);
         var a;
     }
     expect_stdout: [
@@ -2677,7 +2676,7 @@ cross_references_3: {
                 };
                 return Math.square(n) + Math.cube(n);
             };
-        }(Math)(2));
+        }()(2));
         console.log(Math.square(3), Math.cube(3));
     }
     expect_stdout: [
@@ -4778,3 +4777,440 @@ issue_4006: {
     }
     expect_stdout: "-1"
 }
+
+issue_4155: {
+    options = {
+        functions: true,
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a;
+            (function() {
+                console.log(a);
+            })(a);
+            var b = function() {};
+            b && console.log(typeof b);
+        })();
+    }
+    expect: {
+        (function() {
+            void console.log(b);
+            var b = function() {};
+            b && console.log(typeof b);
+        })();
+    }
+    expect_stdout: [
+        "undefined",
+        "function",
+    ]
+}
+
+issue_4159: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 42, c = function(b) {
+            (b = a) && console.log(a++, b);
+        }(c = a);
+    }
+    expect: {
+        var a = 42;
+        (b = a) && console.log(a++, b);
+        var b;
+    }
+    expect_stdout: "42 42"
+}
+
+direct_inline: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            function g(c) {
+                return c >> 1;
+            }
+            return g(a) + g(b);
+        }
+        console.log(f(13, 31));
+    }
+    expect: {
+        function f(a, b) {
+            return (a >> 1) + (b >> 1);
+        }
+        console.log(f(13, 31));
+    }
+    expect_stdout: "21"
+}
+
+direct_inline_catch_redefined: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            return a;
+        }
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, f(), g());
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            return a;
+        }
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, a, g());
+    }
+    expect_stdout: true
+}
+
+issue_4171_1: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            try {
+                while (a)
+                    var e = function() {};
+            } catch (e) {
+                return function() {
+                    return e;
+                };
+            }
+        }(!console));
+    }
+    expect: {
+        console.log(function(a) {
+            try {
+                while (a)
+                    var e = function() {};
+            } catch (e) {
+                return function() {
+                    return e;
+                };
+            }
+        }(!console));
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4171_2: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            try {
+                while (a);
+            } catch (e) {
+                return function() {
+                    return e;
+                };
+            } finally {
+                var e = function() {};
+            }
+        }(!console));
+    }
+    expect: {
+        console.log(function(a) {
+            try {
+                while (a);
+            } catch (e) {
+                return function() {
+                    return e;
+                };
+            } finally {
+                function e() {}
+            }
+        }(!console));
+    }
+    expect_stdout: "undefined"
+}
+
+catch_defun: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        try {
+            throw 42;
+        } catch (a) {
+            function f() {
+                return typeof a;
+            }
+        }
+        console.log(f());
+    }
+    expect: {
+        try {
+            throw 42;
+        } catch (o) {
+            function t() {
+                return typeof o;
+            }
+        }
+        console.log(t());
+    }
+    expect_stdout: true
+}
+
+catch_no_argname: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        function f() {
+            return a;
+        }
+        try {
+            throw a;
+        } catch {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, f(), g());
+    }
+    expect: {
+        var a = "PASS";
+        try {
+            throw a;
+        } catch {
+            console.log(a, a, a);
+        }
+        console.log(a, a, a);
+    }
+    expect_stdout: [
+        "PASS PASS PASS",
+        "PASS PASS PASS",
+    ]
+    node_version: ">=10"
+}
+
+issue_4186: {
+    options = {
+        conditionals: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        console.log(typeof function() {
+            return function() {
+                function f() {
+                    if (1)
+                        g();
+                    else
+                        (function() {
+                            return f;
+                        });
+                }
+                return f;
+                function g() {
+                    if (1) {
+                        if (0)
+                            h;
+                        else
+                            h();
+                        var key = 0;
+                    }
+                }
+                function h() {
+                    return factory;
+                }
+            };
+        }()());
+    }
+    expect: {
+        console.log(typeof function() {
+            return function f() {
+                1 ? void (1 && (0 ? h : h(), 0)) : function() {
+                    return f;
+                };
+            };
+            function h() {
+                return factory;
+            }
+        }());
+    }
+    expect_stdout: "function"
+}
+
+issue_4233: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            try {
+                var a = function() {};
+                try {
+                    throw 42;
+                } catch (a) {
+                    (function() {
+                        console.log(typeof a);
+                    })();
+                    var a;
+                }
+            } catch (e) {}
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                var a = function() {};
+                try {
+                    throw 42;
+                } catch (a) {
+                    (function() {
+                        console.log(typeof a);
+                    })();
+                    var a;
+                }
+            } catch (e) {}
+        })();
+    }
+    expect_stdout: "number"
+}
+
+issue_4259: {
+    options = {
+        collapse_vars: true,
+        functions: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function b() {
+            var c = b;
+            for (b in c);
+        };
+        a();
+        console.log(typeof a);
+    }
+    expect: {
+        function a() {
+            for (a in a);
+        }
+        a();
+        console.log(typeof a);
+    }
+    expect_stdout: "function"
+}
+
+issue_4261: {
+    options = {
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw 42;
+        } catch (e) {
+            (function() {
+                function f() {
+                    e.p;
+                }
+                function g() {
+                    while (f());
+                }
+                (function() {
+                    while (console.log(g()));
+                })();
+            })();
+        }
+    }
+    expect: {
+        try {
+            throw 42;
+        } catch (e) {
+            (function() {
+                function g() {
+                    while (void e.p);
+                }
+                (function() {
+                    while (console.log(g()));
+                })();
+            })();
+        }
+    }
+    expect_stdout: true
+}
+
+issue_4265: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        inline: true,
+        sequences: true,
+    }
+    input: {
+        function f() {
+            console;
+            if ([ function() {
+                return this + console.log(a);
+                a;
+                var a;
+            }() ]);
+            return 0;
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            return console, function() {
+                return console.log(a);
+                var a;
+            }(), 0;
+        }
+        f();
+    }
+    expect_stdout: "undefined"
+}

test/compress/ie8.js

@@ -2714,3 +2714,193 @@ issue_2737: {
     }
     expect_stdout: "function"
 }
+
+single_use_catch_redefined: {
+    options = {
+        ie8: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect_stdout: true
+}
+
+single_use_inline_catch_redefined: {
+    options = {
+        ie8: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect_stdout: true
+}
+
+direct_inline_catch_redefined: {
+    options = {
+        ie8: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            return a;
+        }
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, f(), g());
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            return a;
+        }
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, a, g());
+    }
+    expect_stdout: true
+}
+
+issue_4186: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        ie8: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        function f() {
+            (function NaN() {
+                var a = 1;
+                while (a--)
+                    try {} finally {
+                        console.log(0/0);
+                        var b;
+                    }
+            })(f);
+        }
+        f();
+        NaN;
+    }
+    expect: {
+        (function() {
+            (function NaN() {
+                var n = 1;
+                while (n--)
+                    console.log(0/0);
+            })();
+        })();
+        NaN;
+    }
+    expect_stdout: "NaN"
+}
+
+issue_4235: {
+    options = {
+        ie8: true,
+        unused: true,
+    }
+    input: {
+        try {} catch (e) {}
+        console.log(function e() {
+            var e = 0;
+        }());
+    }
+    expect: {
+        try {} catch (e) {}
+        console.log(function e() {}());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4250: {
+    options = {
+        ie8: true,
+        loops: true,
+        unused: true,
+    }
+    input: {
+        console.log(function f() {
+            (function() {
+                for (f in "f");
+            })();
+            return f;
+            var f;
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            (function() {
+                for (f in "f");
+            })();
+            return f;
+            var f;
+        }());
+    }
+    expect_stdout: "0"
+}

test/compress/if_return.js

@@ -594,3 +594,157 @@ iife_if_return_simple: {
     }
     expect_stdout: "PASS"
 }
+
+nested_if_break: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        for (var i = 0; i < 3; i++)
+            L1: if ("number" == typeof i) {
+                if (0 === i) break L1;
+                console.log(i);
+            }
+    }
+    expect: {
+        for (var i = 0; i < 3; i++)
+            L1: if ("number" == typeof i)
+                if (0 !== i) console.log(i);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+nested_if_continue: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        join_vars: true,
+        loops: true,
+    }
+    input: {
+        function f(n) {
+            var i = 0;
+            do {
+                if ("number" == typeof n) {
+                    if (0 === n) {
+                        console.log("even", i);
+                        continue;
+                    }
+                    if (1 === n) {
+                        console.log("odd", i);
+                        continue;
+                    }
+                    i++;
+                }
+            } while (0 <= (n -= 2));
+        }
+        f(37);
+        f(42);
+    }
+    expect: {
+        function f(n) {
+            for (var i = 0;
+                "number" == typeof n
+                    && (0 !== n
+                        ? 1 !== n
+                            ? i++
+                            : console.log("odd", i)
+                        : console.log("even", i)),
+                0 <= (n -= 2););
+        }
+        f(37);
+        f(42);
+    }
+    expect_stdout: [
+        "odd 18",
+        "even 21",
+    ]
+}
+
+nested_if_return: {
+    options = {
+        conditionals: true,
+        if_return: true,
+    }
+    input: {
+        function f() {
+            if (A) {
+                if (B)
+                    return B;
+                if (C)
+                    return D;
+                if (E)
+                    return F;
+                if (G)
+                    return H;
+                if (I) {
+                    if (J)
+                        return K;
+                    return;
+                }
+                if (L) {
+                    if (M)
+                        return;
+                    return N;
+                }
+            }
+        }
+    }
+    expect: {
+        function f() {
+            if (A)
+                return B || (C ? D : E ? F : G ? H : I ? J ? K : void 0 : L && !M ? N : void 0);
+        }
+    }
+}
+
+issue_866_1: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: false,
+    };
+    input: {
+        function f(a) {
+            if (a)
+                return "";
+            console.log(a);
+        }
+    }
+    expect: {
+        function f(a) {
+            if (a)
+                return "";
+            console.log(a);
+        }
+    }
+}
+
+issue_866_2: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+    }
+    input: {
+        (function() {
+            if (a)
+                if (b)
+                    c;
+                else
+                    return d;
+        })();
+    }
+    expect: {
+        (function() {
+            if (a) {
+                if (!b)
+                    return d;
+                c;
+            }
+        })();
+    }
+}

test/compress/issue-1034.js

@@ -39,7 +39,7 @@ non_hoisted_function_after_return: {
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:4,16]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:10,12]",
-        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:11,21]"
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:11,21]",
     ]
 }
 
@@ -84,19 +84,16 @@ non_hoisted_function_after_return_2a: {
         }
     }
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:4,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:4,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:7,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:4,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:7,16]",
         "WARN: Dropping unused variable a [test/compress/issue-1034.js:4,20]",
         "WARN: Dropping unused function nope [test/compress/issue-1034.js:11,21]",
-        "INFO: pass 0: last_count: Infinity, count: 36",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:9,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:9,12]",
+        "INFO: pass 0: last_count: Infinity, count: 35",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:9,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
         "INFO: Dropping unused variable b [test/compress/issue-1034.js:7,20]",
         "INFO: Dropping unused variable c [test/compress/issue-1034.js:9,16]",
-        "INFO: pass 1: last_count: 36, count: 18",
+        "INFO: pass 1: last_count: 35, count: 18",
     ]
 }
 
@@ -138,10 +135,7 @@ non_hoisted_function_after_return_2b: {
         }
     }
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:6,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:6,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:8,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:8,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
     ]
 }
@@ -242,19 +236,16 @@ non_hoisted_function_after_return_2a_strict: {
     }
     expect_stdout: "5 6"
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:5,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:5,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:8,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:8,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:5,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,16]",
         "WARN: Dropping unused variable a [test/compress/issue-1034.js:5,20]",
         "WARN: Dropping unused function nope [test/compress/issue-1034.js:12,21]",
-        "INFO: pass 0: last_count: Infinity, count: 47",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:10,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:10,12]",
+        "INFO: pass 0: last_count: Infinity, count: 46",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:10,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:13,12]",
         "INFO: Dropping unused variable b [test/compress/issue-1034.js:8,20]",
         "INFO: Dropping unused variable c [test/compress/issue-1034.js:10,16]",
-        "INFO: pass 1: last_count: 47, count: 29",
+        "INFO: pass 1: last_count: 46, count: 29",
     ]
 }
 
@@ -301,10 +292,7 @@ non_hoisted_function_after_return_2b_strict: {
     }
     expect_stdout: "5 6"
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:7,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:9,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:9,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:9,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:13,12]",
     ]
 }

test/compress/issue-1052.js

@@ -16,7 +16,7 @@ multiple_functions: {
         ( function() {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
-            if ( window );
+            if ( !window );
             function f() {}
             function g() {}
         } )();
@@ -38,7 +38,7 @@ single_function: {
     }
     expect: {
         ( function() {
-            if ( window );
+            if ( !window );
             function f() {}
         } )();
     }
@@ -67,7 +67,7 @@ deeply_nested: {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
             if ( window )
-                if (document);
+                if ( !document );
             function f() {}
             function g() {}
             function h() {}

test/compress/issue-1105.js

@@ -151,15 +151,18 @@ Infinity_not_in_with_scope: {
         unused: true,
     }
     input: {
-        var o = { Infinity: 'oInfinity' };
+        var o = { Infinity: "FAIL" };
         var vInfinity = "Infinity";
         vInfinity = Infinity;
+        console.log(vInfinity);
     }
     expect: {
-        var o = { Infinity: 'oInfinity' }
-        var vInfinity = "Infinity"
-        vInfinity = 1/0
+        var o = { Infinity: "FAIL" };
+        var vInfinity = "Infinity";
+        vInfinity = 1/0;
+        console.log(vInfinity);
     }
+    expect_stdout: "Infinity"
 }
 
 Infinity_in_with_scope: {
@@ -167,15 +170,18 @@ Infinity_in_with_scope: {
         unused: true,
     }
     input: {
-        var o = { Infinity: 'oInfinity' };
+        var o = { Infinity: "PASS" };
         var vInfinity = "Infinity";
         with (o) { vInfinity = Infinity; }
+        console.log(vInfinity);
     }
     expect: {
-        var o = { Infinity: 'oInfinity' }
-        var vInfinity = "Infinity"
-        with (o) vInfinity = Infinity
+        var o = { Infinity: "PASS" };
+        var vInfinity = "Infinity";
+        with (o) vInfinity = Infinity;
+        console.log(vInfinity);
     }
+    expect_stdout: "PASS"
 }
 
 assorted_Infinity_NaN_undefined_in_with_scope: {

test/compress/join_vars.js

@@ -277,8 +277,8 @@ join_object_assignments_forin: {
     }
     expect: {
         console.log(function() {
-            var o = { a: "PASS" };
-            for (var a in o)
+            var o = { a: "PASS" }, a;
+            for (a in o)
                 return o[a];
         }());
     }

test/compress/keep_fargs.js

@@ -306,7 +306,6 @@ issue_2298: {
     expect: {
         !function() {
             (function() {
-                0;
                 try {
                     !function() {
                         (void 0)[1] = "foo";

test/compress/loops.js

@@ -201,7 +201,7 @@ evaluate: {
     }
 }
 
-issue_1532: {
+issue_1532_1: {
     options = {
         evaluate: true,
         loops: true,
@@ -210,18 +210,56 @@ issue_1532: {
         function f(x, y) {
             do {
                 if (x) break;
-                foo();
+                console.log(y);
             } while (false);
         }
+        f(null, "PASS");
+        f(42, "FAIL");
+    }
+    expect: {
+        function f(x, y) {
+            for (; !x && (console.log(y), false););
+        }
+        f(null, "PASS");
+        f(42, "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_1532_2: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        function f(x, y) {
+            do {
+                if (x) {
+                    console.log(x);
+                    break;
+                }
+                console.log(y);
+            } while (false);
+        }
+        f(null, "PASS");
+        f(42, "FAIL");
     }
     expect: {
         function f(x, y) {
             do {
-                if (x) break;
-                foo();
-            } while (false);
+                if (x) {
+                    console.log(x);
+                    break;
+                }
+            } while (console.log(y), false);
         }
+        f(null, "PASS");
+        f(42, "FAIL");
     }
+    expect_stdout: [
+        "PASS",
+        "42",
+    ]
 }
 
 issue_186: {
@@ -509,8 +547,8 @@ dead_code_condition: {
         console.log(a);
     }
     expect: {
-        var c;
         var a = 0, b = 5;
+        var c;
         a += 1, 0,
         console.log(a);
     }
@@ -756,7 +794,37 @@ empty_for_in_side_effects: {
     expect_warnings: [
         "WARN: Dropping unused variable b [test/compress/loops.js:4,16]",
         "INFO: Dropping unused loop variable a [test/compress/loops.js:1,17]",
-        "WARN: Side effects in object of for-in loop [test/compress/loops.js:1,17]",
+        "WARN: Side effects in object of for-in loop [test/compress/loops.js:2,17]",
+    ]
+}
+
+empty_for_in_prop_init: {
+    options = {
+        loops: true,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        console.log(function f() {
+            var a = "bar";
+            for ((a, f)[a] in console.log("foo"));
+            return a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var a = "bar";
+            console.log("foo");
+            return a;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    expect_warnings: [
+        "INFO: Dropping unused loop variable f [test/compress/loops.js:3,21]",
+        "WARN: Side effects in object of for-in loop [test/compress/loops.js:3,30]",
     ]
 }
 
@@ -933,3 +1001,256 @@ issue_3634_2: {
     }
     expect_stdout: "1"
 }
+
+issue_4075: {
+    options = {
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL";
+        (function() {
+            for (a in { PASS: 0 });
+        })()
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        (function() {
+            for (a in { PASS: 0 });
+        })()
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4082: {
+    options = {
+        keep_fargs: "strict",
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        (function(a) {
+            for (a in "foo")
+                var b;
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        (function(a) {
+            for (a in "foo");
+        })();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4084: {
+    options = {
+        keep_fargs: "strict",
+        loops: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            function f(a) {
+                var b = a++;
+                for (a in "foo");
+            }
+            f();
+            return typeof a;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            (function() {
+                0;
+            })();
+            return typeof a;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4091_1: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            for (var e in 42);
+        }
+        console.log(e && e);
+    }
+    expect: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4091_2: {
+    options = {
+        loops: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            for (e in 42);
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect: {
+        try {
+            throw "FAIL";
+        } catch (e) {
+            var e;
+        }
+        console.log(e && e);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4182_1: {
+    options = {
+        loops: true,
+    }
+    input: {
+        (function() {
+            do {
+                try {
+                    return;
+                } finally {
+                    continue;
+                }
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect: {
+        (function() {
+            do {
+                try {
+                    return;
+                } finally {
+                    continue;
+                }
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4182_2: {
+    options = {
+        loops: true,
+    }
+    input: {
+        (function() {
+            L: do {
+                do {
+                    try {
+                        return;
+                    } finally {
+                        continue L;
+                    }
+                    console.log("FAIL");
+                } while (0);
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect: {
+        (function() {
+            L: do {
+                do {
+                    try {
+                        return;
+                    } finally {
+                        continue L;
+                    }
+                } while (console.log("FAIL"), 0);
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+do_continue: {
+    options = {
+        loops: true,
+    }
+    input: {
+        try {
+            do {
+                continue;
+            } while ([ A ]);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            do {
+                continue;
+            } while ([ A ]);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4240: {
+    options = {
+        loops: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            function f() {
+                var o = { PASS: 42 };
+                for (a in o);
+            }
+            (function() {
+                if (f());
+            })();
+            console.log(a);
+        })();
+    }
+    expect: {
+        (function(a) {
+            (function() {
+                if (function() {
+                    for (a in { PASS: 42 });
+                }());
+            })();
+            console.log(a);
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/numbers.js

@@ -91,7 +91,7 @@ evaluate_1: {
     expect: {
         console.log(
             x + 1 + 2,
-            2 * x,
+            2 * +x,
             +x + 1 + 2,
             1 + x + 2 + 3,
             3 | x,
@@ -130,7 +130,7 @@ evaluate_1_unsafe_math: {
     expect: {
         console.log(
             x + 1 + 2,
-            2 * x,
+            2 * +x,
             +x + 3,
             1 + x + 2 + 3,
             3 | x,
@@ -148,45 +148,52 @@ evaluate_1_unsafe_math: {
 evaluate_2: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: false,
     }
     input: {
-        var x = "42", y = null;
-        [
-            x + 1 + 2,
-            x * 1 * 2,
-            +x + 1 + 2,
-            1 + x + 2 + 3,
-            1 | x | 2 | 3,
-            1 + x-- + 2 + 3,
-            1 + (x*y + 2) + 3,
-            1 + (2 + x + 3),
-            1 + (2 + ~x + 3),
-            -y + (2 + ~x + 3),
-            1 & (2 & x & 3),
-            1 + (2 + (x |= 0) + 3),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var x = "" + num, y = null;
+            [
+                x + 1 + 2,
+                x * 1 * 2,
+                +x + 1 + 2,
+                1 + x + 2 + 3,
+                1 | x | 2 | 3,
+                1 + x-- + 2 + 3,
+                1 + (x*y + 2) + 3,
+                1 + (2 + x + 3),
+                1 + (2 + ~x + 3),
+                -y + (2 + ~x + 3),
+                1 & (2 & x & 3),
+                1 + (2 + (x |= 0) + 3),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect: {
-        var x = "42", y = null;
-        [
-            x + 1 + 2,
-            2 * x,
-            +x + 1 + 2,
-            1 + x + 2 + 3,
-            3 | x,
-            1 + x-- + 2 + 3,
-            x*y + 2 + 1 + 3,
-            1 + (2 + x + 3),
-            2 + ~x + 3 + 1,
-            2 + ~x + 3 - y,
-            0 & x,
-            2 + (x |= 0) + 3 + 1,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var x = "" + num, y = null;
+            [
+                x + "12",
+                2 * x,
+                +x + 1 + 2,
+                1 + x + "23",
+                3 | x,
+                1 + x-- + 2 + 3,
+                x*y + 2 + 1 + 3,
+                2 + x + 3 + 1,
+                2 + ~x + 3 + 1,
+                2 + ~x + 3,
+                0 & x,
+                2 + (x |= 0) + 3 + 1,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect_stdout: [
         "string 4212",
@@ -207,45 +214,52 @@ evaluate_2: {
 evaluate_2_unsafe_math: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: true,
     }
     input: {
-        var x = "42", y = null;
-        [
-            x + 1 + 2,
-            x * 1 * 2,
-            +x + 1 + 2,
-            1 + x + 2 + 3,
-            1 | x | 2 | 3,
-            1 + x-- + 2 + 3,
-            1 + (x*y + 2) + 3,
-            1 + (2 + x + 3),
-            1 + (2 + ~x + 3),
-            -y + (2 + ~x + 3),
-            1 & (2 & x & 3),
-            1 + (2 + (x |= 0) + 3),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var x = "" + num, y = null;
+            [
+                x + 1 + 2,
+                x * 1 * 2,
+                +x + 1 + 2,
+                1 + x + 2 + 3,
+                1 | x | 2 | 3,
+                1 + x-- + 2 + 3,
+                1 + (x*y + 2) + 3,
+                1 + (2 + x + 3),
+                1 + (2 + ~x + 3),
+                -y + (2 + ~x + 3),
+                1 & (2 & x & 3),
+                1 + (2 + (x |= 0) + 3),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect: {
-        var x = "42", y = null;
-        [
-            x + 1 + 2,
-            2 * x,
-            +x + 3,
-            1 + x + 2 + 3,
-            3 | x,
-            6 + x--,
-            x*y + 6,
-            1 + (2 + x + 3),
-            6 + ~x,
-            5 + ~x - y,
-            0 & x,
-            6 + (x |= 0),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var x = "" + num, y = null;
+            [
+                x + "12",
+                2 * x,
+                +x + 3,
+                1 + x + "23",
+                3 | x,
+                6 + x--,
+                x*y + 6,
+                6 + x,
+                6 + ~x,
+                5 + ~x,
+                0 & x,
+                6 + (x |= 0),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect_stdout: [
         "string 4212",
@@ -310,45 +324,52 @@ evaluate_4: {
 evaluate_5: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: false,
     }
     input: {
-        var a = "1";
-        [
-            +a + 2 + 3,
-            +a + 2 - 3,
-            +a - 2 + 3,
-            +a - 2 - 3,
-            2 + +a + 3,
-            2 + +a - 3,
-            2 - +a + 3,
-            2 - +a - 3,
-            2 + 3 + +a,
-            2 + 3 - +a,
-            2 - 3 + +a,
-            2 - 3 - +a,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var a = "" + num;
+            [
+                +a + 2 + 3,
+                +a + 2 - 3,
+                +a - 2 + 3,
+                +a - 2 - 3,
+                2 + +a + 3,
+                2 + +a - 3,
+                2 - +a + 3,
+                2 - +a - 3,
+                2 + 3 + +a,
+                2 + 3 - +a,
+                2 - 3 + +a,
+                2 - 3 - +a,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(1);
     }
     expect: {
-        var a = "1";
-        [
-            +a + 2 + 3,
-            +a + 2 - 3,
-            a - 2 + 3,
-            a - 2 - 3,
-            +a + 2 + 3,
-            +a + 2 - 3,
-            2 - a + 3,
-            2 - a - 3,
-            +a + 5,
-            5 - a,
-            +a - 1,
-            -1 - a,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var a = "" + num;
+            [
+                +a + 2 + 3,
+                +a + 2 - 3,
+                a - 2 + 3,
+                a - 2 - 3,
+                +a + 2 + 3,
+                +a + 2 - 3,
+                2 - a + 3,
+                2 - a - 3,
+                +a + 5,
+                5 - a,
+                +a - 1,
+                -1 - a,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(1);
     }
     expect_stdout: [
         "number 6",
@@ -369,45 +390,52 @@ evaluate_5: {
 evaluate_5_unsafe_math: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: true,
     }
     input: {
-        var a = "1";
-        [
-            +a + 2 + 3,
-            +a + 2 - 3,
-            +a - 2 + 3,
-            +a - 2 - 3,
-            2 + +a + 3,
-            2 + +a - 3,
-            2 - +a + 3,
-            2 - +a - 3,
-            2 + 3 + +a,
-            2 + 3 - +a,
-            2 - 3 + +a,
-            2 - 3 - +a,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var a = "" + num;
+            [
+                +a + 2 + 3,
+                +a + 2 - 3,
+                +a - 2 + 3,
+                +a - 2 - 3,
+                2 + +a + 3,
+                2 + +a - 3,
+                2 - +a + 3,
+                2 - +a - 3,
+                2 + 3 + +a,
+                2 + 3 - +a,
+                2 - 3 + +a,
+                2 - 3 - +a,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(1);
     }
     expect: {
-        var a = "1";
-        [
-            +a + 5,
-            +a + -1,
-            a - -1,
-            a - 5,
-            +a + 5,
-            +a + -1,
-            5 - a,
-            -1 - a,
-            +a + 5,
-            5 - a,
-            +a - 1,
-            -1 - a,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num) {
+            var a = "" + num;
+            [
+                +a + 5,
+                +a + -1,
+                a - -1,
+                a - 5,
+                +a + 5,
+                +a + -1,
+                5 - a,
+                -1 - a,
+                +a + 5,
+                5 - a,
+                +a - 1,
+                -1 - a,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(1);
     }
     expect_stdout: [
         "number 6",
@@ -546,37 +574,44 @@ evaluate_6_unsafe_math: {
 evaluate_7: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: false,
     }
     input: {
-        var x = "42", y;
-        [
-            +x + 2 + (3 + !y),
-            +x + 2 + (3 - !y),
-            +x + 2 - (3 + !y),
-            +x + 2 - (3 - !y),
-            +x - 2 + (3 + !y),
-            +x - 2 + (3 - !y),
-            +x - 2 - (3 + !y),
-            +x - 2 - (3 - !y),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num, y) {
+            var x = "" + num;
+            [
+                +x + 2 + (3 + !y),
+                +x + 2 + (3 - !y),
+                +x + 2 - (3 + !y),
+                +x + 2 - (3 - !y),
+                +x - 2 + (3 + !y),
+                +x - 2 + (3 - !y),
+                +x - 2 - (3 + !y),
+                +x - 2 - (3 - !y),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect: {
-        var x = "42", y;
-        [
-            +x + 2 + (3 + !y),
-            +x + 2 + (3 - !y),
-            +x + 2 - (3 + !y),
-            +x + 2 - (3 - !y),
-            x - 2 + (3 + !y),
-            x - 2 + (3 - !y),
-            x - 2 - (3 + !y),
-            x - 2 - (3 - !y),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num, y) {
+            var x = "" + num;
+            [
+                +x + 2 + (3 + !y),
+                +x + 2 + (3 - !y),
+                +x + 2 - (3 + !y),
+                +x + 2 - (3 - !y),
+                x - 2 + (3 + !y),
+                x - 2 + (3 - !y),
+                x - 2 - (3 + !y),
+                x - 2 - (3 - !y),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect_stdout: [
         "number 48",
@@ -593,37 +628,44 @@ evaluate_7: {
 evaluate_7_unsafe_math: {
     options = {
         evaluate: true,
+        reduce_vars: true,
         unsafe_math: true,
     }
     input: {
-        var x = "42", y;
-        [
-            +x + 2 + (3 + !y),
-            +x + 2 + (3 - !y),
-            +x + 2 - (3 + !y),
-            +x + 2 - (3 - !y),
-            +x - 2 + (3 + !y),
-            +x - 2 + (3 - !y),
-            +x - 2 - (3 + !y),
-            +x - 2 - (3 - !y),
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num, y) {
+            var x = "" + num;
+            [
+                +x + 2 + (3 + !y),
+                +x + 2 + (3 - !y),
+                +x + 2 - (3 + !y),
+                +x + 2 - (3 - !y),
+                +x - 2 + (3 + !y),
+                +x - 2 + (3 - !y),
+                +x - 2 - (3 + !y),
+                +x - 2 - (3 - !y),
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect: {
-        var x = "42", y;
-        [
-            +x + 5 + !y,
-            +x + 5 - !y,
-            +x + -1 - !y,
-            +x + -1 + !y,
-            x - -1 + !y,
-            x - -1 - !y,
-            x - 5 - !y,
-            x - 5 + !y,
-        ].forEach(function(n) {
-            console.log(typeof n, n);
-        });
+        function f(num, y) {
+            var x = "" + num;
+            [
+                +x + 5 + !y,
+                +x + 5 - !y,
+                +x + -1 - !y,
+                +x + -1 + !y,
+                x - -1 + !y,
+                x - -1 - !y,
+                x - 5 - !y,
+                x - 5 + !y,
+            ].forEach(function(n) {
+                console.log(typeof n, n);
+            });
+        }
+        f(42);
     }
     expect_stdout: [
         "number 48",
@@ -637,6 +679,22 @@ evaluate_7_unsafe_math: {
     ]
 }
 
+evaluate_8_unsafe_math: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        var a = [ "42" ];
+        console.log(a * (1 / 7));
+    }
+    expect: {
+        var a = [ "42" ];
+        console.log(+a / 7);
+    }
+    expect_stdout: "6"
+}
+
 NaN_redefined: {
     options = {
         evaluate: true,
@@ -1251,3 +1309,29 @@ issue_3695: {
     }
     expect_stdout: "NaN"
 }
+
+issue_4137: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log(+(A = []) * (A[0] = 1));
+    }
+    expect: {
+        console.log(+(A = []) * (A[0] = 1));
+    }
+    expect_stdout: "0"
+}
+
+issue_4142: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log("" + +(0 === console));
+    }
+    expect: {
+        console.log("" + +(0 === console));
+    }
+    expect_stdout: "0"
+}

test/compress/objects.js

@@ -221,3 +221,142 @@ numeric_literal: {
         "8 7 8",
     ]
 }
+
+evaluate_computed_key: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            ["foo" + "bar"]: "PASS",
+        }.foobar);
+    }
+    expect: {
+        console.log({
+            foobar: "PASS",
+        }.foobar);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+keep_computed_key: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        ({
+            [console.log("PASS")]: 42,
+        });
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4269_1: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            get 0() {
+                return "FAIL";
+            },
+            [0]: "PASS",
+        }[0]);
+    }
+    expect: {
+        console.log({
+            get 0() {
+                return "FAIL";
+            },
+            [0]: "PASS",
+        }[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4269_2: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            get [0]() {
+                return "FAIL";
+            },
+            0: "PASS",
+        }[0]);
+    }
+    expect: {
+        console.log({
+            get [0]() {
+                return "FAIL";
+            },
+            0: "PASS",
+        }[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4269_3: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            ["foo"]: "bar",
+            get 42() {
+                return "FAIL";
+            },
+            42: "PASS",
+        }[42]);
+    }
+    expect: {
+        console.log({
+            ["foo"]: "bar",
+            get 42() {
+                return "FAIL";
+            },
+            42: "PASS",
+        }[42]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4269_4: {
+    options = {
+        evaluate: true,
+        objects: true,
+    }
+    input: {
+        console.log({
+            get 42() {
+                return "FAIL";
+            },
+            ["foo"]: "bar",
+            42: "PASS",
+        }[42]);
+    }
+    expect: {
+        console.log({
+            get 42() {
+                return "FAIL";
+            },
+            ["foo"]: "bar",
+            42: "PASS",
+        }[42]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}

test/compress/properties.js

@@ -1123,11 +1123,7 @@ new_this: {
             }
         }.f(42);
     }
-    expect: {
-        new function(a) {
-            this.a = a;
-        }(42);
-    }
+    expect: {}
 }
 
 issue_2513: {

test/compress/pure_getters.js

@@ -848,9 +848,8 @@ collapse_vars_1_true: {
     }
     expect: {
         function f(a, b) {
-            for (;;) {
+            for (;;)
                 if (a.g() || b.p) break;
-            }
         }
     }
 }

test/compress/reduce_vars.js

@@ -120,7 +120,7 @@ modified: {
     expect: {
         function f0() {
             var b = 2;
-            b++;
+            +b;
             console.log(2);
             console.log(4);
         }
@@ -1624,7 +1624,7 @@ defun_label: {
     expect_stdout: true
 }
 
-double_reference: {
+double_reference_1: {
     options = {
         reduce_funcs: true,
         reduce_vars: true,
@@ -1638,6 +1638,32 @@ double_reference: {
             g();
         }
     }
+    expect: {
+        function f() {
+            var g = function g() {
+                g();
+            };
+            g();
+        }
+    }
+}
+
+double_reference_2: {
+    options = {
+        functions: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var g = function g() {
+                g();
+            };
+            g();
+        }
+    }
     expect: {
         function f() {
             (function g() {
@@ -1647,6 +1673,60 @@ double_reference: {
     }
 }
 
+double_reference_3: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var x = function f() {
+            return f;
+        };
+        function g() {
+            return x();
+        }
+        console.log(g() === g());
+    }
+    expect: {
+        var x = function f() {
+            return f;
+        };
+        function g() {
+            return x();
+        }
+        console.log(g() === g());
+    }
+    expect_stdout: "true"
+}
+
+double_reference_4: {
+    options = {
+        comparisons: true,
+        functions: true,
+        inline: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var x = function f() {
+            return f;
+        };
+        function g() {
+            return x();
+        }
+        console.log(g() === g());
+    }
+    expect: {
+        console.log(true);
+    }
+    expect_stdout: "true"
+}
+
 iife_arguments_1: {
     options = {
         reduce_funcs: true,
@@ -1686,8 +1766,35 @@ iife_arguments_2: {
     }
     expect: {
         (function() {
-            console.log(function f() {
+            var x = function f() {
                 return f;
+            };
+            console.log(x() === arguments[0]);
+        })();
+    }
+    expect_stdout: true
+}
+
+iife_arguments_3: {
+    options = {
+        functions: true,
+        passes: 2,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var x = function f() {
+                return f;
+            };
+            console.log(x() === arguments[0]);
+        })();
+    }
+    expect: {
+        (function() {
+            console.log(function x() {
+                return x;
             }() === arguments[0]);
         })();
     }
@@ -1892,7 +1999,7 @@ issue_1606: {
             var a, b;
             function g(){};
             b = 2;
-            x(b);
+            x(2);
         }
     }
 }
@@ -2069,6 +2176,7 @@ issue_1670_6: {
         keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
+        sequences: true,
         side_effects: true,
         switches: true,
         unused: true,
@@ -2086,10 +2194,9 @@ issue_1670_6: {
         })(1);
     }
     expect: {
-        (function(a) {
-            a = 1;
-            console.log(a);
-        })(1);
+        (function() {
+            console.log(1);
+        })();
     }
     expect_stdout: "1"
 }
@@ -2308,7 +2415,7 @@ redefine_farg_2: {
         console.log(typeof [], "number",function(a, b) {
             a = b;
             return typeof a;
-        }([]));
+        }());
     }
     expect_stdout: "object number undefined"
 }
@@ -5267,11 +5374,11 @@ defun_catch_4: {
         try {
             throw 42;
         } catch (a) {
+            function a() {}
             console.log(a);
         }
     }
-    expect_stdout: "42"
-    node_version: "<=4"
+    expect_stdout: true
 }
 
 defun_catch_5: {
@@ -5293,10 +5400,10 @@ defun_catch_5: {
             throw 42;
         } catch (a) {
             console.log(a);
+            function a() {}
         }
     }
-    expect_stdout: "42"
-    node_version: "<=4"
+    expect_stdout: true
 }
 
 defun_catch_6: {
@@ -5483,7 +5590,7 @@ lvalues_def_1: {
     }
     expect: {
         var b = 1;
-        var a = b++, b = NaN;
+        var a = +b, b = NaN;
         console.log(a, b);
     }
     expect_stdout: "1 NaN"
@@ -7428,3 +7535,69 @@ global_assign: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4188_1: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            try {
+                while (A)
+                    var a = function() {}, b = a;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                while (A)
+                    var a = function() {}, b = a;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+        })();
+    }
+    expect_stdout: "object undefined"
+}
+
+issue_4188_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+            while (!console)
+                var a = function() {}, b = a;
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+            while (!console)
+                var a = function() {}, b = a;
+        })();
+    }
+    expect_stdout: "number undefined"
+}

test/compress/sequences.js

@@ -877,7 +877,7 @@ for_init_var: {
     expect_stdout: "PASS"
 }
 
-forin: {
+forin_1: {
     options = {
         sequences: true,
     }
@@ -895,6 +895,49 @@ forin: {
     expect_stdout: "PASS"
 }
 
+forin_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            p: 1,
+            q: 2,
+        };
+        var k = "k";
+        for ((console.log("exp"), o)[function() {
+            console.log("prop");
+            return k;
+        }()] in function() {
+            console.log("obj");
+            return o;
+        }())
+            console.log(o.k, o[o.k]);
+    }
+    expect: {
+        var o = {
+            p: 1,
+            q: 2,
+        };
+        for ((console.log("exp"), o)[console.log("prop"), "k"] in console.log("obj"), o)
+            console.log(o.k, o[o.k]);
+    }
+    expect_stdout: [
+        "obj",
+        "exp",
+        "prop",
+        "p 1",
+        "exp",
+        "prop",
+        "q 2",
+    ]
+}
+
 call: {
     options = {
         sequences: true,
@@ -1112,3 +1155,25 @@ issue_3703: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4079: {
+    options = {
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        try {
+            typeof (0, A);
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            A;
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}

test/compress/side_effects.js

@@ -245,6 +245,31 @@ unsafe_builtin_2: {
     expect_stdout: "object PASS PASS"
 }
 
+unsafe_builtin_3: {
+    options = {
+        conditionals: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var o = {};
+        if (42 < Math.random())
+            o.p = "FAIL";
+        else
+            o.p = "PASS";
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect: {
+        var o = {};
+        o.p = 42 < Math.random() ? "FAIL" : "PASS";
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect_stdout: "p PASS"
+}
+
 unsafe_string_replace: {
     options = {
         side_effects: true,
@@ -391,3 +416,20 @@ issue_4008: {
         "PASS",
     ]
 }
+
+trim_new: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        new function(a) {
+            console.log(a);
+        }("PASS");
+    }
+    expect: {
+        (function(a) {
+            console.log(a);
+        })("PASS");
+    }
+    expect_stdout: "PASS"
+}

test/compress/unicode.js

@@ -1,3 +1,37 @@
+ascii_only_false: {
+    options = {}
+    beautify = {
+        ascii_only: false,
+    }
+    input: {
+        console.log(
+            "\x000\x001\x007\x008\x00",
+            "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+            "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
+            "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff"
+        );
+    }
+    expect_exact: 'console.log("\\x000\\x001\\x007\\x008\\0","\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\f\\r\x0e\x0f","\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\');'
+    expect_stdout: true
+}
+
+ascii_only_true: {
+    options = {}
+    beautify = {
+        ascii_only: true,
+    }
+    input: {
+        console.log(
+            "\x000\x001\x007\x008\x00",
+            "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+            "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
+            "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff"
+        );
+    }
+    expect_exact: 'console.log("\\x000\\x001\\x007\\x008\\0","\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\f\\r\\x0e\\x0f","\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f",\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\');'
+    expect_stdout: true
+}
+
 unicode_parse_variables: {
     options = {}
     input: {
@@ -141,3 +175,35 @@ issue_2569: {
     }
     expect_exact: 'new RegExp("[\\udc42-\\udcaa\\udd74-\\udd96\\ude45-\\ude4f\\udea3-\\udecc]");'
 }
+
+surrogate_pair: {
+    beautify = {
+        ascii_only: false,
+    }
+    input: {
+        var \u{2f800} = {
+            \u{2f801}: "\u{100000}",
+        };
+        \u{2f800}.\u{2f802} = "\u{100001}";
+        console.log(typeof \u{2f800}, \u{2f800}.\u{2f801}, \u{2f800}["\u{2f802}"]);
+    }
+    expect_exact: 'var \ud87e\udc00={"\ud87e\udc01":"\udbc0\udc00"};\ud87e\udc00.\ud87e\udc02="\udbc0\udc01";console.log(typeof \ud87e\udc00,\ud87e\udc00.\ud87e\udc01,\ud87e\udc00["\ud87e\udc02"]);'
+    expect_stdout: "object \udbc0\udc00 \udbc0\udc01"
+    node_version: ">=4"
+}
+
+surrogate_pair_ascii: {
+    beautify = {
+        ascii_only: true,
+    }
+    input: {
+        var \u{2f800} = {
+            \u{2f801}: "\u{100000}",
+        };
+        \u{2f800}.\u{2f802} = "\u{100001}";
+        console.log(typeof \u{2f800}, \u{2f800}.\u{2f801}, \u{2f800}["\u{2f802}"]);
+    }
+    expect_exact: 'var \\u{2f800}={"\\ud87e\\udc01":"\\udbc0\\udc00"};\\u{2f800}.\\u{2f802}="\\udbc0\\udc01";console.log(typeof \\u{2f800},\\u{2f800}.\\u{2f801},\\u{2f800}["\\ud87e\\udc02"]);'
+    expect_stdout: "object \udbc0\udc00 \udbc0\udc01"
+    node_version: ">=4"
+}

test/compress/varify.js

@@ -0,0 +1,236 @@
+reduce_merge_const: {
+    options = {
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        const a = console;
+        console.log(typeof a);
+        var b = typeof a;
+        console.log(b);
+    }
+    expect: {
+        var b = console;
+        console.log(typeof b);
+        b = typeof b;
+        console.log(b);
+    }
+    expect_stdout: [
+        "object",
+        "object",
+    ]
+}
+
+reduce_merge_let: {
+    options = {
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        let a = console;
+        console.log(typeof a);
+        var b = typeof a;
+        console.log(b);
+    }
+    expect: {
+        "use strict";
+        var b = console;
+        console.log(typeof b);
+        b = typeof b;
+        console.log(b);
+    }
+    expect_stdout: [
+        "object",
+        "object",
+    ]
+    node_version: ">=4"
+}
+
+reduce_block_const: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        {
+            const a = typeof console;
+            console.log(a);
+        }
+    }
+    expect: {
+        var a = typeof console;
+        console.log(a);
+    }
+    expect_stdout: "object"
+}
+
+reduce_block_let: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        {
+            let a = typeof console;
+            console.log(a);
+        }
+    }
+    expect: {
+        "use strict";
+        var a = typeof console;
+        console.log(a);
+    }
+    expect_stdout: "object"
+    node_version: ">=4"
+}
+
+hoist_props_const: {
+    options = {
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        {
+            const o = {
+                p: "PASS",
+            };
+            console.log(o.p);
+        }
+    }
+    expect: {
+        var o_p = "PASS";
+        console.log(o_p);
+    }
+    expect_stdout: "PASS"
+}
+
+hoist_props_let: {
+    options = {
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        {
+            let o = {
+                p: "PASS",
+            };
+            console.log(o.p);
+        }
+    }
+    expect: {
+        "use strict";
+        var o_p = "PASS";
+        console.log(o_p);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+scope_adjustment_const: {
+    options = {
+        conditionals: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        for (var k in [ 42 ])
+            console.log(function f() {
+                if (k) {
+                    const a = 0;
+                }
+            }());
+    }
+    expect: {
+        for (var k in [ 42 ])
+            console.log(void (k && 0));
+    }
+    expect_stdout: "undefined"
+}
+
+scope_adjustment_let: {
+    options = {
+        conditionals: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        for (var k in [ 42 ])
+            console.log(function f() {
+                if (k) {
+                    let a = 0;
+                }
+            }());
+    }
+    expect: {
+        "use strict";
+        for (var k in [ 42 ])
+            console.log(void (k && 0));
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_4191_const: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        const a = function() {};
+        console.log(typeof a, a());
+    }
+    expect: {
+        function a() {};
+        console.log(typeof a, a());
+    }
+    expect_stdout: "function undefined"
+}
+
+issue_4191_let: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        let a = function() {};
+        console.log(typeof a, a());
+    }
+    expect: {
+        "use strict";
+        function a() {};
+        console.log(typeof a, a());
+    }
+    expect_stdout: "function undefined"
+    node_version: ">=4"
+}

test/input/issue-3294/output.js

@@ -1,2 +1,2 @@
-new function(){console.log(3)};
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUErQyxJQUFyQyxXQUFnQkEsUUFBUUMsSUFBSSJ9
+console.log(3);
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUEwQkEsUUFBUUMsSUFBSSJ9

test/input/issue-520/output.js

@@ -1,2 +1,2 @@
-new function(){console.log(3)};
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUErQyxJQUFyQyxXQUFnQkEsUUFBUUMsSUFBSSJ9
+console.log(3);
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUEwQkEsUUFBUUMsSUFBSSJ9

test/input/reduce/label.js

@@ -1,9 +1,3 @@
-var o = this;
-
-for (var k in o) L17060: {
-    a++;
+UNUSED: {
+    console.log(0 - .1 - .1 - .1);
 }
-
-var a;
-
-console.log(k);

test/input/reduce/label.reduced.js

@@ -1,15 +1,12 @@
 // (beautified)
-var o = this;
-
-for (var k in o) {}
-
-var a;
-
-console.log(k);
-// output: a
+console.log(0 - 1 - .1 - .1);
+// output: -1.2000000000000002
 // 
-// minify: k
+// minify: -1.2
 // 
 // options: {
+//   "compress": {
+//     "unsafe_math": true
+//   },
 //   "mangle": false
 // }

test/jetstream.js

@@ -60,7 +60,7 @@ if (typeof phantom == "undefined") {
         var port = server.address().port;
         if (debug) {
             console.log("http://localhost:" + port + "/");
-        } else {
+        } else (function install() {
             child_process.spawn(process.platform == "win32" ? "npm.cmd" : "npm", [
                 "install",
                 "phantomjs-prebuilt@2.1.14",
@@ -71,7 +71,10 @@ if (typeof phantom == "undefined") {
             ], {
                 stdio: [ "ignore", 1, 2 ]
             }).on("exit", function(code) {
-                if (code) throw new Error("npm install failed!");
+                if (code) {
+                    console.log("npm install failed with code", code);
+                    return install();
+                }
                 var program = require("phantomjs-prebuilt").exec(process.argv[1], port);
                 program.stdout.pipe(process.stdout);
                 program.stderr.pipe(process.stderr);
@@ -82,7 +85,7 @@ if (typeof phantom == "undefined") {
                     process.exit(0);
                 });
             });
-        }
+        })();
     });
     server.timeout = 0;
 } else {

test/mocha/number-literal.js

@@ -28,4 +28,65 @@ describe("Number literals", function() {
             assert.throws(test(inputs[i]), error, inputs[i]);
         }
     });
+    it("Should parse binary, hexadecimal, octal and underscore correctly", function() {
+        [
+            "42",
+            "4_2",
+            "052",
+            "0o52",
+            "0O52",
+            "0o5_2",
+            "0x2a",
+            "0X2A",
+            "0x2_a",
+            "0b101010",
+            "0B101010",
+            "0b101_010",
+            "0.0000000042e+10",
+            "0.0000000042E+10",
+            "0.0_000000042e+10",
+            "0.0000000042e+1_0",
+            "0.000_000_004_2e+1_0",
+            "0.000_000_004_2e+1_0-0B101_010+0x2_A-0o5_2+4_2",
+        ].forEach(function(code) {
+            var result = UglifyJS.minify(code, {
+                compress: {
+                    expression: true,
+                },
+            });
+            if (result.error) throw result.error;
+            assert.strictEqual(result.code, "42;");
+        });
+    });
+    it("Should reject invalid use of underscore", function() {
+        [
+            "_42",
+            "_+42",
+            "+_42",
+        ].forEach(function(code) {
+            var node = UglifyJS.parse(code, {
+                expression: true,
+            });
+            assert.ok(!node.is_constant(), code);
+            assert.ok(!(node instanceof UglifyJS.AST_Statement), code);
+        });
+        [
+            "42_",
+            "4__2",
+            "0_52",
+            "05_2",
+            "0_o52",
+            "0o_52",
+            "0.0000000042_e10",
+            "0.0000000042e_10",
+            "0.0000000042e_+10",
+            "0.0000000042e+_10",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
 });

test/mocha/reduce.js

@@ -24,6 +24,9 @@ describe("test/reduce.js", function() {
     });
     it("Should eliminate unreferenced labels", function() {
         var result = reduce_test(read("test/input/reduce/label.js"), {
+            compress: {
+                unsafe_math: true,
+            },
             mangle: false,
         }, {
             verbose: false,

test/mocha/string-literal.js

@@ -1,64 +1,58 @@
 var assert = require("assert");
+var run_code = require("../sandbox").run_code;
 var UglifyJS = require("../node");
 
 describe("String literals", function() {
     it("Should throw syntax error if a string literal contains a newline", function() {
-        var inputs = [
+        [
             "'\n'",
             "'\r'",
             '"\r\n"',
             "'\u2028'",
-            '"\u2029"'
-        ];
-
-        var test = function(input) {
-            return function() {
+            '"\u2029"',
+        ].forEach(function(input) {
+            assert.throws(function() {
                 var ast = UglifyJS.parse(input);
-            };
-        };
-
-        var error = function(e) {
-            return e instanceof UglifyJS.JS_Parse_Error
-                && e.message === "Unterminated string constant";
-        };
-
-        for (var input in inputs) {
-            assert.throws(test(inputs[input]), error);
-        }
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error
+                    && e.message === "Unterminated string constant";
+            });
+        });
+    });
+    it("Should handle line continuation correctly", function() {
+        [
+            '"\\\r"',
+            '"\\\n"',
+            '"\\\r\n"',
+        ].forEach(function(str) {
+            var code = "console.log(" + str + ");";
+            var result = UglifyJS.minify(code);
+            if (result.error) throw result.error;
+            assert.strictEqual(run_code(result.code), run_code(code));
+        });
     });
-
     it("Should not throw syntax error if a string has a line continuation", function() {
-        var output = UglifyJS.parse('var a = "a\\\nb";').print_to_string();
-        assert.equal(output, 'var a="ab";');
+        var ast = UglifyJS.parse('var a = "a\\\nb";');
+        assert.equal(ast.print_to_string(), 'var a="ab";');
     });
-
     it("Should throw error in strict mode if string contains escaped octalIntegerLiteral", function() {
-        var inputs = [
+        [
             '"use strict";\n"\\76";',
             '"use strict";\nvar foo = "\\76";',
             '"use strict";\n"\\1";',
             '"use strict";\n"\\07";',
-            '"use strict";\n"\\011"'
-        ];
-
-        var test = function(input) {
-            return function() {
+            '"use strict";\n"\\011"',
+        ].forEach(function(input) {
+            assert.throws(function() {
                 var output = UglifyJS.parse(input);
-            }
-        };
-
-        var error = function(e) {
-            return e instanceof UglifyJS.JS_Parse_Error
-                && e.message === "Legacy octal escape sequences are not allowed in strict mode";
-        }
-
-        for (var input in inputs) {
-            assert.throws(test(inputs[input]), error);
-        }
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error
+                    && e.message === "Legacy octal escape sequences are not allowed in strict mode";
+            });
+        });
     });
-
     it("Should not throw error outside strict mode if string contains escaped octalIntegerLiteral", function() {
-        var tests = [
+        [
             [ ';"\\76";', ';">";' ],
             [ ';"\\0";', ';"\\0";' ],
             [ ';"\\08"', ';"\\x008";' ],
@@ -66,19 +60,15 @@ describe("String literals", function() {
             [ ';"\\0008"', ';"\\x008";' ],
             [ ';"use\\\n strict";\n"\\07";', ';"use strict";"\07";' ],
             [ '"use strict" === "use strict";\n"\\76";', '"use strict"==="use strict";">";' ],
-        ];
-
-        for (var test in tests) {
-            var output = UglifyJS.parse(tests[test][0]).print_to_string();
-            assert.equal(output, tests[test][1]);
-        }
+        ].forEach(function(test) {
+            var ast = UglifyJS.parse(test[0]);
+            assert.equal(ast.print_to_string(), test[1]);
+        });
     });
-
     it("Should not throw error when digit is 8 or 9", function() {
         assert.equal(UglifyJS.parse('"use strict";;"\\08"').print_to_string(), '"use strict";;"\\x008";');
         assert.equal(UglifyJS.parse('"use strict";;"\\09"').print_to_string(), '"use strict";;"\\x009";');
     });
-
     it("Should not unescape unpaired surrogates", function() {
         var code = [];
         for (var i = 0; i <= 0xF; i++) {
@@ -115,4 +105,33 @@ describe("String literals", function() {
         assert.ok(code.length > ascii.code.length);
         assert.strictEqual(eval(code), eval(ascii.code));
     });
+    it("Should reject invalid Unicode escape sequence", function() {
+        [
+            'var foo = "\\u-111"',
+            'var bar = "\\u{-1}"',
+            'var baz = "\\ugggg"',
+        ].forEach(function(test) {
+            assert.throws(function() {
+                UglifyJS.parse(test);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error
+                    && e.message === "Invalid hex-character pattern in string";
+            });
+        });
+    });
+    it("Should reject invalid code points in Unicode escape sequence", function() {
+        [
+            // A bit over the valid range
+            '"\\u{110000}"',
+            // 32-bit overflow resulting in "a"
+            '"\\u{100000061}"',
+        ].forEach(function(test) {
+            assert.throws(function() {
+                UglifyJS.parse(test);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error
+                    && /^Invalid character code: /.test(e.message);
+            });
+        });
+    });
 });

test/mocha/tokens.js

@@ -5,7 +5,7 @@ describe("tokens", function() {
     it("Should give correct positions for accessors", function() {
         // location               0         1         2         3         4
         //                        01234567890123456789012345678901234567890123456789
-        var ast = UglifyJS.parse("var obj = { get latest() { return undefined; } }");
+        var ast = UglifyJS.parse("var obj = { get [prop]() { return undefined; } }");
         // test all AST_ObjectProperty tokens are set as expected
         var found = false;
         ast.walk(new UglifyJS.TreeWalker(function(node) {
@@ -13,9 +13,9 @@ describe("tokens", function() {
                 found = true;
                 assert.equal(node.start.pos, 12);
                 assert.equal(node.end.endpos, 46);
-                assert(node.key instanceof UglifyJS.AST_SymbolAccessor);
-                assert.equal(node.key.start.pos, 16);
-                assert.equal(node.key.end.endpos, 22);
+                assert(node.key instanceof UglifyJS.AST_SymbolRef);
+                assert.equal(node.key.start.pos, 17);
+                assert.equal(node.key.end.endpos, 21);
                 assert(node.value instanceof UglifyJS.AST_Accessor);
                 assert.equal(node.value.start.pos, 22);
                 assert.equal(node.value.end.endpos, 46);

test/mocha/with.js

@@ -17,7 +17,7 @@ describe("With", function() {
         var ast = UglifyJS.parse("with(e) {f(1, 2)}");
         ast.figure_out_scope();
         assert.equal(ast.uses_with, true);
-        assert.equal(ast.body[0].expression.scope.uses_with, true);
-        assert.equal(ast.body[0].body.body[0].body.expression.scope.uses_with, true);
+        assert.equal(ast.body[0].expression.scope.resolve().uses_with, true);
+        assert.equal(ast.body[0].body.body[0].body.expression.scope.resolve().uses_with, true);
     });
 });

test/reduce.js

@@ -112,19 +112,18 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
             // no structural AST changes before this point.
             if (node.start._permute >= REPLACEMENTS.length) return;
 
-            if (parent instanceof U.AST_Assign
-                    && parent.left === node
-                || parent instanceof U.AST_Unary
-                    && parent.expression === node
-                    && ["++", "--", "delete"].indexOf(parent.operator) >= 0) {
-                // ignore lvalues
+            // ignore lvalues
+            if (parent instanceof U.AST_Assign && parent.left === node) return;
+            if (parent instanceof U.AST_Unary && parent.expression === node) switch (parent.operator) {
+              case "++":
+              case "--":
+              case "delete":
                 return;
             }
-            if ((parent instanceof U.AST_For || parent instanceof U.AST_ForIn)
-                && parent.init === node && node instanceof U.AST_Var) {
-                // preserve for (var ...)
-                return node;
-            }
+            // preserve for (var xxx; ...)
+            if (parent instanceof U.AST_For && parent.init === node && node instanceof U.AST_Definitions) return node;
+            // preserve for (xxx in ...)
+            if (parent instanceof U.AST_ForIn && parent.init === node) return node;
 
             // node specific permutations with no parent logic
 
@@ -146,7 +145,9 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                 return permute < 2 ? expr : wrap_with_console_log(expr);
             }
             else if (node instanceof U.AST_BlockStatement) {
-                if (in_list) {
+                if (in_list && node.body.filter(function(node) {
+                    return node instanceof U.AST_Const;
+                }).length == 0) {
                     node.start._permute++;
                     CHANGED = true;
                     return List.splice(node.body);
@@ -411,7 +412,7 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                     start: {},
                 });
             }
-            else if (node instanceof U.AST_Var) {
+            else if (node instanceof U.AST_Definitions) {
                 // remove empty var statement
                 if (node.definitions.length == 0) return in_list ? List.skip : new U.AST_EmptyStatement({
                     start: {},
@@ -428,7 +429,7 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                     if (node.TYPE == "Call" && node.expression.print_to_string() == "console.log") {
                         return to_sequence(node.args);
                     }
-                    if (node instanceof U.AST_Catch) {
+                    if (node instanceof U.AST_Catch && node.argname) {
                         descend(node, this);
                         node.body.unshift(new U.AST_SimpleStatement({
                             body: wrap_with_console_log(new U.AST_SymbolRef(node.argname)),
@@ -452,6 +453,7 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                 node.start = JSON.parse(JSON.stringify(node.start));
                 node.start._permute = 0;
             }));
+            var before_iterations = testcase;
             for (var c = 0; c < max_iterations; ++c) {
                 if (verbose && pass == 1 && c % 25 == 0) {
                     log("// reduce test pass " + pass + ", iteration " + c + ": " + testcase.length + " bytes");
@@ -494,12 +496,31 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                     }
                 }
             }
-            if (c == 0) break;
+            if (before_iterations === testcase) break;
             if (verbose) {
                 log("// reduce test pass " + pass + ": " + testcase.length + " bytes");
             }
         }
-        testcase = try_beautify(testcase, minify_options, differs.unminified_result, result_cache, max_timeout);
+        var beautified = U.minify(testcase, {
+            compress: false,
+            mangle: false,
+            output: {
+                beautify: true,
+                braces: true,
+                comments: true,
+            },
+        });
+        testcase = {
+            code: testcase,
+        };
+        if (!beautified.error) {
+            diff = test_for_diff(beautified.code, minify_options, result_cache, max_timeout);
+            if (diff && !diff.timed_out && !diff.error) {
+                testcase = beautified;
+                testcase.code = "// (beautified)\n" + testcase.code;
+                differs = diff;
+            }
+        }
         var lines = [ "" ];
         if (isNaN(max_timeout)) {
             lines.push("// minify error: " + to_comment(strip_color_codes(differs.minified_result.stack)));
@@ -538,34 +559,6 @@ function trim_trailing_whitespace(value) {
     return ("" + value).replace(/\s+$/, "");
 }
 
-function try_beautify(testcase, minify_options, expected, result_cache, timeout) {
-    var result = U.minify(testcase, {
-        compress: false,
-        mangle: false,
-        output: {
-            beautify: true,
-            braces: true,
-            comments: true,
-        },
-    });
-    if (result.error) return {
-        code: testcase,
-    };
-    var toplevel = sandbox.has_toplevel(minify_options);
-    if (isNaN(timeout)) {
-        if (!U.minify(result.code, minify_options).error) return {
-            code: testcase,
-        };
-    } else {
-        var actual = run_code(result.code, toplevel, result_cache, timeout);
-        if (!sandbox.same_stdout(expected, actual)) return {
-            code: testcase,
-        };
-    }
-    result.code = "// (beautified)\n" + result.code;
-    return result;
-}
-
 function has_exit(fn) {
     var found = false;
     var tw = new U.TreeWalker(function(node) {
@@ -600,7 +593,7 @@ function is_error(result) {
 }
 
 function is_timed_out(result) {
-    return is_error(result) && /timed out/.test(result);
+    return is_error(result) && /timed out/.test(result.message);
 }
 
 function is_statement(node) {
@@ -650,7 +643,15 @@ function wrap_with_console_log(node) {
 
 function run_code(code, toplevel, result_cache, timeout) {
     var key = crypto.createHash("sha1").update(code).digest("base64");
-    return result_cache[key] || (result_cache[key] = sandbox.run_code(code, toplevel, timeout));
+    var value = result_cache[key];
+    if (!value) {
+        var start = Date.now();
+        result_cache[key] = value = {
+            result: sandbox.run_code(code, toplevel, timeout),
+            elapsed: Date.now() - start,
+        };
+    }
+    return value;
 }
 
 function compare_run_code(code, minify_options, result_cache, max_timeout) {
@@ -658,21 +659,19 @@ function compare_run_code(code, minify_options, result_cache, max_timeout) {
     if (minified.error) return minified;
 
     var toplevel = sandbox.has_toplevel(minify_options);
-    var elapsed = Date.now();
-    var unminified_result = run_code(code, toplevel, result_cache, max_timeout);
-    elapsed = Date.now() - elapsed;
-    var timeout = Math.min(100 * elapsed, max_timeout);
-    var minified_result = run_code(minified.code, toplevel, result_cache, timeout);
+    var unminified = run_code(code, toplevel, result_cache, max_timeout);
+    var timeout = Math.min(100 * unminified.elapsed, max_timeout);
+    var minified_result = run_code(minified.code, toplevel, result_cache, timeout).result;
 
-    if (sandbox.same_stdout(unminified_result, minified_result)) {
-        return is_timed_out(unminified_result) && is_timed_out(minified_result) && {
+    if (sandbox.same_stdout(unminified.result, minified_result)) {
+        return is_timed_out(unminified.result) && is_timed_out(minified_result) && {
             timed_out: true,
         };
     }
     return {
-        unminified_result: unminified_result,
+        unminified_result: unminified.result,
         minified_result: minified_result,
-        elapsed: elapsed,
+        elapsed: unminified.elapsed,
     };
 }
 

test/ufuzz/actions.js

@@ -1,11 +1,47 @@
-require("../../tools/exit");
-
 var get = require("https").get;
 var parse = require("url").parse;
-var base = process.argv[2];
-var token = process.argv[3];
+
+var base, token, run_number, eldest = true;
+exports.init = function(url, auth, num) {
+    base = url;
+    token = auth;
+    run_number = num;
+};
+exports.should_stop = function(callback) {
+    read(base + "/actions/runs?per_page=100", function(reply) {
+        if (!reply || !Array.isArray(reply.workflow_runs)) return;
+        var runs = reply.workflow_runs.filter(function(workflow) {
+            return workflow.status != "completed";
+        }).sort(function(a, b) {
+            return b.run_number - a.run_number;
+        });
+        var found = false, remaining = 20;
+        (function next() {
+            if (!runs.length) return;
+            var workflow = runs.pop();
+            if (workflow.event == "schedule" && workflow.run_number == run_number) found = true;
+            read(workflow.jobs_url, function(reply) {
+                if (!reply || !Array.isArray(reply.jobs)) return;
+                if (!reply.jobs.every(function(job) {
+                    if (job.status == "completed") return true;
+                    remaining--;
+                    return found || workflow.event != "schedule";
+                })) return;
+                if (remaining >= 0) {
+                    next();
+                } else {
+                    callback();
+                }
+            });
+        })();
+    });
+};
 
 function read(url, callback) {
+    var done = function(reply) {
+        done = function() {};
+        callback(reply);
+    };
     var options = parse(url);
     options.headers = {
         "Authorization": "Token " + token,
@@ -17,33 +53,15 @@ function read(url, callback) {
         response.on("data", function(chunk) {
             chunks.push(chunk);
         }).on("end", function() {
-            callback(JSON.parse(chunks.join("")));
+            var reply;
+            try {
+                reply = JSON.parse(chunks.join(""))
+            } catch (e) {}
+            done(reply);
+        }).on("error", function() {
+            done();
         });
+    }).on("error", function() {
+        done();
     });
 }
-
-var queued = 0, total = 0, earliest, now = Date.now();
-process.on("beforeExit", function() {
-    if (queued > 3) {
-        process.stdout.write("0");
-    } else if (now - earliest > 0 && total > 1) {
-        process.stdout.write(Math.min(20 * (now - earliest) / (total - 1), 6300000).toFixed(0));
-    } else {
-        process.stdout.write("3600000");
-    }
-});
-read(base + "/actions/workflows/ufuzz.yml/runs?event=schedule", function(reply) {
-    reply.workflow_runs.filter(function(workflow) {
-        return /^(in_progress|queued|)$/.test(workflow.status);
-    }).forEach(function(workflow) {
-        read(workflow.jobs_url, function(reply) {
-            reply.jobs.forEach(function(job) {
-                if (job.status == "queued") queued++;
-                total++;
-                if (!job.started_at) return;
-                var start = new Date(job.started_at);
-                if (!(earliest < start)) earliest = start;
-            });
-        });
-    });
-});

test/ufuzz/index.js

@@ -275,6 +275,8 @@ var CANNOT_RETURN = true;
 var NO_DEFUN = false;
 var DEFUN_OK = true;
 var DONT_STORE = true;
+var NO_CONST = true;
+var NO_DUPLICATE = true;
 
 var VAR_NAMES = [
     "a",
@@ -312,6 +314,7 @@ var TYPEOF_OUTCOMES = [
     "crap",
 ];
 
+var block_vars = [];
 var unique_vars = [];
 var loops = 0;
 var funcs = 0;
@@ -329,6 +332,7 @@ function strictMode() {
 
 function createTopLevelCode() {
     VAR_NAMES.length = INITIAL_NAMES_LEN; // prune any previous names still in the list
+    block_vars.length = 0;
     unique_vars.length = 0;
     loops = 0;
     funcs = 0;
@@ -353,11 +357,15 @@ function createFunctions(n, recurmax, allowDefun, canThrow, stmtDepth) {
     return s;
 }
 
-function createParams() {
+function createParams(noDuplicate) {
+    var len = unique_vars.length;
     var params = [];
     for (var n = rng(4); --n >= 0;) {
-        params.push(createVarName(MANDATORY));
+        var name = createVarName(MANDATORY);
+        if (noDuplicate) unique_vars.push(name);
+        params.push(name);
     }
+    unique_vars.length = len;
     return params.join(", ");
 }
 
@@ -374,33 +382,77 @@ function filterDirective(s) {
     return s;
 }
 
+function createBlockVariables(recurmax, stmtDepth, canThrow, fn) {
+    var block_len = block_vars.length;
+    var var_len = VAR_NAMES.length;
+    var consts = [];
+    var lets = [];
+    unique_vars.push("a", "b", "c", "undefined", "NaN", "Infinity");
+    while (!rng(block_vars.length > block_len ? 10 : 100)) {
+        var name = createVarName(MANDATORY, DONT_STORE);
+        if (rng(2)) {
+            consts.push(name);
+        } else {
+            lets.push(name);
+        }
+        block_vars.push(name);
+    }
+    unique_vars.length -= 6;
+    fn(function() {
+        if (rng(2)) {
+            return createDefinitions("const", consts) + "\n" + createDefinitions("let", lets) + "\n";
+        } else {
+            return createDefinitions("let", lets) + "\n" + createDefinitions("const", consts) + "\n";
+        }
+    });
+    block_vars.length = block_len;
+    if (consts.length || lets.length) VAR_NAMES.splice(var_len, consts.length + lets.length);
+
+    function createDefinitions(type, names) {
+        if (!names.length) return "";
+        var save = VAR_NAMES;
+        VAR_NAMES = VAR_NAMES.filter(function(name) {
+            return names.indexOf(name) < 0;
+        });
+        var len = VAR_NAMES.length;
+        var s = type + " " + names.map(function(name) {
+            var value = createExpression(recurmax, NO_COMMA, stmtDepth, canThrow);
+            VAR_NAMES.push(name);
+            return name + " = " + value;
+        }).join(", ") + ";";
+        VAR_NAMES = save.concat(VAR_NAMES.slice(len));
+        return s;
+    }
+}
+
 function createFunction(recurmax, allowDefun, canThrow, stmtDepth) {
     if (--recurmax < 0) { return ";"; }
     if (!STMT_COUNT_FROM_GLOBAL) stmtDepth = 0;
-    var namesLenBefore = VAR_NAMES.length;
+    var s = [];
     var name;
-    if (allowDefun || rng(5) > 0) {
-        name = "f" + funcs++;
-    } else {
-        unique_vars.push("a", "b", "c");
-        name = createVarName(MANDATORY, !allowDefun);
-        unique_vars.length -= 3;
-    }
-    var s = [
-        "function " + name + "(" + createParams() + "){",
-        strictMode()
-    ];
-    if (rng(5) === 0) {
-        // functions with functions. lower the recursion to prevent a mess.
-        s.push(createFunctions(rng(5) + 1, Math.ceil(recurmax * 0.7), DEFUN_OK, canThrow, stmtDepth));
-    } else {
-        // functions with statements
-        s.push(createStatements(3, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth));
-    }
-    s.push("}", "");
-    s = filterDirective(s).join("\n");
+    createBlockVariables(recurmax, stmtDepth, canThrow, function(defns) {
+        var namesLenBefore = VAR_NAMES.length;
+        if (allowDefun || rng(5) > 0) {
+            name = "f" + funcs++;
+        } else {
+            unique_vars.push("a", "b", "c");
+            name = createVarName(MANDATORY, !allowDefun);
+            unique_vars.length -= 3;
+        }
+        s.push("function " + name + "(" + createParams() + "){", strictMode());
+        s.push(defns());
+        if (rng(5) === 0) {
+            // functions with functions. lower the recursion to prevent a mess.
+            s.push(createFunctions(rng(5) + 1, Math.ceil(recurmax * 0.7), DEFUN_OK, canThrow, stmtDepth));
+        } else {
+            // functions with statements
+            s.push(_createStatements(3, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth));
+        }
+        s.push("}", "");
+        s = filterDirective(s).join("\n");
 
-    VAR_NAMES.length = namesLenBefore;
+        VAR_NAMES.length = namesLenBefore;
+    });
 
     if (!allowDefun) {
         // avoid "function statements" (decl inside statements)
@@ -414,7 +466,7 @@ function createFunction(recurmax, allowDefun, canThrow, stmtDepth) {
     return s + ";";
 }
 
-function createStatements(n, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) {
+function _createStatements(n, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) {
     if (--recurmax < 0) { return ";"; }
     var s = "";
     while (--n > 0) {
@@ -423,6 +475,15 @@ function createStatements(n, recurmax, canThrow, canBreak, canContinue, cannotRe
     return s;
 }
 
+function createStatements(n, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) {
+    var s = "";
+    createBlockVariables(recurmax, stmtDepth, canThrow, function(defns) {
+        s += defns() + "\n";
+        s += _createStatements(n, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth);
+    });
+    return s;
+}
+
 function enableLoopControl(flag, defaultValue) {
     return Array.isArray(flag) && flag.indexOf("") < 0 ? flag.concat("") : flag || defaultValue;
 }
@@ -496,11 +557,16 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
         var label = createLabel(canBreak, canContinue);
         canBreak = label.break || enableLoopControl(canBreak, CAN_BREAK);
         canContinue = label.continue || enableLoopControl(canContinue, CAN_CONTINUE);
-        var optElementVar = "";
-        if (rng(5) > 1) {
-            optElementVar = "c = 1 + c; var " + createVarName(MANDATORY) + " = expr" + loop + "[key" + loop + "]; ";
-        }
-        return "{var expr" + loop + " = " + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + "; " + label.target + " for (var key" + loop + " in expr" + loop + ") {" + optElementVar + createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) + "}}";
+        var key = rng(10) ? "key" + loop : getVarName(NO_CONST);
+        return [
+            "{var expr" + loop + " = " + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + "; ",
+            label.target + " for (",
+            /^key/.test(key) ? "var " : "",
+            key + " in expr" + loop + ") {",
+            rng(5) > 1 ? "c = 1 + c; var " + createVarName(MANDATORY) + " = expr" + loop + "[" + key + "]; " : "",
+            createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
+            "}}",
+        ].join("");
       case STMT_SEMI:
         return use_strict && rng(20) === 0 ? '"use strict";' : ";";
       case STMT_EXPR:
@@ -566,13 +632,18 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
             // the catch var should only be accessible in the catch clause...
             // we have to do go through some trouble here to prevent leaking it
             var nameLenBefore = VAR_NAMES.length;
-            var catchName = createVarName(MANDATORY);
-            var freshCatchName = VAR_NAMES.length !== nameLenBefore;
-            if (!catch_redef) unique_vars.push(catchName);
-            s += " catch (" + catchName + ") { " + createStatements(3, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) + " }";
-            // remove catch name
-            if (!catch_redef) unique_vars.pop();
-            if (freshCatchName) VAR_NAMES.splice(nameLenBefore, 1);
+            createBlockVariables(recurmax, stmtDepth, canThrow, function(defns) {
+                var catchName = createVarName(MANDATORY);
+                var freshCatchName = VAR_NAMES.length !== nameLenBefore;
+                if (!catch_redef) unique_vars.push(catchName);
+                s += " catch (" + catchName + ") { ";
+                s += defns() + "\n";
+                s += _createStatements(3, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth);
+                s += " }";
+                // remove catch name
+                if (!catch_redef) unique_vars.pop();
+                if (freshCatchName) VAR_NAMES.splice(nameLenBefore, 1);
+            });
         }
         if (n !== 0) s += " finally { " + createStatements(3, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) + " }";
         return s;
@@ -592,7 +663,7 @@ function createSwitchParts(recurmax, n, canThrow, canBreak, canContinue, cannotR
         if (hadDefault || rng(5) > 0) {
             s.push(
                 "case " + createExpression(recurmax, NO_COMMA, stmtDepth, canThrow) + ":",
-                createStatements(rng(3) + 1, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
+                _createStatements(rng(3) + 1, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
                 rng(10) > 0 ? " break;" : "/* fall-through */",
                 ""
             );
@@ -600,7 +671,7 @@ function createSwitchParts(recurmax, n, canThrow, canBreak, canContinue, cannotR
             hadDefault = true;
             s.push(
                 "default:",
-                createStatements(rng(3) + 1, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
+                _createStatements(rng(3) + 1, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
                 ""
             );
         }
@@ -648,7 +719,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
       case p++:
         return getVarName();
       case p++:
-        return getVarName() + createAssignment() + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow);
+        return getVarName(NO_CONST) + createAssignment() + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow);
       case p++:
         return createExpression(recurmax, COMMA_OK, stmtDepth, canThrow);
       case p++:
@@ -694,19 +765,22 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
             );
             break;
           default:
-            var instantiate = rng(4) ? "new " : "";
-            s.push(
-                instantiate + "function " + name + "(){",
-                strictMode()
-            );
-            if (instantiate) for (var i = rng(4); --i >= 0;) {
-                if (rng(2)) s.push("this." + getDotKey(true) + createAssignment() + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ";");
-                else  s.push("this[" + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + "]" + createAssignment() + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ";");
-            }
-            s.push(
-                createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
-                rng(2) == 0 ? "}" : "}()"
-            );
+            createBlockVariables(recurmax, stmtDepth, canThrow, function(defns) {
+                var instantiate = rng(4) ? "new " : "";
+                s.push(
+                    instantiate + "function " + name + "(){",
+                    strictMode(),
+                    defns()
+                );
+                if (instantiate) for (var i = rng(4); --i >= 0;) {
+                    if (rng(2)) s.push("this." + getDotKey(true) + createAssignment() + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ";");
+                    else  s.push("this[" + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + "]" + createAssignment() + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ";");
+                }
+                s.push(
+                    _createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+                    rng(2) == 0 ? "}" : "}()"
+                );
+            });
             break;
         }
         VAR_NAMES.length = nameLenBefore;
@@ -839,31 +913,51 @@ function getDotKey(assign) {
     return key;
 }
 
-function createAccessor(recurmax, stmtDepth, canThrow) {
+function createObjectKey(recurmax, stmtDepth, canThrow) {
+    return rng(10) ? KEYS[rng(KEYS.length)] : "[" + createExpression(recurmax, NO_COMMA, stmtDepth, canThrow) + "]";
+}
+
+function createObjectFunction(recurmax, stmtDepth, canThrow) {
     var namesLenBefore = VAR_NAMES.length;
     var s;
-    var prop1 = getDotKey();
-    if (rng(2) == 0) {
-        s = [
-            "get " + prop1 + "(){",
-            strictMode(),
-            createStatements(2, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
-            createStatement(recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth, STMT_RETURN_ETC),
-            "},"
-        ];
-    } else {
-        var prop2;
-        do {
-            prop2 = getDotKey();
-        } while (prop1 == prop2);
-        s = [
-            "set " + prop1 + "(" + createVarName(MANDATORY) + "){",
-            strictMode(),
-            createStatements(2, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
-            "this." + prop2 + createAssignment() + _createBinaryExpr(recurmax, COMMA_OK, stmtDepth, canThrow) + ";",
-            "},"
-        ];
-    }
+    createBlockVariables(recurmax, stmtDepth, canThrow, function(defns) {
+        switch (rng(3)) {
+          case 0:
+            s = [
+                "get " + createObjectKey(recurmax, stmtDepth, canThrow) + "(){",
+                strictMode(),
+                defns(),
+                _createStatements(2, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+                createStatement(recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth, STMT_RETURN_ETC),
+                "},",
+            ];
+            break;
+          case 1:
+            var prop1 = createObjectKey(recurmax, stmtDepth, canThrow);
+            var prop2;
+            do {
+                prop2 = getDotKey();
+            } while (prop1 == prop2);
+            s = [
+                "set " + prop1 + "(" + createVarName(MANDATORY) + "){",
+                strictMode(),
+                defns(),
+                _createStatements(2, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+                "this." + prop2 + createAssignment() + _createBinaryExpr(recurmax, COMMA_OK, stmtDepth, canThrow) + ";",
+                "},",
+            ];
+            break;
+          default:
+            s = [
+                createObjectKey(recurmax, stmtDepth, canThrow) + "(" + createParams(NO_DUPLICATE) + "){",
+                strictMode(),
+                defns(),
+                _createStatements(3, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+                "},",
+            ]
+            break;
+        }
+    });
     VAR_NAMES.length = namesLenBefore;
     return filterDirective(s).join("\n");
 }
@@ -871,13 +965,16 @@ function createAccessor(recurmax, stmtDepth, canThrow) {
 function createObjectLiteral(recurmax, stmtDepth, canThrow) {
     recurmax--;
     var obj = ["({"];
-    for (var i = rng(6); --i >= 0;) {
-        if (rng(20) == 0) {
-            obj.push(createAccessor(recurmax, stmtDepth, canThrow));
-        } else {
-            var key = KEYS[rng(KEYS.length)];
-            obj.push(key + ":(" + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + "),");
-        }
+    for (var i = rng(6); --i >= 0;) switch (rng(30)) {
+      case 0:
+        obj.push(createObjectFunction(recurmax, stmtDepth, canThrow));
+        break;
+      case 1:
+        obj.push(getVarName() + ",");
+        break;
+      default:
+        obj.push(createObjectKey(recurmax, stmtDepth, canThrow) + ":(" + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + "),");
+        break;
     }
     obj.push("})");
     return obj.join("\n");
@@ -901,7 +998,7 @@ function _createSimpleBinaryExpr(recurmax, noComma, stmtDepth, canThrow) {
       case 1:
         return "(" + createUnarySafePrefix() + "(" + _createSimpleBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + "))";
       case 2:
-        assignee = getVarName();
+        assignee = getVarName(NO_CONST);
         return "(" + assignee + createAssignment() + _createBinaryExpr(recurmax, noComma, stmtDepth, canThrow) + ")";
       case 3:
         assignee = getVarName();
@@ -963,9 +1060,10 @@ function createUnaryPostfix() {
     return UNARY_POSTFIX[rng(UNARY_POSTFIX.length)];
 }
 
-function getVarName() {
+function getVarName(noConst) {
     // try to get a generated name reachable from current scope. default to just `a`
-    return VAR_NAMES[INITIAL_NAMES_LEN + rng(VAR_NAMES.length - INITIAL_NAMES_LEN)] || "a";
+    var name = VAR_NAMES[INITIAL_NAMES_LEN + rng(VAR_NAMES.length - INITIAL_NAMES_LEN)];
+    return !name || noConst && block_vars.indexOf(name) >= 0 ? "a" : name;
 }
 
 function createVarName(maybe, dontStore) {
@@ -975,7 +1073,7 @@ function createVarName(maybe, dontStore) {
         do {
             name = VAR_NAMES[rng(VAR_NAMES.length)];
             if (suffix) name += "_" + suffix;
-        } while (unique_vars.indexOf(name) >= 0);
+        } while (unique_vars.indexOf(name) >= 0 || block_vars.indexOf(name) >= 0);
         if (suffix && !dontStore) VAR_NAMES.push(name);
         return name;
     }
@@ -1253,10 +1351,6 @@ function patch_try_catch(orig, toplevel) {
     }
 }
 
-var fallback_options = [ JSON.stringify({
-    compress: false,
-    mangle: false
-}) ];
 var minify_options = require("./options.json").map(JSON.stringify);
 var original_code, original_result, errored;
 var uglify_code, uglify_result, ok;
@@ -1264,10 +1358,19 @@ for (var round = 1; round <= num_iterations; round++) {
     process.stdout.write(round + " of " + num_iterations + "\r");
 
     original_code = createTopLevelCode();
-    var orig_result = [ sandbox.run_code(original_code) ];
+    var orig_result = [ sandbox.run_code(original_code), sandbox.run_code(original_code, true) ];
     errored = typeof orig_result[0] != "string";
-    if (!errored) orig_result.push(sandbox.run_code(original_code, true));
-    (errored ? fallback_options : minify_options).forEach(function(options) {
+    if (errored) {
+        println("//=============================================================");
+        println("// original code");
+        try_beautify(original_code, false, orig_result[0], println);
+        println();
+        println();
+        println("original result:");
+        println(orig_result[0]);
+        println();
+    }
+    minify_options.forEach(function(options) {
         var o = JSON.parse(options);
         var toplevel = sandbox.has_toplevel(o);
         o.validate = true;
@@ -1282,13 +1385,20 @@ for (var round = 1; round <= num_iterations; round++) {
                 ok = sandbox.same_stdout(sandbox.run_code(sort_globals(original_code)), sandbox.run_code(sort_globals(uglify_code)));
             }
             // ignore numerical imprecision caused by `unsafe_math`
-            if (!ok && typeof uglify_result == "string" && o.compress && o.compress.unsafe_math) {
+            if (!ok && o.compress && o.compress.unsafe_math && typeof original_result == "string" && typeof uglify_result == "string") {
                 ok = fuzzy_match(original_result, uglify_result);
                 if (!ok) {
                     var fuzzy_result = sandbox.run_code(original_code.replace(/( - 0\.1){3}/g, " - 0.3"), toplevel);
                     ok = sandbox.same_stdout(fuzzy_result, uglify_result);
                 }
             }
+            // ignore difference in error message caused by Temporal Dead Zone
+            if (!ok && errored && uglify_result.name == "ReferenceError" && original_result.name == "ReferenceError") ok = true;
+            // ignore spurious time-outs
+            if (!ok && errored && /timed out/.test(original_result.message) && !/timed out/.test(uglify_result.message)) {
+                if (!orig_result[toplevel ? 3 : 2]) orig_result[toplevel ? 3 : 2] = sandbox.run_code(original_code, toplevel, 10000);
+                ok = sandbox.same_stdout(orig_result[toplevel ? 3 : 2], uglify_result);
+            }
             // ignore difference in error message caused by `in`
             // ignore difference in depth of termination caused by infinite recursion
             if (!ok) {
@@ -1303,16 +1413,6 @@ for (var round = 1; round <= num_iterations; round++) {
             ok = errored && uglify_code.name == original_result.name;
         }
         if (verbose || (verbose_interval && !(round % INTERVAL_COUNT)) || !ok) log(options);
-        else if (errored) {
-            println("//=============================================================");
-            println("// original code");
-            try_beautify(original_code, toplevel, original_result, println);
-            println();
-            println();
-            println("original result:");
-            println(original_result);
-            println();
-        }
         if (!ok && isFinite(num_iterations)) {
             println();
             process.exit(1);

test/ufuzz/job.js

@@ -1,39 +1,71 @@
+var actions = require("./actions");
 var child_process = require("child_process");
 
-var ping = 5 * 60 * 1000;
-var period = +process.argv[2];
-var endTime = Date.now() + period;
-for (var i = 0; i < 2; i++) spawn(endTime);
-
-function spawn(endTime) {
-    var child = child_process.spawn("node", [
-        "--max-old-space-size=2048",
-        "test/ufuzz"
-    ], {
-        stdio: [ "ignore", "pipe", "pipe" ]
-    }).on("exit", respawn);
-    var stdout = "";
-    child.stdout.on("data", function(data) {
-        stdout += data;
+var args = [
+    "--max-old-space-size=2048",
+    "test/ufuzz",
+];
+var iterations;
+switch (process.argv.length) {
+  case 3:
+    iterations = +process.argv[2];
+    args.push(iterations);
+    break;
+  case 5:
+    actions.init(process.argv[2], process.argv[3], +process.argv[4]);
+    break;
+  default:
+    throw new Error("invalid parameters");
+}
+var tasks = [ run(), run() ];
+if (iterations) return;
+var alive = setInterval(function() {
+    actions.should_stop(function() {
+        clearInterval(alive);
+        tasks.forEach(function(kill) {
+            kill();
+        });
     });
-    var stderr = "";
-    child.stderr.on("data", trap).pipe(process.stdout);
-    var keepAlive = setInterval(function() {
-        var end = stdout.lastIndexOf("\r");
-        console.log(stdout.slice(stdout.lastIndexOf("\r", end - 1) + 1, end));
-        stdout = stdout.slice(end + 1);
-    }, ping);
-    var timer = setTimeout(function() {
-        clearInterval(keepAlive);
+}, 8 * 60 * 1000);
+
+function run() {
+    var child, stdout, stderr, log;
+    spawn();
+    return function() {
+        clearInterval(log);
         child.removeListener("exit", respawn);
         child.kill();
-    }, endTime - Date.now());
+    };
+
+    function spawn() {
+        child = child_process.spawn("node", args, {
+            stdio: [ "ignore", "pipe", "pipe" ]
+        }).on("exit", respawn);
+        stdout = "";
+        child.stdout.on("data", function(data) {
+            stdout += data;
+        });
+        stderr = "";
+        child.stderr.on("data", trap).pipe(process.stdout);
+        log = setInterval(function() {
+            stdout = stdout.replace(/[^\r\n]+\r(?=[^\r\n]+\r)/g, "");
+            var end = stdout.lastIndexOf("\r");
+            if (end < 0) return;
+            console.log(stdout.slice(0, end));
+            stdout = stdout.slice(end + 1);
+        }, 5 * 60 * 1000);
+    }
 
     function respawn() {
         console.log(stdout.replace(/[^\r\n]*\r/g, ""));
-        clearInterval(keepAlive);
-        clearTimeout(timer);
-        spawn(endTime);
+        clearInterval(log);
+        if (!iterations) {
+            spawn();
+        } else if (process.exitCode) {
+            tasks.forEach(function(kill) {
+                kill();
+            });
+        }
     }
 
     function trap(data) {