harmony-v3.1.0

Avoid collision with local variable `undefined` under certain corner cases.

fixes #2298

README.md

@@ -148,19 +148,19 @@ debugging your compressed JavaScript.  To get a source map, pass
 
 Additional options:
 
-- `--source-map filename=<NAME>` to specify the name of the source map.
+- `--source-map "filename='<NAME>'"` to specify the name of the source map.
 
-- `--source-map root=<URL>` to pass the URL where the original files can be found.
+- `--source-map "root='<URL>'"` to pass the URL where the original files can be found.
   Otherwise UglifyJS assumes HTTP `X-SourceMap` is being used and will omit the
   `//# sourceMappingURL=` directive.
 
-- `--source-map url=<URL>` to specify the URL where the source map can be found.
+- `--source-map "url='<URL>'"` to specify the URL where the source map can be found.
 
 For example:
 
     uglifyjs js/file1.js js/file2.js \
              -o foo.min.js -c -m \
-             --source-map root="http://foo.com/src",url=foo.min.js.map
+             --source-map "root='http://foo.com/src',url='foo.min.js.map'"
 
 The above will compress and mangle `file1.js` and `file2.js`, will drop the
 output in `foo.min.js` and the source map in `foo.min.js.map`.  The source
@@ -179,8 +179,8 @@ CoffeeScript → compiled JS, UglifyJS can generate a map from CoffeeScript →
 compressed JS by mapping every token in the compiled JS to its original
 location.
 
-To use this feature pass `--source-map content="/path/to/input/source.map"`
-or `--source-map content=inline` if the source map is included inline with
+To use this feature pass `--source-map "content='/path/to/input/source.map'"`
+or `--source-map "content=inline"` if the source map is included inline with
 the sources.
 
 ## CLI compress options
@@ -211,7 +211,7 @@ When mangling is enabled but you want to prevent certain names from being
 mangled, you can declare those names with `--mangle reserved` — pass a
 comma-separated list of names.  For example:
 
-    uglifyjs ... -m reserved=[$,require,exports]
+    uglifyjs ... -m reserved=['$','require','exports']
 
 to prevent the `require`, `exports` and `$` names from being changed.
 
@@ -646,9 +646,16 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 - `evaluate` -- attempt to evaluate constant expressions
 
-- `arrows` (default `true`) -- convert ES5 style anonymous function expressions
-  to arrow functions if permissible by language semantics.
-  Note: `arrows` requires that the `ecma` compress option is set to `6` or greater.
+- `arrows` (default `true`) -- Converts `()=>{return x}` to `()=>x`. Class
+  and object literal methods will also be converted to arrow expressions if
+  the resultant code is shorter: `m(){return x}` becomes `m:()=>x`.
+  This transform requires that the `ecma` compress option is set to `6` or greater.
+
+- `unsafe_arrows` (default `false`) -- Convert ES5 style anonymous function
+  expressions to arrow functions if the function body does not reference `this`.
+  Note: it is not always safe to perform this conversion if code relies on the
+  the function having a `prototype`, which arrow functions lack.
+  This transform requires that the `ecma` compress option is set to `6` or greater.
 
 - `booleans` -- various optimizations for boolean context, for example `!!a
   ? b : c → a ? b : c`

lib/compress.js

@@ -84,6 +84,7 @@ function Compressor(options, false_by_default) {
         toplevel      : !!(options && options["top_retain"]),
         typeofs       : !false_by_default,
         unsafe        : false,
+        unsafe_arrows : false,
         unsafe_comps  : false,
         unsafe_Func   : false,
         unsafe_math   : false,
@@ -729,7 +730,7 @@ merge(Compressor.prototype, {
         return node instanceof AST_SymbolRef && node.definition().undeclared;
     }
 
-    var global_names = makePredicate("Array Boolean console Error Function Math Number RegExp Object String");
+    var global_names = makePredicate("Array Boolean clearInterval clearTimeout console Date decodeURI decodeURIComponent encodeURI encodeURIComponent Error escape eval EvalError Function isFinite isNaN JSON Math Number parseFloat parseInt RangeError ReferenceError RegExp Object setInterval setTimeout String SyntaxError TypeError unescape URIError");
     AST_SymbolRef.DEFMETHOD("is_declared", function(compressor) {
         return !this.definition().undeclared
             || compressor.option("unsafe") && global_names(this.name);
@@ -926,7 +927,7 @@ merge(Compressor.prototype, {
                             }
                         } else {
                             var arg = iife.args[i];
-                            if (!arg) arg = make_node(AST_Undefined, sym);
+                            if (!arg) arg = make_node(AST_Undefined, sym).transform(compressor);
                             else if (has_overlapping_symbol(fn, arg)) arg = null;
                             if (arg) candidates.unshift(make_node(AST_VarDef, sym, {
                                 name: sym,
@@ -1427,9 +1428,14 @@ merge(Compressor.prototype, {
         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;
+                if (this.properties[i]._dot_throw(compressor)) return true;
             return false;
         });
+        def(AST_ObjectProperty, return_false);
+        def(AST_ObjectGetter, return_true);
+        def(AST_Expansion, function(compressor) {
+            return this.expression._dot_throw(compressor);
+        });
         def(AST_Function, return_false);
         def(AST_Arrow, return_false);
         def(AST_UnaryPostfix, return_false);
@@ -1731,6 +1737,7 @@ merge(Compressor.prototype, {
                 var val = {};
                 for (var i = 0, len = this.properties.length; i < len; i++) {
                     var prop = this.properties[i];
+                    if (prop instanceof AST_Expansion) return this;
                     var key = prop.key;
                     if (key instanceof AST_Symbol) {
                         key = key.name;
@@ -2074,16 +2081,27 @@ merge(Compressor.prototype, {
         if (!compressor.option("side_effects")) return false;
         if (this.pure !== undefined) return this.pure;
         var pure = false;
-        var comments, last_comment;
+        var comments, pure_comment;
         if (this.start
             && (comments = this.start.comments_before)
             && comments.length
-            && /[@#]__PURE__/.test((last_comment = comments[comments.length - 1]).value)) {
-            pure = last_comment;
+            && (pure_comment = find_if(function (comment) {
+                return /[@#]__PURE__/.test(comment.value);
+            }, comments))) {
+            pure = pure_comment;
         }
         return this.pure = pure;
     });
 
+    var global_pure_fns = makePredicate("Boolean decodeURI decodeURIComponent Date encodeURI encodeURIComponent Error escape EvalError isFinite isNaN Number Object parseFloat parseInt RangeError ReferenceError String SyntaxError TypeError unescape URIError");
+    AST_Call.DEFMETHOD("is_expr_pure", function(compressor) {
+        if (compressor.option("unsafe")) {
+            var expr = this.expression;
+            if (is_undeclared_ref(expr) && global_pure_fns(expr.name)) return true;
+        }
+        return this.has_pure_annotation(compressor) || !compressor.pure_funcs(this);
+    });
+
     // determine if expression has side effects
     (function(def){
         def(AST_Node, return_true);
@@ -2093,7 +2111,7 @@ merge(Compressor.prototype, {
         def(AST_This, return_false);
 
         def(AST_Call, function(compressor){
-            if (!this.has_pure_annotation(compressor) && compressor.pure_funcs(this)) return true;
+            if (!this.is_expr_pure(compressor)) return true;
             for (var i = this.args.length; --i >= 0;) {
                 if (this.args[i].has_side_effects(compressor))
                     return true;
@@ -2563,17 +2581,18 @@ merge(Compressor.prototype, {
                 // We fix it at this stage by moving the `var` outside the `for`.
                 if (node instanceof AST_For) {
                     descend(node, this);
+                    var block;
                     if (node.init instanceof AST_BlockStatement) {
-                        var block = node.init;
+                        block = node.init;
                         node.init = block.body.pop();
                         block.body.push(node);
-                        return in_list ? MAP.splice(block.body) : block;
-                    } else if (node.init instanceof AST_SimpleStatement) {
+                    }
+                    if (node.init instanceof AST_SimpleStatement) {
                         node.init = node.init.body;
                     } else if (is_empty(node.init)) {
                         node.init = null;
                     }
-                    return node;
+                    return !block ? node : in_list ? MAP.splice(block.body) : block;
                 }
                 if (node instanceof AST_LabeledStatement && node.body instanceof AST_For) {
                     descend(node, this);
@@ -2769,7 +2788,7 @@ merge(Compressor.prototype, {
         def(AST_Constant, return_null);
         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.is_expr_pure(compressor)) {
                 if (is_func_expr(this.expression)
                     && (!this.expression.name || !this.expression.name.definition().references.length)) {
                     var node = this.clone();
@@ -3279,6 +3298,7 @@ merge(Compressor.prototype, {
                 });
                 a.push(var_);
             }
+            remove(def.name.definition().orig, def.name);
             return a;
         }, []);
         if (assignments.length == 0) return null;
@@ -4493,6 +4513,8 @@ merge(Compressor.prototype, {
             && alternative.TYPE === consequent.TYPE
             && consequent.args.length == 1
             && alternative.args.length == 1
+            && !(consequent.args[0] instanceof AST_Expansion)
+            && !(alternative.args[0] instanceof AST_Expansion)
             && consequent.expression.equivalent_to(alternative.expression)
             && !consequent.expression.has_side_effects(compressor)) {
             consequent.args[0] = make_node(AST_Conditional, self, {
@@ -4742,7 +4764,7 @@ merge(Compressor.prototype, {
 
     OPT(AST_Function, function(self, compressor){
         tighten_body(self.body, compressor);
-        if (compressor.option("arrows")
+        if (compressor.option("unsafe_arrows")
             && compressor.option("ecma") >= 6
             && !self.name
             && !self.is_generator

lib/output.js

@@ -157,7 +157,7 @@ function OutputStream(options) {
               case "\u2029": return "\\u2029";
               case "\ufeff": return "\\ufeff";
               case "\0":
-                  return /[0-7]/.test(get_full_char(str, i+1)) ? "\\x00" : "\\0";
+                  return /[0-9]/.test(get_full_char(str, i+1)) ? "\\x00" : "\\0";
             }
             return s;
         });
@@ -689,6 +689,7 @@ function OutputStream(options) {
                                                                * ==> 20 (side effect, set a := 10 and b := 20) */
             || p instanceof AST_Arrow                         // x => (x, x)
             || p instanceof AST_DefaultAssign                 // x => (x = (0, function(){}))
+            || p instanceof AST_Expansion                     // [...(a, b)]
         ;
     });
 

lib/parse.js

@@ -1522,7 +1522,7 @@ function parse($TEXT, options) {
                 }
                 if (is_expand) {
                     if (!is("punc", "]")) {
-                        unexpected(); // Must be last element
+                        croak("Rest element must be last element");
                     }
                     elements[elements.length - 1] = new AST_Expansion({
                         start: expand_token,
@@ -1547,18 +1547,33 @@ function parse($TEXT, options) {
                 } else {
                     expect(",");
                 }
+                if (is("expand", "...")) {
+                    is_expand = true;
+                    expand_token = S.token;
+                    used_parameters.mark_spread(S.token);
+                    next();
+                }
                 if (is("name") && (is_token(peek(), "punc") || is_token(peek(), "operator")) && [",", "}", "="].indexOf(peek().value) !== -1) {
                     used_parameters.add_parameter(S.token);
-                    elements.push(new AST_ObjectKeyVal({
-                        start: prev(),
-                        key: S.token.value,
-                        value: new symbol_type({
-                            start: S.token,
-                            name: S.token.value,
-                            end: S.token
-                        }),
-                        end: prev()
-                    }));
+                    var value = new symbol_type({
+                        start: S.token,
+                        name: S.token.value,
+                        end: S.token,
+                    });
+                    if (is_expand) {
+                        elements.push(new AST_Expansion({
+                            start: expand_token,
+                            expression: value,
+                            end: value.end,
+                        }));
+                    } else {
+                        elements.push(new AST_ObjectKeyVal({
+                            start: prev(),
+                            key: S.token.value,
+                            value: value,
+                            end: value.end,
+                        }));
+                    }
                     next();
                 } else if (is("punc", "}")) {
                     continue; // Allow trailing hole
@@ -1589,7 +1604,12 @@ function parse($TEXT, options) {
                         }));
                     }
                 }
-                if (is("operator", "=")) {
+                if (is_expand) {
+                    if (!is("punc", "}")) {
+                        croak("Rest element must be last element");
+                    }
+                }
+                else if (is("operator", "=")) {
                     used_parameters.mark_default_assignment(S.token);
                     next();
                     elements[elements.length - 1].value = new AST_DefaultAssign({
@@ -2143,7 +2163,18 @@ function parse($TEXT, options) {
             if (!options.strict && is("punc", "}"))
                 // allow trailing comma
                 break;
+
             start = S.token;
+            if (start.type == "expand") {
+                next();
+                a.push(new AST_Expansion({
+                    start: start,
+                    expression: expression(false),
+                    end: prev(),
+                }));
+                continue;
+            }
+
             var name = as_property_name();
             var value;
 

lib/scope.js

@@ -203,6 +203,21 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             || node instanceof AST_SymbolLet
             || node instanceof AST_SymbolConst) {
             var def = ((node instanceof AST_SymbolBlockDeclaration) ? scope : defun).def_variable(node);
+            if (!all(def.orig, function(sym) {
+                if (sym === node) return true;
+                if (node instanceof AST_SymbolBlockDeclaration) {
+                    return sym instanceof AST_SymbolLambda;
+                }
+                return !(sym instanceof AST_SymbolLet || sym instanceof AST_SymbolConst);
+            })) {
+                js_error(
+                    node.name + " redeclared",
+                    node.start.file,
+                    node.start.line,
+                    node.start.col,
+                    node.start.pos
+                );
+            }
             if (!(node instanceof AST_SymbolFunarg)) mark_export(def, 2);
             def.destructuring = in_destructuring;
             if (defun !== scope) {
@@ -300,6 +315,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
                     ref.reference(options);
                 });
                 node.thedef = def;
+                node.reference(options);
                 return true;
             }
         }));
@@ -357,7 +373,7 @@ AST_IterationStatement.DEFMETHOD("is_block_scope", return_true);
 AST_Lambda.DEFMETHOD("init_scope_vars", function(){
     AST_Scope.prototype.init_scope_vars.apply(this, arguments);
     this.uses_arguments = false;
-    this.def_variable(new AST_SymbolConst({
+    this.def_variable(new AST_SymbolFunarg({
         name: "arguments",
         start: this.start,
         end: this.end

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": "3.0.27",
+  "version": "3.1.0",
   "engines": {
     "node": ">=0.8.0"
   },
@@ -31,8 +31,8 @@
   },
   "devDependencies": {
     "acorn": "~5.1.1",
-    "mocha": "~3.4.2",
-    "semver": "~5.3.0"
+    "mocha": "~3.5.1",
+    "semver": "~5.4.1"
   },
   "scripts": {
     "test": "node test/run-tests.js"

test/compress/arrow.js

@@ -213,7 +213,7 @@ no_leading_parentheses: {
 
 async_identifiers: {
     options = {
-        arrows: true,
+        unsafe_arrows: true,
         ecma: 6,
     }
     input: {
@@ -237,7 +237,7 @@ async_identifiers: {
 
 async_function_expression: {
     options = {
-        arrows: true,
+        unsafe_arrows: true,
         ecma: 6,
         evaluate: true,
         side_effects: true,
@@ -262,7 +262,7 @@ async_function_expression: {
 
 issue_27: {
     options = {
-        arrows: true,
+        unsafe_arrows: true,
         collapse_vars: true,
         ecma: 6,
         unused: true,
@@ -283,7 +283,7 @@ issue_27: {
 
 issue_2105_1: {
     options = {
-        arrows: true,
+        unsafe_arrows: true,
         collapse_vars: true,
         ecma: 6,
         inline: true,
@@ -501,7 +501,7 @@ issue_485_crashing_1530: {
 
 issue_2084: {
     options = {
-        arrows: true,
+        unsafe_arrows: true,
         collapse_vars: true,
         conditionals: true,
         ecma: 6,
@@ -577,6 +577,7 @@ concise_methods_with_computed_property2: {
 async_object_literal: {
     options = {
         arrows: true,
+        unsafe_arrows: true,
         ecma: 6,
         evaluate: true,
     }
@@ -597,3 +598,35 @@ async_object_literal: {
         };
     }
 }
+
+issue_2271: {
+    options = {
+        arrows: true,
+        ecma: 6,
+        evaluate: true,
+        unsafe_arrows: false,
+    }
+    input: {
+        var Foo = function() {};
+        Foo.prototype.set = function(value) {
+            this.value = value;
+            return this;
+        }
+        Foo.prototype.print = function() {
+            console.log(this.value);
+        }
+        new Foo().set("PASS").print();
+    }
+    expect: {
+        var Foo = function() {};
+        Foo.prototype.set = function(value) {
+            this.value = value;
+            return this;
+        }
+        Foo.prototype.print = function() {
+            console.log(this.value);
+        }
+        new Foo().set("PASS").print();
+    }
+    expect_stdout: "PASS"
+}

test/compress/ascii.js

@@ -13,7 +13,7 @@ ascii_only_true: {
                    "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\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_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: {
@@ -31,5 +31,5 @@ ascii_only_false: {
                    "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\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_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

@@ -2616,3 +2616,45 @@ issue_2250_2: {
         bar();
     }
 }
+
+issue_2298: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            function f() {
+                var a = undefined;
+                var undefined = a++;
+                try {
+                    !function g(b) {
+                        b[1] = "foo";
+                    }();
+                    console.log("FAIL");
+                } catch (e) {
+                    console.log("PASS");
+                }
+            }
+            f();
+        }();
+    }
+    expect: {
+        !function() {
+            (function() {
+                var a = undefined;
+                var undefined = a++;
+                try {
+                    !function(b) {
+                        (void 0)[1] = "foo";
+                    }();
+                    console.log("FAIL");
+                } catch (e) {
+                    console.log("PASS");
+                }
+            })();
+        }();
+    }
+    expect_stdout: "PASS"
+}

test/compress/concat-strings.js

@@ -21,7 +21,7 @@ concat_1: {
         var c = 1 + x() + 2 + "boo";
         var d = 1 + x() + 2 + 3 + "boo";
         var e = 1 + x() + 2 + "X3boo";
-        var f = "\x00360\08\0";
+        var f = "\x00360\x008\0";
     }
 }
 

test/compress/dead-code.js

@@ -388,18 +388,54 @@ issue_2233_1: {
         Array.isArray;
         Boolean;
         console.log;
+        Date;
+        decodeURI;
+        decodeURIComponent;
+        encodeURI;
+        encodeURIComponent;
         Error.name;
+        escape;
+        eval;
+        EvalError;
         Function.length;
+        isFinite;
+        isNaN;
+        JSON;
         Math.random;
         Number.isNaN;
+        parseFloat;
+        parseInt;
         RegExp;
         Object.defineProperty;
         String.fromCharCode;
+        RangeError;
+        ReferenceError;
+        SyntaxError;
+        TypeError;
+        unescape;
+        URIError;
     }
     expect: {}
     expect_stdout: true
 }
 
+global_timeout_and_interval_symbols: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+        unsafe: true,
+    }
+    input: {
+        // These global symbols do not exist in the test sandbox
+        // and must be tested separately.
+        clearInterval;
+        clearTimeout;
+        setInterval;
+        setTimeout;
+    }
+    expect: {}
+}
+
 issue_2233_2: {
     options = {
         pure_getters: "strict",
@@ -456,3 +492,71 @@ issue_2233_3: {
         UndeclaredGlobal;
     }
 }
+
+global_fns: {
+    options = {
+        side_effects: true,
+        unsafe: true,
+    }
+    input: {
+        Boolean(1, 2);
+        decodeURI(1, 2);
+        decodeURIComponent(1, 2);
+        Date(1, 2);
+        encodeURI(1, 2);
+        encodeURIComponent(1, 2);
+        Error(1, 2);
+        escape(1, 2);
+        EvalError(1, 2);
+        isFinite(1, 2);
+        isNaN(1, 2);
+        Number(1, 2);
+        Object(1, 2);
+        parseFloat(1, 2);
+        parseInt(1, 2);
+        RangeError(1, 2);
+        ReferenceError(1, 2);
+        String(1, 2);
+        SyntaxError(1, 2);
+        TypeError(1, 2);
+        unescape(1, 2);
+        URIError(1, 2);
+        try {
+            Function(1, 2);
+        } catch (e) {
+            console.log(e.name);
+        }
+        try {
+            RegExp(1, 2);
+        } catch (e) {
+            console.log(e.name);
+        }
+        try {
+            Array(NaN);
+        } catch (e) {
+            console.log(e.name);
+        }
+    }
+    expect: {
+        try {
+            Function(1, 2);
+        } catch (e) {
+            console.log(e.name);
+        }
+        try {
+            RegExp(1, 2);
+        } catch (e) {
+            console.log(e.name);
+        }
+        try {
+            Array(NaN);
+        } catch (e) {
+            console.log(e.name);
+        }
+    }
+    expect_stdout: [
+        "SyntaxError",
+        "SyntaxError",
+        "RangeError",
+    ]
+}

test/compress/destructuring.js

@@ -65,10 +65,10 @@ nested_destructuring_objects: {
     }
     input: {
         const [{a},b] = c;
-        let [{a},b] = c;
-        var [{a},b] = c;
+        let [{d},e] = f;
+        var [{g},h] = i;
     }
-    expect_exact: 'const[{a},b]=c;let[{a},b]=c;var[{a},b]=c;';
+    expect_exact: 'const[{a},b]=c;let[{d},e]=f;var[{g},h]=i;';
 }
 
 destructuring_constdef_in_loops: {
@@ -274,8 +274,8 @@ reduce_vars: {
         var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
         ({aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}});
         const [{a},b] = c;
-        let [{a},b] = c;
-        var [{a},b] = c;
+        let [{d},e] = f;
+        var [{g},h] = i;
         [{a},b] = c;
         for (const [x,y] in pairs);
         for (let [x,y] in pairs);
@@ -292,8 +292,8 @@ reduce_vars: {
         var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
         ({aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}});
         const [{a},b] = c;
-        let [{a},b] = c;
-        var [{a},b] = c;
+        let [{d},e] = f;
+        var [{g},h] = i;
         [{a},b] = c;
         for (const [x,y] in pairs);
         for (let [x,y] in pairs);

test/compress/drop-unused.js

@@ -1513,3 +1513,25 @@ issue_2226_3: {
     }
     expect_stdout: "3"
 }
+
+issue_2288: {
+    options = {
+        unused: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        function foo(o) {
+            for (var j = o.a, i = 0; i < 0; i++);
+            for (var i = 0; i < 0; i++);
+        }
+    }
+    expect: {
+        function foo(o) {
+            o.a;
+            for (i = 0; i < 0; i++);
+            for (var i = 0; i < 0; i++);
+        }
+    }
+}

test/compress/expansions.js

@@ -26,3 +26,46 @@ expand_parameters: {
     expect_exact: "(function(a,...b){});(function(...args){});"
 }
 
+avoid_spread_in_ternary: {
+    options = {
+        comparisons: true,
+        conditionals: true,
+        evaluate: true,
+    }
+    input: {
+        function print(...x) {
+            console.log(...x);
+        }
+        var a = [1, 2], b = [3, 4];
+
+        if (Math)
+            print(a);
+        else
+            print(b);
+
+        if (Math)
+            print(...a);
+        else
+            print(b);
+
+        if (Math.no_such_property)
+            print(a);
+        else
+            print(...b);
+    }
+    expect: {
+        function print(...x) {
+            console.log(...x);
+        }
+        var a = [ 1, 2 ], b = [ 3, 4 ];
+        print(Math ? a : b);
+        Math ? print(...a) : print(b);
+        Math.no_such_property ? print(a) : print(...b);
+    }
+    expect_stdout: [
+        "[ 1, 2 ]",
+        "1 2",
+        "3 4",
+    ]
+    node_version: ">=6"
+}

test/compress/harmony.js

@@ -211,13 +211,13 @@ export_statement: {
     }
     input: {
         export default 1 + 2;
-        export var foo = 4;
-        export let foo = 6;
-        export const foo = 6;
-        export function foo() {};
-        export class foo { };
+        export var a = 4;
+        export let b = 6;
+        export const c = 6;
+        export function d() {};
+        export class e {};
     }
-    expect_exact: "export default 3;export var foo=4;export let foo=6;export const foo=6;export function foo(){};export class foo{};"
+    expect_exact: "export default 3;export var a=4;export let b=6;export const c=6;export function d(){};export class e{};"
 }
 
 export_default_object_expression: {
@@ -695,3 +695,112 @@ export_default_class_decl: {
     }
     expect_exact: "export default class Car{};export class Cab{};"
 }
+
+object_rest_spread: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var   { w: w1, ...V } = { w: 7, x: 1, y: 2 }; console.log(w1, V);
+        let   { w: w2, ...L } = { w: 8, x: 3, y: 4 }; console.log(w2, L);
+        const { w: w3, ...C } = { w: 9, x: 5, y: 6 }; console.log(w3, C);
+
+        let b;
+        ({ b, ...V } = { a: 1, b: 2, c: 3 }); console.log(V);
+        ({ b, ...L } = { a: 4, b: 5, c: 6 }); console.log(L);
+
+        (function({ y, ...p }){ console.log(p); })({ x: 1, y: 2, z: 3 });
+        (({ y, ...p }) =>     { console.log(p); })({ x: 4, y: 5, z: 6 });
+
+        const T = { a: 1, b: 2 }; console.log({ ...T, w: 0, ...{}, ...L, ...{K: 9} });
+    }
+    expect: {
+        var   { w: o, ...l } = { w: 7, x: 1, y: 2 }; console.log(o, l);
+        let   { w: c, ...n } = { w: 8, x: 3, y: 4 }; console.log(c, n);
+        const { w: e, ...s } = { w: 9, x: 5, y: 6 }; console.log(e, s);
+
+        let g;
+        ({ b: g, ...l } = { a: 1, b: 2, c: 3 }); console.log(l);
+        ({ b: g, ...n } = { a: 4, b: 5, c: 6 }); console.log(n);
+
+        (function({ y: o, ...l }) { console.log(l); })({ x: 1, y: 2, z: 3 });
+        (({ y: o, ...l }) =>      { console.log(l); })({ x: 4, y: 5, z: 6 });
+
+        const w = { a: 1, b: 2 }; console.log({ ...w, w: 0, ...{}, ...n, ...{ K: 9 } });
+    }
+}
+
+object_spread_unsafe: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        join_vars: true,
+        passes: 3,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var o1 = { x: 1, y: 2 };
+        var o2 = { x: 3, z: 4 };
+        var cloned = { ...o1 };
+        var merged = { ...o1, ...o2 };
+        console.log(cloned, merged);
+    }
+    expect: {
+        var o = { x: 1, y: 2 }, l = { ...o }, x = { ...o, ...{ x: 3, z: 4 } };
+        console.log(l, x);
+    }
+}
+
+array_spread_of_sequence: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var a = [1];
+        console.log([...(a, a)]);
+        console.log([...a, a]);
+        console.log([...(a || a)]);
+        console.log([...a || a]);
+    }
+    expect: {
+        var o = [1];
+        console.log([...(o, o)]);
+        console.log([...o, o]);
+        console.log([...o || o]);
+        console.log([...o || o]);
+    }
+    expect_stdout: [
+        "[ 1 ]",
+        "[ 1, [ 1 ] ]",
+        "[ 1 ]",
+        "[ 1 ]",
+    ]
+    node_version: ">=6"
+}
+
+object_spread_of_sequence: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var a = {x: 1};
+        console.log({ ...(a, a) });
+        console.log({ ...a, a });
+        console.log({ ...(a || a) });
+        console.log({ ...a || a });
+    }
+    expect: {
+        var o = { x: 1 };
+        console.log({ ...(o, o) });
+        console.log({ ...o, a: o });
+        console.log({ ...o || o });
+        console.log({ ...o || o });
+    }
+}

test/compress/hoist_vars.js

@@ -88,3 +88,24 @@ sequences_funs: {
         }
     }
 }
+
+issue_2295: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+    }
+    input: {
+        function foo(o) {
+            var a = o.a;
+            if (a) return a;
+            var a = 1;
+        }
+    }
+    expect: {
+        function foo(o) {
+            var a = o.a;
+            if (a) return a;
+            a = 1;
+        }
+    }
+}

test/compress/issue-1261.js

@@ -96,6 +96,13 @@ pure_function_calls_toplevel: {
             })();
         })();
 
+        // pure top-level calls will be dropped regardless of the leading comments position
+        var MyClass = /*#__PURE__*//*@class*/(function(){
+            function MyClass() {}
+            MyClass.prototype.method = function() {};
+            return MyClass;
+        })();
+
         // comment #__PURE__ comment
         bar(), baz(), quux();
         a.b(), /* @__PURE__ */ c.d.e(), f.g();
@@ -110,10 +117,12 @@ pure_function_calls_toplevel: {
         "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:92,37]",
         "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:92,16]",
         "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:90,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:100,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:101,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:107,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:108,31]",
         "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:84,33]",
         "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:84,12]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:100,45]",
+        "WARN: Dropping unused variable MyClass [test/compress/issue-1261.js:100,12]",
     ]
 }
 
@@ -148,29 +157,29 @@ should_warn: {
         baz();
     }
     expect_warnings: [
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:128,61]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:128,23]",
-        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:128,23]",
-        "WARN: Boolean || always true [test/compress/issue-1261.js:129,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:129,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:129,23]",
-        "WARN: Condition left of || always true [test/compress/issue-1261.js:130,8]",
-        "WARN: Condition always true [test/compress/issue-1261.js:130,8]",
-        "WARN: Boolean && always false [test/compress/issue-1261.js:131,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:131,23]",
-        "WARN: Condition always false [test/compress/issue-1261.js:131,23]",
-        "WARN: Condition left of && always false [test/compress/issue-1261.js:132,8]",
-        "WARN: Condition always false [test/compress/issue-1261.js:132,8]",
-        "WARN: + in boolean context always true [test/compress/issue-1261.js:133,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:133,23]",
-        "WARN: Condition always true [test/compress/issue-1261.js:133,23]",
-        "WARN: + in boolean context always true [test/compress/issue-1261.js:134,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:134,31]",
-        "WARN: Condition always true [test/compress/issue-1261.js:134,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,23]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:136,24]",
-        "WARN: Condition always true [test/compress/issue-1261.js:136,8]",
-        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:137,31]",
-        "WARN: Condition always false [test/compress/issue-1261.js:137,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:137,61]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:137,23]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:137,23]",
+        "WARN: Boolean || always true [test/compress/issue-1261.js:138,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:138,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:138,23]",
+        "WARN: Condition left of || always true [test/compress/issue-1261.js:139,8]",
+        "WARN: Condition always true [test/compress/issue-1261.js:139,8]",
+        "WARN: Boolean && always false [test/compress/issue-1261.js:140,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:140,23]",
+        "WARN: Condition always false [test/compress/issue-1261.js:140,23]",
+        "WARN: Condition left of && always false [test/compress/issue-1261.js:141,8]",
+        "WARN: Condition always false [test/compress/issue-1261.js:141,8]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:142,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:142,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:142,23]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:143,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:143,31]",
+        "WARN: Condition always true [test/compress/issue-1261.js:143,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:144,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:145,24]",
+        "WARN: Condition always true [test/compress/issue-1261.js:145,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:146,31]",
+        "WARN: Condition always false [test/compress/issue-1261.js:146,8]",
     ]
 }

test/compress/issue-203.js

@@ -36,9 +36,10 @@ compress_new_function_with_destruct: {
 compress_new_function_with_destruct_arrows: {
     options = {
         arrows: true,
+        unsafe_arrows: true,
         unsafe: true,
         unsafe_Func: true,
-        ecma: 6
+        ecma: 6,
     }
     beautify = {
         ecma: 6

test/compress/parameters.js

@@ -142,11 +142,11 @@ destructuring_arguments_3: {
     }
     input: {
         function fn3({x: {y: {z: {} = 42}}}) {}
-        const { cover = (function () {}), xCover = (0, function() {})  } = {};
-        let { cover = (function () {}), xCover = (0, function() {})  } = {};
-        var { cover = (function () {}), xCover = (0, function() {})  } = {};
+        const { a = (function () {}), b = (0, function() {})  } = {};
+        let { c = (function () {}), d = (0, function() {})  } = {};
+        var { e = (function () {}), f = (0, function() {})  } = {};
     }
-    expect_exact: "function fn3({x:{y:{z:{}=42}}}){}const{cover=function(){},xCover=(0,function(){})}={};let{cover=function(){},xCover=(0,function(){})}={};var{cover=function(){},xCover=(0,function(){})}={};"
+    expect_exact: "function fn3({x:{y:{z:{}=42}}}){}const{a=function(){},b=(0,function(){})}={};let{c=function(){},d=(0,function(){})}={};var{e=function(){},f=(0,function(){})}={};"
 }
 
 default_arguments: {

test/compress/pure_getters.js

@@ -385,3 +385,76 @@ set_mutable_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_2265_1: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        ({ ...{} }).p;
+        ({ ...g }).p;
+    }
+    expect: {
+        ({ ...g }).p;
+    }
+}
+
+issue_2265_2: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = {
+            get b() {
+                throw 0;
+            }
+        };
+        ({...a}).b;
+    }
+    expect: {
+        var a = {
+            get b() {
+                throw 0;
+            }
+        };
+        ({...a}).b;
+    }
+}
+
+issue_2265_3: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = {
+            set b() {
+                throw 0;
+            }
+        };
+        ({...a}).b;
+    }
+    expect: {}
+}
+
+issue_2265_4: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = { b: 1 };
+        ({...a}).b;
+    }
+    expect: {}
+}

test/compress/screw-ie8.js

@@ -325,3 +325,69 @@ issue_2120_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_2254_1: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        "eeeeee";
+        try {
+            console.log(f("PASS"));
+        } catch (e) {}
+        function f(s) {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                return s;
+            }
+        }
+    }
+    expect: {
+        "eeeeee";
+        try {
+            console.log(f("PASS"));
+        } catch (e) {}
+        function f(e) {
+            try {
+                throw "FAIL";
+            } catch (t) {
+                return e;
+            }
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2254_2: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        "eeeeee";
+        try {
+            console.log(f("PASS"));
+        } catch (e) {}
+        function f(s) {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                return s;
+            }
+        }
+    }
+    expect: {
+        "eeeeee";
+        try {
+            console.log(f("PASS"));
+        } catch (e) {}
+        function f(t) {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                return t;
+            }
+        }
+    }
+    expect_stdout: "PASS"
+}

test/mocha/lhs-expressions.js

@@ -253,13 +253,19 @@ describe("Left-hand side expressions", function () {
         // Multiple spreads are not allowed in destructuring array
         expect("[...a, ...b] = [1, 2, 3, 4]", "Spread must the be last element in destructuring array");
 
-        // Spread in obvious object pattern
-        expect("({...a} = foo)", "Unexpected token: expand (...)");
+        // Array spread must be last in destructuring declaration
+        expect("let [ ...x, a ] = o;", "Rest element must be last element");
+
+        // Only one spread per destructuring array declaration
+        expect("let [ a, ...x, ...y ] = o;", "Rest element must be last element");
 
         // Spread in block should not be allowed
         expect("{...a} = foo", "Unexpected token: expand (...)");
 
-        // Not in standard yet
-        expect("let foo = {bar: 42}, bar; bar = {...foo}", "Unexpected token: expand (...)");
+        // Object spread must be last in destructuring declaration
+        expect("let { ...x, a } = o;", "Rest element must be last element");
+
+        // Only one spread per destructuring declaration
+        expect("let { a, ...x, ...y } = o;", "Rest element must be last element");
     });
 });

test/mocha/minify.js

@@ -291,4 +291,34 @@ describe("minify", function() {
             assert.strictEqual(result.code, "alert({bar:42});");
         });
     });
+
+    describe("duplicated block-scoped declarations", function() {
+        [
+            "let a=1;let a=2;",
+            "let a=1;var a=2;",
+            "var a=1;let a=2;",
+            "let[a]=[1];var a=2;",
+            "let a=1;var[a]=[2];",
+            "let[a]=[1];var[a]=[2];",
+            "const a=1;const a=2;",
+            "const a=1;var a=2;",
+            "var a=1;const a=2;",
+            "const[a]=[1];var a=2;",
+            "const a=1;var[a]=[2];",
+            "const[a]=[1];var[a]=[2];",
+        ].forEach(function(code) {
+            it(code, function() {
+                var result = Uglify.minify(code, {
+                    compress: false,
+                    mangle: false
+                });
+                assert.strictEqual(result.error, undefined);
+                assert.strictEqual(result.code, code);
+                result = Uglify.minify(code);
+                var err = result.error;
+                assert.ok(err instanceof Error);
+                assert.strictEqual(err.stack.split(/\n/)[0], "SyntaxError: a redeclared");
+            });
+        });
+    });
 });

test/mocha/string-literal.js

@@ -61,9 +61,9 @@ describe("String literals", function() {
         var tests = [
             ['"\\76";', ';">";'],
             ['"\\0"', '"\\0";'],
-            ['"\\08"', '"\\08";'],
-            ['"\\008"', '"\\08";'],
-            ['"\\0008"', '"\\08";'],
+            ['"\\08"', '"\\x008";'],
+            ['"\\008"', '"\\x008";'],
+            ['"\\0008"', '"\\x008";'],
             ['"use strict" === "use strict";\n"\\76";', '"use strict"==="use strict";">";'],
             ['"use\\\n strict";\n"\\07";', ';"use strict";"\07";']
         ];
@@ -75,8 +75,8 @@ describe("String literals", function() {
     });
 
     it("Should not throw error when digit is 8 or 9", function() {
-        assert.equal(UglifyJS.parse('"use strict";"\\08"').print_to_string(), '"use strict";"\\08";');
-        assert.equal(UglifyJS.parse('"use strict";"\\09"').print_to_string(), '"use strict";"\\09";');
+        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() {

test/mocha/unicode.js

@@ -146,6 +146,7 @@ describe("Unicode", function() {
 
     if (semver.satisfies(process.version, ">=4")) {
         it("Should not unescape unpaired surrogates", function() {
+            this.timeout(5000);
             var code = [];
             for (var i = 0; i <= 0x20001; i++) {
                 code.push("\\u{" + i.toString(16) + "}");