v3.11.6

fixes #4274

README.md

@@ -784,6 +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 {

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;
@@ -754,6 +754,17 @@ var AST_Const = DEFNODE("Const", null, {
     },
 }, 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() {
@@ -1004,24 +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);
@@ -1029,7 +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);
@@ -1037,7 +1051,6 @@ 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);
@@ -1054,10 +1067,6 @@ var AST_Symbol = DEFNODE("Symbol", "scope name thedef", {
     },
 });
 
-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);
@@ -1066,6 +1075,10 @@ 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/compress.js

@@ -97,6 +97,7 @@ function Compressor(options, false_by_default) {
         unsafe_regexp   : false,
         unsafe_undefined: false,
         unused          : !false_by_default,
+        varify          : !false_by_default,
     }, true);
     var evaluate = this.options["evaluate"];
     this.eval_threshold = /eager/.test(evaluate) ? 1 / 0 : +evaluate;
@@ -191,7 +192,11 @@ merge(Compressor.prototype, {
                 node.walk(new TreeWalker(function() {
                     count++;
                 }));
-                AST_Node.info("pass " + pass + ": last_count: " + min_count + ", count: " + count);
+                AST_Node.info("pass {pass}: last_count: {min_count}, count: {count}", {
+                    pass: pass,
+                    min_count: min_count,
+                    count: count,
+                });
                 if (count < min_count) {
                     min_count = count;
                     stopping = false;
@@ -488,7 +493,9 @@ merge(Compressor.prototype, {
             if (!(declare || all(def.orig, function(sym) {
                 return !(sym instanceof AST_SymbolConst);
             }))) return false;
-            if (def.fixed === undefined) return true;
+            if (def.fixed === undefined) return declare || all(def.orig, function(sym) {
+                return !(sym instanceof AST_SymbolLet);
+            });
             if (def.fixed === null && def.safe_ids) {
                 def.safe_ids[def.id] = false;
                 delete def.safe_ids;
@@ -1159,7 +1166,9 @@ merge(Compressor.prototype, {
 
     function as_statement_array(thing) {
         if (thing === null) return [];
-        if (thing instanceof AST_BlockStatement) return thing.body;
+        if (thing instanceof AST_BlockStatement) return all(thing.body, function(stat) {
+            return !(stat instanceof AST_Const || stat instanceof AST_Let);
+        }) ? thing.body : [ thing ];
         if (thing instanceof AST_EmptyStatement) return [];
         if (thing instanceof AST_Statement) return [ thing ];
         throw new Error("Can't convert thing to statement array");
@@ -1337,11 +1346,11 @@ merge(Compressor.prototype, {
                         replaced++;
                     }
                     CHANGED = abort = true;
-                    AST_Node.info("Collapsing {name} [{file}:{line},{col}]", {
-                        name: node.print_to_string(),
+                    AST_Node.info("Collapsing {node} [{file}:{line},{col}]", {
+                        node: node,
                         file: node.start.file,
                         line: node.start.line,
-                        col: node.start.col
+                        col: node.start.col,
                     });
                     if (candidate instanceof AST_UnaryPostfix) {
                         if (lhs instanceof AST_SymbolRef) lhs.definition().fixed = false;
@@ -1417,8 +1426,9 @@ merge(Compressor.prototype, {
                     if (!--replaced) abort = true;
                     if (is_lhs(node, multi_replacer.parent())) return node;
                     def.replaced++;
-                    value_def.replaced--;
-                    return rvalue.clone();
+                    var ref = rvalue.clone();
+                    value_def.references.push(ref);
+                    return ref;
                 }
                 // Skip (non-executed) functions and (leading) default case in switch statements
                 if (node instanceof AST_Default || node instanceof AST_Scope) return node;
@@ -1549,12 +1559,17 @@ merge(Compressor.prototype, {
                 if (node instanceof AST_Defun) return funarg && lhs.name === node.name.name;
                 if (node instanceof AST_DWLoop) return true;
                 if (node instanceof AST_LoopControl) return true;
+                if (node instanceof AST_SymbolRef) {
+                    if (node.is_declared(compressor) ? node.fixed_value() || all(node.definition().orig, function(sym) {
+                        return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
+                    }) : parent instanceof AST_Assign && parent.operator == "=" && parent.left === node) return false;
+                    if (!replace_all) return true;
+                    scan_rhs = false;
+                    return false;
+                }
                 if (node instanceof AST_Try) return true;
                 if (node instanceof AST_With) return true;
-                if (replace_all) return false;
-                return node instanceof AST_SymbolRef
-                    && !node.is_declared(compressor)
-                    && !(parent instanceof AST_Assign && parent.operator == "=" && parent.left === node);
+                return false;
             }
 
             function in_conditional(node, parent) {
@@ -1616,7 +1631,7 @@ merge(Compressor.prototype, {
                     if (side_effects && may_modify(node)) return true;
                     var def = node.definition();
                     return (in_try || def.scope.resolve() !== scope) && !all(def.orig, function(sym) {
-                        return !(sym instanceof AST_SymbolConst);
+                        return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
                     });
                 }
                 if (node instanceof AST_This) return symbol_in_lvalues(node, parent);
@@ -1703,6 +1718,8 @@ merge(Compressor.prototype, {
                     extract_candidates(expr.condition);
                     extract_candidates(expr.consequent);
                     extract_candidates(expr.alternative);
+                } else if (expr instanceof AST_Definitions) {
+                    expr.definitions.forEach(extract_candidates);
                 } else if (expr instanceof AST_Dot) {
                     extract_candidates(expr.expression);
                 } else if (expr instanceof AST_DWLoop) {
@@ -1734,11 +1751,10 @@ merge(Compressor.prototype, {
                     }
                 } else if (expr instanceof AST_Object) {
                     expr.properties.forEach(function(prop) {
-                        if (prop instanceof AST_ObjectKeyVal) {
-                            hit_stack.push(prop);
-                            extract_candidates(prop.value);
-                            hit_stack.pop();
-                        }
+                        hit_stack.push(prop);
+                        if (prop.key instanceof AST_Node) extract_candidates(prop.key);
+                        if (prop instanceof AST_ObjectKeyVal) extract_candidates(prop.value);
+                        hit_stack.pop();
                     });
                 } else if (expr instanceof AST_Sequence) {
                     expr.expressions.forEach(extract_candidates);
@@ -1756,18 +1772,18 @@ merge(Compressor.prototype, {
                     } else {
                         extract_candidates(expr.expression);
                     }
-                } else if (expr instanceof AST_Var) {
-                    expr.definitions.forEach(extract_candidates);
                 } else if (expr instanceof AST_VarDef) {
-                    if (expr.value) {
-                        var def = expr.name.definition();
-                        if (def.references.length > def.replaced) {
-                            candidates.push(hit_stack.slice());
+                    if (expr.name instanceof AST_SymbolVar) {
+                        if (expr.value) {
+                            var def = expr.name.definition();
+                            if (def.references.length > def.replaced) {
+                                candidates.push(hit_stack.slice());
+                            }
+                        } else {
+                            declare_only[expr.name.name] = (declare_only[expr.name.name] || 0) + 1;
                         }
-                        extract_candidates(expr.value);
-                    } else {
-                        declare_only[expr.name.name] = (declare_only[expr.name.name] || 0) + 1;
                     }
+                    if (expr.value) extract_candidates(expr.value);
                 }
                 hit_stack.pop();
             }
@@ -1784,7 +1800,7 @@ merge(Compressor.prototype, {
                 if (parent instanceof AST_Exit) return node;
                 if (parent instanceof AST_If) return node;
                 if (parent instanceof AST_IterationStatement) return node;
-                if (parent instanceof AST_ObjectKeyVal) return node;
+                if (parent instanceof AST_ObjectProperty) return node;
                 if (parent instanceof AST_PropAccess) return node;
                 if (parent instanceof AST_Sequence) {
                     return (parent.tail_node() === node ? find_stop : find_stop_unused)(parent, level + 1);
@@ -1842,7 +1858,7 @@ merge(Compressor.prototype, {
                     if (parent.condition !== node) return node;
                     return find_stop_value(parent, level + 1);
                 }
-                if (parent instanceof AST_ObjectKeyVal) {
+                if (parent instanceof AST_ObjectProperty) {
                     var obj = scanner.parent(level + 1);
                     return all(obj.properties, function(prop) {
                         return prop instanceof AST_ObjectKeyVal;
@@ -1890,7 +1906,7 @@ merge(Compressor.prototype, {
                 if (parent instanceof AST_Exit) return find_stop_unused(parent, level + 1);
                 if (parent instanceof AST_If) return find_stop_unused(parent, level + 1);
                 if (parent instanceof AST_IterationStatement) return node;
-                if (parent instanceof AST_ObjectKeyVal) {
+                if (parent instanceof AST_ObjectProperty) {
                     var obj = scanner.parent(level + 1);
                     return all(obj.properties, function(prop) {
                         return prop instanceof AST_ObjectKeyVal;
@@ -1971,6 +1987,7 @@ merge(Compressor.prototype, {
             }
 
             function foldable(expr) {
+                if (expr instanceof AST_Assign && expr.right.single_use) return;
                 var lhs_ids = Object.create(null);
                 var marker = new TreeWalker(function(node) {
                     if (node instanceof AST_SymbolRef) lhs_ids[node.definition().id] = true;
@@ -2177,7 +2194,7 @@ merge(Compressor.prototype, {
                 var stat = statements[i];
                 if (stat instanceof AST_BlockStatement) {
                     if (all(stat.body, function(stat) {
-                        return !(stat instanceof AST_Const);
+                        return !(stat instanceof AST_Const || stat instanceof AST_Let);
                     })) {
                         CHANGED = true;
                         eliminate_spurious_blocks(stat.body);
@@ -2513,7 +2530,7 @@ merge(Compressor.prototype, {
                 var line = block.body[i];
                 if (line instanceof AST_Var && declarations_only(line)) {
                     decls.push(line);
-                } else if (stat || line instanceof AST_Const) {
+                } else if (stat || line instanceof AST_Const || line instanceof AST_Let) {
                     return false;
                 } else {
                     stat = line;
@@ -2683,9 +2700,12 @@ merge(Compressor.prototype, {
                 if (prop instanceof AST_Node) break;
                 prop = "" + prop;
                 var diff = prop == "__proto__" || compressor.has_directive("use strict") ? function(node) {
-                    return node.key != prop && node.key.name != prop;
+                    return typeof node.key == "string" && node.key != prop;
                 } : function(node) {
-                    return node.key.name != prop;
+                    if (node instanceof AST_ObjectGetter || node instanceof AST_ObjectSetter) {
+                        return typeof node.key == "string" && node.key != prop;
+                    }
+                    return true;
                 };
                 if (!all(value.properties, diff)) break;
                 value.properties.push(make_node(AST_ObjectKeyVal, node, {
@@ -2795,14 +2815,15 @@ merge(Compressor.prototype, {
     }
 
     function extract_declarations_from_unreachable_code(compressor, stat, target) {
-        if (!(stat instanceof AST_Defun)) {
+        if (!(stat instanceof AST_Definitions || stat instanceof AST_Defun)) {
             AST_Node.warn("Dropping unreachable code [{file}:{line},{col}]", stat.start);
         }
         var block;
         stat.walk(new TreeWalker(function(node, descend) {
             if (node instanceof AST_Definitions) {
-                AST_Node.warn("Declarations in unreachable code! [{file}:{line},{col}]", node.start);
-                node.remove_initializers(compressor);
+                if (node.remove_initializers(compressor)) {
+                    AST_Node.warn("Dropping initialization in unreachable code [{file}:{line},{col}]", node.start);
+                }
                 push(node);
                 return true;
             }
@@ -2829,7 +2850,7 @@ merge(Compressor.prototype, {
         function push(node) {
             if (block) {
                 block.push(node);
-                if (node instanceof AST_Const) block.required = true;
+                if (node instanceof AST_Const || node instanceof AST_Let) block.required = true;
             } else {
                 target.push(node);
             }
@@ -2969,10 +2990,9 @@ merge(Compressor.prototype, {
         def(AST_Lambda, return_false);
         def(AST_Null, return_true);
         def(AST_Object, function(compressor) {
-            if (!is_strict(compressor)) return false;
-            for (var i = this.properties.length; --i >=0;)
-                if (this.properties[i].value instanceof AST_Accessor) return true;
-            return false;
+            return is_strict(compressor) && !all(this.properties, function(prop) {
+                return prop instanceof AST_ObjectKeyVal;
+            });
         });
         def(AST_Sequence, function(compressor) {
             return this.tail_node()._dot_throw(compressor);
@@ -3269,7 +3289,12 @@ merge(Compressor.prototype, {
         }
 
         function warn(node) {
-            AST_Node.warn("global_defs " + node.print_to_string() + " redefined [{file}:{line},{col}]", node.start);
+            AST_Node.warn("global_defs {node} redefined [{file}:{line},{col}]", {
+                node: node,
+                file: node.start.file,
+                line: node.start.line,
+                col: node.start.col,
+            });
         }
 
         AST_Toplevel.DEFMETHOD("resolve_defines", function(compressor) {
@@ -3563,12 +3588,13 @@ merge(Compressor.prototype, {
                 var val = {};
                 for (var i = 0; i < this.properties.length; i++) {
                     var prop = this.properties[i];
+                    if (!(prop instanceof AST_ObjectKeyVal)) return this;
                     var key = prop.key;
-                    if (key instanceof AST_Symbol) key = key.name;
-                    if (prop.value instanceof AST_Function) {
-                        if (typeof Object.prototype[key] == "function") return this;
-                        continue;
+                    if (key instanceof AST_Node) {
+                        key = key._eval(compressor, ignore_side_effects, cached, depth);
+                        if (key === prop.key) return this;
                     }
+                    if (prop.value instanceof AST_Function && typeof Object.prototype[key] == "function") return this;
                     val[key] = prop.value._eval(compressor, ignore_side_effects, cached, depth);
                     if (val[key] === prop.value) return this;
                 }
@@ -3874,10 +3900,10 @@ merge(Compressor.prototype, {
                     return val[key].apply(val, args);
                 } catch (ex) {
                     AST_Node.warn("Error evaluating {code} [{file}:{line},{col}]", {
-                        code: this.print_to_string(),
+                        code: this,
                         file: this.start.file,
                         line: this.start.line,
-                        col: this.start.col
+                        col: this.start.col,
                     });
                 } finally {
                     if (val instanceof RegExp) val.lastIndex = 0;
@@ -4086,7 +4112,8 @@ merge(Compressor.prototype, {
             return any(this.properties, compressor);
         });
         def(AST_ObjectProperty, function(compressor) {
-            return this.value.has_side_effects(compressor);
+            return this.key instanceof AST_Node && this.key.has_side_effects(compressor)
+                || this.value.has_side_effects(compressor);
         });
         def(AST_Sub, function(compressor) {
             return this.expression.may_throw_on_access(compressor)
@@ -4106,7 +4133,7 @@ merge(Compressor.prototype, {
         def(AST_SymbolDeclaration, return_false);
         def(AST_SymbolRef, function(compressor) {
             return !(this.is_declared(compressor) && all(this.definition().orig, function(sym) {
-                return !(sym instanceof AST_SymbolConst);
+                return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
             }));
         });
         def(AST_This, return_false);
@@ -4198,7 +4225,8 @@ merge(Compressor.prototype, {
             return any(this.properties, compressor);
         });
         def(AST_ObjectProperty, function(compressor) {
-            return this.value.may_throw(compressor);
+            return this.key instanceof AST_Node && this.key.may_throw(compressor)
+                || this.value.may_throw(compressor);
         });
         def(AST_Return, function(compressor) {
             return this.value && this.value.may_throw(compressor);
@@ -4294,7 +4322,7 @@ merge(Compressor.prototype, {
             return all(this.properties);
         });
         def(AST_ObjectProperty, function() {
-            return this.value.is_constant_expression();
+            return typeof this.key == "string" && this.value.is_constant_expression();
         });
         def(AST_Unary, function() {
             return this.expression.is_constant_expression();
@@ -4360,7 +4388,7 @@ merge(Compressor.prototype, {
             return make_node(AST_EmptyStatement, node);
           case 1:
             var stat = node.body[0];
-            if (!(stat instanceof AST_Const)) return stat;
+            if (!(stat instanceof AST_Const || stat instanceof AST_Let)) return stat;
         }
         return node;
     }
@@ -4448,6 +4476,11 @@ merge(Compressor.prototype, {
                 pop();
                 return true;
             }
+            if (node instanceof AST_Break) {
+                var target = tw.loopcontrol_target(node);
+                if (!(target instanceof AST_IterationStatement)) insert(target);
+                return true;
+            }
             if (node instanceof AST_Conditional) {
                 node.condition.walk(tw);
                 push();
@@ -4460,14 +4493,27 @@ merge(Compressor.prototype, {
             }
             if (node instanceof AST_Const) {
                 node.definitions.forEach(function(defn) {
-                    var def = defn.name.definition();
-                    references[def.id] = false;
-                    def = def.redefined();
-                    if (def) references[def.id] = false;
+                    references[defn.name.definition().id] = false;
                     defn.value.walk(tw);
                 });
                 return true;
             }
+            if (node instanceof AST_Continue) {
+                var target = tw.loopcontrol_target(node);
+                if (target instanceof AST_Do) insert(target);
+                return true;
+            }
+            if (node instanceof AST_Do) {
+                push();
+                segment.block = node;
+                segment.loop = true;
+                var save = segment;
+                node.body.walk(tw);
+                if (segment.inserted === node) segment = save;
+                node.condition.walk(tw);
+                pop();
+                return true;
+            }
             if (node instanceof AST_For) {
                 if (node.init) node.init.walk(tw);
                 push();
@@ -4501,21 +4547,22 @@ merge(Compressor.prototype, {
                 }
                 return true;
             }
-            if (node instanceof AST_IterationStatement) {
-                push();
-                segment.block = node;
-                segment.loop = true;
-                descend();
-                pop();
-                return true;
-            }
             if (node instanceof AST_LabeledStatement) {
                 push();
                 segment.block = node;
+                var save = segment;
                 node.body.walk(tw);
+                if (segment.inserted === node) segment = save;
                 pop();
                 return true;
             }
+            if (node instanceof AST_Let) {
+                node.definitions.forEach(function(defn) {
+                    references[defn.name.definition().id] = false;
+                    if (defn.value) defn.value.walk(tw);
+                });
+                return true;
+            }
             if (node instanceof AST_Scope) {
                 push();
                 segment.block = node;
@@ -4541,7 +4588,10 @@ merge(Compressor.prototype, {
                 segment = save;
                 node.body.forEach(function(branch) {
                     push();
+                    segment.block = node;
+                    var save = segment;
                     walk_body(branch, tw);
+                    if (segment.inserted === node) segment = save;
                     pop();
                 });
                 return true;
@@ -4594,6 +4644,14 @@ merge(Compressor.prototype, {
                 }
                 return true;
             }
+            if (node instanceof AST_While) {
+                push();
+                segment.block = node;
+                segment.loop = true;
+                descend();
+                pop();
+                return true;
+            }
         });
         tw.directives = Object.create(compressor.directives);
         self.walk(tw);
@@ -4618,7 +4676,10 @@ merge(Compressor.prototype, {
                 if (!tail_refs) continue;
                 if (head_refs.start.block !== tail_refs.start.block
                     || !mergeable(head_refs, tail_refs)
-                    || head_refs.start.loop && !mergeable(tail_refs, head_refs)) {
+                    || head_refs.start.loop && !mergeable(tail_refs, head_refs)
+                    || !all(tail_refs, function(sym) {
+                        return sym.scope.find_variable(def.name) === def;
+                    })) {
                     skipped.unshift(tail);
                     continue;
                 }
@@ -4685,6 +4746,27 @@ merge(Compressor.prototype, {
             });
         }
 
+        function insert(target) {
+            var stack = [];
+            while (true) {
+                if (HOP(segment, "block")) {
+                    var block = segment.block;
+                    if (block instanceof AST_LabeledStatement) block = block.body;
+                    if (block === target) break;
+                }
+                stack.push(segment);
+                pop();
+            }
+            segment.inserted = segment.block;
+            push();
+            while (stack.length) {
+                var seg = stack.pop();
+                push();
+                if (HOP(seg, "block")) segment.block = seg.block;
+                if (HOP(seg, "loop")) segment.loop = seg.loop;
+            }
+        }
+
         function must_visit(base, segment) {
             return base === segment || base.isPrototypeOf(segment);
         }
@@ -4715,7 +4797,7 @@ merge(Compressor.prototype, {
             if (!(sym instanceof AST_SymbolRef)) return;
             if (compressor.exposed(sym.definition())) return;
             if (!all(sym.definition().orig, function(sym) {
-                return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLambda);
+                return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLambda || sym instanceof AST_SymbolLet);
             })) return;
             return sym;
         };
@@ -4764,6 +4846,10 @@ merge(Compressor.prototype, {
                     node.definitions.forEach(function(defn) {
                         var def = defn.name.definition();
                         var_defs_by_id.add(def.id, defn);
+                        if (node instanceof AST_Var && def.orig[0] instanceof AST_SymbolCatch) {
+                            var redef = def.redefined();
+                            if (redef) var_defs_by_id.add(redef.id, defn);
+                        }
                         if ((!drop_vars || (node instanceof AST_Const ? def.redefined() : def.const_redefs))
                             && !(def.id in in_use_ids)) {
                             in_use_ids[def.id] = true;
@@ -4948,7 +5034,7 @@ merge(Compressor.prototype, {
                         var old_def, var_defs = var_defs_by_id.get(sym.id);
                         if (!def.value) {
                             if (var_defs.length > 1) {
-                                AST_Node.warn("Dropping duplicated declaration of variable {name} [{file}:{line},{col}]", template(def.name));
+                                AST_Node.info("Dropping declaration of variable {name} [{file}:{line},{col}]", template(def.name));
                                 remove(var_defs, def);
                                 sym.eliminated++;
                             } else {
@@ -4956,7 +5042,7 @@ merge(Compressor.prototype, {
                             }
                         } else if (compressor.option("functions")
                             && !compressor.option("ie8")
-                            && !(node instanceof AST_Const)
+                            && !(node instanceof AST_Const || node instanceof AST_Let)
                             && var_defs.length == 1
                             && sym.assignments == 0
                             && def.value instanceof AST_Function
@@ -5100,7 +5186,7 @@ merge(Compressor.prototype, {
                 return in_list ? List.skip : make_node(AST_EmptyStatement, node);
               case 1:
                 var stat = node.body[0];
-                if (!(stat instanceof AST_Const)) return stat;
+                if (!(stat instanceof AST_Const || stat instanceof AST_Let)) return stat;
             } else if (node instanceof AST_For) {
                 // Certain combination of unused name + side effect leads to invalid AST:
                 //    https://github.com/mishoo/UglifyJS/issues/44
@@ -5139,7 +5225,10 @@ merge(Compressor.prototype, {
                 var def = sym.definition();
                 if (!def) return;
                 if (def.id in in_use_ids) return;
-                if (def.scope !== self && member(def, self.enclosed)) return;
+                if (def.scope !== self) {
+                    var d = self.find_variable(sym);
+                    if ((d && d.redefined() || d) === def) return;
+                }
                 log(sym, "Dropping unused loop variable {name}");
                 if (for_ins[def.id] === node) delete for_ins[def.id];
                 var body = [];
@@ -5182,7 +5271,7 @@ merge(Compressor.prototype, {
                 name: sym.name,
                 file: sym.start.file,
                 line: sym.start.line,
-                col : sym.start.col
+                col : sym.start.col,
             };
         }
 
@@ -5351,7 +5440,7 @@ merge(Compressor.prototype, {
                     vars.set(def.name.name, def);
                     ++vars_found;
                 });
-                var seq = node.to_assignments(compressor);
+                var seq = node.to_assignments();
                 var p = tt.parent();
                 if (p instanceof AST_ForIn && p.init === node) {
                     if (seq) return seq;
@@ -5659,13 +5748,13 @@ merge(Compressor.prototype, {
             return right instanceof AST_Object
                 && right.properties.length > 0
                 && all(right.properties, function(prop) {
-                    return prop instanceof AST_ObjectKeyVal;
+                    return prop instanceof AST_ObjectKeyVal && typeof prop.key == "string";
                 })
                 && all(def.references, function(ref) {
                     return ref.fixed_value() === right;
                 })
                 && all(def.orig, function(sym) {
-                    return !(sym instanceof AST_SymbolConst);
+                    return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
                 });
         }
     });
@@ -5849,12 +5938,14 @@ merge(Compressor.prototype, {
             return safe_to_drop(this, compressor) ? null : this;
         });
         def(AST_Object, function(compressor, first_in_statement) {
-            var values = trim(this.properties, compressor, first_in_statement);
+            var exprs = [];
+            this.properties.forEach(function(prop) {
+                if (prop.key instanceof AST_Node) exprs.push(prop.key);
+                exprs.push(prop.value);
+            });
+            var values = trim(exprs, compressor, first_in_statement);
             return values && make_sequence(this, values);
         });
-        def(AST_ObjectProperty, function(compressor, first_in_statement) {
-            return this.value.drop_side_effect_free(compressor, first_in_statement);
-        });
         def(AST_Sequence, function(compressor, first_in_statement) {
             var expressions = trim(this.expressions, compressor, first_in_statement);
             if (!expressions) return null;
@@ -5883,7 +5974,7 @@ merge(Compressor.prototype, {
         });
         function drop_symbol(ref) {
             return all(ref.definition().orig, function(sym) {
-                return !(sym instanceof AST_SymbolConst);
+                return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
             });
         }
         def(AST_SymbolRef, function(compressor) {
@@ -5896,10 +5987,7 @@ merge(Compressor.prototype, {
                 this.write_only = !exp.has_side_effects(compressor);
                 return this;
             }
-            if (this.operator == "typeof" && exp instanceof AST_SymbolRef) {
-                if (drop_symbol(exp)) return null;
-                if (exp.is_declared(compressor)) return exp;
-            }
+            if (this.operator == "typeof" && exp instanceof AST_SymbolRef && drop_symbol(exp)) return null;
             var node = exp.drop_side_effect_free(compressor, first_in_statement);
             if (first_in_statement && node && is_iife_call(node)) {
                 if (node === exp && this.operator == "!") return this;
@@ -6621,49 +6709,52 @@ merge(Compressor.prototype, {
         this.definitions.forEach(function(def) {
             def.value = make_node(AST_Undefined, def).optimize(compressor);
         });
+        return true;
     });
 
-    AST_Var.DEFMETHOD("remove_initializers", function() {
+    function remove_initializers() {
+        var CHANGED = false;
         this.definitions.forEach(function(def) {
+            if (!def.value) return;
             def.value = null;
+            CHANGED = true;
         });
-    });
+        return CHANGED;
+    }
 
-    AST_Definitions.DEFMETHOD("to_assignments", function(compressor) {
-        var reduce_vars = compressor.option("reduce_vars");
-        var assignments = this.definitions.reduce(function(a, def) {
-            if (def.value) {
-                var name = make_node(AST_SymbolRef, def.name, def.name);
-                a.push(make_node(AST_Assign, def, {
+    AST_Let.DEFMETHOD("remove_initializers", remove_initializers);
+    AST_Var.DEFMETHOD("remove_initializers", remove_initializers);
+
+    AST_Definitions.DEFMETHOD("to_assignments", function() {
+        var assignments = this.definitions.reduce(function(a, defn) {
+            var def = defn.name.definition();
+            if (defn.value) {
+                var name = make_node(AST_SymbolRef, defn.name, defn.name);
+                a.push(make_node(AST_Assign, defn, {
                     operator : "=",
                     left     : name,
-                    right    : def.value
+                    right    : defn.value
                 }));
-                if (reduce_vars) name.definition().fixed = false;
+                def.references.push(name);
             }
-            def = def.name.definition();
             def.eliminated++;
-            def.replaced--;
             return a;
         }, []);
         if (assignments.length == 0) return null;
         return make_sequence(this, assignments);
     });
 
-    OPT(AST_Const, function(self, compressor) {
-        return all(self.definitions, function(defn) {
+    function varify(self, compressor) {
+        return compressor.option("varify") && all(self.definitions, function(defn) {
             var node = defn.name;
             if (!node.fixed_value()) return false;
             var def = node.definition();
             if (compressor.exposed(def)) return false;
             var scope = def.scope.resolve();
-            if (def.scope === scope) return true;
-            if (scope instanceof AST_Toplevel) return !scope.variables.has(node.name) && !scope.globals.has(node.name);
-            var s = def.scope;
-            do {
+            for (var s = def.scope; s !== scope;) {
                 s = s.parent_scope;
                 if (s.var_names()[node.name]) return false;
-            } while (s !== scope);
+            }
             return true;
         }) ? make_node(AST_Var, self, {
             definitions: self.definitions.map(function(defn) {
@@ -6678,7 +6769,10 @@ merge(Compressor.prototype, {
                 });
             })
         }) : self;
-    });
+    }
+
+    OPT(AST_Const, varify);
+    OPT(AST_Let, varify);
 
     function lift_sequence_in_expression(node, compressor) {
         var exp = node.expression;
@@ -6780,7 +6874,7 @@ merge(Compressor.prototype, {
                             length: length,
                             file: self.start.file,
                             line: self.start.line,
-                            col: self.start.col
+                            col: self.start.col,
                         });
                         break;
                     }
@@ -6837,10 +6931,10 @@ merge(Compressor.prototype, {
                         }));
                     } catch (ex) {
                         AST_Node.warn("Error converting {expr} [{file}:{line},{col}]", {
-                            expr: self.print_to_string(),
+                            expr: self,
                             file: self.start.file,
                             line: self.start.line,
-                            col: self.start.col
+                            col: self.start.col,
                         });
                     }
                 }
@@ -7080,7 +7174,7 @@ merge(Compressor.prototype, {
                         return node;
                     }
                 }
-                var child, in_loop, scope;
+                var insert, in_loop, scope;
                 if (replacing && can_inject_symbols()) {
                     fn._squeezed = true;
                     if (exp !== fn) fn.parent_scope = exp.scope;
@@ -7250,7 +7344,7 @@ merge(Compressor.prototype, {
 
         function can_inject_symbols() {
             var defined = Object.create(null);
-            var level = 0;
+            var level = 0, child;
             scope = compressor.self();
             while (!(scope instanceof AST_Scope)) {
                 if (scope.variables) scope.variables.each(function(def) {
@@ -7271,6 +7365,8 @@ merge(Compressor.prototype, {
                     if (scope.fixed_value() instanceof AST_Scope) return false;
                 }
             }
+            insert = scope.body.indexOf(child) + 1;
+            if (!insert) return false;
             var safe_to_inject = (!(scope instanceof AST_Toplevel) || compressor.toplevel.vars)
                 && (exp !== fn || fn.parent_scope.resolve() === compressor.find_parent(AST_Scope));
             var inline = compressor.option("inline");
@@ -7373,7 +7469,7 @@ merge(Compressor.prototype, {
                     return true;
                 }
             });
-            args.unshift(scope.body.indexOf(child) + 1, 0);
+            args.unshift(insert, 0);
             if (decls.length) args.push(make_node(AST_Var, fn, {
                 definitions: decls
             }));
@@ -7551,7 +7647,9 @@ merge(Compressor.prototype, {
                 // typeof always returns a non-empty string, thus it's
                 // always true in booleans
                 AST_Node.warn("Boolean expression always true [{file}:{line},{col}]", self.start);
-                return (exp instanceof AST_SymbolRef ? make_node(AST_True, self) : make_sequence(self, [
+                return (exp instanceof AST_SymbolRef && all(exp.definition().orig, function(sym) {
+                    return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
+                }) ? make_node(AST_True, self) : make_sequence(self, [
                     exp,
                     make_node(AST_True, self)
                 ])).optimize(compressor);
@@ -8341,7 +8439,7 @@ merge(Compressor.prototype, {
                     fixed.name = make_node(AST_SymbolLambda, fixed.name, fixed.name);
                 }
                 if (fixed instanceof AST_Lambda) {
-                    var scope = self.scope;
+                    var scope = self.scope.resolve();
                     fixed.enclosed.forEach(function(def) {
                         if (fixed.variables.has(def.name)) return;
                         if (scope.var_names()[def.name]) return;
@@ -9227,22 +9325,21 @@ merge(Compressor.prototype, {
             var props = expr.properties;
             for (var i = props.length; --i >= 0;) {
                 var prop = props[i];
-                if ("" + prop.key == key) {
-                    if (!all(props, function(prop) {
-                        return prop instanceof AST_ObjectKeyVal;
-                    })) break;
-                    if (!safe_to_flatten(prop.value, compressor)) break;
-                    return make_node(AST_Sub, this, {
-                        expression: make_node(AST_Array, expr, {
-                            elements: props.map(function(prop) {
-                                return prop.value;
-                            })
-                        }),
-                        property: make_node(AST_Number, this, {
-                            value: i
+                if (prop.key != key) continue;
+                if (!all(props, function(prop) {
+                    return prop instanceof AST_ObjectKeyVal && typeof prop.key == "string";
+                })) break;
+                if (!safe_to_flatten(prop.value, compressor)) break;
+                return make_node(AST_Sub, this, {
+                    expression: make_node(AST_Array, expr, {
+                        elements: props.map(function(prop) {
+                            return prop.value;
                         })
-                    });
-                }
+                    }),
+                    property: make_node(AST_Number, this, {
+                        value: i
+                    })
+                });
             }
         }
     });
@@ -9253,7 +9350,7 @@ merge(Compressor.prototype, {
                 prop: self.property,
                 file: self.start.file,
                 line: self.start.line,
-                col: self.start.col
+                col: self.start.col,
             });
         }
         var parent = compressor.parent();
@@ -9309,25 +9406,28 @@ merge(Compressor.prototype, {
 
     OPT(AST_Object, function(self, compressor) {
         if (!compressor.option("objects") || compressor.has_directive("use strict")) return self;
+        for (var i = self.properties.length; --i >= 0;) {
+            var prop = self.properties[i];
+            var key = prop.key;
+            if (key instanceof AST_Node) key = key.evaluate(compressor);
+            if (typeof key != "string" || /[0-9]+/.test(key)) break;
+            if (key !== prop.key) prop.key = "" + key;
+        }
         var keys = new Dictionary();
         var values = [];
         self.properties.forEach(function(prop) {
-            if (typeof prop.key != "string") {
+            if (prop instanceof AST_ObjectKeyVal && typeof prop.key == "string") {
+                if (prop.value.has_side_effects(compressor)) flush();
+                keys.add(prop.key, prop.value);
+            } else {
                 flush();
                 values.push(prop);
-                return;
             }
-            if (prop.value.has_side_effects(compressor)) {
-                flush();
-            }
-            keys.add(prop.key, prop.value);
         });
         flush();
-        if (self.properties.length != values.length) {
-            return make_node(AST_Object, self, {
-                properties: values
-            });
-        }
+        if (self.properties.length != values.length) return make_node(AST_Object, self, {
+            properties: values
+        });
         return self;
 
         function flush() {

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

@@ -107,6 +107,9 @@ function OutputStream(options) {
     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) {
@@ -696,6 +699,7 @@ function OutputStream(options) {
             // (false, true) ? (a = 10, b = 20) : (c = 30)
             // ==> 20 (side effect, set a := 10 and b := 20)
             || 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
@@ -990,7 +994,7 @@ function OutputStream(options) {
     /* -----[ if ]----- */
     function make_then(self, output) {
         var b = self.body;
-        if (output.option("braces") && !(b instanceof AST_Const)
+        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
@@ -1124,6 +1128,7 @@ function OutputStream(options) {
         };
     }
     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) {
@@ -1285,25 +1290,33 @@ function OutputStream(options) {
         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(output) {
         var self = this;
-        print_property_name(self.key, self.quote, output);
+        print_property_key(self, output);
         output.colon();
         self.value.print(output);
     });
@@ -1312,7 +1325,7 @@ function OutputStream(options) {
             var self = this;
             output.print(type);
             output.space();
-            print_property_name(self.key.name, self.quote, output);
+            print_property_key(self, output);
             self.value._codegen(output, true);
         };
     }
@@ -1381,7 +1394,7 @@ function OutputStream(options) {
     });
 
     function force_statement(stat, output) {
-        if (output.option("braces") && !(stat instanceof AST_Const)) {
+        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();
@@ -1484,14 +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

@@ -44,7 +44,7 @@
 
 "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 = "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",
@@ -58,8 +58,6 @@ RESERVED_WORDS = makePredicate(RESERVED_WORDS);
 KEYWORDS_BEFORE_EXPRESSION = makePredicate(KEYWORDS_BEFORE_EXPRESSION);
 KEYWORDS_ATOM = makePredicate(KEYWORDS_ATOM);
 
-var OPERATOR_CHARS = makePredicate(characters("+-*&%=<>!?|~^"));
-
 var RE_BIN_NUMBER = /^0b([01]+)$/i;
 var RE_HEX_NUMBER = /^0x([0-9a-f]+)$/i;
 var RE_OCT_NUMBER = /^0o?([0-7]+)$/i;
@@ -111,31 +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;
 }
@@ -148,32 +136,8 @@ function is_digit(code) {
     return code >= 48 && code <= 57;
 }
 
-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) {
@@ -342,7 +306,7 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
               case (after_e = false, 46): // .
                 return (!has_dot && !has_x && !has_e) ? (has_dot = true) : false;
             }
-            return is_digit(code) || is_letter(code) || ch == "_";
+            return is_digit(code) || /[_0-9a-fo]/i.test(ch);
         });
         if (prefix) num = prefix + num;
         if (/^0[0-7_]+$/.test(num)) {
@@ -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);
@@ -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":
@@ -870,9 +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);
 
@@ -880,6 +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");
@@ -1058,7 +1035,7 @@ function parse($TEXT, options) {
         S.input.push_directives_stack();
         S.in_loop = 0;
         S.labels = [];
-        var body = block_(true);
+        var body = block_();
         if (S.input.has_directive("use strict")) {
             if (name) strict_verify_symbol(name);
             argnames.forEach(strict_verify_symbol);
@@ -1087,12 +1064,12 @@ function parse($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;
@@ -1202,6 +1179,14 @@ function parse($TEXT, options) {
         });
     };
 
+    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(),
@@ -1234,7 +1219,7 @@ function parse($TEXT, options) {
         var tok = S.token, ret;
         switch (tok.type) {
           case "name":
-            ret = _make_symbol(AST_SymbolRef);
+            ret = _make_symbol(AST_SymbolRef, tok);
             break;
           case "num":
             ret = new AST_Number({ start: tok, end: tok, value: tok.value });
@@ -1352,51 +1337,62 @@ function parse($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":
@@ -1407,7 +1403,13 @@ function parse($TEXT, options) {
           case "keyword":
           case "atom":
             next();
-            return tmp.value;
+            return "" + tmp.value;
+          case "punc":
+            if (tmp.value != "[") unexpected();
+            next();
+            var key = expression(false);
+            expect("]");
+            return key;
           default:
             unexpected();
         }
@@ -1420,12 +1422,12 @@ function parse($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,
         });
     }
 
@@ -1439,7 +1441,7 @@ function parse($TEXT, options) {
             if (!noerror) croak("Name expected");
             return null;
         }
-        var sym = _make_symbol(type);
+        var sym = _make_symbol(type, S.token);
         if (S.input.has_directive("use strict") && sym instanceof AST_SymbolDeclaration) {
             strict_verify_symbol(sym);
         }
@@ -1628,7 +1630,7 @@ function parse($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);
         }
@@ -165,11 +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);
         }
@@ -198,11 +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);
         }

lib/scope.js

@@ -169,6 +169,8 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
         } 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, null);
             entangle(defun, scope);
@@ -275,6 +277,9 @@ 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 = new_def.redefined();

lib/transform.js

@@ -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

@@ -143,8 +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": "3.11.3",
+  "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/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/collapse_vars.js

@@ -8556,3 +8556,49 @@ issue_4070: {
     }
     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/conditionals.js

@@ -83,13 +83,11 @@ ifs_3_should_warn: {
         "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: Declarations in unreachable code! [test/compress/conditionals.js:4,12]",
         "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: Declarations in unreachable code! [test/compress/conditionals.js:13,12]",
         "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:3,12]",
         "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:10,12]",
     ]

test/compress/const.js

@@ -161,31 +161,6 @@ merge_vars_3: {
     expect_stdout: true
 }
 
-reduce_merge_vars: {
-    options = {
-        merge_vars: true,
-        reduce_vars: true,
-        toplevel: true,
-        unused: 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",
-    ]
-}
-
 use_before_init_1: {
     options = {
         reduce_vars: true,
@@ -312,24 +287,6 @@ reduce_block_1: {
     expect_stdout: "object"
 }
 
-reduce_block_1_toplevel: {
-    options = {
-        reduce_vars: true,
-        toplevel: true,
-    }
-    input: {
-        {
-            const a = typeof console;
-            console.log(a);
-        }
-    }
-    expect: {
-        var a = typeof console;
-        console.log(a);
-    }
-    expect_stdout: "object"
-}
-
 reduce_block_2: {
     options = {
         reduce_vars: true,
@@ -373,7 +330,7 @@ reduce_block_2_toplevel: {
     expect_stdout: true
 }
 
-hoist_props_1: {
+hoist_props: {
     options = {
         hoist_props: true,
         reduce_vars: true,
@@ -397,28 +354,6 @@ hoist_props_1: {
     expect_stdout: "PASS"
 }
 
-hoist_props_2: {
-    options = {
-        hoist_props: true,
-        passes: 2,
-        reduce_vars: true,
-        toplevel: true,
-    }
-    input: {
-        {
-            const o = {
-                p: "PASS",
-            };
-            console.log(o.p);
-        }
-    }
-    expect: {
-        var o_p = "PASS";
-        console.log(o_p);
-    }
-    expect_stdout: "PASS"
-}
-
 loop_block_1: {
     options = {
         loops: true,
@@ -503,7 +438,7 @@ catch_ie8_1: {
     }
     expect: {
         try {} catch (a) {}
-        console.log(function a() {
+        console.log(function() {
         }());
     }
     expect_stdout: "undefined"
@@ -559,29 +494,6 @@ dead_block_after_return: {
     expect_stdout: true
 }
 
-const_to_var_scope_adjustment: {
-    options = {
-        conditionals: true,
-        inline: true,
-        reduce_vars: true,
-        toplevel: true,
-        unused: 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"
-}
-
 do_if_continue_1: {
     options = {
         if_return: true,
@@ -687,7 +599,7 @@ legacy_scope: {
     expect_stdout: true
 }
 
-issue_4191_1: {
+issue_4191: {
     options = {
         functions: true,
         reduce_vars: true,
@@ -708,24 +620,6 @@ issue_4191_1: {
     expect_stdout: true
 }
 
-issue_4191_2: {
-    options = {
-        functions: true,
-        reduce_vars: true,
-        toplevel: true,
-        unused: true,
-    }
-    input: {
-        const a = function() {};
-        console.log(typeof a, a());
-    }
-    expect: {
-        function a() {};
-        console.log(typeof a, a());
-    }
-    expect_stdout: "function undefined"
-}
-
 issue_4193: {
     options = {
         dead_code: true,
@@ -1151,3 +1045,183 @@ issue_4225: {
     }
     expect_stdout: true
 }
+
+issue_4229: {
+    options = {
+        ie8: true,
+        side_effects: true,
+    }
+    input: {
+        (function f() {
+            f;
+            const f = 42;
+        })();
+    }
+    expect: {
+        (function f() {
+            f;
+            const f = 42;
+        })();
+    }
+    expect_stdout: true
+}
+
+issue_4231: {
+    options = {
+        ie8: true,
+        side_effects: true,
+    }
+    input: {
+        typeof a == 0;
+        console.log(typeof function a() {
+            const a = 0;
+        });
+    }
+    expect: {
+        console.log(typeof function a() {
+            const a = 0;
+        });
+    }
+    expect_stdout: "function"
+}
+
+issue_4245: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        const a = f();
+        function f() {
+            typeof a;
+        }
+    }
+    expect: {
+        const a = f();
+        function f() {
+            a,
+            1;
+        }
+    }
+    expect_stdout: true
+}
+
+issue_4248: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            (function() {
+                a = "PASS";
+                b[a];
+                const b = 0;
+            })();
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect: {
+        var a = "FAIL";
+        try {
+            (function() {
+                a = "PASS";
+                b[a];
+                const b = 0;
+            })();
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4261: {
+    options = {
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        {
+            const a = 42;
+            (function() {
+                function f() {
+                    console.log(a);
+                }
+                function g() {
+                    while (f());
+                }
+                (function() {
+                    while (g());
+                })();
+            })();
+        }
+    }
+    expect: {
+        {
+            const a = 42;
+            (function() {
+                function g() {
+                    while (void console.log(a));
+                }
+                (function() {
+                    while (g());
+                })();
+            })();
+        }
+    }
+    expect_stdout: "42"
+}
+
+issue_4274_1: {
+    options = {
+        loops: true,
+    }
+    input: {
+        for (;;) {
+            if (console.log("PASS")) {
+                const a = 0;
+            } else {
+                break;
+                var a;
+            }
+        }
+    }
+    expect: {
+        for (; console.log("PASS");) {
+            {
+                const a = 0;
+            }
+            var a;
+        }
+    }
+    expect_stdout: true
+}
+
+issue_4274_2: {
+    options = {
+        loops: true,
+    }
+    input: {
+        for (;;) {
+            if (!console.log("PASS")) {
+                break;
+                var a;
+            } else {
+                const a = 0;
+            }
+        }
+    }
+    expect: {
+        for (; console.log("PASS");) {
+            {
+                const a = 0;
+            }
+            var a;
+        }
+    }
+    expect_stdout: true
+}

test/compress/dead-code.js

@@ -61,8 +61,6 @@ dead_code_2_should_warn: {
     expect_stdout: true
     expect_warnings: [
         "WARN: Dropping unreachable code [test/compress/dead-code.js:8,12]",
-        "WARN: Declarations in unreachable code! [test/compress/dead-code.js:10,16]",
-        "WARN: Dropping unreachable code [test/compress/dead-code.js:10,16]",
     ]
     node_version: "<=4"
 }
@@ -103,11 +101,9 @@ dead_code_constant_boolean_should_warn_more: {
         "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: Declarations in unreachable code! [test/compress/dead-code.js:3,12]",
         "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: Declarations in unreachable code! [test/compress/dead-code.js:9,12]",
         "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]",
     ]

test/compress/drop-unused.js

@@ -3085,3 +3085,30 @@ issue_4184: {
     }
     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

@@ -3047,3 +3047,30 @@ issue_4214: {
     }
     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

@@ -2081,7 +2081,7 @@ issue_3016_1: {
         var b = 1;
         do {
             3[b];
-        } while(0);
+        } while (0);
         console.log(b);
     }
     expect_stdout: "1"
@@ -2112,7 +2112,7 @@ issue_3016_2: {
         do {
             a = 3,
             a[b];
-        } while(0);
+        } while (0);
         var a;
         console.log(b);
     }
@@ -2145,7 +2145,7 @@ issue_3016_2_ie8: {
         do {
             a = 3,
             a[b];
-        } while(0);
+        } while (0);
         var a;
         console.log(b);
     }
@@ -2175,7 +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: [
@@ -2208,7 +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: [
@@ -5076,3 +5076,141 @@ issue_4186: {
     }
     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

@@ -2859,3 +2859,48 @@ issue_4186: {
     }
     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/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]",
     ]
 }
 
@@ -84,15 +84,12 @@ 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: 35",
-        "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: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]",
@@ -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]",
     ]
 }
@@ -242,15 +236,12 @@ 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: 46",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:10,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:10,12]",
+        "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]",
@@ -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/loops.js

@@ -1222,3 +1222,35 @@ do_continue: {
     }
     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/merge_vars.js

@@ -3011,3 +3011,175 @@ issue_4168_use_strict: {
     }
     expect_stdout: "PASS true 42"
 }
+
+issue_4237_1: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            do {
+                var b = a++;
+                if (b)
+                    return "FAIL";
+                continue;
+                var c = 42;
+            } while ("undefined" != typeof c);
+            return "PASS";
+        }(0));
+    }
+    expect: {
+        console.log(function(a) {
+            do {
+                var b = a++;
+                if (b)
+                    return "FAIL";
+                continue;
+                var c = 42;
+            } while ("undefined" != typeof c);
+            return "PASS";
+        }(0));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4237_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        loops: true,
+        merge_vars: true,
+        switches: true,
+    }
+    input: {
+        console.log(function(a) {
+            do {
+                switch (0) {
+                  case 0:
+                    var b = a++;
+                  default:
+                    while (b)
+                        return "FAIL";
+                }
+                try {
+                    var c = 0;
+                } finally {
+                    continue;
+                }
+                var d = 0;
+            } while ("undefined" != typeof d);
+            return "PASS";
+        }(0));
+    }
+    expect: {
+        console.log(function(a) {
+            do {
+                switch (0) {
+                  case 0:
+                    var b = a++;
+                    if (b)
+                        return "FAIL";
+                }
+                try {
+                    var c = 0;
+                } finally {
+                    continue;
+                }
+                var d = 0;
+            } while ("undefined" != typeof d);
+            return "PASS";
+        }(0));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4253: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        switch (0) {
+          default:
+            var a = "FAIL";
+            a = a && a;
+            try {
+                break;
+            } catch (e) {}
+            var b = 42;
+        }
+        console.log(b);
+    }
+    expect: {
+        switch (0) {
+          default:
+            var a = "FAIL";
+            a = a && a;
+            try {
+                break;
+            } catch (e) {}
+            var b = 42;
+        }
+        console.log(b);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4255: {
+    options = {
+        dead_code: true,
+        loops: true,
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        L: for (var a = 2; --a;)
+            for (var b = 0; console.log(b); --b)
+                break L;
+    }
+    expect: {
+        L: for (var a = 2; --a;) {
+            var b = 0;
+            if (console.log(b))
+                break L;
+        }
+    }
+    expect_stdout: "0"
+}
+
+issue_4257: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 0;
+        for (var i = 0; i < 2; i++)
+            switch (--a) {
+              case 0:
+                var b = 0;
+                break;
+              case 0:
+              default:
+                var c = 1 + (0 | (b && A));
+                console.log(c);
+            }
+    }
+    expect: {
+        var a = 0;
+        for (var i = 0; i < 2; i++)
+            switch (--a) {
+              case 0:
+                var b = 0;
+                break;
+              case 0:
+              default:
+                var c = 1 + (0 | (b && A));
+                console.log(c);
+            }
+    }
+    expect_stdout: [
+        "1",
+        "1",
+    ]
+}

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/reduce_vars.js

@@ -1999,7 +1999,7 @@ issue_1606: {
             var a, b;
             function g(){};
             b = 2;
-            x(b);
+            x(2);
         }
     }
 }

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/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/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/reduce.js

@@ -593,7 +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) {

test/ufuzz/index.js

@@ -276,6 +276,7 @@ var NO_DEFUN = false;
 var DEFUN_OK = true;
 var DONT_STORE = true;
 var NO_CONST = true;
+var NO_DUPLICATE = true;
 
 var VAR_NAMES = [
     "a",
@@ -356,11 +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(", ");
 }
 
@@ -381,32 +386,43 @@ 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);
-        consts.push(name);
+        if (rng(2)) {
+            consts.push(name);
+        } else {
+            lets.push(name);
+        }
         block_vars.push(name);
     }
     unique_vars.length -= 6;
     fn(function() {
-        var s = [];
-        if (consts.length) {
-            var save = VAR_NAMES;
-            VAR_NAMES = VAR_NAMES.filter(function(name) {
-                return consts.indexOf(name) < 0;
-            });
-            var len = VAR_NAMES.length;
-            s.push("const " + consts.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));
+        if (rng(2)) {
+            return createDefinitions("const", consts) + "\n" + createDefinitions("let", lets) + "\n";
+        } else {
+            return createDefinitions("let", lets) + "\n" + createDefinitions("const", consts) + "\n";
         }
-        return s.join("\n");
     });
     block_vars.length = block_len;
-    if (consts.length) VAR_NAMES.splice(var_len, consts.length);
+    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) {
@@ -897,21 +913,27 @@ 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;
     createBlockVariables(recurmax, stmtDepth, canThrow, function(defns) {
-        var prop1 = getDotKey();
-        if (rng(2) == 0) {
+        switch (rng(3)) {
+          case 0:
             s = [
-                "get " + prop1 + "(){",
+                "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),
-                "},"
+                "},",
             ];
-        } else {
+            break;
+          case 1:
+            var prop1 = createObjectKey(recurmax, stmtDepth, canThrow);
             var prop2;
             do {
                 prop2 = getDotKey();
@@ -922,8 +944,18 @@ function createAccessor(recurmax, stmtDepth, canThrow) {
                 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;
@@ -933,13 +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");
@@ -1358,7 +1393,12 @@ for (var round = 1; round <= num_iterations; round++) {
                 }
             }
             // ignore difference in error message caused by Temporal Dead Zone
-            if (!ok && errored) ok = uglify_result.name == "ReferenceError" && original_result.name == "ReferenceError";
+            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) {