harmony-v3.1.8

fixes #2442

lib/compress.js

@@ -156,7 +156,9 @@ merge(Compressor.prototype, {
         }
         var passes = +this.options.passes || 1;
         var last_count = 1 / 0;
+        var mangle = { ie8: this.option("ie8") };
         for (var pass = 0; pass < passes; pass++) {
+            node.figure_out_scope(mangle);
             if (pass > 0 || this.option("reduce_vars"))
                 node.reset_opt_flags(this);
             node = node.transform(this);
@@ -291,7 +293,7 @@ merge(Compressor.prototype, {
         self.transform(tt);
     });
 
-    AST_Node.DEFMETHOD("reset_opt_flags", function(compressor) {
+    AST_Toplevel.DEFMETHOD("reset_opt_flags", function(compressor) {
         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
@@ -322,13 +324,19 @@ merge(Compressor.prototype, {
                         d.fixed = false;
                     } else if (d.fixed) {
                         var value = node.fixed_value();
-                        if (unused && !compressor.exposed(d)) {
+                        if (value && ref_once(d) && !compressor.exposed(d)) {
-                            d.single_use = value
+                            if (value instanceof AST_Lambda) {
-                                && d.references.length == 1
+                                d.single_use = d.scope === node.scope
+                                        && !(d.orig[0] instanceof AST_SymbolFunarg)
+                                    || value.is_constant_expression(node.scope);
+                            } else {
+                                d.single_use = d.scope === node.scope
                                     && loop_ids[d.id] === in_loop
-                                && d.scope === node.scope
                                     && value.is_constant_expression();
                                 }
+                        } else {
+                            d.single_use = false;
+                        }
                         if (is_modified(node, value, 0, is_immutable(value))) {
                             if (d.single_use) {
                                 d.single_use = "m";
@@ -390,6 +398,10 @@ merge(Compressor.prototype, {
                     } else {
                         d.fixed = node;
                         mark(d, true);
+                        if (ref_once(d)) {
+                            d.single_use = d.scope === d.references[0].scope
+                                || node.is_constant_expression(d.references[0].scope);
+                        }
                     }
                     var save_ids = safe_ids;
                     safe_ids = Object.create(null);
@@ -542,6 +554,7 @@ merge(Compressor.prototype, {
                 }
                 return true;
             }
+            return def.fixed instanceof AST_Defun;
         }
 
         function safe_to_assign(def, value) {
@@ -567,7 +580,7 @@ merge(Compressor.prototype, {
         function reset_def(def) {
             def.direct_access = false;
             def.escaped = false;
-            if (def.scope.uses_eval) {
+            if (def.scope.uses_eval || def.scope.uses_with) {
                 def.fixed = false;
             } else if (def.orig[0] instanceof AST_SymbolConst || !compressor.exposed(def)) {
                 def.fixed = undefined;
@@ -579,8 +592,15 @@ merge(Compressor.prototype, {
             def.single_use = undefined;
         }
 
+        function ref_once(def) {
+            return unused && !def.scope.uses_eval && !def.scope.uses_with && def.references.length == 1;
+        }
+
         function is_immutable(value) {
-            return value && (value.is_constant() || value instanceof AST_Lambda);
+            if (!value) return false;
+            return value.is_constant()
+                || value instanceof AST_Lambda
+                || value instanceof AST_This;
         }
 
         function read_property(obj, key) {
@@ -608,7 +628,7 @@ merge(Compressor.prototype, {
                 || !immutable
                     && parent instanceof AST_Call
                     && parent.expression === node
-                    && (!(value instanceof AST_Function) || value.contains_this())) {
+                    && (!(value instanceof AST_Function) || value.contains_this(parent))) {
                 return true;
             } else if (parent instanceof AST_Array || parent instanceof AST_Object) {
                 return is_modified(parent, parent, level + 1);
@@ -619,7 +639,11 @@ merge(Compressor.prototype, {
 
         function mark_escaped(d, node, value, level) {
             var parent = tw.parent(level);
-            if (value instanceof AST_Constant || value instanceof AST_Function) return;
+            if (value instanceof AST_Constant
+                || value instanceof AST_Function
+                || value instanceof AST_ClassExpression) {
+                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
@@ -811,6 +835,14 @@ merge(Compressor.prototype, {
             || compressor.option("unsafe") && global_names(this.name);
     });
 
+    function drop_decl(def) {
+        def._eliminiated = (def._eliminiated || 0) + 1;
+        if (def.orig.length == def._eliminiated) {
+            def.scope.functions.del(def.name);
+            def.scope.variables.del(def.name);
+        }
+    }
+
     function tighten_body(statements, compressor) {
         var CHANGED, max_iter = 10;
         do {
@@ -844,6 +876,7 @@ merge(Compressor.prototype, {
         function collapse(statements, compressor) {
             var scope = compressor.find_parent(AST_Scope).get_defun_scope();
             if (scope.uses_eval || scope.uses_with) return statements;
+            var args;
             var candidates = [];
             var stat_index = statements.length;
             while (--stat_index >= 0) {
@@ -864,7 +897,7 @@ merge(Compressor.prototype, {
                     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;
+                    var abort = false, replaced = false, can_replace = !args || !hit;
                     var tt = new TreeTransformer(function(node, descend) {
                         if (abort) return node;
                         // Skip nodes before `candidate` as quickly as possible
@@ -891,7 +924,8 @@ merge(Compressor.prototype, {
                             return node;
                         }
                         // Replace variable with assignment when found
-                        if (!(node instanceof AST_SymbolDeclaration)
+                        if (can_replace
+                            && !(node instanceof AST_SymbolDeclaration)
                             && !is_lhs(node, parent)
                             && lhs.equivalent_to(node)) {
                             CHANGED = replaced = abort = true;
@@ -942,6 +976,12 @@ merge(Compressor.prototype, {
                         // Skip (non-executed) functions and (leading) default case in switch statements
                         if (node instanceof AST_Default || node instanceof AST_Scope) return node;
                     });
+                    if (!can_replace) {
+                        for (var j = compressor.self().argnames.lastIndexOf(candidate.__name || candidate.name) + 1; j < args.length; j++) {
+                            args[j].transform(tt);
+                        }
+                        can_replace = true;
+                    }
                     for (var i = stat_index; !abort && i < statements.length; i++) {
                         statements[i].transform(tt);
                     }
@@ -987,9 +1027,16 @@ merge(Compressor.prototype, {
                     })) {
                     var fn_strict = compressor.has_directive("use strict");
                     if (fn_strict && fn.body.indexOf(fn_strict) < 0) fn_strict = false;
+                    var len = fn.argnames.length;
+                    args = iife.args.slice(len);
                     var names = Object.create(null);
-                    for (var i = fn.argnames.length; --i >= 0;) {
+                    for (var i = len; --i >= 0;) {
                         var sym = fn.argnames[i];
+                        var arg = iife.args[i];
+                        args.unshift(make_node(AST_VarDef, sym, {
+                            name: sym,
+                            value: arg
+                        }));
                         if (sym.name in names) continue;
                         names[sym.name] = true;
                         if (sym instanceof AST_Expansion) {
@@ -1003,9 +1050,9 @@ merge(Compressor.prototype, {
                                         elements: elements
                                     })
                                 }));
+                                candidates[0].__name = sym;
                             }
                         } else {
-                            var arg = iife.args[i];
                             if (!arg) arg = make_node(AST_Undefined, sym).transform(compressor);
                             else if (has_overlapping_symbol(fn, arg, fn_strict)) arg = null;
                             if (arg) candidates.unshift(make_node(AST_VarDef, sym, {
@@ -1037,7 +1084,8 @@ merge(Compressor.prototype, {
             function get_lhs(expr) {
                 if (expr instanceof AST_VarDef && expr.name instanceof AST_SymbolDeclaration) {
                     var def = expr.name.definition();
-                    if (def.orig.length > 1 && !(expr.name instanceof AST_SymbolFunarg)
+                    if (def.orig.length - (def._eliminiated || 0) > 1
+                            && !(expr.name instanceof AST_SymbolFunarg)
                         || def.references.length == 1 && !compressor.exposed(def)) {
                         return make_node(AST_SymbolRef, expr.name, expr.name);
                     }
@@ -1047,6 +1095,10 @@ merge(Compressor.prototype, {
                 }
             }
 
+            function get_rvalue(expr) {
+                return expr[expr instanceof AST_Assign ? "right" : "value"];
+            }
+
             function get_lvalues(expr) {
                 var lvalues = Object.create(null);
                 if (expr instanceof AST_Unary) return lvalues;
@@ -1057,7 +1109,7 @@ merge(Compressor.prototype, {
                         lvalues[sym.name] = lvalues[sym.name] || is_lhs(node, tw.parent());
                     }
                 });
-                expr[expr instanceof AST_Assign ? "right" : "value"].walk(tw);
+                get_rvalue(expr).walk(tw);
                 return lvalues;
             }
 
@@ -1086,7 +1138,9 @@ merge(Compressor.prototype, {
                     if (node === expr) {
                         found = true;
                         if (node instanceof AST_VarDef) {
-                            remove(node.name.definition().orig, node.name);
+                            drop_decl(node.name.definition());
+                            node.value = null;
+                            return node;
                         }
                         return in_list ? MAP.skip : null;
                     }
@@ -1095,16 +1149,13 @@ merge(Compressor.prototype, {
                       case 0: return null;
                       case 1: return node.expressions[0];
                     }
-                    if (node instanceof AST_Definitions && node.definitions.length == 0
+                    if (node instanceof AST_SimpleStatement && !node.body) return null;
-                        || node instanceof AST_SimpleStatement && !node.body) {
-                        return null;
-                    }
                 }));
             }
 
             function value_has_side_effects(expr) {
                 if (expr instanceof AST_Unary) return false;
-                return expr[expr instanceof AST_Assign ? "right" : "value"].has_side_effects(compressor);
+                return get_rvalue(expr).has_side_effects(compressor);
             }
 
             function references_in_scope(def) {
@@ -2261,18 +2312,22 @@ merge(Compressor.prototype, {
         }
         def(AST_Node, return_false);
         def(AST_Constant, return_true);
-        def(AST_Function, function(){
+        def(AST_Lambda, function(scope){
             var self = this;
             var result = true;
             self.walk(new TreeWalker(function(node) {
                 if (!result) return true;
                 if (node instanceof AST_SymbolRef) {
                     var def = node.definition();
-                    if (self.enclosed.indexOf(def) >= 0
+                    if (member(def, self.enclosed)
-                        && self.variables.get(def.name) !== def) {
+                        && !self.variables.has(def.name)) {
-                        result = false;
+                        if (scope) {
-                        return true;
+                            var scope_def = scope.find_variable(node);
+                            if (def.undeclared ? !scope_def : scope_def === def) return true;
                         }
+                        result = false;
+                    }
+                    return true;
                 }
             }));
             return result;
@@ -2389,7 +2444,7 @@ merge(Compressor.prototype, {
         // this scope (not in nested scopes).
         var scope = this;
         var tw = new TreeWalker(function(node, descend){
-            if (node !== self) {
+            if (node === self) return;
             if (node instanceof AST_Defun || node instanceof AST_DefClass) {
                 var in_export = tw.parent() instanceof AST_Export;
                 if (in_export || !drop_funcs && scope === self) {
@@ -2402,6 +2457,9 @@ merge(Compressor.prototype, {
                 initializations.add(node.name.name, node);
                 return true; // don't go in nested scopes
             }
+            if (node instanceof AST_SymbolFunarg && scope === self) {
+                var_defs_by_id.add(node.definition().id, node);
+            }
             if (node instanceof AST_Definitions && scope === self) {
                 var in_export = tw.parent() instanceof AST_Export;
                 node.definitions.forEach(function(def){
@@ -2435,8 +2493,11 @@ merge(Compressor.prototype, {
                 });
                 return true;
             }
-                if (assign_as_unused(node) instanceof AST_SymbolRef && scope === self
+            var sym;
-                    && !is_ref_of(node.left, AST_SymbolBlockDeclaration)) {
+            if (scope === self
+                && (sym = assign_as_unused(node)) instanceof AST_SymbolRef
+                && !is_ref_of(node.left, AST_SymbolBlockDeclaration)
+                && self.variables.get(sym.name) === sym.definition()) {
                 if (node instanceof AST_Assign) node.right.walk(tw);
                 return true;
             }
@@ -2458,7 +2519,6 @@ merge(Compressor.prototype, {
             if (node.destructuring && destructuring_value) {
                 initializations.add(node.name, destructuring_value);
             }
-            }
         });
         self.walk(tw);
         // pass 2: for every used symbol we need to walk its
@@ -2522,9 +2582,11 @@ merge(Compressor.prototype, {
                     }
                 }
                 if ((node instanceof AST_Defun || node instanceof AST_DefClass) && node !== self) {
-                    var keep = (node.name.definition().id in in_use_ids) || !drop_funcs && node.name.definition().global;
+                    var def = node.name.definition();
+                    var keep = (def.id in in_use_ids) || !drop_funcs && def.global;
                     if (!keep) {
                         compressor[node.name.unreferenced() ? "warn" : "info"]("Dropping unused function {name} [{file}:{line},{col}]", template(node.name));
+                        drop_decl(def);
                         return make_node(AST_EmptyStatement, node);
                     }
                     return node;
@@ -2549,7 +2611,7 @@ merge(Compressor.prototype, {
                                 if (var_defs.length > 1 && !def.value) {
                                     compressor.warn("Dropping duplicated definition of variable {name} [{file}:{line},{col}]", template(def.name));
                                     remove(var_defs, def);
-                                    remove(sym.orig, def.name);
+                                    drop_decl(sym);
                                     return;
                                 }
                             }
@@ -2582,7 +2644,7 @@ merge(Compressor.prototype, {
                             } else {
                                 compressor[def.name.unreferenced() ? "warn" : "info"]("Dropping unused variable {name} [{file}:{line},{col}]", template(def.name));
                             }
-                            remove(sym.orig, def.name);
+                            drop_decl(sym);
                         }
                     });
                     if (head.length == 0 && tail.length == 1 && tail[0].name instanceof AST_SymbolVar) {
@@ -2591,7 +2653,7 @@ merge(Compressor.prototype, {
                             var def = tail.pop();
                             compressor.warn("Converting duplicated definition of variable {name} to assignment [{file}:{line},{col}]", template(def.name));
                             remove(var_defs, def);
-                            remove(def.name.definition().orig, def.name);
+                            drop_decl(def.name.definition());
                             side_effects.unshift(make_node(AST_Assign, def, {
                                 operator: "=",
                                 left: make_node(AST_SymbolRef, def.name, def.name),
@@ -2623,8 +2685,7 @@ merge(Compressor.prototype, {
                     var def = assign_as_unused(node);
                     if (def instanceof AST_SymbolRef
                         && !((def = def.definition()).id in in_use_ids)
-                        && (drop_vars || !def.global)
+                        && (drop_vars || !def.global)) {
-                        && self.variables.get(def.name) === def) {
                         if (node instanceof AST_Assign) {
                             return maintain_this_binding(parent, node, node.right.transform(tt));
                         }
@@ -3440,7 +3501,7 @@ merge(Compressor.prototype, {
                 });
                 a.push(var_);
             }
-            remove(def.name.definition().orig, def.name);
+            drop_decl(def.name.definition());
             return a;
         }, []);
         if (assignments.length == 0) return null;
@@ -3723,6 +3784,7 @@ merge(Compressor.prototype, {
                 && !exp.uses_arguments
                 && !exp.uses_eval
                 && (exp.body instanceof AST_Node || exp.body.length == 1)
+                && !exp.contains_this()
                 && all(exp.argnames, function(arg) {
                     if (arg instanceof AST_Expansion) return arg.expression.__unused;
                     return arg.__unused;
@@ -3737,23 +3799,6 @@ merge(Compressor.prototype, {
                         expression: stat.body
                     });
                 }
-                if (value) {
-                    var tw = new TreeWalker(function(node) {
-                        if (!value) return true;
-                        if (node instanceof AST_SymbolRef) {
-                            var ref = node.scope.find_variable(node);
-                            if (ref && ref.scope.parent_scope === fn.parent_scope) {
-                                value = null;
-                                return true;
-                            }
-                        }
-                        if (node instanceof AST_This && !tw.find_parent(AST_Scope)) {
-                            value = null;
-                            return true;
-                        }
-                    });
-                    value.walk(tw);
-                }
                 if (value) {
                     var args = self.args.concat(value);
                     return make_sequence(self, args).optimize(compressor);
@@ -4043,7 +4088,8 @@ merge(Compressor.prototype, {
     function is_object(node) {
         return node instanceof AST_Array
             || node instanceof AST_Lambda
-            || node instanceof AST_Object;
+            || node instanceof AST_Object
+            || node instanceof AST_Class;
     }
 
     OPT(AST_Binary, function(self, compressor){
@@ -4448,21 +4494,37 @@ merge(Compressor.prototype, {
             if (fixed instanceof AST_Defun) {
                 d.fixed = fixed = make_node(AST_Function, fixed, fixed);
             }
-            if (compressor.option("unused")
+            if (fixed && d.single_use) {
-                && fixed
+                var recurse;
-                && d.references.length == 1
+                if (fixed instanceof AST_Function) {
-                && (d.single_use || is_func_expr(fixed)
+                    for (var i = 0; recurse = compressor.parent(i); i++) {
-                    && !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
+                        if (recurse instanceof AST_Lambda) {
-                    && !d.scope.uses_eval
+                            var name = recurse.name;
-                    && compressor.find_parent(AST_Scope) === fixed.parent_scope)) {
+                            if (name && name.definition() === d) break;
+                        }
+                    }
+                }
+                if (!recurse) {
                     var value = fixed.optimize(compressor);
                     return value === fixed ? fixed.clone(true) : value;
                 }
-            if (compressor.option("evaluate") && fixed) {
+            }
-                if (d.should_replace === undefined) {
+            if (fixed && d.should_replace === undefined) {
-                    var init = fixed.evaluate(compressor);
+                var init;
-                    if (init !== fixed && (compressor.option("unsafe_regexp") || !(init instanceof RegExp))) {
+                if (fixed instanceof AST_This) {
-                        init = make_node_from_constant(init, fixed);
+                    if (!(d.orig[0] instanceof AST_SymbolFunarg)
+                        && all(d.references, function(ref) {
+                            return d.scope === ref.scope;
+                        })) {
+                        init = fixed;
+                    }
+                } else {
+                    var ev = fixed.evaluate(compressor);
+                    if (ev !== fixed && (compressor.option("unsafe_regexp") || !(ev instanceof RegExp))) {
+                        init = make_node_from_constant(ev, fixed);
+                    }
+                }
+                if (init) {
                     var value_length = init.optimize(compressor).print_to_string().length;
                     var fn;
                     if (has_symbol_ref(fixed)) {
@@ -4491,7 +4553,6 @@ merge(Compressor.prototype, {
                 return d.should_replace();
             }
         }
-        }
         return self;
 
         function has_symbol_ref(value) {
@@ -4827,11 +4888,11 @@ merge(Compressor.prototype, {
             }
         }
         if (is_lhs(self, compressor.parent())) return self;
-        if (compressor.option("properties") && key !== prop) {
+        if (key !== prop) {
-            var node = self.flatten_object(property, compressor);
+            var sub = self.flatten_object(property, compressor);
-            if (node) {
+            if (sub) {
-                expr = self.expression = node.expression;
+                expr = self.expression = sub.expression;
-                prop = self.property = node.property;
+                prop = self.property = sub.property;
             }
         }
         if (compressor.option("properties") && compressor.option("side_effects")
@@ -4877,7 +4938,8 @@ merge(Compressor.prototype, {
         return self;
     });
 
-    AST_Lambda.DEFMETHOD("contains_this", function() {
+    AST_Lambda.DEFMETHOD("contains_this", function(grandparent) {
+        if (grandparent instanceof AST_New) return false;
         var result;
         var self = this;
         self.walk(new TreeWalker(function(node) {
@@ -4889,6 +4951,7 @@ merge(Compressor.prototype, {
     });
 
     AST_PropAccess.DEFMETHOD("flatten_object", function(key, compressor) {
+        if (!compressor.option("properties")) return;
         var arrows = compressor.option("unsafe_arrows") && compressor.option("ecma") >= 6;
         var expr = this.expression;
         if (expr instanceof AST_Object) {
@@ -4902,7 +4965,7 @@ merge(Compressor.prototype, {
                     })) break;
                     var value = prop.value;
                     if ((value instanceof AST_Accessor || value instanceof AST_Function)
-                        && value.contains_this()) break;
+                        && value.contains_this(compressor.parent())) break;
                     return make_node(AST_Sub, this, {
                         expression: make_node(AST_Array, expr, {
                             elements: props.map(function(prop) {
@@ -4952,10 +5015,8 @@ merge(Compressor.prototype, {
             }
         }
         if (is_lhs(self, compressor.parent())) return self;
-        if (compressor.option("properties")) {
+        var sub = self.flatten_object(self.property, compressor);
-            var node = self.flatten_object(self.property, compressor);
+        if (sub) return sub.optimize(compressor);
-            if (node) return node.optimize(compressor);
-        }
         var ev = self.evaluate(compressor);
         if (ev !== self) {
             ev = make_node_from_constant(ev, self).optimize(compressor);

lib/minify.js

@@ -141,11 +141,9 @@ function minify(files, options) {
         if (options.wrap) {
             toplevel = toplevel.wrap_commonjs(options.wrap);
         }
-        if (timings) timings.scope1 = Date.now();
-        if (options.compress) toplevel.figure_out_scope(options.mangle);
         if (timings) timings.compress = Date.now();
         if (options.compress) toplevel = new Compressor(options.compress).compress(toplevel);
-        if (timings) timings.scope2 = Date.now();
+        if (timings) timings.scope = Date.now();
         if (options.mangle) toplevel.figure_out_scope(options.mangle);
         if (timings) timings.mangle = Date.now();
         if (options.mangle) {
@@ -203,9 +201,9 @@ function minify(files, options) {
         if (timings) {
             timings.end = Date.now();
             result.timings = {
-                parse: 1e-3 * (timings.scope1 - timings.parse),
+                parse: 1e-3 * (timings.compress - timings.parse),
-                scope: 1e-3 * (timings.compress - timings.scope1 + timings.mangle - timings.scope2),
+                compress: 1e-3 * (timings.scope - timings.compress),
-                compress: 1e-3 * (timings.scope2 - timings.compress),
+                scope: 1e-3 * (timings.mangle - timings.scope),
                 mangle: 1e-3 * (timings.properties - timings.mangle),
                 properties: 1e-3 * (timings.output - timings.properties),
                 output: 1e-3 * (timings.end - timings.output),

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": "3.1.6",
+  "version": "3.1.8",
   "engines": {
     "node": ">=0.8.0"
   },

test/compress/arrow.js

@@ -314,17 +314,12 @@ issue_2105_1: {
         });
     }
     expect: {
-        (() => {
+        ({
-            var quux = () => {
-                console.log("PASS");
-            };
-            return {
             prop() {
                 console.log;
-                    quux();
+                console.log("PASS");
             }
-            };
+        }).prop();
-        })().prop();
     }
     expect_stdout: "PASS"
     node_version: ">=4"
@@ -360,17 +355,12 @@ issue_2105_2: {
         });
     }
     expect: {
-        (() => {
+        ({
-            var quux = () => {
-                console.log("PASS");
-            };
-            return {
             prop: () => {
                 console.log;
-                    quux();
+                console.log("PASS");
             }
-            };
+        }).prop();
-        })().prop();
     }
     expect_stdout: "PASS"
     node_version: ">=6"

test/compress/collapse_vars.js

@@ -1487,6 +1487,7 @@ issue_1605_1: {
     options = {
         collapse_vars: true,
         toplevel: false,
+        unused: true,
     }
     input: {
         function foo(x) {
@@ -1509,6 +1510,7 @@ issue_1605_2: {
     options = {
         collapse_vars: true,
         toplevel: "vars",
+        unused: true,
     }
     input: {
         function foo(x) {
@@ -1636,6 +1638,7 @@ issue_1631_3: {
 var_side_effects_1: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     input: {
         var print = console.log.bind(console);
@@ -1658,6 +1661,7 @@ var_side_effects_1: {
 var_side_effects_2: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     input: {
         var print = console.log.bind(console);
@@ -1683,6 +1687,7 @@ var_side_effects_3: {
         collapse_vars: true,
         pure_getters: true,
         unsafe: true,
+        unused: true,
     }
     input: {
         var print = console.log.bind(console);
@@ -1758,6 +1763,7 @@ iife_2: {
         }(foo);
     }
     expect: {
+        var foo;
         !function(x) {
             console.log(x);
         }(bar());
@@ -2044,6 +2050,7 @@ ref_scope: {
 chained_1: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     input: {
         var a = 2;
@@ -2060,6 +2067,7 @@ chained_1: {
 chained_2: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     input: {
         var a;
@@ -2160,6 +2168,7 @@ inner_lvalues: {
 double_def: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     input: {
         var a = x, a = a && y;
@@ -2174,6 +2183,7 @@ double_def: {
 toplevel_single_reference: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     input: {
         var a;
@@ -2183,11 +2193,12 @@ toplevel_single_reference: {
         }
     }
     expect: {
+        for (var b in x) {
             var a;
-        for (var b in x)
             b(a = b);
         }
     }
+}
 
 unused_orig: {
     options = {
@@ -2215,10 +2226,11 @@ unused_orig: {
     expect: {
         var a = 1;
         console.log(function(b) {
-            var a;
             var c = b;
-            for (var d in c)
+            for (var d in c) {
+                var a;
                 return --b + (a = c[0]);
+            }
             a && a.NaN;
         }([2]), a);
     }
@@ -2565,7 +2577,9 @@ issue_2250_1: {
     options = {
         collapse_vars: true,
         conditionals: true,
+        passes: 2,
         reduce_vars: true,
+        unused: true,
     }
     input: {
         function f(x) {
@@ -2607,6 +2621,7 @@ issue_2250_2: {
         reduce_vars: true,
         side_effects: true,
         toplevel: true,
+        unused: true,
     }
     input: {
         {
@@ -3163,6 +3178,7 @@ pure_getters_chain: {
     options = {
         collapse_vars: true,
         pure_getters: true,
+        unused: true,
     }
     input: {
         function o(t, r) {
@@ -3183,6 +3199,7 @@ pure_getters_chain: {
 conditional_1: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     input: {
         function f(a, b) {
@@ -3207,6 +3224,7 @@ conditional_1: {
 conditional_2: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     input: {
         function f(a, b) {
@@ -3223,3 +3241,117 @@ conditional_2: {
     }
     expect_stdout: "5 5"
 }
+
+issue_2425_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = 8;
+        (function(b) {
+            b.toString();
+        })(--a, a |= 10);
+        console.log(a);
+    }
+    expect: {
+        var a = 8;
+        (function(b) {
+            b.toString();
+        })(--a, a |= 10);
+        console.log(a);
+    }
+    expect_stdout: "15"
+}
+
+issue_2425_2: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = 8;
+        (function(b, c) {
+            b.toString();
+        })(--a, a |= 10);
+        console.log(a);
+    }
+    expect: {
+        var a = 8;
+        (function(b, c) {
+            b.toString();
+        })(--a, a |= 10);
+        console.log(a);
+    }
+    expect_stdout: "15"
+}
+
+issue_2425_3: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = 8;
+        (function(b, b) {
+            b.toString();
+        })(--a, a |= 10);
+        console.log(a);
+    }
+    expect: {
+        var a = 8;
+        (function(b, b) {
+            (a |= 10).toString();
+        })(--a);
+        console.log(a);
+    }
+    expect_stdout: "15"
+}
+
+issue_2437: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        inline: true,
+        join_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            bar();
+        }
+        function bar() {
+            if (xhrDesc) {
+                var req = new XMLHttpRequest();
+                var result = !!req.onreadystatechange;
+                Object.defineProperty(XMLHttpRequest.prototype, 'onreadystatechange', xhrDesc || {});
+                return result;
+            }
+            else {
+                var req = new XMLHttpRequest();
+                var detectFunc = function () { };
+                req.onreadystatechange = detectFunc;
+                var result = req[SYMBOL_FAKE_ONREADYSTATECHANGE_1] === detectFunc;
+                req.onreadystatechange = null;
+                return result;
+            }
+        }
+        foo();
+    }
+    expect: {
+        !function() {
+            if (xhrDesc)
+                return result = !!(req = new XMLHttpRequest()).onreadystatechange,
+                    Object.defineProperty(XMLHttpRequest.prototype, "onreadystatechange", xhrDesc || {}),
+                    result;
+            var req = new XMLHttpRequest(), detectFunc = function() {};
+            req.onreadystatechange = detectFunc;
+            var result = req[SYMBOL_FAKE_ONREADYSTATECHANGE_1] === detectFunc;
+            req.onreadystatechange = null;
+        }();
+    }
+}

test/compress/drop-unused.js

@@ -1294,11 +1294,11 @@ issue_2063: {
     }
 }
 
-issue_2105: {
+issue_2105_1: {
     options = {
         collapse_vars: true,
         inline: true,
-        passes: 3,
+        passes: 2,
         reduce_vars: true,
         side_effects: true,
         unused: true,
@@ -1324,17 +1324,50 @@ issue_2105: {
         });
     }
     expect: {
-        (function() {
+        ({
-            var quux = function() {
-                console.log("PASS");
-            };
-            return {
             prop: function() {
                 console.log;
-                    quux();
+                console.log("PASS");
             }
+        }).prop();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2105_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        !function(factory) {
+            factory();
+        }( function() {
+            return function(fn) {
+                fn()().prop();
+            }( function() {
+                function bar() {
+                    var quux = function() {
+                        console.log("PASS");
+                    }, foo = function() {
+                        console.log;
+                        quux();
                     };
-        })().prop();
+                    return { prop: foo };
+                }
+                return bar;
+            } );
+        });
+    }
+    expect: {
+        console.log("PASS");
     }
     expect_stdout: "PASS"
 }

test/compress/functions.js

@@ -508,3 +508,41 @@ issue_2114_2: {
     }
     expect_stdout: "2"
 }
+
+issue_2428: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        function bar(k) {
+            console.log(k);
+        }
+        function foo(x) {
+            return bar(x);
+        }
+        function baz(a) {
+            foo(a);
+        }
+        baz(42);
+        baz("PASS");
+    }
+    expect: {
+        function baz(a) {
+            console.log(a);
+        }
+        baz(42);
+        baz("PASS");
+    }
+    expect_stdout: [
+        "42",
+        "PASS",
+    ]
+}

test/compress/hoist_props.js

@@ -369,3 +369,145 @@ contains_this_3: {
     }
     expect_stdout: "1 1 true"
 }
+
+hoist_class: {
+    options = {
+        comparisons: true,
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        keep_fnames: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function run(c, v) {
+            return new c(v).value;
+        }
+        var o = {
+            p: class Foo {
+                constructor(value) {
+                    this.value = value * 10;
+                }
+            },
+            x: 1,
+            y: 2,
+        };
+        console.log(o.p.name, o.p === o.p, run(o.p, o.x), run(o.p, o.y));
+    }
+    expect: {
+        function run(c, v) {
+            return new c(v).value;
+        }
+        var o_p = class Foo {
+            constructor(value) {
+                this.value = 10 * value;
+            }
+        };
+        console.log(o_p.name, true, run(o_p, 1), run(o_p, 2));
+    }
+    node_version: ">=6"
+    expect_stdout: "Foo true 10 20"
+}
+
+hoist_class_with_new: {
+    options = {
+        comparisons: true,
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        keep_fnames: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            p: class Foo {
+                constructor(value) {
+                    this.value = value * 10;
+                }
+            },
+            x: 1,
+            y: 2,
+        };
+        console.log(o.p.name, o.p === o.p, new o.p(o.x).value, new o.p(o.y).value);
+    }
+    expect: {
+        // FIXME: class `o.p` not hoisted due to `new`
+        var o = {
+            p: class Foo {
+                constructor(value) {
+                    this.value = 10 * value;
+                }
+            },
+            x: 1,
+            y: 2
+        };
+        console.log(o.p.name, o.p == o.p, new o.p(o.x).value, new o.p(o.y).value);
+    }
+    node_version: ">=6"
+    expect_stdout: "Foo true 10 20"
+}
+
+hoist_function_with_call: {
+    options = {
+        comparisons: true,
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        keep_fnames: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            p: function Foo(value) {
+                return 10 * value;
+            },
+            x: 1,
+            y: 2
+        };
+        console.log(o.p.name, o.p === o.p, o.p(o.x), o.p(o.y));
+    }
+    expect: {
+        var o_p = function Foo(value){
+            return 10 * value
+        };
+        console.log(o_p.name, true, o_p(1), o_p(2));
+    }
+    expect_stdout: "Foo true 10 20"
+}
+
+new_this: {
+    options = {
+        evaluate: true,
+        hoist_props: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {
+            a: 1,
+            b: 2,
+            f: function(a) {
+                this.b = a;
+            }
+        };
+        console.log(new o.f(o.a).b, o.b);
+    }
+    expect: {
+        console.log(new function(a) {
+            this.b = a;
+        }(1).b, 2);
+    }
+    expect_stdout: "1 2"
+}

test/compress/issue-2001.js

@@ -177,6 +177,7 @@ export_mangle_2: {
 export_mangle_3: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     mangle = {
         toplevel: true,
@@ -195,6 +196,7 @@ export_mangle_3: {
 export_mangle_4: {
     options = {
         collapse_vars: true,
+        unused: true,
     }
     mangle = {
         toplevel: true,

test/compress/issue-973.js

@@ -51,6 +51,7 @@ this_binding_collapse_vars: {
     options = {
         collapse_vars: true,
         toplevel: true,
+        unused: true,
     };
     input: {
         var c = a; c();

test/compress/properties.js

@@ -1282,3 +1282,22 @@ computed_property: {
     ]
     node_version: ">=4"
 }
+
+new_this: {
+    options = {
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        new {
+            f: function(a) {
+                this.a = a;
+            }
+        }.f(42);
+    }
+    expect: {
+        new function(a) {
+            this.a = a;
+        }(42);
+    }
+}

test/compress/reduce_vars.js

@@ -2131,14 +2131,13 @@ redefine_farg_1: {
     }
     expect: {
         function f(a) {
-            var a;
             return typeof a;
         }
         function g() {
             return "number";
         }
         function h(a, b) {
-            var a = b;
+            a = b;
             return typeof a;
         }
         console.log(f([]), g([]), h([]));
@@ -2173,10 +2172,9 @@ redefine_farg_2: {
     }
     expect: {
         console.log(function(a) {
-            var a;
             return typeof a;
         }([]), "number",function(a, b) {
-            var a = b;
+            a = b;
             return typeof a;
         }([]));
     }
@@ -2185,11 +2183,13 @@ redefine_farg_2: {
 
 redefine_farg_3: {
     options = {
+        cascade: true,
         evaluate: true,
         inline: true,
         keep_fargs: false,
-        passes: 3,
+        passes: 2,
         reduce_vars: true,
+        sequences: true,
         side_effects: true,
         toplevel: true,
         unused: true,
@@ -3537,3 +3537,596 @@ escaped_prop: {
     }
     expect_stdout: "2"
 }
+
+issue_2420_1: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function run() {
+            var self = this;
+            if (self.count++)
+                self.foo();
+            else
+                self.bar();
+        }
+        var o = {
+            count: 0,
+            foo: function() { console.log("foo"); },
+            bar: function() { console.log("bar"); },
+        };
+        run.call(o);
+        run.call(o);
+    }
+    expect: {
+        function run() {
+            if (this.count++)
+                this.foo();
+            else
+                this.bar();
+        }
+        var o = {
+            count: 0,
+            foo: function() { console.log("foo"); },
+            bar: function() { console.log("bar"); },
+        };
+        run.call(o);
+        run.call(o);
+    }
+    expect_stdout: [
+        "bar",
+        "foo",
+    ]
+}
+
+issue_2420_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var that = this;
+            if (that.bar)
+                that.foo();
+            else
+                !function(that, self) {
+                    console.log(this === that, self === this, that === self);
+                }(that, this);
+        }
+        f.call({
+            bar: 1,
+            foo: function() { console.log("foo", this.bar); },
+        });
+        f.call({});
+    }
+    expect: {
+        function f() {
+            if (this.bar)
+                this.foo();
+            else
+                !function(that, self) {
+                    console.log(this === that, self === this, that === self);
+                }(this, this);
+        }
+        f.call({
+            bar: 1,
+            foo: function() { console.log("foo", this.bar); },
+        });
+        f.call({});
+    }
+    expect_stdout: [
+        "foo 1",
+        "false false true",
+    ]
+}
+
+issue_2420_3: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var that = this;
+            if (that.bar)
+                that.foo();
+            else
+                ((that, self) => {
+                    console.log(this === that, self === this, that === self);
+                })(that, this);
+        }
+        f.call({
+            bar: 1,
+            foo: function() { console.log("foo", this.bar); },
+        });
+        f.call({});
+    }
+    expect: {
+        function f() {
+            if (this.bar)
+                this.foo();
+            else
+                ((that, self) => {
+                    console.log(this === that, self === this, that === self);
+                })(this, this);
+        }
+        f.call({
+            bar: 1,
+            foo: function() { console.log("foo", this.bar); },
+        });
+        f.call({});
+    }
+    expect_stdout: [
+        "foo 1",
+        "true true true",
+    ]
+    node_version: ">=4"
+}
+
+issue_2423_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function c() { return 1; }
+        function p() { console.log(c()); }
+        p();
+        p();
+    }
+    expect: {
+        function p() { console.log(function() { return 1; }()); }
+        p();
+        p();
+    }
+    expect_stdout: [
+        "1",
+        "1",
+    ]
+}
+
+issue_2423_2: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function c() { return 1; }
+        function p() { console.log(c()); }
+        p();
+        p();
+    }
+    expect: {
+        function p() { console.log(1); }
+        p();
+        p();
+    }
+    expect_stdout: [
+        "1",
+        "1",
+    ]
+}
+
+issue_2423_3: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function c() { return 1; }
+        function p() { console.log(c()); }
+        p();
+    }
+    expect: {
+        (function() { console.log(function() { return 1; }()); })();
+    }
+    expect_stdout: "1"
+}
+
+issue_2423_4: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function c() { return 1; }
+        function p() { console.log(c()); }
+        p();
+    }
+    expect: {
+        console.log(1);
+    }
+    expect_stdout: "1"
+}
+
+issue_2423_5: {
+    options = {
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function x() {
+            y();
+        }
+        function y() {
+            console.log(1);
+        }
+        function z() {
+            function y() {
+                console.log(2);
+            }
+            x();
+        }
+        z();
+        z();
+    }
+    expect: {
+        function z() {
+            console.log(1);
+        }
+        z();
+        z();
+    }
+    expect_stdout: [
+        "1",
+        "1",
+    ]
+}
+
+issue_2423_6: {
+    options = {
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function x() {
+            y();
+        }
+        function y() {
+            console.log(1);
+        }
+        function z() {
+            function y() {
+                console.log(2);
+            }
+            x();
+            y();
+        }
+        z();
+        z();
+    }
+    expect: {
+        function z(){
+            console.log(1);
+            console.log(2);
+        }
+        z();
+        z();
+    }
+    expect_stdout: [
+        "1",
+        "2",
+        "1",
+        "2",
+    ]
+}
+
+issue_2440_eval_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            return bar();
+        }
+        baz = {
+            quux: foo
+        };
+        exec = function() {
+            return eval("foo()");
+        };
+    }
+    expect: {
+        function foo() {
+            return bar();
+        }
+        baz = {
+            quux: foo
+        };
+        exec = function() {
+            return eval("foo()");
+        };
+    }
+}
+
+issue_2440_eval_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        baz = {
+            quux: foo
+        };
+        exec = function() {
+            return eval("foo()");
+        };
+        function foo() {
+            return bar();
+        }
+    }
+    expect: {
+        baz = {
+            quux: foo
+        };
+        exec = function() {
+            return eval("foo()");
+        };
+        function foo() {
+            return bar();
+        }
+    }
+}
+
+issue_2440_with_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            return bar();
+        }
+        baz = {
+            quux: foo
+        };
+        with (o) whatever();
+    }
+    expect: {
+        function foo() {
+            return bar();
+        }
+        baz = {
+            quux: foo
+        };
+        with (o) whatever();
+    }
+}
+
+issue_2440_with_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        baz = {
+            quux: foo
+        };
+        with (o) whatever();
+        function foo() {
+            return bar();
+        }
+    }
+    expect: {
+        baz = {
+            quux: foo
+        };
+        with (o) whatever();
+        function foo() {
+            return bar();
+        }
+    }
+}
+
+issue_2442: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function foo() {
+            foo();
+        }
+    }
+    expect: {}
+}
+
+recursive_inlining_1: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            function foo() { bar(); }
+            function bar() { foo(); }
+            console.log("PASS");
+        }();
+    }
+    expect: {
+        !function() {
+            console.log("PASS");
+        }();
+    }
+    expect_stdout: "PASS"
+}
+
+recursive_inlining_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            function foo() { qux(); }
+            function bar() { foo(); }
+            function qux() { bar(); }
+            console.log("PASS");
+        }();
+    }
+    expect: {
+        !function() {
+            console.log("PASS");
+        }();
+    }
+    expect_stdout: "PASS"
+}
+
+recursive_inlining_3: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            function foo(x) { console.log("foo", x); if (x) bar(x-1); }
+            function bar(x) { console.log("bar", x); if (x) qux(x-1); }
+            function qux(x) { console.log("qux", x); if (x) foo(x-1); }
+            qux(4);
+        }();
+    }
+    expect: {
+        !function() {
+            function qux(x) {
+                console.log("qux", x);
+                if (x) (function(x) {
+                    console.log("foo", x);
+                    if (x) (function(x) {
+                        console.log("bar", x);
+                        if (x) qux(x - 1);
+                    })(x - 1);
+                })(x - 1);
+            }
+            qux(4);
+        }();
+    }
+    expect_stdout: [
+        "qux 4",
+        "foo 3",
+        "bar 2",
+        "qux 1",
+        "foo 0",
+    ]
+}
+
+recursive_inlining_4: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            function foo(x) { console.log("foo", x); if (x) bar(x-1); }
+            function bar(x) { console.log("bar", x); if (x) qux(x-1); }
+            function qux(x) { console.log("qux", x); if (x) foo(x-1); }
+            qux(4);
+            bar(5);
+        }();
+    }
+    expect: {
+        !function() {
+            function bar(x) {
+                console.log("bar", x);
+                if (x) qux(x - 1);
+            }
+            function qux(x) {
+                console.log("qux", x);
+                if (x) (function(x) {
+                    console.log("foo", x);
+                    if (x) bar(x - 1);
+                })(x - 1);
+            }
+            qux(4);
+            bar(5);
+        }();
+    }
+    expect_stdout: [
+        "qux 4",
+        "foo 3",
+        "bar 2",
+        "qux 1",
+        "foo 0",
+        "bar 5",
+        "qux 4",
+        "foo 3",
+        "bar 2",
+        "qux 1",
+        "foo 0",
+    ]
+}
+
+recursive_inlining_5: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            function foo(x) { console.log("foo", x); if (x) bar(x-1); }
+            function bar(x) { console.log("bar", x); if (x) qux(x-1); }
+            function qux(x) { console.log("qux", x); if (x) foo(x-1); }
+            qux(4);
+            bar(5);
+            foo(3);
+        }();
+    }
+    expect: {
+        !function() {
+            function foo(x) {
+                console.log("foo", x);
+                if (x) bar(x - 1);
+            }
+            function bar(x) {
+                console.log("bar", x);
+                if (x) qux(x - 1);
+            }
+            function qux(x) {
+                console.log("qux", x);
+                if (x) foo(x - 1);
+            }
+            qux(4);
+            bar(5);
+            foo(3);
+        }();
+    }
+    expect_stdout: [
+        "qux 4",
+        "foo 3",
+        "bar 2",
+        "qux 1",
+        "foo 0",
+        "bar 5",
+        "qux 4",
+        "foo 3",
+        "bar 2",
+        "qux 1",
+        "foo 0",
+        "foo 3",
+        "bar 2",
+        "qux 1",
+        "foo 0",
+    ]
+}

test/ufuzz.js

@@ -162,6 +162,7 @@ var VALUES = [
     '"object"',
     '"number"',
     '"function"',
+    'this',
 ];
 
 var BINARY_OPS_NO_COMMA = [
@@ -349,10 +350,10 @@ function createParams() {
     return params.join(', ');
 }
 
-function createArgs() {
+function createArgs(recurmax, stmtDepth, canThrow) {
     var args = [];
     for (var n = rng(4); --n >= 0;) {
-        args.push(createValue());
+        args.push(rng(2) ? createValue() : createExpression(recurmax - 1, COMMA_OK, stmtDepth, canThrow));
     }
     return args.join(', ');
 }
@@ -390,9 +391,10 @@ function createFunction(recurmax, inGlobal, noDecl, canThrow, stmtDepth) {
 
     VAR_NAMES.length = namesLenBefore;
 
-    if (noDecl) s = 'var ' + createVarName(MANDATORY) + ' = ' + s + '(' + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + ');';
+    if (noDecl) s = 'var ' + createVarName(MANDATORY) + ' = ' + s;
     // avoid "function statements" (decl inside statements)
-    else if (inGlobal || rng(10) > 0) s += 'var ' + createVarName(MANDATORY) + ' = ' + name + '(' + createArgs() + ');';
+    else if (inGlobal || rng(10) > 0) s += 'var ' + createVarName(MANDATORY) + ' = ' + name;
+    s += '(' + createArgs(recurmax, stmtDepth, canThrow) + ');';
 
     return s;
 }
@@ -626,6 +628,9 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
       case p++:
       case p++:
         return createValue();
+      case p++:
+      case p++:
+        return getVarName();
       case p++:
         return createExpression(recurmax, COMMA_OK, stmtDepth, canThrow);
       case p++: