Merge branch 'master' into harmony

README.md

@@ -67,10 +67,13 @@ The available options are:
                                 JS that was generated from some other original
                                 code.
   --screw-ie8                   Use this flag if you don't wish to support
-                                Internet Explorer 6-8 quirks.
+                                Internet Explorer 6/7/8.
                                 By default UglifyJS will not try to be IE-proof.
-  --support-ie8                 Use this flag to support Internet Explorer 6-8 quirks.
+  --support-ie8                 Use this flag to support Internet Explorer 6/7/8.
-                                Note: may break standards compliant `catch` identifiers.
+                                Equivalent to setting `screw_ie8: false` in `minify()`
+                                for `compress`, `mangle` and `output` options.
+                                Note: `--support-ie8` may generate incorrect code
+                                for `try`/`catch` in ES5 compliant browsers.
   --expr                        Parse a single expression, rather than a
                                 program (for parsing JSON)
   -p, --prefix                  Skip prefix for original filenames that appear
@@ -285,6 +288,17 @@ of mangled property names.
 Using the name cache is not necessary if you compress all your files in a
 single call to UglifyJS.
 
+#### Mangling unquoted names (`--mangle-props=unquoted` or `--mangle-props=2`)
+
+Using quoted property name (`o["foo"]`) reserves the property name (`foo`)
+so that it is not mangled throughout the entire script even when used in an
+unquoted style (`o.foo`). Example:
+
+```
+$ echo 'var o={"foo":1, bar:3}; o.foo += o.bar; console.log(o.foo);' | uglifyjs --mangle-props=2 -mc
+var o={"foo":1,a:3};o.foo+=o.a,console.log(o.foo);
+```
+
 #### Debugging property name mangling
 
 You can also pass `--mangle-props-debug` in order to mangle property names

bin/uglifyjs

@@ -26,8 +26,8 @@ mangling you need to use `-c` and `-m`.\
     .describe("source-map-inline", "Write base64-encoded source map to the end of js output.  Disabled by default")
     .describe("source-map-include-sources", "Pass this flag if you want to include the content of source files in the source map as sourcesContent property.")
     .describe("in-source-map", "Input source map, useful if you're compressing JS that was generated from some other original code.")
-    .describe("screw-ie8", "Do not support Internet Explorer 6-8 quirks. This flag is enabled by default.")
+    .describe("screw-ie8", "Do not support Internet Explorer 6/7/8. This flag is enabled by default.")
-    .describe("support-ie8", "Support non-standard Internet Explorer 6-8 javascript. Note: may break standards compliant `catch` identifiers.")
+    .describe("support-ie8", "Support non-standard Internet Explorer 6/7/8 javascript. Note: may generate incorrect code for try/catch in ES5 compliant browsers.")
     .describe("expr", "Parse a single expression, rather than a program (for parsing JSON)")
     .describe("p", "Skip prefix for original filenames that appear in source maps. \
 For example -p 3 will drop 3 directories from file names and ensure they are relative paths. \
@@ -428,10 +428,11 @@ async.eachLimit(files, 1, function (file, cb) {
 
     var SCOPE_IS_NEEDED = COMPRESS || MANGLE || ARGS.lint
     var TL_CACHE = readNameCache("vars");
+    if (MANGLE) MANGLE.cache = TL_CACHE;
 
     if (SCOPE_IS_NEEDED) {
         time_it("scope", function(){
-            TOPLEVEL.figure_out_scope({ screw_ie8: screw_ie8, cache: TL_CACHE });
+            TOPLEVEL.figure_out_scope(MANGLE || { screw_ie8: screw_ie8, cache: TL_CACHE });
             if (ARGS.lint) {
                 TOPLEVEL.scope_warnings();
             }
@@ -446,7 +447,7 @@ async.eachLimit(files, 1, function (file, cb) {
 
     if (SCOPE_IS_NEEDED) {
         time_it("scope", function(){
-            TOPLEVEL.figure_out_scope({ screw_ie8: screw_ie8, cache: TL_CACHE });
+            TOPLEVEL.figure_out_scope(MANGLE || { screw_ie8: screw_ie8, cache: TL_CACHE });
             if (MANGLE && !TL_CACHE) {
                 TOPLEVEL.compute_char_frequency(MANGLE);
             }
@@ -454,7 +455,6 @@ async.eachLimit(files, 1, function (file, cb) {
     }
 
     if (MANGLE) time_it("mangle", function(){
-        MANGLE.cache = TL_CACHE;
         TOPLEVEL.mangle_names(MANGLE);
     });
 

lib/compress.js

@@ -152,6 +152,12 @@ merge(Compressor.prototype, {
 
     AST_Node.DEFMETHOD("clear_opt_flags", function(){
         this.walk(new TreeWalker(function(node){
+            if (node instanceof AST_SymbolRef) {
+                var d = node.definition();
+                if (d && d.init) {
+                    delete d.init._evaluated;
+                }
+            }
             if (!(node instanceof AST_Directive || node instanceof AST_Constant)) {
                 node._squeezed = false;
                 node._optimized = false;
@@ -349,7 +355,7 @@ merge(Compressor.prototype, {
                     if (ref.scope.uses_eval || ref.scope.uses_with) break;
 
                     // Constant single use vars can be replaced in any scope.
-                    if (!(var_decl.value instanceof AST_RegExp) && var_decl.value.is_constant(compressor)) {
+                    if (var_decl.value.is_constant()) {
                         var ctt = new TreeTransformer(function(node) {
                             if (node === ref)
                                 return replace_var(node, ctt.parent(), true);
@@ -989,6 +995,11 @@ merge(Compressor.prototype, {
         node.DEFMETHOD("is_string", func);
     });
 
+    function isLHS(node, parent) {
+        return parent instanceof AST_Unary && (parent.operator === "++" || parent.operator === "--")
+            || parent instanceof AST_Assign && parent.left === node;
+    }
+
     function best_of(ast1, ast2) {
         return ast1.print_to_string().length >
             ast2.print_to_string().length
@@ -1006,39 +1017,61 @@ merge(Compressor.prototype, {
         // constant; otherwise it's the original or a replacement node.
         AST_Node.DEFMETHOD("evaluate", function(compressor){
             if (!compressor.option("evaluate")) return [ this ];
+            var val;
             try {
-                var val = this._eval(compressor);
+                val = this._eval(compressor);
-                return [ best_of(make_node_from_constant(compressor, val, this), this), val ];
             } catch(ex) {
                 if (ex !== def) throw ex;
                 return [ this ];
             }
+            var node;
+            try {
+                node = make_node_from_constant(compressor, val, this);
+            } catch(ex) {
+                return [ this ];
+            }
+            return [ best_of(node, this), val ];
         });
-        AST_Node.DEFMETHOD("is_constant", function(compressor){
+        var unaryPrefix = makePredicate("! ~ - +");
+        AST_Node.DEFMETHOD("is_constant", function(){
             // Accomodate when compress option evaluate=false
-            // as well as the common constant expressions !0 and !1
+            // as well as the common constant expressions !0 and -1
-            return this instanceof AST_Constant
+            if (this instanceof AST_Constant) {
-                || (this instanceof AST_UnaryPrefix && this.operator == "!"
+                return !(this instanceof AST_RegExp);
-                    && this.expression instanceof AST_Constant)
+            } else {
-                || this.evaluate(compressor).length > 1;
+                return this instanceof AST_UnaryPrefix
+                    && this.expression instanceof AST_Constant
+                    && unaryPrefix(this.operator);
+            }
         });
         // Obtain the constant value of an expression already known to be constant.
-        // Result only valid iff this.is_constant(compressor) is true.
+        // 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) return this.value;
+            if (this instanceof AST_Constant && !(this instanceof AST_RegExp)) {
-            // Accomodate the common constant expressions !0 and !1 when option evaluate=false.
+                return this.value;
-            if (this instanceof AST_UnaryPrefix
-                && this.operator == "!"
-                && this.expression instanceof AST_Constant) {
-                return !this.expression.value;
             }
-            var result = this.evaluate(compressor)
+            // 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.length > 1) {
                 return result[1];
             }
-            // should never be reached
+            throw new Error(string_template("Cannot evaluate constant [{file}:{line},{col}]", this.start));
-            return undefined;
         });
         def(AST_Statement, function(){
             throw new Error(string_template("Cannot evaluate a statement [{file}:{line},{col}]", this.start));
@@ -1071,6 +1104,32 @@ merge(Compressor.prototype, {
             if (this.segments.length !== 1) throw def;
             return this.segments[0].value;
         });
+        def(AST_Array, function(compressor){
+            if (compressor.option("unsafe")) {
+                return this.elements.map(function(element) {
+                    return ev(element, compressor);
+                });
+            }
+            throw def;
+        });
+        def(AST_Object, function(compressor){
+            if (compressor.option("unsafe")) {
+                var val = {};
+                for (var i = 0, len = this.properties.length; i < len; i++) {
+                    var prop = this.properties[i];
+                    var key = prop.key;
+                    if (key instanceof AST_Node) {
+                        key = ev(key, compressor);
+                    }
+                    if (typeof Object.prototype[key] === 'function') {
+                        throw def;
+                    }
+                    val[key] = ev(prop.value, compressor);
+                }
+                return val;
+            }
+            throw def;
+        });
         def(AST_UnaryPrefix, function(compressor){
             var e = this.expression;
             switch (this.operator) {
@@ -1140,6 +1199,12 @@ merge(Compressor.prototype, {
             try {
                 var d = this.definition();
                 if (d && (d.constant || compressor.option("reduce_vars") && !d.modified) && d.init) {
+                    if (compressor.option("unsafe")) {
+                        if (!HOP(d.init, '_evaluated')) {
+                            d.init._evaluated = ev(d.init, compressor);
+                        }
+                        return d.init._evaluated;
+                    }
                     return ev(d.init, compressor);
                 }
             } finally {
@@ -1147,11 +1212,16 @@ merge(Compressor.prototype, {
             }
             throw def;
         });
-        def(AST_Dot, function(compressor){
+        def(AST_PropAccess, function(compressor){
-            if (compressor.option("unsafe") && this.property == "length") {
+            if (compressor.option("unsafe")) {
-                var str = ev(this.expression, compressor);
+                var key = this.property;
-                if (typeof str == "string")
+                if (key instanceof AST_Node) {
-                    return str.length;
+                    key = ev(key, compressor);
+                }
+                var val = ev(this.expression, compressor);
+                if (val && HOP(val, key)) {
+                    return val[key];
+                }
             }
             throw def;
         });
@@ -2494,6 +2564,16 @@ merge(Compressor.prototype, {
     var commutativeOperators = makePredicate("== === != !== * & | ^");
 
     OPT(AST_Binary, function(self, compressor){
+        var lhs = self.left.evaluate(compressor);
+        var rhs = self.right.evaluate(compressor);
+        if (lhs.length > 1 && lhs[0].is_constant() !== self.left.is_constant()
+            || rhs.length > 1 && rhs[0].is_constant() !== self.right.is_constant()) {
+            return make_node(AST_Binary, self, {
+                operator: self.operator,
+                left: lhs[0],
+                right: rhs[0]
+            }).optimize(compressor);
+        }
         function reverse(op, force) {
             if (force || !(self.left.has_side_effects(compressor) || self.right.has_side_effects(compressor))) {
                 if (op) self.operator = op;
@@ -2566,32 +2646,6 @@ merge(Compressor.prototype, {
             }
             break;
         }
-        if (compressor.option("conditionals")) {
-            if (self.operator == "&&") {
-                var ll = self.left.evaluate(compressor);
-                if (ll.length > 1) {
-                    if (ll[1]) {
-                        compressor.warn("Condition left of && always true [{file}:{line},{col}]", self.start);
-                        return maintain_this_binding(compressor.parent(), self, self.right.evaluate(compressor)[0]);
-                    } else {
-                        compressor.warn("Condition left of && always false [{file}:{line},{col}]", self.start);
-                        return maintain_this_binding(compressor.parent(), self, ll[0]);
-                    }
-                }
-            }
-            else if (self.operator == "||") {
-                var ll = self.left.evaluate(compressor);
-                if (ll.length > 1) {
-                    if (ll[1]) {
-                        compressor.warn("Condition left of || always true [{file}:{line},{col}]", self.start);
-                        return maintain_this_binding(compressor.parent(), self, ll[0]);
-                    } else {
-                        compressor.warn("Condition left of || always false [{file}:{line},{col}]", self.start);
-                        return maintain_this_binding(compressor.parent(), self, self.right.evaluate(compressor)[0]);
-                    }
-                }
-            }
-        }
         if (compressor.option("booleans") && compressor.in_boolean_context()) switch (self.operator) {
           case "&&":
             var ll = self.left.evaluate(compressor);
@@ -2665,6 +2719,30 @@ merge(Compressor.prototype, {
             return self.left;
         }
         if (compressor.option("evaluate")) {
+            switch (self.operator) {
+              case "&&":
+                if (self.left.is_constant()) {
+                    if (self.left.constant_value(compressor)) {
+                        compressor.warn("Condition left of && always true [{file}:{line},{col}]", self.start);
+                        return maintain_this_binding(compressor.parent(), self, self.right);
+                    } else {
+                        compressor.warn("Condition left of && always false [{file}:{line},{col}]", self.start);
+                        return maintain_this_binding(compressor.parent(), self, self.left);
+                    }
+                }
+                break;
+              case "||":
+                if (self.left.is_constant()) {
+                    if (self.left.constant_value(compressor)) {
+                        compressor.warn("Condition left of || always true [{file}:{line},{col}]", self.start);
+                        return maintain_this_binding(compressor.parent(), self, self.left);
+                    } else {
+                        compressor.warn("Condition left of || always false [{file}:{line},{col}]", self.start);
+                        return maintain_this_binding(compressor.parent(), self, self.right);
+                    }
+                }
+                break;
+            }
             if (self.operator == "+") {
                 if (self.left instanceof AST_Constant
                     && self.right instanceof AST_Binary
@@ -2738,14 +2816,6 @@ merge(Compressor.prototype, {
     });
 
     OPT(AST_SymbolRef, function(self, compressor){
-        function isLHS(symbol, parent) {
-            return (
-                parent instanceof AST_Binary &&
-                parent.operator === '=' &&
-                parent.left === symbol
-            );
-        }
-
         if (self.undeclared() && !isLHS(self, compressor.parent())) {
             var defines = compressor.option("global_defs");
             if (defines && HOP(defines, self.name)) {
@@ -2899,14 +2969,14 @@ merge(Compressor.prototype, {
             });
         }
         // y?1:1 --> 1
-        if (consequent.is_constant(compressor)
+        if (consequent.is_constant()
-            && alternative.is_constant(compressor)
+            && alternative.is_constant()
             && consequent.equivalent_to(alternative)) {
-            var consequent_value = consequent.constant_value(compressor);
+            var consequent_value = consequent.evaluate(compressor)[0];
             if (self.condition.has_side_effects(compressor)) {
-                return AST_Seq.from_array([self.condition, make_node_from_constant(compressor, consequent_value, self)]);
+                return AST_Seq.from_array([self.condition, consequent_value]);
             } else {
-                return make_node_from_constant(compressor, consequent_value, self);
+                return consequent_value;
             }
         }
 
@@ -3023,7 +3093,7 @@ merge(Compressor.prototype, {
                 });
             }
         }
-        return self;
+        return self.evaluate(compressor)[0];
     });
 
     OPT(AST_Dot, function(self, compressor){

lib/scope.js

@@ -232,6 +232,17 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
     var cls = null;
     var globals = self.globals = new Dictionary();
     var tw = new TreeWalker(function(node, descend){
+        function isModified(node, level) {
+            var parent = tw.parent(level);
+            if (parent instanceof AST_Unary && (parent.operator === "++" || parent.operator === "--")
+                || parent instanceof AST_Assign && parent.left === node
+                || parent instanceof AST_Call && parent.expression === node) {
+                return true;
+            } else if (parent instanceof AST_PropAccess && parent.expression === node) {
+                return isModified(parent, level + 1);
+            }
+        }
+
         if (node instanceof AST_Lambda) {
             var prev_func = func;
             func = node;
@@ -252,8 +263,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
         }
         if (node instanceof AST_SymbolRef) {
             var name = node.name;
-            var parent = tw.parent();
+            if (name == "eval" && tw.parent() instanceof AST_Call) {
-            if (name == "eval" && parent instanceof AST_Call) {
                 for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) {
                     s.uses_eval = true;
                 }
@@ -275,11 +285,10 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
                 sym = g;
             }
             node.thedef = sym;
-            if (parent instanceof AST_Unary && (parent.operator === '++' || parent.operator === '--')
+            if (isModified(node, 0)) {
-             || parent instanceof AST_Assign && parent.left === node) {
                 sym.modified = true;
             }
-            node.reference();
+            node.reference(options);
             return true;
         }
     });
@@ -323,13 +332,18 @@ AST_Lambda.DEFMETHOD("init_scope_vars", function(){
     this.variables.set(symbol.name, def);
 });
 
-AST_SymbolRef.DEFMETHOD("reference", function() {
+AST_SymbolRef.DEFMETHOD("reference", function(options) {
     var def = this.definition();
     def.references.push(this);
     var s = this.scope;
     while (s) {
         push_uniq(s.enclosed, def);
         if (s === def.scope) break;
+        if (options.keep_fnames) {
+            s.variables.each(function(d) {
+                push_uniq(def.scope.enclosed, d);
+            });
+        }
         s = s.parent_scope;
     }
     this.frame = this.scope.nesting - def.scope.nesting;
@@ -401,11 +415,6 @@ AST_Function.DEFMETHOD("next_mangled", function(options, def){
     }
 });
 
-AST_Scope.DEFMETHOD("references", function(sym){
-    if (sym instanceof AST_Symbol) sym = sym.definition();
-    return this.enclosed.indexOf(sym) < 0 ? null : sym;
-});
-
 AST_Symbol.DEFMETHOD("unmangleable", function(options){
     var def = this.definition();
     return def && def.unmangleable(options);

test/compress/arrays.js

@@ -147,3 +147,53 @@ spread_with_logical_expression_at_middle: {
         var a = [1, 1, ...[2, 3, 5], 8]
     }
 }
+
+for_loop: {
+    options = {
+        unsafe      : true,
+        unused      : true,
+        evaluate    : true,
+        reduce_vars : true
+    };
+    input: {
+        function f0() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < a.length; i++) {
+                console.log(a[i]);
+            }
+        }
+
+        function f1() {
+            var a = [1, 2, 3];
+            for (var i = 0, len = a.length; i < len; i++) {
+                console.log(a[i]);
+            }
+        }
+
+        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]++;
+        }
+    }
+}

test/compress/conditionals.js

@@ -635,166 +635,6 @@ ternary_boolean_alternative: {
     }
 }
 
-conditional_and: {
-    options = {
-        conditionals: true,
-        evaluate    : true
-    };
-    input: {
-        var a;
-        // compress these
-
-        a = true     && condition;
-        a = 1        && console.log("a");
-        a = 2 * 3    && 2 * condition;
-        a = 5 == 5   && condition + 3;
-        a = "string" && 4 - condition;
-        a = 5 + ""   && condition / 5;
-        a = -4.5     && 6 << condition;
-        a = 6        && 7;
-
-        a = false     && condition;
-        a = NaN       && console.log("b");
-        a = 0         && console.log("c");
-        a = undefined && 2 * condition;
-        a = null      && condition + 3;
-        a = 2 * 3 - 6 && 4 - condition;
-        a = 10 == 7   && condition / 5;
-        a = !"string" && 6 % condition;
-        a = 0         && 7;
-
-        // don't compress these
-
-        a = condition        && true;
-        a = console.log("a") && 2;
-        a = 4 - condition    && "string";
-        a = 6 << condition   && -4.5;
-
-        a = condition        && false;
-        a = console.log("b") && NaN;
-        a = console.log("c") && 0;
-        a = 2 * condition    && undefined;
-        a = condition + 3    && null;
-
-    }
-    expect: {
-        var a;
-
-        a = condition;
-        a = console.log("a");
-        a = 2 * condition;
-        a = condition + 3;
-        a = 4 - condition;
-        a = condition / 5;
-        a = 6 << condition;
-        a = 7;
-
-        a = false;
-        a = NaN;
-        a = 0;
-        a = void 0;
-        a = null;
-        a = 0;
-        a = false;
-        a = false;
-        a = 0;
-
-        a = condition        && true;
-        a = console.log("a") && 2;
-        a = 4 - condition    && "string";
-        a = 6 << condition   && -4.5;
-
-        a = condition        && false;
-        a = console.log("b") && NaN;
-        a = console.log("c") && 0;
-        a = 2 * condition    && void 0;
-        a = condition + 3    && null;
-    }
-}
-
-conditional_or: {
-    options = {
-        conditionals: true,
-        evaluate    : true
-    };
-    input: {
-        var a;
-        // compress these
-
-        a = true     || condition;
-        a = 1        || console.log("a");
-        a = 2 * 3    || 2 * condition;
-        a = 5 == 5   || condition + 3;
-        a = "string" || 4 - condition;
-        a = 5 + ""   || condition / 5;
-        a = -4.5     || 6 << condition;
-        a = 6        || 7;
-
-        a = false     || condition;
-        a = 0         || console.log("b");
-        a = NaN       || console.log("c");
-        a = undefined || 2 * condition;
-        a = null      || condition + 3;
-        a = 2 * 3 - 6 || 4 - condition;
-        a = 10 == 7   || condition / 5;
-        a = !"string" || 6 % condition;
-        a = null      || 7;
-
-        a = console.log(undefined && condition || null);
-        a = console.log(undefined || condition && null);
-
-        // don't compress these
-
-        a = condition        || true;
-        a = console.log("a") || 2;
-        a = 4 - condition    || "string";
-        a = 6 << condition   || -4.5;
-
-        a = condition        || false;
-        a = console.log("b") || NaN;
-        a = console.log("c") || 0;
-        a = 2 * condition    || undefined;
-        a = condition + 3    || null;
-
-    }
-    expect: {
-        var a;
-
-        a = true;
-        a = 1;
-        a = 6;
-        a = true;
-        a = "string";
-        a = "5";
-        a = -4.5;
-        a = 6;
-
-        a = condition;
-        a = console.log("b");
-        a = console.log("c");
-        a = 2 * condition;
-        a = condition + 3;
-        a = 4 - condition;
-        a = condition / 5;
-        a = 6 % condition;
-        a = 7;
-
-        a = console.log(null);
-        a = console.log(condition && null);
-
-        a = condition        || true;
-        a = console.log("a") || 2;
-        a = 4 - condition    || "string";
-        a = 6 << condition   || -4.5;
-
-        a = condition        || false;
-        a = console.log("b") || NaN;
-        a = console.log("c") || 0;
-        a = 2 * condition    || void 0;
-        a = condition + 3    || null;
-    }
-}
-
 trivial_boolean_ternary_expressions : {
     options = {
         conditionals: true,
@@ -906,3 +746,26 @@ issue_1154: {
         function g6() { return g(), "number"; }
     }
 }
+
+no_evaluate: {
+    options = {
+        conditionals: true,
+        evaluate    : false
+    }
+    input: {
+        function f(b) {
+            a = b ? !0 : !0;
+            a = b ? ~1 : ~1;
+            a = b ? -2 : -2;
+            a = b ? +3 : +3;
+        }
+    }
+    expect: {
+        function f(b) {
+            a = !0;
+            a = ~1;
+            a = -2;
+            a = +3;
+        }
+    }
+}

test/compress/evaluate.js

@@ -1,3 +1,187 @@
+and: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a;
+        // compress these
+
+        a = true     && condition;
+        a = 1        && console.log("a");
+        a = 2 * 3    && 2 * condition;
+        a = 5 == 5   && condition + 3;
+        a = "string" && 4 - condition;
+        a = 5 + ""   && condition / 5;
+        a = -4.5     && 6 << condition;
+        a = 6        && 7;
+
+        a = false     && condition;
+        a = NaN       && console.log("b");
+        a = 0         && console.log("c");
+        a = undefined && 2 * condition;
+        a = null      && condition + 3;
+        a = 2 * 3 - 6 && 4 - condition;
+        a = 10 == 7   && condition / 5;
+        a = !"string" && 6 % condition;
+        a = 0         && 7;
+
+        // don't compress these
+
+        a = condition        && true;
+        a = console.log("a") && 2;
+        a = 4 - condition    && "string";
+        a = 6 << condition   && -4.5;
+
+        a = condition        && false;
+        a = console.log("b") && NaN;
+        a = console.log("c") && 0;
+        a = 2 * condition    && undefined;
+        a = condition + 3    && null;
+
+    }
+    expect: {
+        var a;
+
+        a = condition;
+        a = console.log("a");
+        a = 2 * condition;
+        a = condition + 3;
+        a = 4 - condition;
+        a = condition / 5;
+        a = 6 << condition;
+        a = 7;
+
+        a = false;
+        a = NaN;
+        a = 0;
+        a = void 0;
+        a = null;
+        a = 0;
+        a = false;
+        a = false;
+        a = 0;
+
+        a = condition        && true;
+        a = console.log("a") && 2;
+        a = 4 - condition    && "string";
+        a = 6 << condition   && -4.5;
+
+        a = condition        && false;
+        a = console.log("b") && NaN;
+        a = console.log("c") && 0;
+        a = 2 * condition    && void 0;
+        a = condition + 3    && null;
+    }
+}
+
+or: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a;
+        // compress these
+
+        a = true     || condition;
+        a = 1        || console.log("a");
+        a = 2 * 3    || 2 * condition;
+        a = 5 == 5   || condition + 3;
+        a = "string" || 4 - condition;
+        a = 5 + ""   || condition / 5;
+        a = -4.5     || 6 << condition;
+        a = 6        || 7;
+
+        a = false     || condition;
+        a = 0         || console.log("b");
+        a = NaN       || console.log("c");
+        a = undefined || 2 * condition;
+        a = null      || condition + 3;
+        a = 2 * 3 - 6 || 4 - condition;
+        a = 10 == 7   || condition / 5;
+        a = !"string" || 6 % condition;
+        a = null      || 7;
+
+        a = console.log(undefined && condition || null);
+        a = console.log(undefined || condition && null);
+
+        // don't compress these
+
+        a = condition        || true;
+        a = console.log("a") || 2;
+        a = 4 - condition    || "string";
+        a = 6 << condition   || -4.5;
+
+        a = condition        || false;
+        a = console.log("b") || NaN;
+        a = console.log("c") || 0;
+        a = 2 * condition    || undefined;
+        a = condition + 3    || null;
+
+    }
+    expect: {
+        var a;
+
+        a = true;
+        a = 1;
+        a = 6;
+        a = true;
+        a = "string";
+        a = "5";
+        a = -4.5;
+        a = 6;
+
+        a = condition;
+        a = console.log("b");
+        a = console.log("c");
+        a = 2 * condition;
+        a = condition + 3;
+        a = 4 - condition;
+        a = condition / 5;
+        a = 6 % condition;
+        a = 7;
+
+        a = console.log(null);
+        a = console.log(condition && null);
+
+        a = condition        || true;
+        a = console.log("a") || 2;
+        a = 4 - condition    || "string";
+        a = 6 << condition   || -4.5;
+
+        a = condition        || false;
+        a = console.log("b") || NaN;
+        a = console.log("c") || 0;
+        a = 2 * condition    || void 0;
+        a = condition + 3    || null;
+    }
+}
+
+unary_prefix: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        a = !0 && b;
+        a = !0 || b;
+        a = ~1 && b;
+        a = ~1 || b;
+        a = -2 && b;
+        a = -2 || b;
+        a = +3 && b;
+        a = +3 || b;
+    }
+    expect: {
+        a = b;
+        a = !0;
+        a = b;
+        a = -2;
+        a = b;
+        a = -2;
+        a = b;
+        a = 3;
+    }
+}
+
 negative_zero: {
     options = { evaluate: true }
     input: {
@@ -95,12 +279,18 @@ pow_with_number_constants: {
         evaluate: true
     }
     input: {
-        var a = 5 ** NaN; /* NaN exponent results to NaN */
+        var a = 5 ** NaN;
-        var b = 42 ** +0; /* +0 exponent results to NaN */
+        /* NaN exponent results to NaN */
-        var c = 42 ** -0; /* -0 exponent results to NaN */
+        var b = 42 ** +0;
-        var d = NaN ** 1; /* NaN with non-zero exponent is NaN */
+        /* +0 exponent results to NaN */
-        var e = 2 ** Infinity; /* abs(base) > 1 with Infinity as exponent is Infinity */
+        var c = 42 ** -0;
-        var f = 2 ** -Infinity; /* abs(base) > 1 with -Infinity as exponent is +0 */
+        /* -0 exponent results to NaN */
+        var d = NaN ** 1;
+        /* NaN with non-zero exponent is NaN */
+        var e = 2 ** Infinity;
+        /* abs(base) > 1 with Infinity as exponent is Infinity */
+        var f = 2 ** -Infinity;
+        /* abs(base) > 1 with -Infinity as exponent is +0 */
         var g = (-7) ** (0.5);
         var h = 2324334 ** 34343443;
         var i = (-2324334) ** 34343443;
@@ -125,3 +315,380 @@ pow_with_number_constants: {
         var m = 3 ** -10;
     }
 }
+
+unsafe_constant: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            true.a,
+            false.a,
+            null.a,
+            undefined.a
+        );
+    }
+    expect: {
+        console.log(
+            true.a,
+            false.a,
+            null.a,
+            (void 0).a
+        );
+    }
+}
+
+unsafe_object: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:1}) + 1,
+            ({a:1}).a + 1,
+            ({a:1}).b + 1,
+            ({a:1}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:1}) + 1,
+            2,
+            ({a:1}).b + 1,
+            1..b + 1
+        );
+    }
+}
+
+unsafe_object_nested: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:{b:1}}) + 1,
+            ({a:{b:1}}).a + 1,
+            ({a:{b:1}}).b + 1,
+            ({a:{b:1}}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:{b:1}}) + 1,
+            ({a:{b:1}}).a + 1,
+            ({a:{b:1}}).b + 1,
+            2
+        );
+    }
+}
+
+unsafe_object_complex: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:{b:1},b:1}) + 1,
+            ({a:{b:1},b:1}).a + 1,
+            ({a:{b:1},b:1}).b + 1,
+            ({a:{b:1},b:1}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:{b:1},b:1}) + 1,
+            ({a:{b:1},b:1}).a + 1,
+            2,
+            2
+        );
+    }
+}
+
+unsafe_object_repeated: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:{b:1},a:1}) + 1,
+            ({a:{b:1},a:1}).a + 1,
+            ({a:{b:1},a:1}).b + 1,
+            ({a:{b:1},a:1}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:{b:1},a:1}) + 1,
+            2,
+            ({a:{b:1},a:1}).b + 1,
+            1..b + 1
+        );
+    }
+}
+
+unsafe_function: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:{b:1},b:function(){}}) + 1,
+            ({a:{b:1},b:function(){}}).a + 1,
+            ({a:{b:1},b:function(){}}).b + 1,
+            ({a:{b:1},b:function(){}}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:{b:1},b:function(){}}) + 1,
+            ({a:{b:1},b:function(){}}).a + 1,
+            ({a:{b:1},b:function(){}}).b + 1,
+            ({a:{b:1},b:function(){}}).a.b + 1
+        );
+    }
+}
+
+unsafe_integer_key: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({0:1}) + 1,
+            ({0:1})[0] + 1,
+            ({0:1})["0"] + 1,
+            ({0:1})[1] + 1,
+            ({0:1})[0][1] + 1,
+            ({0:1})[0]["1"] + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({0:1}) + 1,
+            2,
+            2,
+            ({0:1})[1] + 1,
+            1[1] + 1,
+            1["1"] + 1
+        );
+    }
+}
+
+unsafe_integer_key_complex: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({0:{1:1},1:1}) + 1,
+            ({0:{1:1},1:1})[0] + 1,
+            ({0:{1:1},1:1})["0"] + 1,
+            ({0:{1:1},1:1})[1] + 1,
+            ({0:{1:1},1:1})[0][1] + 1,
+            ({0:{1:1},1:1})[0]["1"] + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({0:{1:1},1:1}) + 1,
+            "[object Object]1",
+            "[object Object]1",
+            2,
+            2,
+            2
+        );
+    }
+}
+
+unsafe_float_key: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({2.72:1}) + 1,
+            ({2.72:1})[2.72] + 1,
+            ({2.72:1})["2.72"] + 1,
+            ({2.72:1})[3.14] + 1,
+            ({2.72:1})[2.72][3.14] + 1,
+            ({2.72:1})[2.72]["3.14"] + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({2.72:1}) + 1,
+            2,
+            2,
+            ({2.72:1})[3.14] + 1,
+            1[3.14] + 1,
+            1["3.14"] + 1
+        );
+    }
+}
+
+unsafe_float_key_complex: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({2.72:{3.14:1},3.14:1}) + 1,
+            ({2.72:{3.14:1},3.14:1})[2.72] + 1,
+            ({2.72:{3.14:1},3.14:1})["2.72"] + 1,
+            ({2.72:{3.14:1},3.14:1})[3.14] + 1,
+            ({2.72:{3.14:1},3.14:1})[2.72][3.14] + 1,
+            ({2.72:{3.14:1},3.14:1})[2.72]["3.14"] + 1
+        );
+    }
+    expect: {
+        console.log(
+            "[object Object]1",
+            "[object Object]1",
+            "[object Object]1",
+            2,
+            2,
+            2
+        );
+    }
+}
+
+unsafe_array: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            [1, , 3][1],
+            [1, 2, 3, a] + 1,
+            [1, 2, 3, 4] + 1,
+            [1, 2, 3, a][0] + 1,
+            [1, 2, 3, 4][0] + 1,
+            [1, 2, 3, 4][6 - 5] + 1,
+            [1, , 3, 4][6 - 5] + 1,
+            [[1, 2], [3, 4]][0] + 1,
+            [[1, 2], [3, 4]][6 - 5][1] + 1,
+            [[1, 2], , [3, 4]][6 - 5][1] + 1
+        );
+    }
+    expect: {
+        console.log(
+            void 0,
+            [1, 2, 3, a] + 1,
+            "1,2,3,41",
+            [1, 2, 3, a][0] + 1,
+            2,
+            3,
+            NaN,
+            "1,21",
+            5,
+            (void 0)[1] + 1
+        );
+    }
+}
+
+unsafe_string: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            "1234" + 1,
+            "1234"[0] + 1,
+            "1234"[6 - 5] + 1,
+            ("12" + "34")[0] + 1,
+            ("12" + "34")[6 - 5] + 1,
+            [1, 2, 3, 4].join("")[0] + 1
+        );
+    }
+    expect: {
+        console.log(
+            "12341",
+            "11",
+            "21",
+            "11",
+            "21",
+            "11"
+        );
+    }
+}
+
+unsafe_array_bad_index: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            [1, 2, 3, 4].a + 1,
+            [1, 2, 3, 4]["a"] + 1,
+            [1, 2, 3, 4][3.14] + 1
+        );
+    }
+    expect: {
+        console.log(
+            [1, 2, 3, 4].a + 1,
+            [1, 2, 3, 4]["a"] + 1,
+            [1, 2, 3, 4][3.14] + 1
+        );
+    }
+}
+
+unsafe_string_bad_index: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            "1234".a + 1,
+            "1234"["a"] + 1,
+            "1234"[3.14] + 1
+        );
+    }
+    expect: {
+        console.log(
+            "1234".a + 1,
+            "1234"["a"] + 1,
+            "1234"[3.14] + 1
+        );
+    }
+}
+
+unsafe_prototype_function: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        var a = ({valueOf: 0}) < 1;
+        var b = ({toString: 0}) < 1;
+        var c = ({valueOf: 0}) + "";
+        var d = ({toString: 0}) + "";
+        var e = (({valueOf: 0}) + "")[2];
+        var f = (({toString: 0}) + "")[2];
+        var g = ({valueOf: 0}).valueOf();
+        var h = ({toString: 0}).toString();
+    }
+    expect: {
+        var a = ({valueOf: 0}) < 1;
+        var b = ({toString: 0}) < 1;
+        var c = ({valueOf: 0}) + "";
+        var d = ({toString: 0}) + "";
+        var e = (({valueOf: 0}) + "")[2];
+        var f = (({toString: 0}) + "")[2];
+        var g = ({valueOf: 0}).valueOf();
+        var h = "" + ({toString: 0});
+    }
+}

test/compress/issue-1431.js

@@ -0,0 +1,122 @@
+level_one: {
+    options = {
+        keep_fnames: true
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function n(a) {
+                    return a * a;
+                }
+                return x(n);
+            };
+        }
+    }
+    expect: {
+        function f(r) {
+            return function() {
+                function n(n) {
+                    return n * n;
+                }
+                return r(n);
+            };
+        }
+    }
+}
+
+level_two: {
+    options = {
+        keep_fnames: true
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function r(a) {
+                    return a * a;
+                }
+                return function() {
+                    function n(a) {
+                        return a * a;
+                    }
+                    return x(n);
+                };
+            };
+        }
+    }
+    expect: {
+        function f(t) {
+            return function() {
+                function r(n) {
+                    return n * n;
+                }
+                return function() {
+                    function n(n) {
+                        return n * n;
+                    }
+                    return t(n);
+                };
+            };
+        }
+    }
+}
+
+level_three: {
+    options = {
+        keep_fnames: true
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function r(a) {
+                    return a * a;
+                }
+                return [
+                    function() {
+                        function t(a) {
+                            return a * a;
+                        }
+                        return t;
+                    },
+                    function() {
+                        function n(a) {
+                            return a * a;
+                        }
+                        return x(n);
+                    }
+                ];
+            };
+        }
+    }
+    expect: {
+        function f(t) {
+            return function() {
+                function r(n) {
+                    return n * n;
+                }
+                return [
+                    function() {
+                        function t(n) {
+                            return n * n;
+                        }
+                        return t;
+                    },
+                    function() {
+                        function n(n) {
+                            return n * n;
+                        }
+                        return t(n);
+                    }
+                ];
+            };
+        }
+    }
+}

test/compress/issue-208.js

@@ -1,11 +1,29 @@
 do_not_update_lhs: {
-    options = { global_defs: { DEBUG: false } };
+    options = {
-    input: { DEBUG = false; }
+        global_defs: { DEBUG: 0 }
-    expect: { DEBUG = false; }
+    }
+    input: {
+        DEBUG++;
+        DEBUG += 1;
+        DEBUG = 1;
+    }
+    expect: {
+        DEBUG++;
+        DEBUG += 1;
+        DEBUG = 1;
+    }
 }
 
 do_update_rhs: {
-    options = { global_defs: { DEBUG: false } };
+    options = {
-    input: { MY_DEBUG = DEBUG; }
+        global_defs: { DEBUG: 0 }
-    expect: { MY_DEBUG = false; }
+    }
+    input: {
+        MY_DEBUG = DEBUG;
+        MY_DEBUG += DEBUG;
+    }
+    expect: {
+        MY_DEBUG = 0;
+        MY_DEBUG += 0;
+    }
 }

test/compress/properties.js

@@ -54,7 +54,56 @@ dot_properties_es5: {
     }
 }
 
-evaluate_length: {
+sub_properties: {
+    options = {
+        evaluate: true,
+        properties: true
+    };
+    input: {
+        a[0] = 0;
+        a["0"] = 1;
+        a[3.14] = 2;
+        a["3" + ".14"] = 3;
+        a["i" + "f"] = 4;
+        a["foo" + " bar"] = 5;
+        a[0 / 0] = 6;
+        a[null] = 7;
+        a[undefined] = 8;
+    }
+    expect: {
+        a[0] = 0;
+        a[0] = 1;
+        a[3.14] = 2;
+        a[3.14] = 3;
+        a.if = 4;
+        a["foo bar"] = 5;
+        a[NaN] = 6;
+        a[null] = 7;
+        a[void 0] = 8;
+    }
+}
+
+evaluate_array_length: {
+    options = {
+        properties: true,
+        unsafe: true,
+        evaluate: true
+    };
+    input: {
+        a = [1, 2, 3].length;
+        a = [1, 2, 3].join()["len" + "gth"];
+        a = [1, 2, b].length;
+        a = [1, 2, 3].join(b).length;
+    }
+    expect: {
+        a = 3;
+        a = 5;
+        a = [1, 2, b].length;
+        a = [1, 2, 3].join(b).length;
+    }
+}
+
+evaluate_string_length: {
     options = {
         properties: true,
         unsafe: true,

test/compress/reduce_vars.js

@@ -136,30 +136,30 @@ modified: {
         }
 
         function f2() {
-            var a = 1, b = 2, c = 3;
+            var b = 2, c = 3;
             b = c;
-            console.log(a + b);
+            console.log(1 + b);
-            console.log(b + c);
+            console.log(b + 3);
             console.log(4);
-            console.log(a + b + c);
+            console.log(1 + b + 3);
         }
 
         function f3() {
-            var a = 1, b = 2, c = 3;
+            var b = 2, c = 3;
             b *= c;
-            console.log(a + b);
+            console.log(1 + b);
-            console.log(b + c);
+            console.log(b + 3);
             console.log(4);
-            console.log(a + b + c);
+            console.log(1 + b + 3);
         }
 
         function f4() {
-            var a = 1, b = 2, c = 3;
+            var b = 2, c = 3;
             b = c;
-            console.log(a + b);
+            console.log(1 + b);
             console.log(b + c);
-            console.log(a + c);
+            console.log(1 + c);
-            console.log(a + b + c);
+            console.log(1 + b + c);
         }
 
         function f5(a) {
@@ -169,3 +169,184 @@ modified: {
         }
    }
 }
+
+unsafe_evaluate: {
+    options = {
+        evaluate     : true,
+        reduce_vars  : true,
+        unsafe       : true,
+        unused       : true
+    }
+    input: {
+        function f0(){
+            var a = {
+                b:1
+            };
+            console.log(a.b + 3);
+        }
+
+        function f1(){
+            var a = {
+                b:{
+                    c:1
+                },
+                d:2
+            };
+            console.log(a.b + 3, a.d + 4, a.b.c + 5, a.d.c + 6);
+        }
+    }
+    expect: {
+        function f0(){
+            console.log(4);
+        }
+
+        function f1(){
+            var a = {
+                b:{
+                    c:1
+                },
+                d:2
+            };
+            console.log(a.b + 3, 6, 6, 2..c + 6);
+        }
+    }
+}
+
+unsafe_evaluate_object: {
+    options = {
+        evaluate     : true,
+        reduce_vars  : true,
+        unsafe       : true
+    }
+    input: {
+        function f0(){
+            var a = 1;
+            var b = {};
+            b[a] = 2;
+            console.log(a + 3);
+        }
+
+        function f1(){
+            var a = {
+                b:1
+            };
+            a.b = 2;
+            console.log(a.b + 3);
+        }
+    }
+    expect: {
+        function f0(){
+            var a = 1;
+            var b = {};
+            b[a] = 2;
+            console.log(4);
+        }
+
+        function f1(){
+            var a = {
+                b:1
+            };
+            a.b = 2;
+            console.log(a.b + 3);
+        }
+    }
+}
+
+unsafe_evaluate_array: {
+    options = {
+        evaluate     : true,
+        reduce_vars  : true,
+        unsafe       : true
+    }
+    input: {
+        function f0(){
+            var a = 1;
+            var b = [];
+            b[a] = 2;
+            console.log(a + 3);
+        }
+
+        function f1(){
+            var a = [1];
+            a[2] = 3;
+            console.log(a.length);
+        }
+
+        function f2(){
+            var a = [1];
+            a.push(2);
+            console.log(a.length);
+        }
+    }
+    expect: {
+        function f0(){
+            var a = 1;
+            var b = [];
+            b[a] = 2;
+            console.log(4);
+        }
+
+        function f1(){
+            var a = [1];
+            a[2] = 3;
+            console.log(a.length);
+        }
+
+        function f2(){
+            var a = [1];
+            a.push(2);
+            console.log(a.length);
+        }
+    }
+}
+
+unsafe_evaluate_equality: {
+    options = {
+        evaluate     : true,
+        reduce_vars  : true,
+        unsafe       : true,
+        unused       : true
+    }
+    input: {
+        function f0(){
+            var a = {};
+            console.log(a === a);
+        }
+
+        function f1(){
+            var a = [];
+            console.log(a === a);
+        }
+
+        function f2(){
+            var a = {a:1, b:2};
+            var b = a;
+            var c = a;
+            console.log(b === c);
+        }
+
+        function f3(){
+            var a = [1, 2, 3];
+            var b = a;
+            var c = a;
+            console.log(b === c);
+        }
+    }
+    expect: {
+        function f0(){
+            console.log(true);
+        }
+
+        function f1(){
+            console.log(true);
+        }
+
+        function f2(){
+            console.log(true);
+        }
+
+        function f3(){
+            console.log(true);
+        }
+    }
+}

test/compress/screw-ie8.js

@@ -46,6 +46,8 @@ do_screw_try_catch: {
 }
 
 dont_screw_try_catch: {
+    // This test is known to generate incorrect code for screw_ie8=false.
+    // Update expected result in the event this bug is ever fixed.
     options = { screw_ie8: false };
     mangle = { screw_ie8: false };
     beautify = { screw_ie8: false };
@@ -102,6 +104,8 @@ do_screw_try_catch_undefined: {
 }
 
 dont_screw_try_catch_undefined: {
+    // This test is known to generate incorrect code for screw_ie8=false.
+    // Update expected result in the event this bug is ever fixed.
     options = { screw_ie8: false };
     mangle = { screw_ie8: false };
     beautify = { screw_ie8: false };
@@ -123,8 +127,8 @@ dont_screw_try_catch_undefined: {
             } catch (n) {
                 console.log("caught: "+n)
             }
-            console.log("undefined is " + void 0);
+            console.log("undefined is " + n);
-            return void 0===o
+            return o === n
         }
     }
 }

test/input/issue-1431/sample.js

@@ -0,0 +1,14 @@
+function f(x) {
+    return function() {
+        function n(a) {
+            return a * a;
+        }
+        return x(n);
+    };
+}
+
+function g(op) {
+    return op(1) + op(2);
+}
+
+console.log(f(g)() == 5);

test/mocha/cli.js

@@ -70,4 +70,34 @@ describe("bin/uglifyjs", function () {
             done();
         });
     });
+    it("Should work with --keep-fnames (mangle only)", function (done) {
+       var command = uglifyjscmd + ' test/input/issue-1431/sample.js --keep-fnames -m';
+
+       exec(command, function (err, stdout) {
+           if (err) throw err;
+
+           assert.strictEqual(stdout, "function f(r){return function(){function n(n){return n*n}return r(n)}}function g(n){return n(1)+n(2)}console.log(f(g)()==5);\n");
+           done();
+       });
+    });
+    it("Should work with --keep-fnames (mangle & compress)", function (done) {
+       var command = uglifyjscmd + ' test/input/issue-1431/sample.js --keep-fnames -m -c';
+
+       exec(command, function (err, stdout) {
+           if (err) throw err;
+
+           assert.strictEqual(stdout, "function f(r){return function(){function n(n){return n*n}return r(n)}}function g(n){return n(1)+n(2)}console.log(5==f(g)());\n");
+           done();
+       });
+    });
+    it("Should work with keep_fnames under mangler options", function (done) {
+       var command = uglifyjscmd + ' test/input/issue-1431/sample.js -m keep_fnames=true';
+
+       exec(command, function (err, stdout) {
+           if (err) throw err;
+
+           assert.strictEqual(stdout, "function f(r){return function(){function n(n){return n*n}return r(n)}}function g(n){return n(1)+n(2)}console.log(f(g)()==5);\n");
+           done();
+       });
+    });
 });

test/run-tests.js

@@ -70,12 +70,12 @@ function test_directory(dir) {
     return path.resolve(tests_dir, dir);
 }
 
-function as_toplevel(input) {
+function as_toplevel(input, mangle_options) {
     if (input instanceof U.AST_BlockStatement) input = input.body;
     else if (input instanceof U.AST_Statement) input = [ input ];
     else throw new Error("Unsupported input syntax");
     var toplevel = new U.AST_Toplevel({ body: input });
-    toplevel.figure_out_scope();
+    toplevel.figure_out_scope(mangle_options);
     return toplevel;
 }
 
@@ -103,11 +103,11 @@ function run_compress_tests() {
             var output_options = test.beautify || {};
             var expect;
             if (test.expect) {
-                expect = make_code(as_toplevel(test.expect), output_options);
+                expect = make_code(as_toplevel(test.expect, test.mangle), output_options);
             } else {
                 expect = test.expect_exact;
             }
-            var input = as_toplevel(test.input);
+            var input = as_toplevel(test.input, test.mangle);
             var input_code = make_code(test.input, {
                 beautify: true,
                 quote_style: 3,

tools/node.js

@@ -94,7 +94,7 @@ exports.minify = function(files, options) {
     if (options.compress) {
         var compress = { warnings: options.warnings };
         UglifyJS.merge(compress, options.compress);
-        toplevel.figure_out_scope();
+        toplevel.figure_out_scope(options.mangle);
         var sq = UglifyJS.Compressor(compress);
         toplevel = sq.compress(toplevel);
     }