harmony-v3.1.6

- trim array items only if `side_effects`
- extend to non-identifier properties

README.md

@@ -102,7 +102,7 @@ a double dash to prevent input files being used as option arguments:
                                 sequences.
     --config-file <file>        Read `minify()` options from JSON file.
     -d, --define <expr>[=value] Global definitions.
-    --ecma <version>            Specifiy ECMAScript release: 5, 6, 7 or 8.
+    --ecma <version>            Specify ECMAScript release: 5, 6, 7 or 8.
     --ie8                       Support non-standard Internet Explorer 8.
                                 Equivalent to setting `ie8: true` in `minify()`
                                 for `compress`, `mangle` and `output` options.
@@ -219,7 +219,7 @@ to prevent the `require`, `exports` and `$` names from being changed.
 is a separate step, different from variable name mangling.  Pass
 `--mangle-props` to enable it.  It will mangle all properties in the
 input code with the exception of built in DOM properties and properties
-in core javascript classes.  For example:
+in core JavaScript classes.  For example:
 
 ```javascript
 // example.js
@@ -234,7 +234,7 @@ x.bar_ = 2;
 x["baz_"] = 3;
 console.log(x.calc());
 ```
-Mangle all properties (except for javascript `builtins`):
+Mangle all properties (except for JavaScript `builtins`):
 ```bash
 $ uglifyjs example.js -c -m --mangle-props
 ```
@@ -604,7 +604,7 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 ## Compress options
 
-- `arrows` (default `true`) -- Converts `()=>{return x}` to `()=>x`. Class
+- `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.
@@ -622,8 +622,8 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   `!(a <= b) → a > b` (only when `unsafe_comps`), attempts to negate binary
   nodes, e.g. `a = !b && !c && !d && !e → a=!(b||c||d||e)` etc.
 
-- `computed_props` -- default `true`. Transforms constant computed properties
+- `computed_props` (default: `true`) -- Transforms constant computed properties
-  into regular ones: `{["computed"]: 1}` is converted into `{computed: 1}`.
+  into regular ones: `{["computed"]: 1}` is converted to `{computed: 1}`.
 
 - `conditionals` (default: `true`) -- apply optimizations for `if`-s and conditional
   expressions
@@ -637,7 +637,7 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 - `drop_debugger` (default: `true`) -- remove `debugger;` statements
 
-- `ecma` -- default `5`. Pass `6` or greater to enable `compress` options that
+- `ecma` (default: `5`) -- Pass `6` or greater to enable `compress` options that
   will transform ES5 code into smaller ES6+ equivalent forms.
 
 - `evaluate` (default: `true`) -- attempt to evaluate constant expressions
@@ -649,6 +649,12 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 - `hoist_funs` (default: `true`) -- hoist function declarations
 
+- `hoist_props` (default: `false`) -- hoist properties from constant object and
+  array literals into regular variables subject to a set of constraints. For example:
+  `var o={p:1, q:2}; f(o.p, o.q);` is converted to `f(1, 2);`. Note: `hoist_props`
+  works best with `mangle` enabled, the `compress` option `passes` set to `2` or higher,
+  and the `compress` option `toplevel` enabled.
+
 - `hoist_vars` (default: `false`) -- hoist `var` declarations (this is `false`
   by default because it seems to increase the size of the output in general)
 
@@ -662,6 +668,10 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   compressor from discarding unused function arguments.  You need this
   for code which relies on `Function.length`.
 
+- `keep_fnames` (default: `false`) -- Pass `true` to prevent the
+  compressor from discarding function names.  Useful for code relying on
+  `Function.prototype.name`. See also: the `keep_fnames` [mangle option](#mangle).
+
 - `keep_infinity` (default: `false`) -- default `false`. Pass `true` to prevent `Infinity` from
   being compressed into `1/0`, which may cause performance issues on Chrome.
 
@@ -726,7 +736,9 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   `foo === void 0`.  Note: recommend to set this value to `false` for IE10 and
   earlier versions due to known issues.
 
-- `unsafe_arrows` (default `false`) -- Convert ES5 style anonymous function
+- `unsafe` (default: `false`) -- apply "unsafe" transformations (discussion below)
+
+- `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.
@@ -739,14 +751,19 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   comparison are switching. Compression only works if both `comparisons` and
   `unsafe_comps` are both set to true.
 
-- `unsafe` (default: `false`) -- apply "unsafe" transformations (discussion below)
-
 - `unsafe_Func` (default: `false`) -- compress and mangle `Function(args, code)`
   when both `args` and `code` are string literals.
 
 - `unsafe_math` (default: `false`) -- optimize numerical expressions like
   `2 * x * 3` into `6 * x`, which may give imprecise floating point results.
 
+- `unsafe_methods` (default: false) -- Converts `{ m: function(){} }` to
+  `{ m(){} }`. `ecma` must be set to `6` or greater to enable this transform.
+  If `unsafe_methods` is a RegExp then key/value pairs with keys matching the
+  RegExp will be converted to concise methods.
+  Note: if enabled there is a risk of getting a "`<method name>` is not a
+  constructor" TypeError should any code try to `new` the former function.
+
 - `unsafe_proto` (default: `false`) -- optimize expressions like
   `Array.prototype.slice.call(a)` into `[].slice.call(a)`
 
@@ -761,17 +778,21 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
 
 ## Mangle options
 
+- `eval` (default `false`). Pass `true` to mangle names visible in scopes
+  where `eval` or `with` are used.
+
 - `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).
+
 - `reserved` (default `[]`). Pass an array of identifiers that should be
   excluded from mangling. Example: `["foo", "bar"]`.
 
 - `toplevel` (default `false`). Pass `true` to mangle names declared in the
   top level scope.
 
-- `eval` (default `false`). Pass `true` to mangle names visible in scopes
-  where `eval` or `with` are used.
-
 - `safari10` (default `false`). Pass `true` to work around the Safari 10 loop
   iterator [bug](https://bugs.webkit.org/show_bug.cgi?id=171041)
   "Cannot declare a let variable twice".
@@ -1088,7 +1109,7 @@ in total it's a bit more than just using UglifyJS's own parser.
 ### Uglify Fast Minify Mode
 
 It's not well known, but whitespace removal and symbol mangling accounts
-for 95% of the size reduction in minified code for most javascript - not
+for 95% of the size reduction in minified code for most JavaScript - not
 elaborate code transforms. One can simply disable `compress` to speed up
 Uglify builds by 3 to 4 times. In this fast `mangle`-only mode Uglify has
 comparable minify speeds and gzip sizes to

bin/uglifyjs

@@ -44,7 +44,7 @@ program.option("-o, --output <file>", "Output file (default STDOUT).");
 program.option("--comments [filter]", "Preserve copyright comments in the output.");
 program.option("--config-file <file>", "Read minify() options from JSON file.");
 program.option("-d, --define <expr>[=value]", "Global definitions.", parse_js("define"));
-program.option("--ecma <version>", "Specifiy ECMAScript release: 5, 6, 7 or 8.");
+program.option("--ecma <version>", "Specify ECMAScript release: 5, 6, 7 or 8.");
 program.option("--ie8", "Support non-standard Internet Explorer 8.");
 program.option("--keep-fnames", "Do not mangle/drop function names. Useful for code relying on Function.prototype.name.");
 program.option("--name-cache <file>", "File to hold mangled name mappings.");

lib/ast.js

@@ -448,10 +448,8 @@ var AST_TemplateString = DEFNODE("TemplateString", "segments", {
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
-            this.segments.forEach(function(seg, i){
+            this.segments.forEach(function(seg){
-                if (i % 2 !== 0) {
+                seg._walk(visitor);
-                    seg._walk(visitor);
-                }
             });
         });
     }
@@ -1042,7 +1040,7 @@ var AST_This = DEFNODE("This", null, {
 
 var AST_Super = DEFNODE("Super", null, {
     $documentation: "The `super` symbol",
-}, AST_Symbol);
+}, AST_This);
 
 var AST_Constant = DEFNODE("Constant", null, {
     $documentation: "Base class for all constants",

lib/compress.js

@@ -63,6 +63,7 @@ function Compressor(options, false_by_default) {
         expression    : false,
         global_defs   : {},
         hoist_funs    : !false_by_default,
+        hoist_props   : false,
         hoist_vars    : false,
         ie8           : false,
         if_return     : !false_by_default,
@@ -157,7 +158,7 @@ merge(Compressor.prototype, {
         var last_count = 1 / 0;
         for (var pass = 0; pass < passes; pass++) {
             if (pass > 0 || this.option("reduce_vars"))
-                node.reset_opt_flags(this, true);
+                node.reset_opt_flags(this);
             node = node.transform(this);
             if (passes > 1) {
                 var count = 0;
@@ -196,6 +197,7 @@ merge(Compressor.prototype, {
         if (node._squeezed) return node;
         var was_scope = false;
         if (node instanceof AST_Scope) {
+            node = node.hoist_properties(this);
             node = node.hoist_declarations(this);
             was_scope = true;
         }
@@ -289,8 +291,9 @@ merge(Compressor.prototype, {
         self.transform(tt);
     });
 
-    AST_Node.DEFMETHOD("reset_opt_flags", function(compressor, rescan) {
+    AST_Node.DEFMETHOD("reset_opt_flags", function(compressor) {
-        var reduce_vars = rescan && compressor.option("reduce_vars");
+        var reduce_vars = compressor.option("reduce_vars");
+        var unused = compressor.option("unused");
         // Stack of look-up tables to keep track of whether a `SymbolDef` has been
         // properly assigned before use:
         // - `push()` & `pop()` when visiting conditional branches
@@ -315,16 +318,25 @@ merge(Compressor.prototype, {
                 if (node instanceof AST_SymbolRef) {
                     var d = node.definition();
                     d.references.push(node);
-                    if (d.fixed === undefined || !safe_to_read(d)
+                    if (d.fixed === undefined || !safe_to_read(d) || d.single_use == "m") {
-                        || is_modified(node, 0, is_immutable(node))) {
                         d.fixed = false;
-                    } else {
+                    } else if (d.fixed) {
-                        var parent = tw.parent();
+                        var value = node.fixed_value();
-                        if (parent instanceof AST_Assign && parent.operator == "=" && node === parent.right
+                        if (unused && !compressor.exposed(d)) {
-                            || parent instanceof AST_Call && node !== parent.expression
+                            d.single_use = value
-                            || parent instanceof AST_Return && node === parent.value && node.scope !== d.scope
+                                && d.references.length == 1
-                            || parent instanceof AST_VarDef && node === parent.value) {
+                                && loop_ids[d.id] === in_loop
-                            d.escaped = true;
+                                && d.scope === node.scope
+                                && value.is_constant_expression();
+                        }
+                        if (is_modified(node, value, 0, is_immutable(value))) {
+                            if (d.single_use) {
+                                d.single_use = "m";
+                            } else {
+                                d.fixed = false;
+                            }
+                        } else {
+                            mark_escaped(d, node, value, 0);
                         }
                     }
                 }
@@ -419,8 +431,7 @@ merge(Compressor.prototype, {
                     pop();
                     return true;
                 }
-                if (node instanceof AST_Binary
+                if (node instanceof AST_Binary && lazy_op(node.operator)) {
-                    && (node.operator == "&&" || node.operator == "||")) {
                     node.left.walk(tw);
                     push();
                     node.right.walk(tw);
@@ -554,6 +565,7 @@ merge(Compressor.prototype, {
         }
 
         function reset_def(def) {
+            def.direct_access = false;
             def.escaped = false;
             if (def.scope.uses_eval) {
                 def.fixed = false;
@@ -567,34 +579,65 @@ merge(Compressor.prototype, {
             def.single_use = undefined;
         }
 
-        function is_immutable(node) {
+        function is_immutable(value) {
-            var value = node.fixed_value();
+            return value && (value.is_constant() || value instanceof AST_Lambda);
-            if (!value) return false;
-            if (value.is_constant()) return true;
-            if (compressor.option("unused")) {
-                var d = node.definition();
-                if (d.single_use === undefined) {
-                    d.single_use = loop_ids[d.id] === in_loop
-                        && d.scope === node.scope
-                        && value.is_constant_expression();
-                }
-                if (d.references.length == 1 && d.single_use) return true;
-            }
-            return value instanceof AST_Lambda;
         }
 
-        function is_modified(node, level, immutable) {
+        function read_property(obj, key) {
+            if (key instanceof AST_Constant) key = key.getValue();
+            if (key instanceof AST_Node) return null;
+            var value;
+            if (obj instanceof AST_Array) {
+                var elements = obj.elements;
+                if (key == "length") return make_node_from_constant(elements.length, obj);
+                if (typeof key == "number" && key in elements) value = elements[key];
+            } else if (obj instanceof AST_Object) {
+                var props = obj.properties;
+                for (var i = props.length; --i >= 0;) {
+                    var prop = props[i];
+                    if (!(prop instanceof AST_ObjectKeyVal)) return;
+                    if (!value && props[i].key === key) value = props[i].value;
+                }
+            }
+            return value instanceof AST_SymbolRef && value.fixed_value() || value;
+        }
+
+        function is_modified(node, value, level, immutable) {
             var parent = tw.parent(level);
             if (is_lhs(node, parent)
-                || !immutable && parent instanceof AST_Call && parent.expression === node) {
+                || !immutable
+                    && parent instanceof AST_Call
+                    && parent.expression === node
+                    && (!(value instanceof AST_Function) || value.contains_this())) {
                 return true;
+            } else if (parent instanceof AST_Array || parent instanceof AST_Object) {
+                return is_modified(parent, parent, level + 1);
             } else if (parent instanceof AST_PropAccess && parent.expression === node) {
-                return !immutable && is_modified(parent, level + 1);
+                return !immutable && is_modified(parent, read_property(value, parent.property), level + 1);
             }
         }
+
+        function mark_escaped(d, node, value, level) {
+            var parent = tw.parent(level);
+            if (value instanceof AST_Constant || value instanceof AST_Function) return;
+            if (parent instanceof AST_Assign && parent.operator == "=" && node === parent.right
+                || parent instanceof AST_Call && node !== parent.expression
+                || parent instanceof AST_Return && node === parent.value && node.scope !== d.scope
+                || parent instanceof AST_VarDef && node === parent.value) {
+                d.escaped = true;
+                return;
+            } else if (parent instanceof AST_Array || parent instanceof AST_Object) {
+                mark_escaped(d, parent, parent, level + 1);
+            } else if (parent instanceof AST_PropAccess && node === parent.expression) {
+                value = read_property(value, parent.property);
+                mark_escaped(d, parent, value, level + 1);
+                if (value) return;
+            }
+            if (level == 0) d.direct_access = true;
+        }
     });
 
-    AST_SymbolRef.DEFMETHOD("fixed_value", function() {
+    AST_Symbol.DEFMETHOD("fixed_value", function() {
         var fixed = this.definition().fixed;
         if (!fixed || fixed instanceof AST_Node) return fixed;
         return fixed();
@@ -610,7 +653,6 @@ merge(Compressor.prototype, {
     }
 
     function is_lhs_read_only(lhs) {
-        if (lhs instanceof AST_Super) return true;
         if (lhs instanceof AST_This) return true;
         if (lhs instanceof AST_SymbolRef) return lhs.definition().orig[0] instanceof AST_SymbolLambda;
         if (lhs instanceof AST_PropAccess) {
@@ -819,6 +861,7 @@ merge(Compressor.prototype, {
                     // 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 one_off = lhs instanceof AST_Symbol && lhs.definition().references.length == 1;
                     var side_effects = value_has_side_effects(candidate);
                     var hit = candidate.name instanceof AST_SymbolFunarg;
                     var abort = false, replaced = false;
@@ -880,17 +923,18 @@ merge(Compressor.prototype, {
                         var sym;
                         if (node instanceof AST_Call
                             || node instanceof AST_Exit
-                            || node instanceof AST_PropAccess && node.has_side_effects(compressor)
+                            || node instanceof AST_PropAccess
+                                && (side_effects || node.expression.may_throw_on_access(compressor))
                             || node instanceof AST_SymbolRef
                                && (lvalues[node.name]
                                    || side_effects && !references_in_scope(node.definition()))
-                            || (sym = lhs_or_def(node)) && get_symbol(sym).name in lvalues
+                            || (sym = lhs_or_def(node))
-                            || parent instanceof AST_Binary
+                                && (sym instanceof AST_PropAccess || sym.name in lvalues)
-                                && (parent.operator == "&&" || parent.operator == "||")
+                            || (side_effects || !one_off)
-                            || parent instanceof AST_Case
+                                && (parent instanceof AST_Binary && lazy_op(parent.operator)
-                            || parent instanceof AST_Conditional
+                                    || parent instanceof AST_Case
-                            || parent instanceof AST_For
+                                    || parent instanceof AST_Conditional
-                            || parent instanceof AST_If) {
+                                    || parent instanceof AST_If)) {
                             if (!(node instanceof AST_Scope)) descend(node, tt);
                             abort = true;
                             return node;
@@ -1003,27 +1047,14 @@ merge(Compressor.prototype, {
                 }
             }
 
-            function get_symbol(node) {
-                while (node instanceof AST_PropAccess) node = node.expression;
-                return node;
-            }
-
             function get_lvalues(expr) {
                 var lvalues = Object.create(null);
                 if (expr instanceof AST_Unary) return lvalues;
-                var scope;
                 var tw = new TreeWalker(function(node, descend) {
-                    if (node instanceof AST_Scope) {
+                    var sym = node;
-                        var save_scope = scope;
+                    while (sym instanceof AST_PropAccess) sym = sym.expression;
-                        descend();
+                    if (sym instanceof AST_SymbolRef || sym instanceof AST_This) {
-                        scope = save_scope;
+                        lvalues[sym.name] = lvalues[sym.name] || is_lhs(node, tw.parent());
-                        return true;
-                    }
-                    if (node instanceof AST_SymbolRef || node instanceof AST_PropAccess) {
-                        var sym = get_symbol(node);
-                        if (sym instanceof AST_SymbolRef) {
-                            lvalues[sym.name] = lvalues[sym.name] || is_lhs(node, tw.parent());
-                        }
                     }
                 });
                 expr[expr instanceof AST_Assign ? "right" : "value"].walk(tw);
@@ -1522,9 +1553,10 @@ merge(Compressor.prototype, {
             return member(this.operator, unary_bool);
         });
         def(AST_Binary, function(){
-            return member(this.operator, binary_bool) ||
+            return member(this.operator, binary_bool)
-                ( (this.operator == "&&" || this.operator == "||") &&
+                || lazy_op(this.operator)
-                  this.left.is_boolean() && this.right.is_boolean() );
+                    && this.left.is_boolean()
+                    && this.right.is_boolean();
         });
         def(AST_Conditional, function(){
             return this.consequent.is_boolean() && this.alternative.is_boolean();
@@ -1596,6 +1628,7 @@ merge(Compressor.prototype, {
         node.DEFMETHOD("is_string", func);
     });
 
+    var lazy_op = makePredicate("&& ||");
     var unary_side_effects = makePredicate("delete ++ --");
 
     function is_lhs(node, parent) {
@@ -1707,35 +1740,6 @@ merge(Compressor.prototype, {
                     && unaryPrefix(this.operator);
             }
         });
-        // Obtain the constant value of an expression already known to be constant.
-        // Result only valid iff this.is_constant() is true.
-        AST_Node.DEFMETHOD("constant_value", function(compressor){
-            // Accomodate when option evaluate=false.
-            if (this instanceof AST_Constant && !(this instanceof AST_RegExp)) {
-                return this.value;
-            }
-            // Accomodate the common constant expressions !0 and -1 when option evaluate=false.
-            if (this instanceof AST_UnaryPrefix
-                && this.expression instanceof AST_Constant) switch (this.operator) {
-              case "!":
-                return !this.expression.value;
-              case "~":
-                return ~this.expression.value;
-              case "-":
-                return -this.expression.value;
-              case "+":
-                return +this.expression.value;
-              default:
-                throw new Error(string_template("Cannot evaluate unary expression {value}", {
-                    value: this.print_to_string()
-                }));
-            }
-            var result = this.evaluate(compressor);
-            if (result !== this) {
-                return result;
-            }
-            throw new Error(string_template("Cannot evaluate constant [{file}:{line},{col}]", this.start));
-        });
         def(AST_Statement, function(){
             throw new Error(string_template("Cannot evaluate a statement [{file}:{line},{col}]", this.start));
         });
@@ -1759,6 +1763,7 @@ merge(Compressor.prototype, {
                 var elements = [];
                 for (var i = 0, len = this.elements.length; i < len; i++) {
                     var element = this.elements[i];
+                    if (element instanceof AST_Function) continue;
                     var value = ev(element, compressor);
                     if (element === value) return this;
                     elements.push(value);
@@ -1783,6 +1788,7 @@ merge(Compressor.prototype, {
                     if (typeof Object.prototype[key] === 'function') {
                         return this;
                     }
+                    if (prop.value instanceof AST_Function) continue;
                     val[key] = ev(prop.value, compressor);
                     if (val[key] === prop.value) return this;
                 }
@@ -2143,7 +2149,6 @@ merge(Compressor.prototype, {
 
         def(AST_EmptyStatement, return_false);
         def(AST_Constant, return_false);
-        def(AST_Super, return_false);
         def(AST_This, return_false);
 
         def(AST_Call, function(compressor){
@@ -2238,6 +2243,10 @@ merge(Compressor.prototype, {
                 return expression.has_side_effects(compressor);
             });
         });
+        def(AST_TemplateSegment, return_false);
+        def(AST_TemplateString, function(compressor){
+            return any(this.segments, compressor);
+        });
     })(function(node, func){
         node.DEFMETHOD("has_side_effects", func);
     });
@@ -2521,9 +2530,8 @@ merge(Compressor.prototype, {
                     return node;
                 }
                 var parent = tt.parent();
-                if (node instanceof AST_Definitions
+                if (node instanceof AST_Definitions && !(parent instanceof AST_ForIn && parent.init === node)) {
-                    && !(parent instanceof AST_ForIn && parent.init === node)
+                    var drop_block = !(parent instanceof AST_Toplevel) && !(node instanceof AST_Var);
-                    && (drop_vars || !(parent instanceof AST_Toplevel) && !(node instanceof AST_Var))) {
                     // place uninitialized names at the start
                     var body = [], head = [], tail = [];
                     // for unused names whose initialization has
@@ -2534,8 +2542,8 @@ merge(Compressor.prototype, {
                         if (def.value) def.value = def.value.transform(tt);
                         if (def.name instanceof AST_Destructuring) return tail.push(def);
                         var sym = def.name.definition();
-                        if (!drop_vars && sym.global) return tail.push(def);
+                        if (drop_block && sym.global) return tail.push(def);
-                        if (sym.id in in_use_ids) {
+                        if (!(drop_vars || drop_block) || sym.id in in_use_ids) {
                             if (def.name instanceof AST_SymbolVar) {
                                 var var_defs = var_defs_by_id.get(sym.id);
                                 if (var_defs.length > 1 && !def.value) {
@@ -2601,11 +2609,11 @@ merge(Compressor.prototype, {
                         }));
                     }
                     switch (body.length) {
-                        case 0:
+                      case 0:
                         return in_list ? MAP.skip : make_node(AST_EmptyStatement, node);
-                        case 1:
+                      case 1:
                         return body[0];
-                        default:
+                      default:
                         return in_list ? MAP.splice(body) : make_node(AST_BlockStatement, node, {
                             body: body
                         });
@@ -2814,6 +2822,71 @@ merge(Compressor.prototype, {
         return self;
     });
 
+    AST_Scope.DEFMETHOD("hoist_properties", function(compressor){
+        var self = this;
+        if (!compressor.option("hoist_props") || compressor.has_directive("use asm")) return self;
+        var defs_by_id = Object.create(null);
+        var var_names = Object.create(null);
+        self.enclosed.forEach(function(def) {
+            var_names[def.name] = true;
+        });
+        self.variables.each(function(def, name) {
+            var_names[name] = true;
+        });
+        return self.transform(new TreeTransformer(function(node) {
+            if (node instanceof AST_VarDef) {
+                var sym = node.name, def, value;
+                if (sym.scope === self
+                    && !(def = sym.definition()).escaped
+                    && !def.single_use
+                    && !def.direct_access
+                    && (value = sym.fixed_value()) === node.value
+                    && value instanceof AST_Object) {
+                    var defs = new Dictionary();
+                    var assignments = [];
+                    value.properties.forEach(function(prop) {
+                        assignments.push(make_node(AST_VarDef, node, {
+                            name: make_sym(prop.key),
+                            value: prop.value
+                        }));
+                    });
+                    defs_by_id[def.id] = defs;
+                    return MAP.splice(assignments);
+                }
+            }
+            if (node instanceof AST_PropAccess && node.expression instanceof AST_SymbolRef) {
+                var defs = defs_by_id[node.expression.definition().id];
+                if (defs) {
+                    var key = node.property;
+                    if (key instanceof AST_Node) key = key.getValue();
+                    var def = defs.get(key);
+                    var sym = make_node(AST_SymbolRef, node, {
+                        name: def.name,
+                        scope: node.expression.scope,
+                        thedef: def
+                    });
+                    sym.reference({});
+                    return sym;
+                }
+            }
+
+            function make_sym(key) {
+                var prefix = sym.name + "_" + key.toString().replace(/[^a-z_$]+/ig, "_");
+                var name = prefix;
+                for (var i = 0; var_names[name]; i++) name = prefix + "$" + i;
+                var new_var = make_node(sym.CTOR, sym, {
+                    name: name,
+                    scope: self
+                });
+                var def = self.def_variable(new_var);
+                defs.set(key, def);
+                self.enclosed.push(def);
+                var_names[name] = true;
+                return new_var;
+            }
+        }));
+    });
+
     // drop_side_effect_free()
     // remove side-effect-free parts which only affects return value
     (function(def){
@@ -2838,7 +2911,6 @@ merge(Compressor.prototype, {
 
         def(AST_Node, return_this);
         def(AST_Constant, return_null);
-        def(AST_Super, return_null);
         def(AST_This, return_null);
         def(AST_Call, function(compressor, first_in_statement){
             if (!this.is_expr_pure(compressor)) {
@@ -2864,14 +2936,12 @@ merge(Compressor.prototype, {
         def(AST_Binary, function(compressor, first_in_statement){
             var right = this.right.drop_side_effect_free(compressor);
             if (!right) return this.left.drop_side_effect_free(compressor, first_in_statement);
-            switch (this.operator) {
+            if (lazy_op(this.operator)) {
-              case "&&":
-              case "||":
                 if (right === this.right) return this;
                 var node = this.clone();
                 node.right = right;
                 return node;
-              default:
+            } else {
                 var left = this.left.drop_side_effect_free(compressor, first_in_statement);
                 if (!left) return this.right.drop_side_effect_free(compressor, first_in_statement);
                 return make_sequence(this, [ left, right ]);
@@ -2955,6 +3025,11 @@ merge(Compressor.prototype, {
         def(AST_Expansion, function(compressor, first_in_statement){
             return this.expression.drop_side_effect_free(compressor, first_in_statement);
         });
+        def(AST_TemplateSegment, return_null);
+        def(AST_TemplateString, function(compressor){
+            var values = trim(this.segments, compressor, first_in_statement);
+            return values && make_sequence(this, values);
+        });
     })(function(node, func){
         node.DEFMETHOD("drop_side_effect_free", func);
     });
@@ -3326,7 +3401,21 @@ merge(Compressor.prototype, {
     });
 
     AST_Definitions.DEFMETHOD("remove_initializers", function(){
-        this.definitions.forEach(function(def){ def.value = null });
+        var decls = [];
+        this.definitions.forEach(function(def) {
+            if (def.name instanceof AST_SymbolDeclaration) {
+                def.value = null;
+                decls.push(def);
+            } else def.name.walk(new TreeWalker(function(node) {
+                if (node instanceof AST_SymbolDeclaration) {
+                    decls.push(make_node(AST_VarDef, def, {
+                        name: node,
+                        value: null
+                    }));
+                }
+            }));
+        });
+        this.definitions = decls;
     });
 
     AST_Definitions.DEFMETHOD("to_assignments", function(compressor){
@@ -3795,7 +3884,7 @@ merge(Compressor.prototype, {
                     }
                     if (cdr instanceof AST_Binary && !(cdr instanceof AST_Assign)) {
                         if (cdr.left.is_constant()) {
-                            if (cdr.operator == "||" || cdr.operator == "&&") {
+                            if (lazy_op(cdr.operator)) {
                                 expressions[++i] = expressions[j];
                                 break;
                             }
@@ -3951,6 +4040,11 @@ merge(Compressor.prototype, {
     });
 
     var commutativeOperators = makePredicate("== === != !== * & | ^");
+    function is_object(node) {
+        return node instanceof AST_Array
+            || node instanceof AST_Lambda
+            || node instanceof AST_Object;
+    }
 
     OPT(AST_Binary, function(self, compressor){
         function reversible() {
@@ -3986,7 +4080,8 @@ merge(Compressor.prototype, {
           case "!==":
             if ((self.left.is_string(compressor) && self.right.is_string(compressor)) ||
                 (self.left.is_number(compressor) && self.right.is_number(compressor)) ||
-                (self.left.is_boolean() && self.right.is_boolean())) {
+                (self.left.is_boolean() && self.right.is_boolean()) ||
+                self.left.equivalent_to(self.right)) {
                 self.operator = self.operator.substr(0, 2);
             }
             // XXX: intentionally falling down to the next case
@@ -4006,6 +4101,13 @@ merge(Compressor.prototype, {
                     if (self.operator.length == 2) self.operator += "=";
                 }
             }
+            // obj !== obj => false
+            else if (self.left instanceof AST_SymbolRef
+                && self.right instanceof AST_SymbolRef
+                && self.left.definition() === self.right.definition()
+                && is_object(self.left.fixed_value())) {
+                return make_node(self.operator[0] == "=" ? AST_True : AST_False, self);
+            }
             break;
         }
         if (compressor.option("booleans") && self.operator == "+" && compressor.in_boolean_context()) {
@@ -4295,8 +4397,7 @@ merge(Compressor.prototype, {
         // "x" + (y + "z")==>  "x" + y + "z"
         if (self.right instanceof AST_Binary
             && self.right.operator == self.operator
-            && (self.operator == "&&"
+            && (lazy_op(self.operator)
-                || self.operator == "||"
                 || (self.operator == "+"
                     && (self.right.left.is_string(compressor)
                         || (self.left.is_string(compressor)
@@ -4348,6 +4449,7 @@ merge(Compressor.prototype, {
                 d.fixed = fixed = make_node(AST_Function, fixed, fixed);
             }
             if (compressor.option("unused")
+                && fixed
                 && d.references.length == 1
                 && (d.single_use || is_func_expr(fixed)
                     && !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
@@ -4701,19 +4803,69 @@ merge(Compressor.prototype, {
     });
 
     OPT(AST_Sub, function(self, compressor){
+        var expr = self.expression;
         var prop = self.property;
-        if (prop instanceof AST_String && compressor.option("properties")) {
+        if (compressor.option("properties")) {
-            prop = prop.getValue();
+            var key = prop.evaluate(compressor);
-            if (is_identifier_string(prop)) {
+            if (key !== prop) {
-                return make_node(AST_Dot, self, {
+                var property = "" + key;
-                    expression : self.expression,
+                if (is_identifier_string(property)
-                    property   : prop
+                    && property.length <= prop.print_to_string().length + 1) {
-                }).optimize(compressor);
+                    return make_node(AST_Dot, self, {
+                        expression: expr,
+                        property: property
+                    }).optimize(compressor);
+                }
+                if (!(prop instanceof AST_Number)) {
+                    var value = parseFloat(property);
+                    if (value.toString() == property) {
+                        prop = self.property = make_node(AST_Number, prop, {
+                            value: value
+                        });
+                    }
+                }
             }
-            var v = parseFloat(prop);
+        }
-            if (!isNaN(v) && v.toString() == prop) {
+        if (is_lhs(self, compressor.parent())) return self;
-                self.property = make_node(AST_Number, self.property, {
+        if (compressor.option("properties") && key !== prop) {
-                    value: v
+            var node = self.flatten_object(property, compressor);
+            if (node) {
+                expr = self.expression = node.expression;
+                prop = self.property = node.property;
+            }
+        }
+        if (compressor.option("properties") && compressor.option("side_effects")
+            && prop instanceof AST_Number && expr instanceof AST_Array) {
+            var index = prop.getValue();
+            var elements = expr.elements;
+            if (index in elements) {
+                var flatten = true;
+                var values = [];
+                for (var i = elements.length; --i > index;) {
+                    var value = elements[i].drop_side_effect_free(compressor);
+                    if (value) {
+                        values.unshift(value);
+                        if (flatten && value.has_side_effects(compressor)) flatten = false;
+                    }
+                }
+                var retValue = elements[index];
+                retValue = retValue instanceof AST_Hole ? make_node(AST_Undefined, retValue) : retValue;
+                if (!flatten) values.unshift(retValue);
+                while (--i >= 0) {
+                    var value = elements[i].drop_side_effect_free(compressor);
+                    if (value) values.unshift(value);
+                    else index--;
+                }
+                if (flatten) {
+                    values.push(retValue);
+                    return make_sequence(self, values).optimize(compressor);
+                } else return make_node(AST_Sub, self, {
+                    expression: make_node(AST_Array, expr, {
+                        elements: values
+                    }),
+                    property: make_node(AST_Number, prop, {
+                        value: index
+                    })
                 });
             }
         }
@@ -4736,30 +4888,47 @@ merge(Compressor.prototype, {
         return result;
     });
 
+    AST_PropAccess.DEFMETHOD("flatten_object", function(key, compressor) {
+        var arrows = compressor.option("unsafe_arrows") && compressor.option("ecma") >= 6;
+        var expr = this.expression;
+        if (expr instanceof AST_Object) {
+            var props = expr.properties;
+            for (var i = props.length; --i >= 0;) {
+                var prop = props[i];
+                if ("" + (prop instanceof AST_ConciseMethod ? prop.key.name : prop.key) == key) {
+                    if (!all(props, function(prop) {
+                        return prop instanceof AST_ObjectKeyVal
+                            || arrows && prop instanceof AST_ConciseMethod && !prop.is_generator;
+                    })) break;
+                    var value = prop.value;
+                    if ((value instanceof AST_Accessor || value instanceof AST_Function)
+                        && value.contains_this()) break;
+                    return make_node(AST_Sub, this, {
+                        expression: make_node(AST_Array, expr, {
+                            elements: props.map(function(prop) {
+                                var v = prop.value;
+                                if (v instanceof AST_Accessor) v = make_node(AST_Function, v, v);
+                                var k = prop.key;
+                                if (k instanceof AST_Node && !(k instanceof AST_SymbolMethod)) {
+                                    return make_sequence(prop, [ k, v ]);
+                                }
+                                return v;
+                            })
+                        }),
+                        property: make_node(AST_Number, this, {
+                            value: i
+                        })
+                    });
+                }
+            }
+        }
+    });
+
     OPT(AST_Dot, function(self, compressor){
         var def = self.resolve_defines(compressor);
         if (def) {
             return def.optimize(compressor);
         }
-        if (compressor.option("unsafe") && self.expression instanceof AST_Object) {
-            var values = self.expression.properties;
-            for (var i = values.length; --i >= 0;) {
-                var key = values[i].key;
-                if ((key instanceof AST_SymbolMethod ? key.name : key) === self.property) {
-                    var value = values[i].value;
-                    if (key instanceof AST_SymbolMethod) {
-                        if (values[i].is_generator) break;
-                        value = make_node(AST_Function, value, value);
-                    }
-                    if (value instanceof AST_Function ? !value.contains_this() : !value.has_side_effects(compressor)) {
-                        var obj = self.expression.clone();
-                        obj.properties = obj.properties.slice();
-                        obj.properties.splice(i, 1);
-                        return make_sequence(self, [ obj, value ]).optimize(compressor);
-                    }
-                }
-            }
-        }
         if (compressor.option("unsafe_proto")
             && self.expression instanceof AST_Dot
             && self.expression.property == "prototype") {
@@ -4782,6 +4951,11 @@ merge(Compressor.prototype, {
                 break;
             }
         }
+        if (is_lhs(self, compressor.parent())) return self;
+        if (compressor.option("properties")) {
+            var node = self.flatten_object(self.property, compressor);
+            if (node) return node.optimize(compressor);
+        }
         var ev = self.evaluate(compressor);
         if (ev !== self) {
             ev = make_node_from_constant(ev, self).optimize(compressor);
@@ -4832,7 +5006,7 @@ merge(Compressor.prototype, {
             var has_special_symbol = false;
             self.walk(new TreeWalker(function(node) {
                 if (has_special_symbol) return true;
-                if (node instanceof AST_Super || node instanceof AST_This) {
+                if (node instanceof AST_This) {
                     has_special_symbol = true;
                     return true;
                 }
@@ -4885,7 +5059,7 @@ merge(Compressor.prototype, {
         }
         self.segments = segments;
 
-        return self;
+        return segments.length == 1 ? make_node(AST_String, self, segments[0]) : self;
     });
 
     OPT(AST_PrefixedTemplateString, function(self, compressor){

lib/output.js

@@ -262,7 +262,7 @@ function OutputStream(options) {
         }
     } : noop;
 
-    var requireSemicolonChars = makePredicate("( [ + * / - , .");
+    var requireSemicolonChars = makePredicate("( [ + * / - , . `");
 
     function print(str) {
         str = String(str);
@@ -1685,9 +1685,6 @@ function OutputStream(options) {
     DEFPRINT(AST_Symbol, function (self, output) {
         self._do_print(output);
     });
-    DEFPRINT(AST_SymbolDeclaration, function(self, output){
-        self._do_print(output);
-    });
     DEFPRINT(AST_Hole, noop);
     DEFPRINT(AST_This, function(self, output){
         output.print("this");

lib/parse.js

@@ -2565,7 +2565,7 @@ function parse($TEXT, options) {
                 unexpected(tmp);
             }
           case "name":
-            if (tmp.value == "yield" && !is_token(peek(), "punc", ":")
+            if (tmp.value == "yield" && !is_token(peek(), "punc", ":") && !is_token(peek(), "punc", "(")
                 && S.input.has_directive("use strict") && !is_in_generator()) {
                 token_error(tmp, "Unexpected yield identifier inside strict mode");
             }

lib/transform.js

@@ -262,11 +262,7 @@ TreeTransformer.prototype = new TreeWalker;
     });
 
     _(AST_TemplateString, function(self, tw) {
-        for (var i = 0; i < self.segments.length; i++) {
+        self.segments = do_list(self.segments, tw);
-            if (!(self.segments[i] instanceof AST_TemplateSegment)) {
-                self.segments[i] = self.segments[i].transform(tw);
-            }
-        }
     });
 
     _(AST_PrefixedTemplateString, function(self, tw) {

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": "3.1.4",
+  "version": "3.1.6",
   "engines": {
     "node": ">=0.8.0"
   },

test/compress/arrays.js

@@ -203,50 +203,110 @@ constant_join_3: {
 
 for_loop: {
     options = {
-        unsafe      : true,
+        evaluate: true,
-        unused      : true,
+        reduce_vars: true,
-        evaluate    : true,
+        unsafe: true,
-        reduce_vars : true
+        unused: true,
     };
     input: {
         function f0() {
             var a = [1, 2, 3];
-            for (var i = 0; i < a.length; i++) {
+            var b = 0;
-                console.log(a[i]);
+            for (var i = 0; i < a.length; i++)
-            }
+                b += a[i];
+            return b;
         }
-
         function f1() {
             var a = [1, 2, 3];
-            for (var i = 0, len = a.length; i < len; i++) {
+            var b = 0;
-                console.log(a[i]);
+            for (var i = 0, len = a.length; i < len; i++)
-            }
+                b += a[i];
+            return b;
         }
-
-        function f2() {
-            var a = [1, 2, 3];
-            for (var i = 0; i < a.length; i++) {
-                a[i]++;
-            }
-        }
-    }
-    expect: {
-        function f0() {
-            var a = [1, 2, 3];
-            for (var i = 0; i < 3; i++)
-                console.log(a[i]);
-        }
-
-        function f1() {
-            var a = [1, 2, 3];
-            for (var i = 0; i < 3; i++)
-                console.log(a[i]);
-        }
-
         function f2() {
             var a = [1, 2, 3];
             for (var i = 0; i < a.length; i++)
                 a[i]++;
+            return a[2];
         }
+        console.log(f0(), f1(), f2());
     }
+    expect: {
+        function f0() {
+            var a = [1, 2, 3];
+            var b = 0;
+            for (var i = 0; i < 3; i++)
+                b += a[i];
+            return b;
+        }
+        function f1() {
+            var a = [1, 2, 3];
+            var b = 0;
+            for (var i = 0; i < 3; i++)
+                b += a[i];
+            return b;
+        }
+        function f2() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < a.length; i++)
+                a[i]++;
+            return a[2];
+        }
+        console.log(f0(), f1(), f2());
+    }
+    expect_stdout: "6 6 4"
+}
+
+index: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a[0], a[1]);
+    }
+    expect: {
+        console.log(1, 2);
+    }
+    expect_stdout: "1 2"
+}
+
+length: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a.length);
+    }
+    expect: {
+        console.log(2);
+    }
+    expect_stdout: "2"
+}
+
+index_length: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = [ 1, 2 ];
+        console.log(a[0], a.length);
+    }
+    expect: {
+        console.log(1, 2);
+    }
+    expect_stdout: "1 2"
 }

test/compress/arrow.js

@@ -631,3 +631,31 @@ issue_2271: {
     }
     expect_stdout: "PASS"
 }
+
+concise_method_with_super: {
+    options = {
+        arrows: true,
+    }
+    input: {
+        var o = {
+            f: "FAIL",
+            g() {
+                return super.f;
+            }
+        }
+        Object.setPrototypeOf(o, { f: "PASS" });
+        console.log(o.g());
+    }
+    expect: {
+        var o = {
+            f: "FAIL",
+            g() {
+                return super.f;
+            }
+        }
+        Object.setPrototypeOf(o, { f: "PASS" });
+        console.log(o.g());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}

test/compress/collapse_vars.js

@@ -2150,7 +2150,7 @@ inner_lvalues: {
         console.log(null, a, b);
     }
     expect: {
-        var a, b = 10;
+        var b = 10;
         var a = (--b || a || 3).toString(), c = --b + -a;
         console.log(null, a, b);
     }
@@ -2808,69 +2808,418 @@ issue_2319_3: {
     expect_stdout: "true"
 }
 
-prop_side_effects_1: {
+issue_2365: {
     options = {
         collapse_vars: true,
-        evaluate: true,
+        pure_getters: true,
-        pure_getters: "strict",
-        reduce_vars: true,
-        toplevel: true,
-        unsafe: true,
-        unused: true,
     }
     input: {
-        var C = 1;
+        console.log(function(a) {
-        console.log(C);
+            var b = a.f;
-        var obj = {
+            a.f++;
-            bar: function() {
+            return b;
-                return C + C;
+        }({ f: 1 }));
+        console.log(function() {
+            var a = { f: 1 }, b = a.f;
+            a.f++;
+            return b;
+        }());
+        console.log({
+            f: 1,
+            g: function() {
+                var b = this.f;
+                this.f++;
+                return b;
             }
-        };
+        }.g());
-        console.log(obj.bar());
     }
     expect: {
-        console.log(1);
+        console.log(function(a) {
+            var b = a.f;
+            a.f++;
+            return b;
+        }({ f: 1 }));
+        console.log(function() {
+            var a = { f: 1 }, b = a.f;
+            a.f++;
+            return b;
+        }());
         console.log({
-            bar: function() {
+            f: 1,
-                return 2;
+            g: function() {
+                var b = this.f;
+                this.f++;
+                return b;
             }
-        }.bar());
+        }.g());
     }
     expect_stdout: [
         "1",
-        "2",
+        "1",
+        "1",
     ]
 }
 
-prop_side_effects_2: {
+issue_2364_1: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo() {
+            var first = arguments[0];
+            var result = inc(first);
+            return foo.amount = first.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data);
+        console.log(foo.amount, answer);
+    }
+    expect: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo() {
+            var first = arguments[0];
+            var result = inc(first);
+            return foo.amount = first.count, result;
+        }
+        var data = {
+            count: 0
+        };
+        var answer = foo(data);
+        console.log(foo.amount, answer);
+    }
+    expect_stdout: "1 0"
+}
+
+issue_2364_2: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function callValidate() {
+            var validate = compilation.validate;
+            var result = validate.apply(null, arguments);
+            return callValidate.errors = validate.errors, result;
+        }
+    }
+    expect: {
+        function callValidate() {
+            var validate = compilation.validate;
+            var result = validate.apply(null, arguments);
+            return callValidate.errors = validate.errors, result;
+        }
+    }
+}
+
+issue_2364_3: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo(bar) {
+            var result = inc(bar);
+            return foo.amount = bar.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data);
+        console.log(foo.amount, answer);
+    }
+    expect: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo(bar) {
+            var result = inc(bar);
+            return foo.amount = bar.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data);
+        console.log(foo.amount, answer);
+    }
+    expect_stdout: "1 0"
+}
+
+issue_2364_4: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo(bar, baz) {
+            var result = inc(bar);
+            return foo.amount = baz.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data, data);
+        console.log(foo.amount, answer);
+    }
+    expect: {
+        function inc(obj) {
+            return obj.count++;
+        }
+        function foo(bar, baz) {
+            var result = inc(bar);
+            return foo.amount = baz.count, result;
+        }
+        var data = {
+            count: 0,
+        };
+        var answer = foo(data, data);
+        console.log(foo.amount, answer);
+    }
+    expect_stdout: "1 0"
+}
+
+issue_2364_5: {
     options = {
         collapse_vars: true,
         evaluate: true,
-        inline: true,
+        pure_getters: true,
-        passes: 2,
+        properties: true,
-        pure_getters: "strict",
         reduce_vars: true,
-        side_effects: true,
-        toplevel: true,
-        unsafe: true,
         unused: true,
     }
     input: {
-        var C = 1;
+        function f0(o, a, h) {
-        console.log(C);
+            var b = 3 - a;
-        var obj = {
+            var obj = o;
-            bar: function() {
+            var seven = 7;
-                return C + C;
+            var prop = 'run';
-            }
+            var t = obj[prop](b)[seven] = h;
-        };
+            return t;
-        console.log(obj.bar());
+        }
     }
     expect: {
-        console.log(1);
+        function f0(o, a, h) {
-        console.log(2);
+            return o.run(3 - a)[7] = h;
+        }
     }
-    expect_stdout: [
+}
-        "1",
+
-        "2",
+issue_2364_6: {
-    ]
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b) {
+            var c = a.p;
+            b.p = "FAIL";
+            return c;
+        }
+        var o = {
+            p: "PASS"
+        }
+        console.log(f(o, o));
+    }
+    expect: {
+        function f(a, b) {
+            var c = a.p;
+            b.p = "FAIL";
+            return c;
+        }
+        var o = {
+            p: "PASS"
+        }
+        console.log(f(o, o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2364_7: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b) {
+            var c = a.p;
+            b.f();
+            return c;
+        }
+        var o = {
+            p: "PASS",
+            f: function() {
+                this.p = "FAIL";
+            }
+        }
+        console.log(f(o, o));
+    }
+    expect: {
+        function f(a, b) {
+            var c = a.p;
+            b.f();
+            return c;
+        }
+        var o = {
+            p: "PASS",
+            f: function() {
+                this.p = "FAIL";
+            }
+        }
+        console.log(f(o, o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2364_8: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b, c) {
+            var d = a[b.f = function() {
+                return "PASS";
+            }];
+            return c.f(d);
+        }
+        var o = {
+            f: function() {
+                return "FAIL";
+            }
+        };
+        console.log(f({}, o, o));
+    }
+    expect: {
+        function f(a, b, c) {
+            var d = a[b.f = function() {
+                return "PASS";
+            }];
+            return c.f(d);
+        }
+        var o = {
+            f: function() {
+                return "FAIL";
+            }
+        };
+        console.log(f({}, o, o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2364_9: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b) {
+            var d = a();
+            return b.f(d);
+        }
+        var o = {
+            f: function() {
+                return "FAIL";
+            }
+        };
+        console.log(f(function() {
+            o.f = function() {
+                return "PASS";
+            };
+        }, o));
+    }
+    expect: {
+        function f(a, b) {
+            var d = a();
+            return b.f(d);
+        }
+        var o = {
+            f: function() {
+                return "FAIL";
+            }
+        };
+        console.log(f(function() {
+            o.f = function() {
+                return "PASS";
+            };
+        }, o));
+    }
+    expect_stdout: "PASS"
+}
+
+pure_getters_chain: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function o(t, r) {
+            var a = t[1], s = t[2], o = t[3], i = t[5];
+            return a <= 23 && s <= 59 && o <= 59 && (!r || i);
+        }
+        console.log(o([ , 23, 59, 59, , 42], 1));
+    }
+    expect: {
+        function o(t, r) {
+            return t[1] <= 23 && t[2] <= 59 && t[3] <= 59 && (!r || t[5]);
+        }
+        console.log(o([ , 23, 59, 59, , 42], 1));
+    }
+    expect_stdout: "42"
+}
+
+conditional_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        function f(a, b) {
+            var c = "";
+            var d = b ? ">" : "<";
+            if (a) c += "=";
+            return c += d;
+        }
+        console.log(f(0, 0), f(0, 1), f(1, 0), f(1, 1));
+    }
+    expect: {
+        function f(a, b) {
+            var c = "";
+            if (a) c += "=";
+            return c += b ? ">" : "<";
+        }
+        console.log(f(0, 0), f(0, 1), f(1, 0), f(1, 1));
+    }
+    expect_stdout: "< > =< =>"
+}
+
+conditional_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        function f(a, b) {
+            var c = a + 1, d = a + 2;
+            return b ? c : d;
+        }
+        console.log(f(3, 0), f(4, 1));
+    }
+    expect: {
+        function f(a, b) {
+            return b ? a + 1 : a + 2;
+        }
+        console.log(f(3, 0), f(4, 1));
+    }
+    expect_stdout: "5 5"
 }

test/compress/comparing.js

@@ -74,3 +74,40 @@ dont_change_in_or_instanceof_expressions: {
         null instanceof null;
     }
 }
+
+self_comparison_1: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        a === a;
+        a !== b;
+        b.c === a.c;
+        b.c !== b.c;
+    }
+    expect: {
+        a == a;
+        a !== b;
+        b.c === a.c;
+        b.c != b.c;
+    }
+}
+
+self_comparison_2: {
+    options = {
+        comparisons: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        function f() {}
+        var o = {};
+        console.log(f != f, o === o);
+    }
+    expect: {
+        function f() {}
+        var o = {};
+        console.log(false, true);
+    }
+    expect_stdout: "false true"
+}

test/compress/dead-code.js

@@ -560,3 +560,64 @@ global_fns: {
         "RangeError",
     ]
 }
+
+issue_2383_1: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+    }
+    input: {
+        if (0) {
+            var {x, y} = foo();
+        }
+    }
+    expect: {
+        var x, y;
+    }
+}
+
+issue_2383_2: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+    }
+    input: {
+        if (0) {
+            var {
+                x = 0,
+                y: [ w, , { z, p: q = 7 } ] = [ 1, 2, { z: 3 } ]
+            } = {};
+        }
+        console.log(x, q, w, z);
+    }
+    expect: {
+        var x, w, z, q;
+        console.log(x, q, w, z);
+    }
+    expect_stdout: "undefined undefined undefined undefined"
+    node_version: ">=6"
+}
+
+issue_2383_3: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+    }
+    input: {
+        var b = 7, y = 8;
+        if (0) {
+            var a = 1, [ x, y, z ] = [ 2, 3, 4 ], b = 5;
+        }
+        console.log(a, x, y, z, b);
+    }
+    expect: {
+        var b = 7, y = 8;
+        var a, x, y, z, b;
+        console.log(a, x, y, z, b);
+    }
+    expect_stdout: "undefined undefined 8 undefined 7"
+    node_version: ">=6"
+}

test/compress/drop-unused.js

@@ -1291,7 +1291,6 @@ issue_2063: {
     }
     expect: {
         var a;
-        var a;
     }
 }
 

test/compress/evaluate.js

@@ -480,10 +480,11 @@ unsafe_object_accessor: {
     }
 }
 
-unsafe_function: {
+prop_function: {
     options = {
-        evaluate  : true,
+        evaluate: true,
-        unsafe    : true
+        properties: true,
+        side_effects: true,
     }
     input: {
         console.log(
@@ -496,9 +497,9 @@ unsafe_function: {
     expect: {
         console.log(
             ({a:{b:1},b:function(){}}) + 1,
-            ({b:function(){}}, {b:1}) + 1,
+            ({b:1}) + 1,
-            ({a:{b:1}}, function(){}) + 1,
+            function(){} + 1,
-            ({b:function(){}}, {b:1}).b + 1
+            2
         );
     }
     expect_stdout: true
@@ -724,10 +725,11 @@ unsafe_string_bad_index: {
     expect_stdout: true
 }
 
-unsafe_prototype_function: {
+prototype_function: {
     options = {
-        evaluate  : true,
+        evaluate: true,
-        unsafe    : true
+        properties: true,
+        side_effects: true,
     }
     input: {
         var a = ({valueOf: 0}) < 1;
@@ -746,8 +748,8 @@ unsafe_prototype_function: {
         var d = ({toString: 0}) + "";
         var e = (({valueOf: 0}) + "")[2];
         var f = (({toString: 0}) + "")[2];
-        var g = ({}, 0)();
+        var g = 0();
-        var h = ({}, 0)();
+        var h = 0();
     }
 }
 
@@ -1288,3 +1290,40 @@ issue_2231_2: {
     }
     expect_stdout: true
 }
+
+self_comparison_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var o = { n: NaN };
+        console.log(o.n == o.n, o.n === o.n, o.n != o.n, o.n !== o.n, typeof o.n);
+    }
+    expect: {
+        console.log(false, false, true, true, "number");
+    }
+    expect_stdout: "false false true true 'number'"
+}
+
+self_comparison_2: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { n: NaN };
+        console.log(o.n == o.n, o.n === o.n, o.n != o.n, o.n !== o.n, typeof o.n);
+    }
+    expect: {
+        console.log(false, false, true, true, "number");
+    }
+    expect_stdout: "false false true true 'number'"
+}

test/compress/functions.js

@@ -151,13 +151,13 @@ issue_1841_2: {
 
 function_returning_constant_literal: {
     options = {
-        reduce_vars: true,
-        unsafe: true,
-        toplevel: true,
-        evaluate: true,
-        cascade: true,
-        unused: true,
         inline: true,
+        passes: 2,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
     }
     input: {
         function greeter() {

test/compress/harmony.js

@@ -902,10 +902,10 @@ issue_2349b: {
         evaluate: true,
         inline: true,
         passes: 3,
+        properties: true,
         reduce_vars: true,
         toplevel: true,
         side_effects: true,
-        unsafe: true,
         unsafe_arrows: true,
         unused: true,
     }

test/compress/hoist_props.js

@@ -0,0 +1,371 @@
+issue_2377_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        var obj_foo = 1, obj_cube = function(x) {
+            return x * x * x;
+        };
+        console.log(obj_foo, obj_cube(3));
+    }
+    expect_stdout: "1 27"
+}
+
+issue_2377_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        console.log(1, function(x) {
+            return x * x * x;
+        }(3));
+    }
+    expect_stdout: "1 27"
+}
+
+issue_2377_3: {
+    options = {
+        evaluate: true,
+        inline: true,
+        hoist_props: true,
+        passes: 3,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.cube(3));
+    }
+    expect: {
+        console.log(1, 27);
+    }
+    expect_stdout: "1 27"
+}
+
+direct_access_1: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        var obj = {
+            a: 1,
+            b: 2,
+        };
+        for (var k in obj) a++;
+        console.log(a, obj.a);
+    }
+    expect: {
+        var a = 0;
+        var obj = {
+            a: 1,
+            b: 2,
+        };
+        for (var k in obj) a++;
+        console.log(a, obj.a);
+    }
+    expect_stdout: "2 1"
+}
+
+direct_access_2: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { a: 1 };
+        var f = function(k) {
+            if (o[k]) return "PASS";
+        };
+        console.log(f("a"));
+    }
+    expect: {
+        var o = { a: 1 };
+        console.log(function(k) {
+            if (o[k]) return "PASS";
+        }("a"));
+    }
+    expect_stdout: "PASS"
+}
+
+direct_access_3: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = { a: 1 };
+        o.b;
+        console.log(o.a);
+    }
+    expect: {
+        var o = { a: 1 };
+        o.b;
+        console.log(o.a);
+    }
+    expect_stdout: "1"
+}
+
+single_use: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var obj = {
+            bar: function() {
+                return 42;
+            },
+        };
+        console.log(obj.bar());
+    }
+    expect: {
+        console.log({
+            bar: function() {
+                return 42;
+            },
+        }.bar());
+    }
+}
+
+name_collision_1: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var obj_foo = 1;
+        var obj_bar = 2;
+        function f() {
+            var obj = {
+                foo: 3,
+                bar: 4,
+                "b-r": 5,
+                "b+r": 6,
+                "b!r": 7,
+            };
+            console.log(obj_foo, obj.foo, obj.bar, obj["b-r"], obj["b+r"], obj["b!r"]);
+        }
+        f();
+    }
+    expect: {
+        var obj_foo = 1;
+        var obj_bar = 2;
+        function f() {
+            var obj_foo$0 = 3,
+                obj_bar = 4,
+                obj_b_r = 5,
+                obj_b_r$0 = 6,
+                obj_b_r$1 = 7;
+            console.log(obj_foo, obj_foo$0, obj_bar, obj_b_r, obj_b_r$0, obj_b_r$1);
+        }
+        f();
+    }
+    expect_stdout: "1 3 4 5 6 7"
+}
+
+name_collision_2: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            p: 1,
+            0: function(x) {
+                return x;
+            },
+            1: function(x) {
+                return x + 1;
+            }
+        }, o__$0 = 2, o__$1 = 3;
+        console.log(o.p === o.p, o[0](4), o[1](5), o__$0, o__$1);
+    }
+    expect: {
+        var o_p = 1,
+            o__ = function(x) {
+                return x;
+            },
+            o__$2 = function(x) {
+                return x + 1;
+            },
+            o__$0 = 2,
+            o__$1 = 3;
+        console.log(o_p === o_p, o__(4), o__$2(5), o__$0, o__$1);
+    }
+    expect_stdout: "true 4 6 2 3"
+}
+
+name_collision_3: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            p: 1,
+            0: function(x) {
+                return x;
+            },
+            1: function(x) {
+                return x + 1;
+            }
+        }, o__$0 = 2, o__$1 = 3;
+        console.log(o.p === o.p, o[0](4), o[1](5));
+    }
+    expect: {
+        var o_p = 1,
+            o__ = function(x) {
+                return x;
+            },
+            o__$2 = function(x) {
+                return x + 1;
+            },
+            o__$0 = 2,
+            o__$1 = 3;
+        console.log(o_p === o_p, o__(4), o__$2(5));
+    }
+    expect_stdout: "true 4 6"
+}
+
+contains_this_1: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p);
+    }
+    expect: {
+        console.log(1, 1);
+    }
+    expect_stdout: "1 1"
+}
+
+contains_this_2: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u);
+    }
+    expect: {
+        console.log(1, 1, function() {
+            return this === this;
+        });
+    }
+    expect_stdout: true
+}
+
+contains_this_3: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u());
+    }
+    expect: {
+        var o = {
+            u: function() {
+                return this === this;
+            },
+            p: 1
+        };
+        console.log(o.p, o.p, o.u());
+    }
+    expect_stdout: "1 1 true"
+}

test/compress/properties.js

@@ -1,7 +1,8 @@
 keep_properties: {
     options = {
-        properties: false
+        evaluate: true,
-    };
+        properties: false,
+    }
     input: {
         a["foo"] = "bar";
     }
@@ -12,6 +13,7 @@ keep_properties: {
 
 dot_properties: {
     options = {
+        evaluate: true,
         properties: true,
     }
     beautify = {
@@ -37,6 +39,7 @@ dot_properties: {
 
 dot_properties_es5: {
     options = {
+        evaluate: true,
         properties: true,
     }
     beautify = {
@@ -61,8 +64,8 @@ dot_properties_es5: {
 sub_properties: {
     options = {
         evaluate: true,
-        properties: true
+        properties: true,
-    };
+    }
     input: {
         a[0] = 0;
         a["0"] = 1;
@@ -81,18 +84,18 @@ sub_properties: {
         a[3.14] = 3;
         a.if = 4;
         a["foo bar"] = 5;
-        a[NaN] = 6;
+        a.NaN = 6;
-        a[null] = 7;
+        a.null = 7;
         a[void 0] = 8;
     }
 }
 
 evaluate_array_length: {
     options = {
+        evaluate: true,
         properties: true,
         unsafe: true,
-        evaluate: true
+    }
-    };
     input: {
         a = [1, 2, 3].length;
         a = [1, 2, 3].join()["len" + "gth"];
@@ -109,10 +112,10 @@ evaluate_array_length: {
 
 evaluate_string_length: {
     options = {
+        evaluate: true,
         properties: true,
         unsafe: true,
-        evaluate: true
+    }
-    };
     input: {
         a = "foo".length;
         a = ("foo" + "bar")["len" + "gth"];
@@ -151,7 +154,8 @@ mangle_properties: {
 
 mangle_unquoted_properties: {
     options = {
-        properties: false
+        evaluate: true,
+        properties: false,
     }
     mangle = {
         properties: {
@@ -250,7 +254,8 @@ mangle_debug_suffix: {
 
 mangle_debug_suffix_keep_quoted: {
     options = {
-        properties: false
+        evaluate: true,
+        properties: false,
     }
     mangle = {
         properties: {
@@ -679,8 +684,8 @@ accessor_this: {
 issue_2208_1: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         console.log({
@@ -698,8 +703,8 @@ issue_2208_1: {
 issue_2208_2: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         console.log({
@@ -723,8 +728,8 @@ issue_2208_2: {
 issue_2208_3: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         a = 42;
@@ -748,8 +753,8 @@ issue_2208_3: {
 issue_2208_4: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         function foo() {}
@@ -772,8 +777,8 @@ issue_2208_4: {
 issue_2208_5: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         console.log({
@@ -792,8 +797,8 @@ issue_2208_5: {
 issue_2208_6: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         console.log({
@@ -809,9 +814,11 @@ issue_2208_6: {
 
 issue_2208_7: {
     options = {
+        ecma: 6,
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
+        unsafe_arrows: true,
     }
     input: {
         console.log({
@@ -829,9 +836,11 @@ issue_2208_7: {
 
 issue_2208_8: {
     options = {
+        ecma: 6,
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
+        unsafe_arrows: true,
     }
     input: {
         console.log({
@@ -851,17 +860,17 @@ issue_2208_8: {
                 return x();
             }
         }.p());
-        console.log(async function() {
+        console.log((async () => {
             return await x();
-        }());
+        })());
     }
 }
 
 issue_2208_9: {
     options = {
         inline: true,
+        properties: true,
         side_effects: true,
-        unsafe: true,
     }
     input: {
         a = 42;
@@ -1052,3 +1061,224 @@ unsafe_methods_regex: {
     ]
     node_version: ">=6"
 }
+
+lhs_prop_1: {
+    options = {
+        evaluate: true,
+        properties: true,
+    }
+    input: {
+        console.log(++{
+            a: 1
+        }.a);
+    }
+    expect: {
+        console.log(++{
+            a: 1
+        }.a);
+    }
+    expect_stdout: "2"
+}
+
+lhs_prop_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        [1][0] = 42;
+        (function(a) {
+            a.b = "g";
+        })("abc");
+        (function(a) {
+            a[2] = "g";
+        })("def");
+        (function(a) {
+            a[""] = "g";
+        })("ghi");
+    }
+    expect: {
+        [1][0] = 42;
+        "abc".b = "g";
+        "def"[2] = "g";
+        "ghi"[""] = "g";
+    }
+}
+
+literal_duplicate_key_side_effects: {
+    options = {
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        console.log({
+            a: "FAIL",
+            a: console.log ? "PASS" : "FAIL"
+        }.a);
+    }
+    expect: {
+        console.log(console.log ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+prop_side_effects_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var C = 1;
+        console.log(C);
+        var obj = {
+            bar: function() {
+                return C + C;
+            }
+        };
+        console.log(obj.bar());
+    }
+    expect: {
+        console.log(1);
+        var obj = {
+            bar: function() {
+                return 2;
+            }
+        };
+        console.log(obj.bar());
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+prop_side_effects_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var C = 1;
+        console.log(C);
+        var obj = {
+            "": function() {
+                return C + C;
+            }
+        };
+        console.log(obj[""]());
+    }
+    expect: {
+        console.log(1);
+        console.log(2);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+accessor_1: {
+    options = {
+        properties: true,
+    }
+    input: {
+        console.log({
+            a: "FAIL",
+            get a() {
+                return "PASS";
+            }
+        }.a);
+    }
+    expect: {
+        console.log({
+            a: "FAIL",
+            get a() {
+                return "PASS";
+            }
+        }.a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+accessor_2: {
+    options = {
+        properties: true,
+    }
+    input: {
+        console.log({
+            get a() {
+                return "PASS";
+            },
+            set a(v) {},
+            a: "FAIL"
+        }.a);
+    }
+    expect: {
+        console.log({
+            get a() {
+                return "PASS";
+            },
+            set a(v) {},
+            a: "FAIL"
+        }.a);
+    }
+    expect_stdout: true
+}
+
+array_hole: {
+    options = {
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(
+            [ 1, 2, , 3][1],
+            [ 1, 2, , 3][2],
+            [ 1, 2, , 3][3]
+        );
+    }
+    expect: {
+        console.log(2, void 0, 3);
+    }
+    expect_stdout: "2 undefined 3"
+}
+
+computed_property: {
+    options = {
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        console.log({
+            a: "bar",
+            [console.log("foo")]: 42,
+        }.a);
+    }
+    expect: {
+        console.log([
+            "bar",
+            console.log("foo")
+        ][0]);
+    }
+    expect_stdout: [
+        "foo",
+        "bar"
+    ]
+    node_version: ">=4"
+}

test/compress/reduce_vars.js

@@ -211,7 +211,116 @@ unsafe_evaluate: {
     }
 }
 
-unsafe_evaluate_object: {
+unsafe_evaluate_side_effect_free_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1}; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(o.p); return o; }());
+        console.log(function(){ var o={p:3}; console.log([o][0].p); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ console.log(1); return 1; }());
+        console.log(function(){ var o={p:2}; console.log(2); return o; }());
+        console.log(function(){ console.log(3); return 3; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_side_effect_free_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1},a=[o]; console.log(a[0].p); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ console.log(1); return 1; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_escaped: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1}; console.log(o, o.p); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(o.p, o); return o.p; }());
+        console.log(function(){ var o={p:3},a=[o]; console.log(a[0].p++); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ var o={p:1}; console.log(o, o.p); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(o.p, o); return o.p; }());
+        console.log(function(){ var o={p:3},a=[o]; console.log(a[0].p++); return o.p; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_modified: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1}; o.p++; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:2}; --o.p; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:3}; o.p += ""; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:4}; o = {}; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:5}; o.p = -9; console.log(o.p); return o.p; }());
+        function inc() { this.p++; }
+        console.log(function(){ var o={p:6}; inc.call(o); console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:7}; console.log([o][0].p++); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ var o={p:1}; o.p++; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:2}; --o.p; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:3}; o.p += ""; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:4}; o = {}; console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:5}; o.p = -9; console.log(o.p); return o.p; }());
+        function inc() { this.p++; }
+        console.log(function(){ var o={p:6}; inc.call(o); console.log(o.p); return o.p; }());
+        console.log(function(){ var o={p:7}; console.log([o][0].p++); return o.p; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_unknown: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(){ var o={p:1}; console.log(o.not_present); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(o.prototype); return o.p; }());
+        console.log(function(){ var o={p:3}; console.log(o.hasOwnProperty); return o.p; }());
+    }
+    expect: {
+        console.log(function(){ var o={p:1}; console.log(o.not_present); return o.p; }());
+        console.log(function(){ var o={p:2}; console.log(o.prototype); return o.p; }());
+        console.log(function(){ var o={p:3}; console.log(o.hasOwnProperty); return o.p; }());
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_object_1: {
     options = {
         evaluate     : true,
         reduce_vars  : true,
@@ -251,7 +360,83 @@ unsafe_evaluate_object: {
     }
 }
 
-unsafe_evaluate_array: {
+unsafe_evaluate_object_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.bar, obj.square(2), obj.cube);
+    }
+    expect: {
+        var obj = {
+            foo: 1,
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(1, 2, obj.square(2), obj.cube);
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_object_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var obj = {
+            get foo() {
+                return 1;
+            },
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.bar, obj.square(2), obj.cube);
+    }
+    expect: {
+        var obj = {
+            get foo() {
+                return 1;
+            },
+            bar: 2,
+            square: function(x) {
+                return x * x;
+            },
+            cube: function(x) {
+                return x * x * x;
+            },
+        };
+        console.log(obj.foo, obj.bar, obj.square(2), obj.cube);
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_array_1: {
     options = {
         evaluate     : true,
         reduce_vars  : true,
@@ -299,6 +484,132 @@ unsafe_evaluate_array: {
     }
 }
 
+unsafe_evaluate_array_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var arr = [
+            1,
+            2,
+            function(x) {
+                return x * x;
+            },
+            function(x) {
+                return x * x * x;
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](2), arr[3]);
+    }
+    expect: {
+        var arr = [
+            1,
+            2,
+            function(x) {
+                return x * x;
+            },
+            function(x) {
+                return x * x * x;
+            },
+        ];
+        console.log(1, 2, arr[2](2), arr[3]);
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_array_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++arr[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](), arr[0]);
+    }
+    expect: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++arr[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](), arr[0]);
+    }
+    expect_stdout: "1 2 2 2"
+}
+
+unsafe_evaluate_array_4: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++this[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2], arr[0]);
+    }
+    expect: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++this[0];
+            },
+        ];
+        console.log(1, 2, arr[2], 1);
+    }
+    expect_stdout: true
+}
+
+unsafe_evaluate_array_5: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++this[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](), arr[0]);
+    }
+    expect: {
+        var arr = [
+            1,
+            2,
+            function() {
+                return ++this[0];
+            },
+        ];
+        console.log(arr[0], arr[1], arr[2](), arr[0]);
+    }
+    expect_stdout: "1 2 2 2"
+}
+
 unsafe_evaluate_equality_1: {
     options = {
         evaluate     : true,
@@ -2766,6 +3077,7 @@ obj_var_2: {
         evaluate: true,
         inline: true,
         passes: 2,
+        properties: true,
         reduce_vars: true,
         side_effects: true,
         toplevel: true,
@@ -2822,10 +3134,10 @@ obj_arg_2: {
         evaluate: true,
         inline: true,
         passes: 2,
+        properties: true,
         reduce_vars: true,
         side_effects: true,
         toplevel: true,
-        unsafe: true,
         unused: true,
     }
     input: {
@@ -3051,3 +3363,177 @@ array_forof_2: {
     expect_stdout: "3"
     node_version: ">=0.12"
 }
+
+const_expr_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.a++;
+        console.log(o.a, o.b);
+    }
+    expect: {
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.a++;
+        console.log(o.a, o.b);
+    }
+    expect_stdout: "2 2"
+}
+
+const_expr_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        Object.prototype.c = function() {
+            this.a++;
+        };
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.c();
+        console.log(o.a, o.b);
+    }
+    expect: {
+        Object.prototype.c = function() {
+            this.a++;
+        };
+        var o = {
+            a: 1,
+            b: 2
+        };
+        o.c();
+        console.log(o.a, o.b);
+    }
+    expect_stdout: "2 2"
+}
+
+issue_2406_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: false,
+        unused: true,
+    }
+    input: {
+        const c = {
+            fn: function() {
+                return this;
+            }
+        };
+        let l = {
+            fn: function() {
+                return this;
+            }
+        };
+        var v = {
+            fn: function() {
+                return this;
+            }
+        };
+        console.log(c.fn(), l.fn(), v.fn());
+    }
+    expect: {
+        const c = {
+            fn: function() {
+                return this;
+            }
+        };
+        let l = {
+            fn: function() {
+                return this;
+            }
+        };
+        var v = {
+            fn: function() {
+                return this;
+            }
+        };
+        console.log(c.fn(), l.fn(), v.fn());
+    }
+}
+
+issue_2406_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        const c = {
+            fn: function() {
+                return this;
+            }
+        };
+        let l = {
+            fn: function() {
+                return this;
+            }
+        };
+        var v = {
+            fn: function() {
+                return this;
+            }
+        };
+        console.log(c.fn(), l.fn(), v.fn());
+    }
+    expect: {
+        console.log({
+            fn: function() {
+                return this;
+            }
+        }.fn(), {
+            fn: function() {
+                return this;
+            }
+        }.fn(), {
+            fn: function() {
+                return this;
+            }
+        }.fn());
+    }
+}
+
+escaped_prop: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var obj = { o: { a: 1 } };
+        (function(o) {
+            o.a++;
+        })(obj.o);
+        (function(o) {
+            console.log(o.a);
+        })(obj.o);
+    }
+    expect: {
+        var obj = { o: { a: 1 } };
+        obj.o.a++;
+        console.log(obj.o.a);
+    }
+    expect_stdout: "2"
+}

test/compress/template-string.js

@@ -59,7 +59,7 @@ template_string_with_constant_expression: {
         var foo = `${4 + 4} equals 4 + 4`;
     }
     expect: {
-        var foo = `8 equals 4 + 4`;
+        var foo = "8 equals 4 + 4";
     }
 }
 
@@ -89,21 +89,21 @@ template_string_with_predefined_constants: {
         var c = `${4**14}`; // 8 in template vs 9 chars - 268435456
     }
     expect: {
-        var foo = `This is undefined`;
+        var foo = "This is undefined";
-        var bar = `This is NaN`;
+        var bar = "This is NaN";
-        var baz = `This is null`;
+        var baz = "This is null";
         var foofoo = `This is ${1/0}`;
         var foobar = "This is ${1/0}";
         var foobaz = 'This is ${1/0}';
         var barfoo = "This is ${NaN}";
         var bazfoo = "This is ${null}";
         var bazbaz = `This is ${1/0}`;
-        var barbar = `This is NaN`;
+        var barbar = "This is NaN";
         var barbar = "This is ${0/0}";
         var barber = 'This is ${0/0}';
 
-        var a = `4194304`;
+        var a = "4194304";
-        var b = `16777216`; // Potential for further concatentation
+        var b = "16777216"; // Potential for further concatentation
         var c = `${4**14}`; // Not worth converting
     }
 }
@@ -123,7 +123,7 @@ template_string_evaluate_with_many_segments: {
     }
     expect: {
         var foo = `Hello ${guest()}, welcome to ${location()}.`;
-        var bar = `1234567890`;
+        var bar = "1234567890";
         var baz = `${foobar()}${foobar()}${foobar()}${foobar()}`;
         var buzz = `1${foobar()}2${foobar()}3${foobar()}`;
     }
@@ -159,7 +159,7 @@ template_string_to_normal_string: {
         var bar = "Decimals " + `${1}${2}${3}${4}${5}${6}${7}${8}${9}${0}`;
     }
     expect: {
-        var foo = `This is undefined`;
+        var foo = "This is undefined";
         var bar = "Decimals 1234567890";
     }
 }
@@ -192,7 +192,7 @@ evaluate_nested_templates: {
         var baz = `${`${`${`foo`}`}`}`;
     }
     expect: {
-        var baz = `foo`;
+        var baz = "foo";
     }
 }
 
@@ -241,8 +241,8 @@ enforce_double_quotes_and_evaluate: {
         var baz = `Hello ${world()}`;
     }
     expect: {
-        var foo = `Hello world`;
+        var foo = "Hello world";
-        var bar = `Hello world`;
+        var bar = "Hello world";
         var baz = `Hello ${world()}`;
     }
 }
@@ -260,8 +260,8 @@ enforce_single_quotes_and_evaluate: {
         var baz = `Hello ${world()}`;
     }
     expect: {
-        var foo = `Hello world`;
+        var foo = "Hello world";
-        var bar = `Hello world`;
+        var bar = "Hello world";
         var baz = `Hello ${world()}`;
     }
 }
@@ -339,7 +339,7 @@ escape_dollar_curly: {
         console.log(`${1-0}\${2-0}$\{3-0}${4-0}`)
         console.log(`$${""}{not an expression}`)
     }
-    expect_exact: "console.log(`\\${ beep }`);console.log(`1\\${2-0}\\${3-0}4`);console.log(`\\${not an expression}`);"
+    expect_exact: 'console.log("${ beep }");console.log("1${2-0}${3-0}4");console.log("${not an expression}");'
 }
 
 template_starting_with_newline: {
@@ -400,3 +400,61 @@ issue_1856_ascii_only: {
     }
     expect_exact: "console.log(`\\\\n\\\\r\\\\u2028\\\\u2029\\n\\r\\u2028\\u2029`);"
 }
+
+side_effects: {
+    options = {
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        `t1`;
+        tag`t2`;
+        `t${3}`;
+        tag`t${4}`;
+        console.log(`
+t${5}`);
+        function f(a) {
+            `t6${a}`;
+            a = `t7${a}` & a;
+            a = `t8${b}` | a;
+            a = f`t9${a}` ^ a;
+        }
+    }
+    expect: {
+        tag`t2`;
+        tag`t${4}`;
+        console.log("\nt5");
+        function f(a) {
+            a &= `t7${a}`;
+            a = `t8${b}` | a;
+            a = f`t9${a}` ^ a;
+        }
+    }
+}
+
+simple_string: {
+    options = {
+        computed_props: true,
+        evaluate: true,
+        properties: true,
+    }
+    input: {
+        console.log({[`foo`]: 1}[`foo`], `hi` == "hi", `world`);
+    }
+    expect: {
+        console.log([ 1 ][0], true, "world");
+    }
+    expect_stdout: "1 true 'world'"
+    node_version: ">=4"
+}
+
+semicolons: {
+    beautify = {
+        semicolons: false,
+    }
+    input: {
+        foo;
+        `bar`;
+    }
+    expect_exact: "foo;`bar`\n"
+}

test/mocha/yield.js

@@ -102,4 +102,15 @@ describe("Yield", function() {
             assert.throws(test(tests[i]), fail, tests[i]);
         }
     });
+
+    it("Should allow yield to be used as class/object property name", function() {
+        var input = [
+            '"use strict";',
+            "({yield:42});",
+            "({yield(){}});",
+            "(class{yield(){}});",
+            "class C{yield(){}}",
+        ].join("");
+        assert.strictEqual(UglifyJS.minify(input, { compress: false }).code, input);
+    });
 });

test/ufuzz.json

@@ -16,11 +16,9 @@
     {},
     {
         "compress": {
-            "toplevel": true
+            "hoist_props": true
         },
-        "mangle": {
+        "toplevel": true
-            "toplevel": true
-        }
     },
     {
         "compress": {