harmony-v3.0.23

... by teaching `collapse_vars` some new tricks.

fixes #2187

README.md

@@ -1,11 +1,11 @@
 uglify-es
 =========
 
-**uglify-es** is an ECMAScript 2015 parser, minifier, compressor and beautifier toolkit.
+**uglify-es** is an ECMAScript parser, minifier, compressor and beautifier toolkit for ES6+.
 
 #### Note:
-- **The `uglify-es` API and CLI is compatible with `uglify-js@3.x`.**
-- **`uglify-es` is not backwards compatible with the `uglify-js@2.x` API and CLI.**
+- **`uglify-es` is API/CLI compatible with `uglify-js@3`.**
+- **`uglify-es` is not backwards compatible with `uglify-js@2`.**
 
 Install
 -------
@@ -109,7 +109,7 @@ a double dash to prevent input files being used as option arguments:
                                 By default UglifyJS will not try to be IE-proof.
     --keep-fnames               Do not mangle/drop function names.  Useful for
                                 code relying on Function.prototype.name.
-    --name-cache                File to hold mangled name mappings.
+    --name-cache <file>         File to hold mangled name mappings.
     --self                      Build UglifyJS as a library (implies --wrap UglifyJS)
     --source-map [options]      Enable source map/specify source map options:
                                 `base`  Path to compute relative paths from input files.
@@ -381,7 +381,47 @@ var code = {
 var options = { toplevel: true };
 var result = UglifyJS.minify(code, options);
 console.log(result.code);
-// console.log(function(n,o){return n+o}(3,7));
+// console.log(3+7);
+```
+
+The `nameCache` option:
+```javascript
+var options = {
+    mangle: {
+        toplevel: true,
+    },
+    nameCache: {}
+};
+var result1 = UglifyJS.minify({
+    "file1.js": "function add(first, second) { return first + second; }"
+}, options);
+var result2 = UglifyJS.minify({
+    "file2.js": "console.log(add(1 + 2, 3 + 4));"
+}, options);
+console.log(result1.code);
+// function n(n,r){return n+r}
+console.log(result2.code);
+// console.log(n(3,7));
+```
+
+You may persist the name cache to the file system in the following way:
+```javascript
+var cacheFileName = "/tmp/cache.json";
+var options = {
+    mangle: {
+        properties: true,
+    },
+    nameCache: JSON.parse(fs.readFileSync(cacheFileName, "utf8"))
+};
+fs.writeFileSync("part1.js", UglifyJS.minify({
+    "file1.js": fs.readFileSync("file1.js", "utf8"),
+    "file2.js": fs.readFileSync("file2.js", "utf8")
+}, options).code, "utf8");
+fs.writeFileSync("part2.js", UglifyJS.minify({
+    "file3.js": fs.readFileSync("file3.js", "utf8"),
+    "file4.js": fs.readFileSync("file4.js", "utf8")
+}, options).code, "utf8");
+fs.writeFileSync(cacheFileName, JSON.stringify(options.nameCache), "utf8");
 ```
 
 An example of a combination of `minify()` options:
@@ -434,6 +474,9 @@ if (result.error) throw result.error;
 
 ## Minify options
 
+- `ecma` (default `undefined`) - pass `5`, `6`, `7` or `8` to override `parse`,
+  `compress` and `output` options.
+
 - `warnings` (default `false`) — pass `true` to return compressor warnings
   in `result.warnings`. Use the value `"verbose"` for more detailed warnings.
 
@@ -459,13 +502,19 @@ if (result.error) throw result.error;
 - `toplevel` (default `false`) - set to `true` if you wish to enable top level
   variable and function name mangling and to drop unused variables and functions.
 
+- `nameCache` (default `null`) - pass an empty object `{}` or a previously
+  used `nameCache` object if you wish to cache mangled variable and
+  property names across multiple invocations of `minify()`. Note: this is
+  a read/write property. `minify()` will read the name cache state of this
+  object and update it during minification so that it may be
+  reused or externally persisted by the user.
+
 - `ie8` (default `false`) - set to `true` to support IE8.
 
 ## Minify options structure
 
 ```javascript
 {
-    warnings: false,
     parse: {
         // parse options
     },
@@ -485,8 +534,11 @@ if (result.error) throw result.error;
     sourceMap: {
         // source map options
     },
+    ecma: 5, // specify one of: 5, 6, 7 or 8
+    nameCache: null, // or specify a name cache object
     toplevel: false,
     ie8: false,
+    warnings: false,
 }
 ```
 
@@ -540,6 +592,9 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 ## Parse options
 
 - `bare_returns` (default `false`) -- support top level `return` statements
+- `ecma` (default: `8`) -- specify one of `5`, `6`, `7` or `8`. Note: this setting
+  is not presently enforced except for ES8 optional trailing commas in function
+  parameter lists and calls with `ecma` `8`.
 - `html5_comments` (default `true`)
 - `shebang` (default `true`) -- support `#!command` as the first line
 
@@ -683,6 +738,9 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   annotation `/*@__PURE__*/` or `/*#__PURE__*/` immediately precedes the call. For
   example: `/*@__PURE__*/foo();`
 
+- `ecma` -- default `5`. Pass `6` or greater to enable `compress` options that
+  will transform ES5 code into smaller ES6+ equivalent forms.
+
 ## Mangle options
 
 - `reserved` (default `[]`). Pass an array of identifiers that should be
@@ -691,6 +749,8 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 - `toplevel` (default `false`). Pass `true` to mangle names declared in the
   top level scope.
 
+- `keep_classnames` (default `false`).  Pass `true` to not mangle class names.
+
 - `keep_fnames` (default `false`).  Pass `true` to not mangle function names.
   Useful for code relying on `Function.prototype.name`. See also: the `keep_fnames`
   [compress option](#compress-options).
@@ -754,9 +814,12 @@ can pass additional arguments that control the code output:
 - `comments` (default `false`) -- pass `true` or `"all"` to preserve all
   comments, `"some"` to preserve some comments, a regular expression string
   (e.g. `/^!/`) or a function.
-- `ecma` (default `5`) -- set output printing mode.  This will only change the
-  output in direct control of the beautifier.  Non-compatible features in the
-  abstract syntax tree will still be outputted as is.
+- `ecma` (default `5`) -- set output printing mode. Set `ecma` to `6` or
+  greater to emit shorthand object properties - i.e.: `{a}` instead of `{a: a}`.
+  The `ecma` option will only change the output in direct control of the
+  beautifier. Non-compatible features in the abstract syntax tree will still
+  be output as is. For example: an `ecma` setting of `5` will **not** convert
+  ES6+ code to ES5.
 - `indent_level` (default 4)
 - `indent_start` (default 0) -- prefix all lines by that many spaces
 - `inline_script` (default `false`) -- escape the slash in occurrences of

bin/uglifyjs

@@ -111,17 +111,8 @@ if (program.mangleProps) {
     if (typeof options.mangle != "object") options.mangle = {};
     options.mangle.properties = program.mangleProps;
 }
-var cache;
 if (program.nameCache) {
-    cache = JSON.parse(read_file(program.nameCache, "{}"));
-    if (options.mangle) {
-        if (typeof options.mangle != "object") options.mangle = {};
-        options.mangle.cache = to_cache("vars");
-        if (options.mangle.properties) {
-            if (typeof options.mangle.properties != "object") options.mangle.properties = {};
-            options.mangle.properties.cache = to_cache("props");
-        }
-    }
+    options.nameCache = JSON.parse(read_file(program.nameCache, "{}"));
 }
 if (program.output == "ast") {
     options.output = {
@@ -271,9 +262,7 @@ function run() {
         print(result.code);
     }
     if (program.nameCache) {
-        fs.writeFileSync(program.nameCache, JSON.stringify(cache, function(key, value) {
-            return value instanceof UglifyJS.Dictionary ? value.toObject() : value;
-        }));
+        fs.writeFileSync(program.nameCache, JSON.stringify(options.nameCache));
     }
     if (result.timings) for (var phase in result.timings) {
         print_error("- " + phase + ": " + result.timings[phase].toFixed(3) + "s");
@@ -386,18 +375,6 @@ function parse_source_map() {
     }
 }
 
-function to_cache(key) {
-    if (cache[key]) {
-        cache[key].props = UglifyJS.Dictionary.fromObject(cache[key].props);
-    } else {
-        cache[key] = {
-            cname: -1,
-            props: new UglifyJS.Dictionary()
-        };
-    }
-    return cache[key];
-}
-
 function skip_key(key) {
     return skip_keys.indexOf(key) >= 0;
 }

lib/ast.js

@@ -345,7 +345,7 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
 var AST_Expansion = DEFNODE("Expansion", "expression", {
     $documentation: "An expandible argument, such as ...rest, a splat, such as [1,2,...all], or an expansion in a variable declaration, such as var [first, ...rest] = list",
     $propdoc: {
-        expression: "AST_Symbol the thing to be expanded"
+        expression: "[AST_Node] the thing to be expanded"
     },
     _walk: function(visitor) {
         var self = this;
@@ -446,7 +446,7 @@ var AST_PrefixedTemplateString = DEFNODE("PrefixedTemplateString", "template_str
 var AST_TemplateString = DEFNODE("TemplateString", "segments", {
     $documentation: "A template string literal",
     $propdoc: {
-        segments: "[AST_TemplateSegment|AST_Expression]* One or more segments, starting with AST_TemplateSegment. AST_Expression may follow AST_TemplateSegment, but each AST_Expression must be followed by AST_TemplateSegment."
+        segments: "[AST_Node*] One or more segments, starting with AST_TemplateSegment. AST_Node may follow AST_TemplateSegment, but each AST_Node must be followed by AST_TemplateSegment."
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){

lib/compress.js

@@ -94,12 +94,9 @@ function Compressor(options, false_by_default) {
     var global_defs = this.options["global_defs"];
     if (typeof global_defs == "object") for (var key in global_defs) {
         if (/^@/.test(key) && HOP(global_defs, key)) {
-            var ast = parse(global_defs[key]);
-            if (ast.body.length == 1 && ast.body[0] instanceof AST_SimpleStatement) {
-                global_defs[key.slice(1)] = ast.body[0].body;
-            } else throw new Error(string_template("Can't handle expression: {value}", {
-                value: global_defs[key]
-            }));
+            global_defs[key.slice(1)] = parse(global_defs[key], {
+                expression: true
+            });
         }
     }
     var pure_funcs = this.options["pure_funcs"];
@@ -366,7 +363,7 @@ merge(Compressor.prototype, {
                     safe_ids = save_ids;
                     return true;
                 }
-                if (node instanceof AST_Function || node instanceof AST_Arrow) {
+                if (is_func_expr(node)) {
                     push();
                     var iife;
                     if (!node.name
@@ -564,6 +561,10 @@ merge(Compressor.prototype, {
         return orig.length == 1 && orig[0] instanceof AST_SymbolLambda;
     });
 
+    function is_func_expr(node) {
+        return node instanceof AST_Arrow || node instanceof AST_Function;
+    }
+
     function is_lhs_read_only(lhs) {
         if (lhs instanceof AST_SymbolRef) return lhs.definition().orig[0] instanceof AST_SymbolLambda;
         if (lhs instanceof AST_PropAccess) {
@@ -748,15 +749,23 @@ merge(Compressor.prototype, {
             var candidates = [];
             var stat_index = statements.length;
             while (--stat_index >= 0) {
+                // Treat parameters as collapsible in IIFE, i.e.
+                //   function(a, b){ ... }(x());
+                // would be translated into equivalent assignments:
+                //   var a = x(), b = undefined;
+                if (stat_index == 0 && compressor.option("unused")) extract_args();
+                // Find collapsible assignments
                 extract_candidates(statements[stat_index]);
                 while (candidates.length > 0) {
                     var candidate = candidates.pop();
                     var lhs = get_lhs(candidate);
                     if (!lhs || is_lhs_read_only(lhs)) continue;
+                    // Locate symbols which may execute code outside of scanning range
                     var lvalues = get_lvalues(candidate);
                     if (lhs instanceof AST_SymbolRef) lvalues[lhs.name] = false;
                     var side_effects = value_has_side_effects(candidate);
-                    var hit = false, abort = false, replaced = false;
+                    var hit = candidate.name instanceof AST_SymbolFunarg;
+                    var abort = false, replaced = false;
                     var tt = new TreeTransformer(function(node, descend) {
                         if (abort) return node;
                         // Skip nodes before `candidate` as quickly as possible
@@ -839,6 +848,58 @@ merge(Compressor.prototype, {
                 }
             }
 
+            function has_overlapping_symbol(fn, arg) {
+                var found = false;
+                arg.walk(new TreeWalker(function(node) {
+                    if (found) return true;
+                    if (node instanceof AST_SymbolRef && fn.variables.has(node.name)) {
+                        var s = node.definition().scope;
+                        if (s !== scope) while (s = s.parent_scope) {
+                            if (s === scope) return true;
+                        }
+                        found = true;
+                    }
+                }));
+                return found;
+            }
+
+            function extract_args() {
+                var iife, fn = compressor.self();
+                if (is_func_expr(fn)
+                    && !fn.name
+                    && !fn.uses_arguments
+                    && !fn.uses_eval
+                    && (iife = compressor.parent()) instanceof AST_Call
+                    && iife.expression === fn
+                    && all(iife.args, function(arg) {
+                        return !(arg instanceof AST_Expansion);
+                    })) {
+                    fn.argnames.forEach(function(sym, i) {
+                        if (sym instanceof AST_Expansion) {
+                            var elements = iife.args.slice(i);
+                            if (all(elements, function(arg) {
+                                return !has_overlapping_symbol(fn, arg);
+                            })) {
+                                candidates.push(make_node(AST_VarDef, sym, {
+                                    name: sym.expression,
+                                    value: make_node(AST_Array, iife, {
+                                        elements: elements
+                                    })
+                                }));
+                            }
+                        } else {
+                            var arg = iife.args[i];
+                            if (!arg) arg = make_node(AST_Undefined, sym);
+                            else if (has_overlapping_symbol(fn, arg)) arg = null;
+                            if (arg) candidates.push(make_node(AST_VarDef, sym, {
+                                name: sym,
+                                value: arg
+                            }));
+                        }
+                    });
+                }
+            }
+
             function extract_candidates(expr) {
                 if (expr instanceof AST_Assign && !expr.left.has_side_effects(compressor)
                     || expr instanceof AST_Unary && (expr.operator == "++" || expr.operator == "--")) {
@@ -859,7 +920,7 @@ merge(Compressor.prototype, {
             function get_lhs(expr) {
                 if (expr instanceof AST_VarDef && expr.name instanceof AST_SymbolDeclaration) {
                     var def = expr.name.definition();
-                    if (def.orig.length > 1
+                    if (def.orig.length > 1 && !(expr.name instanceof AST_SymbolFunarg)
                         || def.references.length == 1 && !compressor.exposed(def)) {
                         return make_node(AST_SymbolRef, expr.name, expr.name);
                     }
@@ -902,6 +963,19 @@ merge(Compressor.prototype, {
             }
 
             function remove_candidate(expr) {
+                if (expr.name instanceof AST_SymbolFunarg) {
+                    var iife = compressor.parent(), argnames = compressor.self().argnames;
+                    var index = argnames.indexOf(expr.name);
+                    if (index < 0) {
+                        iife.args.length = Math.min(iife.args.length, argnames.length - 1);
+                    } else {
+                        var args = iife.args;
+                        if (args[index]) args[index] = make_node(AST_Number, args[index], {
+                            value: 0
+                        });
+                    }
+                    return true;
+                }
                 var found = false;
                 return statements[stat_index].transform(new TreeTransformer(function(node, descend, in_list) {
                     if (found) return node;
@@ -1320,6 +1394,7 @@ merge(Compressor.prototype, {
             return false;
         });
         def(AST_Function, return_false);
+        def(AST_Arrow, return_false);
         def(AST_UnaryPostfix, return_false);
         def(AST_UnaryPrefix, function() {
             return this.operator == "void";
@@ -1593,9 +1668,6 @@ merge(Compressor.prototype, {
         def(AST_Lambda, function(){
             throw def;
         });
-        def(AST_Arrow, function() {
-            throw def;
-        });
         def(AST_Class, function() {
             throw def;
         });
@@ -1649,8 +1721,7 @@ merge(Compressor.prototype, {
               case "typeof":
                 // Function would be evaluated to an array and so typeof would
                 // incorrectly return 'object'. Hence making is a special case.
-                if (e instanceof AST_Function ||
-                    e instanceof AST_Arrow) return typeof function(){};
+                if (is_func_expr(e)) return typeof function(){};
 
                 e = ev(e, compressor);
 
@@ -1822,6 +1893,9 @@ merge(Compressor.prototype, {
         def(AST_Function, function(){
             return basic_negation(this);
         });
+        def(AST_Arrow, function(){
+            return basic_negation(this);
+        });
         def(AST_UnaryPrefix, function(){
             if (this.operator == "!")
                 return this.expression;
@@ -2568,7 +2642,7 @@ merge(Compressor.prototype, {
         def(AST_This, return_null);
         def(AST_Call, function(compressor, first_in_statement){
             if (!this.has_pure_annotation(compressor) && compressor.pure_funcs(this)) {
-                if (this.expression instanceof AST_Function
+                if (is_func_expr(this.expression)
                     && (!this.expression.name || !this.expression.name.definition().references.length)) {
                     var node = this.clone();
                     node.expression.process_expression(false, compressor);
@@ -2672,6 +2746,9 @@ merge(Compressor.prototype, {
             if (expr) merge_sequence(expressions, expr);
             return make_sequence(this, expressions);
         });
+        def(AST_Expansion, function(compressor, first_in_statement){
+            return this.expression.drop_side_effect_free(compressor, first_in_statement);
+        });
     })(function(node, func){
         node.DEFMETHOD("drop_side_effect_free", func);
     });
@@ -3092,16 +3169,16 @@ merge(Compressor.prototype, {
         });
         if (compressor.option("unused")
             && simple_args
-            && (fn instanceof AST_Function
+            && (is_func_expr(fn)
                 || compressor.option("reduce_vars")
                     && fn instanceof AST_SymbolRef
-                    && (fn = fn.fixed_value()) instanceof AST_Function)
+                    && is_func_expr(fn = fn.fixed_value()))
             && !fn.uses_arguments
             && !fn.uses_eval) {
             var pos = 0, last = 0;
             for (var i = 0, len = self.args.length; i < len; i++) {
                 if (fn.argnames[i] instanceof AST_Expansion) {
-                    if (fn.argnames[i].__unused) while (i < len) {
+                    if (fn.argnames[i].expression.__unused) while (i < len) {
                         var node = self.args[i++].drop_side_effect_free(compressor);
                         if (node) {
                             self.args[pos++] = node;
@@ -3269,7 +3346,7 @@ merge(Compressor.prototype, {
             if (self.args.length == 0) return make_node(AST_Function, self, {
                 argnames: [],
                 body: []
-            });
+            }).optimize(compressor);
             if (all(self.args, function(x) {
                 return x instanceof AST_String;
             })) {
@@ -3277,7 +3354,7 @@ merge(Compressor.prototype, {
                 //   https://github.com/mishoo/UglifyJS2/issues/203
                 // if the code argument is a constant, then we can minify it.
                 try {
-                    var code = "NaN(function(" + self.args.slice(0, -1).map(function(arg) {
+                    var code = "n(function(" + self.args.slice(0, -1).map(function(arg) {
                         return arg.value;
                     }).join(",") + "){" + self.args[self.args.length - 1].value + "})";
                     var ast = parse(code);
@@ -3292,24 +3369,30 @@ merge(Compressor.prototype, {
                     var fun;
                     ast.walk(new TreeWalker(function(node) {
                         if (fun) return true;
-                        if (node instanceof AST_Function) {
+                        if (is_func_expr(node)) {
                             fun = node;
                             return true;
                         }
                     }));
-                    if (!fun) return self;
-                    var args = fun.argnames.map(function(arg, i) {
-                        return make_node(AST_String, self.args[i], {
-                            value: arg.print_to_string()
-                        });
-                    });
+                    if (fun.body instanceof AST_Node) {
+                        fun.body = [
+                            make_node(AST_Return, fun.body, {
+                                value: fun.body
+                            })
+                        ];
+                    }
                     var code = OutputStream();
                     AST_BlockStatement.prototype._codegen.call(fun, fun, code);
-                    code = code.toString().replace(/^\{|\}$/g, "");
-                    args.push(make_node(AST_String, self.args[self.args.length - 1], {
-                        value: code
-                    }));
-                    self.args = args;
+                    self.args = [
+                        make_node(AST_String, self, {
+                            value: fun.argnames.map(function(arg) {
+                                return arg.print_to_string();
+                            }).join(",")
+                        }),
+                        make_node(AST_String, self.args[self.args.length - 1], {
+                            value: code.get().replace(/^\{|\}$/g, "")
+                        })
+                    ];
                     return self;
                 } catch (ex) {
                     if (ex instanceof JS_Parse_Error) {
@@ -3321,96 +3404,67 @@ merge(Compressor.prototype, {
                 }
             }
         }
-        var stat = fn instanceof AST_Function && fn.body[0];
+        var stat = is_func_expr(fn) && fn.body;
+        if (stat instanceof AST_Node) {
+            stat = make_node(AST_Return, stat, {
+                value: stat
+            });
+        } else if (stat) {
+            stat = stat[0];
+        }
         if (compressor.option("inline") && stat instanceof AST_Return) {
             var value = stat.value;
             if (!value || value.is_constant_expression()) {
                 var args = self.args.concat(value || make_node(AST_Undefined, self));
-                return make_sequence(self, args).transform(compressor);
+                return make_sequence(self, args).optimize(compressor);
             }
         }
-        if (exp instanceof AST_Function && !exp.is_generator && !exp.async) {
+        if (is_func_expr(exp) && !exp.is_generator && !exp.async) {
             if (compressor.option("inline")
+                && simple_args
                 && !exp.name
-                && exp.body.length == 1
                 && !exp.uses_arguments
                 && !exp.uses_eval
-                && simple_args
+                && (exp.body instanceof AST_Node || exp.body.length == 1)
+                && all(exp.argnames, function(arg) {
+                    if (arg instanceof AST_Expansion) return arg.expression.__unused;
+                    return arg.__unused;
+                })
                 && !self.has_pure_annotation(compressor)) {
                 var value;
                 if (stat instanceof AST_Return) {
-                    value = stat.value.clone(true);
+                    value = stat.value;
                 } else if (stat instanceof AST_SimpleStatement) {
                     value = make_node(AST_UnaryPrefix, stat, {
                         operator: "void",
-                        expression: stat.body.clone(true)
+                        expression: stat.body
                     });
                 }
                 if (value) {
-                    var fn = exp.clone();
-                    fn.argnames = [];
-                    fn.body = [];
-                    if (exp.argnames.length > 0) {
-                        fn.body.push(make_node(AST_Var, self, {
-                            definitions: exp.argnames.map(function(sym, i) {
-                                if (sym instanceof AST_Expansion) {
-                                    return make_node(AST_VarDef, sym, {
-                                        name: sym.expression,
-                                        value: make_node(AST_Array, self, {
-                                            elements: self.args.slice(i).map(function(arg) {
-                                                return arg.clone(true);
-                                            })
-                                        })
-                                    });
-                                }
-                                var arg = self.args[i];
-                                return make_node(AST_VarDef, sym, {
-                                    name: sym,
-                                    value: arg ? arg.clone(true) : make_node(AST_Undefined, self)
-                                });
-                            })
-                        }));
-                    }
-                    if (self.args.length > exp.argnames.length && !(exp.argnames[exp.argnames.length - 1] instanceof AST_Expansion)) {
-                        fn.body.push(make_node(AST_SimpleStatement, self, {
-                            body: make_sequence(self, self.args.slice(exp.argnames.length).map(function(node) {
-                                return node.clone(true);
-                            }))
-                        }));
-                    }
-                    fn.body.push(make_node(AST_Return, self, {
-                        value: value
-                    }));
-                    var body = fn.transform(compressor).body;
-                    if (body.length == 0) return make_node(AST_Undefined, self);
-                    if (body.length == 1 && body[0] instanceof AST_Return) {
-                        value = body[0].value;
-                        if (!value) return make_node(AST_Undefined, self);
-                        var tw = new TreeWalker(function(node) {
-                            if (value === self) return true;
-                            if (node instanceof AST_SymbolRef) {
-                                var ref = node.scope.find_variable(node);
-                                if (ref && ref.scope.parent_scope === fn.parent_scope) {
-                                    value = self;
-                                    return true;
-                                }
-                            }
-                            if (node instanceof AST_This && !tw.find_parent(AST_Scope)) {
-                                value = self;
+                    var tw = new TreeWalker(function(node) {
+                        if (!value) return true;
+                        if (node instanceof AST_SymbolRef) {
+                            var ref = node.scope.find_variable(node);
+                            if (ref && ref.scope.parent_scope === fn.parent_scope) {
+                                value = null;
                                 return true;
                             }
-                        });
-                        value.walk(tw);
-                        if (value !== self) value = best_of(compressor, value, self);
-                    } else {
-                        value = self;
-                    }
-                    if (value !== self) return value;
+                        }
+                        if (node instanceof AST_This && !tw.find_parent(AST_Scope)) {
+                            value = null;
+                            return true;
+                        }
+                    });
+                    value.walk(tw);
+                }
+                if (value) {
+                    var args = self.args.concat(value);
+                    return make_sequence(self, args).optimize(compressor);
                 }
             }
-            if (compressor.option("side_effects") && all(exp.body, is_empty)) {
+            if (compressor.option("side_effects") && !(exp.body instanceof AST_Node) && all(exp.body, is_empty)) {
                 var args = self.args.concat(make_node(AST_Undefined, self));
-                return make_sequence(self, args).transform(compressor);
+                return make_sequence(self, args).optimize(compressor);
             }
         }
         if (compressor.option("drop_console")) {
@@ -4082,7 +4136,7 @@ merge(Compressor.prototype, {
                 d.fixed = fixed = make_node(AST_Function, fixed, fixed);
             }
             if (compressor.option("unused")
-                && fixed instanceof AST_Function
+                && is_func_expr(fixed)
                 && d.references.length == 1
                 && !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
                 && !d.scope.uses_eval

lib/minify.js

@@ -27,6 +27,23 @@ function set_shorthand(name, options, keys) {
     }
 }
 
+function init_cache(cache) {
+    if (!cache) return;
+    if (!("cname" in cache)) cache.cname = -1;
+    if (!("props" in cache)) {
+        cache.props = new Dictionary();
+    } else if (!(cache.props instanceof Dictionary)) {
+        cache.props = Dictionary.fromObject(cache.props);
+    }
+}
+
+function to_json(cache) {
+    return {
+        cname: cache.cname,
+        props: cache.props.toObject()
+    };
+}
+
 function minify(files, options) {
     var warn_function = AST_Node.warn_function;
     try {
@@ -36,6 +53,7 @@ function minify(files, options) {
             ie8: false,
             keep_fnames: false,
             mangle: {},
+            nameCache: null,
             output: {},
             parse: {},
             sourceMap: false,
@@ -54,7 +72,7 @@ function minify(files, options) {
         set_shorthand("warnings", options, [ "compress" ]);
         if (options.mangle) {
             options.mangle = defaults(options.mangle, {
-                cache: null,
+                cache: options.nameCache && (options.nameCache.vars || {}),
                 eval: false,
                 ie8: false,
                 keep_classnames: false,
@@ -64,6 +82,16 @@ function minify(files, options) {
                 safari10: false,
                 toplevel: false,
             }, true);
+            if (options.nameCache && options.mangle.properties) {
+                if (typeof options.mangle.properties != "object") {
+                    options.mangle.properties = {};
+                }
+                if (!("cache" in options.mangle.properties)) {
+                    options.mangle.properties.cache = options.nameCache.props || {};
+                }
+            }
+            init_cache(options.mangle.cache);
+            init_cache(options.mangle.properties.cache);
         }
         if (options.sourceMap) {
             options.sourceMap = defaults(options.sourceMap, {
@@ -157,6 +185,12 @@ function minify(files, options) {
                 }
             }
         }
+        if (options.nameCache && options.mangle) {
+            if (options.mangle.cache) options.nameCache.vars = to_json(options.mangle.cache);
+            if (options.mangle.properties && options.mangle.properties.cache) {
+                options.nameCache.props = to_json(options.mangle.properties.cache);
+            }
+        }
         if (timings) {
             timings.end = Date.now();
             result.timings = {

lib/output.js

@@ -673,6 +673,12 @@ function OutputStream(options) {
                 && this.operator !== "--";
     });
 
+    PARENS(AST_Await, function(output){
+        var p = output.parent();
+        return p instanceof AST_PropAccess && p.expression === this
+            || p instanceof AST_Call && p.expression === this;
+    });
+
     PARENS(AST_Sequence, function(output){
         var p = output.parent();
         return p instanceof AST_Call                          // (foo, bar)() or foo(1, (2, 3), 4)
@@ -1039,11 +1045,11 @@ function OutputStream(options) {
         var needs_parens = parent instanceof AST_Binary ||
             parent instanceof AST_Unary ||
             (parent instanceof AST_Call && self === parent.expression);
+        if (needs_parens) { output.print("(") }
         if (self.async) {
             output.print("async");
             output.space();
         }
-        if (needs_parens) { output.print("(") }
         if (self.argnames.length === 1 && self.argnames[0] instanceof AST_Symbol) {
             self.argnames[0].print(output);
         } else {

lib/parse.js

@@ -509,8 +509,11 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
         }
         var content = "", raw = "", ch, tok;
         next(true, true);
-        while ((ch = next(true, true)) !== "`") {
-            if (ch === "$" && peek() === "{") {
+        while ((ch = next(true, true)) != "`") {
+            if (ch == "\r") {
+                if (peek() == "\n") ++S.pos;
+                ch = "\n";
+            } else if (ch == "$" && peek() == "{") {
                 next(true, true);
                 S.brace_counter++;
                 tok = token(begin ? "template_head" : "template_substitution", content);
@@ -521,7 +524,7 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
             }
 
             raw += ch;
-            if (ch === "\\") {
+            if (ch == "\\") {
                 var tmp = S.pos;
                 ch = read_escaped_char();
                 raw += S.text.substr(tmp, S.pos - tmp);

package.json

@@ -4,7 +4,7 @@
   "homepage": "https://github.com/mishoo/UglifyJS2/tree/harmony",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.0.20",
+  "version": "3.0.23",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -40,5 +40,18 @@
   "scripts": {
     "test": "node test/run-tests.js"
   },
-  "keywords": ["uglify", "uglify-js", "uglify-es", "minify", "minifier", "es5", "es6", "es2015"]
+  "keywords": [
+    "uglify",
+    "uglify-js",
+    "uglify-es",
+    "minify",
+    "minifier",
+    "es5",
+    "es6",
+    "es2015",
+    "es2016",
+    "es2017",
+    "async",
+    "await"
+  ]
 }

test/compress/arrow.js

@@ -280,3 +280,263 @@ issue_27: {
         })(jQuery);
     }
 }
+
+issue_2105_1: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        inline: true,
+        passes: 3,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        !function(factory) {
+            factory();
+        }( function() {
+            return function(fn) {
+                fn()().prop();
+            }( function() {
+                function bar() {
+                    var quux = function() {
+                        console.log("PASS");
+                    }, foo = function() {
+                        console.log;
+                        quux();
+                    };
+                    return { prop: foo };
+                }
+                return bar;
+            } );
+        });
+    }
+    expect: {
+        (() => {
+            var quux = () => {
+                console.log("PASS");
+            };
+            return {
+                prop: () => {
+                    console.log;
+                    quux();
+                }
+            };
+        })().prop();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_2105_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        ((factory) => {
+            factory();
+        })( () => {
+            return ((fn) => {
+                fn()().prop();
+            })( () => {
+                let bar = () => {
+                    var quux = () => {
+                        console.log("PASS");
+                    }, foo = () => {
+                        console.log;
+                        quux();
+                    };
+                    return { prop: foo };
+                };
+                return bar;
+            } );
+        });
+    }
+    expect: {
+        (() => {
+            var quux = () => {
+                console.log("PASS");
+            };
+            return {
+                prop: () => {
+                    console.log;
+                    quux();
+                }
+            };
+        })().prop();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_2136_2: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        inline: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            console.log(x);
+        }
+        !function(a, ...b) {
+            f(b[0]);
+        }(1, 2, 3);
+    }
+    expect: {
+        function f(x) {
+            console.log(x);
+        }
+        f([2,3][0]);
+    }
+    expect_stdout: "2"
+    node_version: ">=6"
+}
+
+issue_2136_3: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        passes: 3,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            console.log(x);
+        }
+        !function(a, ...b) {
+            f(b[0]);
+        }(1, 2, 3);
+    }
+    expect: {
+        console.log(2);
+    }
+    expect_stdout: "2"
+    node_version: ">=6"
+}
+
+call_args: {
+    options = {
+        arrows: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+    }
+    input: {
+        const a = 1;
+        console.log(a);
+        +function(a) {
+            return a;
+        }(a);
+    }
+    expect: {
+        const a = 1;
+        console.log(1);
+        +(1, 1);
+    }
+    expect_stdout: true
+}
+
+call_args_drop_param: {
+    options = {
+        arrows: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        const a = 1;
+        console.log(a);
+        +function(a) {
+            return a;
+        }(a, b);
+    }
+    expect: {
+        const a = 1;
+        console.log(1);
+        +(b, 1);
+    }
+    expect_stdout: true
+}
+
+issue_485_crashing_1530: {
+    options = {
+        arrows: true,
+        conditionals: true,
+        dead_code: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+    }
+    input: {
+        (function(a) {
+            if (true) return;
+            var b = 42;
+        })(this);
+    }
+    expect: {
+        this, void 0;
+    }
+}
+
+issue_2084: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        conditionals: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function() {
+            !function(c) {
+                c = 1 + c;
+                var c = 0;
+                function f14(a_1) {
+                    if (c = 1 + c, 0 !== 23..toString())
+                        c = 1 + c, a_1 && (a_1[0] = 0);
+                }
+                f14();
+            }(-1);
+        }();
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        ((c) => {
+            c = 1 + c,
+            c = 1 + (c = 0),
+            0 !== 23..toString() && (c = 1 + c);
+        })(-1),
+        console.log(c);
+    }
+    expect_stdout: "0"
+    node_version: ">=4"
+}

test/compress/async.js

@@ -6,6 +6,22 @@ await_precedence: {
     expect_exact: "async function f1(){await x+y}async function f2(){await(x+y)}"
 }
 
+await_precedence_prop: {
+    input: {
+        async function f1(){ return (await foo()).bar; }
+        async function f2(){ return (await foo().bar); }
+    }
+    expect_exact: "async function f1(){return(await foo()).bar}async function f2(){return await foo().bar}"
+}
+
+await_precedence_call: {
+    input: {
+        async function f3(){ return (await foo())(); }
+        async function f4(){ return await (foo()()); }
+    }
+    expect_exact: "async function f3(){return(await foo())()}async function f4(){return await foo()()}"
+}
+
 async_function_declaration: {
     options = {
         side_effects: true,
@@ -252,3 +268,27 @@ async_arrow_wait: {
     }
     expect_exact: "var a=async(x,y)=>await x(y);"
 }
+
+async_arrow_iife: {
+    input: {
+        (async () => {
+            await fetch({});
+        })();
+    }
+    expect_exact: "(async()=>{await fetch({})})();"
+}
+
+async_arrow_iife_negate_iife: {
+    options = {
+        negate_iife: true,
+    }
+    input: {
+        (async () => {
+            await fetch();
+        })();
+        (() => {
+            plain();
+        })();
+    }
+    expect_exact: "(async()=>{await fetch()})();(()=>{plain()})();"
+}

test/compress/collapse_vars.js

@@ -2077,10 +2077,10 @@ chained_3: {
     }
     expect: {
         console.log(function(a, b) {
-            var c = a, c = b;
+            var c = 1, c = b;
             b++;
             return c;
-        }(1, 2));
+        }(0, 2));
     }
     expect_stdout: "2"
 }
@@ -2330,3 +2330,73 @@ reassign_const_2: {
     }
     expect_stdout: true
 }
+
+issue_2187_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        !function(foo) {
+            foo();
+            var a = 2;
+            console.log(a);
+        }(function() {
+            console.log(a);
+        });
+    }
+    expect: {
+        var a = 1;
+        !function(foo) {
+            foo();
+            var a = 2;
+            console.log(a);
+        }(function() {
+            console.log(a);
+        });
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+issue_2187_2: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var b = 1;
+        console.log(function(a) {
+            return a && ++b;
+        }(b--));
+    }
+    expect: {
+        var b = 1;
+        console.log(function(a) {
+            return b-- && ++b;
+        }());
+    }
+    expect_stdout: "1"
+}
+
+issue_2187_3: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        unused: true,
+    }
+    input: {
+        var b = 1;
+        console.log(function(a) {
+            return a && ++b;
+        }(b--));
+    }
+    expect: {
+        var b = 1;
+        console.log(b-- && ++b);
+    }
+    expect_stdout: "1"
+}

test/compress/drop-unused.js

@@ -1299,6 +1299,7 @@ issue_2105: {
     options = {
         collapse_vars: true,
         inline: true,
+        passes: 3,
         reduce_vars: true,
         side_effects: true,
         unused: true,
@@ -1324,7 +1325,7 @@ issue_2105: {
         });
     }
     expect: {
-        !void function() {
+        (function() {
             var quux = function() {
                 console.log("PASS");
             };
@@ -1334,7 +1335,7 @@ issue_2105: {
                     quux();
                 }
             };
-        }().prop();
+        })().prop();
     }
     expect_stdout: "PASS"
 }
@@ -1409,3 +1410,20 @@ issue_2136_3: {
     expect_stdout: "2"
     node_version: ">=6"
 }
+
+issue_2163: {
+    options = {
+        pure_funcs: [ "pure" ],
+        side_effects: true,
+    }
+    input: {
+        var c;
+        /*@__PURE__*/f(...a);
+        pure(b, ...c);
+    }
+    expect: {
+        var c;
+        a;
+        b;
+    }
+}

test/compress/functions.js

@@ -265,7 +265,7 @@ issue_203: {
     }
     expect: {
         var m = {};
-        var fn = Function("n", "o", "o.exports=42");
+        var fn = Function("n,o", "o.exports=42");
         fn(null, m, m.exports);
         console.log(m.exports);
     }
@@ -468,11 +468,9 @@ issue_2114_1: {
     }
     expect: {
         var c = 0;
-        !function() {
-            0;
-        }((c += 1, c = 1 + c, function() {
+        c = 1 + (c += 1), function() {
             var b = void (b && (b.b += (c += 1, 0)));
-        }()));
+        }();
         console.log(c);
     }
     expect_stdout: "2"

test/compress/global_defs.js

@@ -174,3 +174,24 @@ issue_1986: {
         console.log(42);
     }
 }
+
+issue_2167: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        global_defs: {
+            "@isDevMode": "function(){}",
+        },
+        side_effects: true,
+    }
+    input: {
+        if (isDevMode()) {
+            greetOverlord();
+        }
+        doWork();
+    }
+    expect: {
+        doWork();
+    }
+}

test/compress/issue-203.js

@@ -8,7 +8,7 @@ compress_new_function: {
         new Function("aa, bb", 'return aa;');
     }
     expect: {
-        Function("n", "r", "return n");
+        Function("n,r", "return n");
     }
 }
 
@@ -27,9 +27,9 @@ compress_new_function_with_destruct: {
         new Function("[[aa]], [{bb}]", 'return aa;');
     }
     expect: {
-        Function("n", "[r]", "return n");
-        Function("n", "{bb:b}", "return n");
-        Function("[[n]]", "[{bb:b}]", "return n");
+        Function("n,[r]", "return n");
+        Function("n,{bb:b}", "return n");
+        Function("[[n]],[{bb:b}]", "return n");
     }
 }
 
@@ -49,8 +49,8 @@ compress_new_function_with_destruct_arrows: {
         new Function("[[aa]], [{bb}]", 'return aa;');
     }
     expect: {
-        Function("aa, [bb]", 'return aa;');
-        Function("aa, {bb}", 'return aa;');
-        Function("[[aa]], [{bb}]", 'return aa;');
+        Function("n,[a]", "return n");
+        Function("b,{bb:n}", "return b");
+        Function("[[b]],[{bb:n}]", "return b");
     }
 }

test/compress/issue-281.js

@@ -419,7 +419,7 @@ wrap_iife_in_return_call: {
     expect_exact: '(void console.log("test"))();'
 }
 
-pure_annotation: {
+pure_annotation_1: {
     options = {
         inline: true,
         side_effects: true,
@@ -432,6 +432,20 @@ pure_annotation: {
     expect_exact: ""
 }
 
+pure_annotation_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        /*@__PURE__*/(function(n) {
+            console.log("hello", n);
+        }(42));
+    }
+    expect_exact: ""
+}
+
 drop_fargs: {
     options = {
         cascade: true,
@@ -449,9 +463,7 @@ drop_fargs: {
     }
     expect: {
         var a = 1;
-        !function() {
-            a++;
-        }(++a && a.var);
+        ++a && a.var, a++;
         console.log(a);
     }
     expect_stdout: "3"
@@ -474,9 +486,7 @@ keep_fargs: {
     }
     expect: {
         var a = 1;
-        !function(a_1) {
-            a++;
-        }(++a && a.var);
+        ++a && a.var, a++;
         console.log(a);
     }
     expect_stdout: "3"

test/mocha/glob.js

@@ -26,12 +26,12 @@ describe("bin/uglifyjs with input file globs", function() {
         });
     });
     it("bin/uglifyjs with multiple input file globs.", function(done) {
-        var command = uglifyjscmd + ' "test/input/issue-1242/???.es5" "test/input/issue-1242/*.js" -mc toplevel';
+        var command = uglifyjscmd + ' "test/input/issue-1242/???.es5" "test/input/issue-1242/*.js" -mc toplevel,passes=2';
 
         exec(command, function(err, stdout) {
             if (err) throw err;
 
-            assert.strictEqual(stdout, 'var print=console.log.bind(console);print("qux",9,6),print("Foo:",2*11);\n');
+            assert.strictEqual(stdout, 'var print=console.log.bind(console);print("qux",9,6),print("Foo:",22);\n');
             done();
         });
     });

test/mocha/minify.js

@@ -1,6 +1,7 @@
 var Uglify = require('../../');
 var assert = require("assert");
 var readFileSync = require("fs").readFileSync;
+var run_code = require("../sandbox").run_code;
 
 function read(path) {
     return readFileSync(path, "utf8");
@@ -20,6 +21,58 @@ describe("minify", function() {
         assert.strictEqual(result.code, "alert(2);");
     });
 
+    it("Should work with mangle.cache", function() {
+        var cache = {};
+        var original = "";
+        var compressed = "";
+        [
+            "bar.es5",
+            "baz.es5",
+            "foo.es5",
+            "qux.js",
+        ].forEach(function(file) {
+            var code = read("test/input/issue-1242/" + file);
+            var result = Uglify.minify(code, {
+                mangle: {
+                    cache: cache,
+                    toplevel: true
+                }
+            });
+            if (result.error) throw result.error;
+            original += code;
+            compressed += result.code;
+        });
+        assert.strictEqual(JSON.stringify(cache).slice(0, 20), '{"cname":5,"props":{');
+        assert.strictEqual(compressed, 'function n(n){return 3*n}function r(n){return n/2}function c(o){l("Foo:",2*o)}var l=console.log.bind(console);var f=n(3),i=r(12);l("qux",f,i),c(11);');
+        assert.strictEqual(run_code(compressed), run_code(original));
+    });
+
+    it("Should work with nameCache", function() {
+        var cache = {};
+        var original = "";
+        var compressed = "";
+        [
+            "bar.es5",
+            "baz.es5",
+            "foo.es5",
+            "qux.js",
+        ].forEach(function(file) {
+            var code = read("test/input/issue-1242/" + file);
+            var result = Uglify.minify(code, {
+                mangle: {
+                    toplevel: true
+                },
+                nameCache: cache
+            });
+            if (result.error) throw result.error;
+            original += code;
+            compressed += result.code;
+        });
+        assert.strictEqual(JSON.stringify(cache).slice(0, 28), '{"vars":{"cname":5,"props":{');
+        assert.strictEqual(compressed, 'function n(n){return 3*n}function r(n){return n/2}function c(o){l("Foo:",2*o)}var l=console.log.bind(console);var f=n(3),i=r(12);l("qux",f,i),c(11);');
+        assert.strictEqual(run_code(compressed), run_code(original));
+    });
+
     describe("keep_quoted_props", function() {
         it("Should preserve quotes in object literals", function() {
             var js = 'var foo = {"x": 1, y: 2, \'z\': 3};';
@@ -212,7 +265,7 @@ describe("minify", function() {
             });
             var err = result.error;
             assert.ok(err instanceof Error);
-            assert.strictEqual(err.stack.split(/\n/)[0], "Error: Can't handle expression: debugger");
+            assert.strictEqual(err.stack.split(/\n/)[0], "SyntaxError: Unexpected token: keyword (debugger)");
         });
         it("should skip inherited properties", function() {
             var foo = Object.create({ skip: this });

test/mocha/template-string.js

@@ -30,4 +30,13 @@ describe("Template string", function() {
             assert.throws(exec(tests[i]), fail, tests[i]);
         }
     });
+    it("Should process all line terminators as LF", function() {
+        [
+            "`a\rb`",
+            "`a\nb`",
+            "`a\r\nb`",
+        ].forEach(function(code) {
+            assert.strictEqual(uglify.parse(code).print_to_string(), "`a\\nb`;");
+        });
+    });
 });