compress AST_Arrow properly (#2170)

lib/compress.js

@@ -366,7 +366,7 @@ merge(Compressor.prototype, {
                     safe_ids = save_ids;
                     return true;
                 }
-                if (node instanceof AST_Function || node instanceof AST_Arrow) {
+                if (is_func_expr(node)) {
                     push();
                     var iife;
                     if (!node.name
@@ -564,6 +564,10 @@ merge(Compressor.prototype, {
         return orig.length == 1 && orig[0] instanceof AST_SymbolLambda;
     });
 
+    function is_func_expr(node) {
+        return node instanceof AST_Arrow || node instanceof AST_Function;
+    }
+
     function is_lhs_read_only(lhs) {
         if (lhs instanceof AST_SymbolRef) return lhs.definition().orig[0] instanceof AST_SymbolLambda;
         if (lhs instanceof AST_PropAccess) {
@@ -707,7 +711,7 @@ merge(Compressor.prototype, {
 
     function is_iife_call(node) {
         if (node instanceof AST_Call && !(node instanceof AST_New)) {
-            return node.expression instanceof AST_Function || is_iife_call(node.expression);
+            return is_func_expr(node.expression) || is_iife_call(node.expression);
         }
         return false;
     }
@@ -1320,6 +1324,7 @@ merge(Compressor.prototype, {
             return false;
         });
         def(AST_Function, return_false);
+        def(AST_Arrow, return_false);
         def(AST_UnaryPostfix, return_false);
         def(AST_UnaryPrefix, function() {
             return this.operator == "void";
@@ -1593,9 +1598,6 @@ merge(Compressor.prototype, {
         def(AST_Lambda, function(){
             throw def;
         });
-        def(AST_Arrow, function() {
-            throw def;
-        });
         def(AST_Class, function() {
             throw def;
         });
@@ -1649,8 +1651,7 @@ merge(Compressor.prototype, {
               case "typeof":
                 // Function would be evaluated to an array and so typeof would
                 // incorrectly return 'object'. Hence making is a special case.
-                if (e instanceof AST_Function ||
+                if (is_func_expr(e)) return typeof function(){};
-                    e instanceof AST_Arrow) return typeof function(){};
 
                 e = ev(e, compressor);
 
@@ -1822,6 +1823,9 @@ merge(Compressor.prototype, {
         def(AST_Function, function(){
             return basic_negation(this);
         });
+        def(AST_Arrow, function(){
+            return basic_negation(this);
+        });
         def(AST_UnaryPrefix, function(){
             if (this.operator == "!")
                 return this.expression;
@@ -2568,7 +2572,7 @@ merge(Compressor.prototype, {
         def(AST_This, return_null);
         def(AST_Call, function(compressor, first_in_statement){
             if (!this.has_pure_annotation(compressor) && compressor.pure_funcs(this)) {
-                if (this.expression instanceof AST_Function
+                if (is_func_expr(this.expression)
                     && (!this.expression.name || !this.expression.name.definition().references.length)) {
                     var node = this.clone();
                     node.expression.process_expression(false, compressor);
@@ -3095,10 +3099,10 @@ merge(Compressor.prototype, {
         });
         if (compressor.option("unused")
             && simple_args
-            && (fn instanceof AST_Function
+            && (is_func_expr(fn)
                 || compressor.option("reduce_vars")
                     && fn instanceof AST_SymbolRef
-                    && (fn = fn.fixed_value()) instanceof AST_Function)
+                    && is_func_expr(fn = fn.fixed_value()))
             && !fn.uses_arguments
             && !fn.uses_eval) {
             var pos = 0, last = 0;
@@ -3272,7 +3276,7 @@ merge(Compressor.prototype, {
             if (self.args.length == 0) return make_node(AST_Function, self, {
                 argnames: [],
                 body: []
-            });
+            }).optimize(compressor);
             if (all(self.args, function(x) {
                 return x instanceof AST_String;
             })) {
@@ -3295,12 +3299,18 @@ merge(Compressor.prototype, {
                     var fun;
                     ast.walk(new TreeWalker(function(node) {
                         if (fun) return true;
-                        if (node instanceof AST_Function) {
+                        if (is_func_expr(node)) {
                             fun = node;
                             return true;
                         }
                     }));
-                    if (!fun) return self;
+                    if (fun.body instanceof AST_Node) {
+                        fun.body = [
+                            make_node(AST_Return, fun.body, {
+                                value: fun.body
+                            })
+                        ];
+                    }
                     var args = fun.argnames.map(function(arg, i) {
                         return make_node(AST_String, self.args[i], {
                             value: arg.print_to_string()
@@ -3324,7 +3334,14 @@ merge(Compressor.prototype, {
                 }
             }
         }
-        var stat = fn instanceof AST_Function && fn.body[0];
+        var stat = is_func_expr(fn) && fn.body;
+        if (stat instanceof AST_Node) {
+            stat = make_node(AST_Return, stat, {
+                value: stat
+            });
+        } else if (stat) {
+            stat = stat[0];
+        }
         if (compressor.option("inline") && stat instanceof AST_Return) {
             var value = stat.value;
             if (!value || value.is_constant_expression()) {
@@ -3332,10 +3349,10 @@ merge(Compressor.prototype, {
                 return make_sequence(self, args).transform(compressor);
             }
         }
-        if (exp instanceof AST_Function && !exp.is_generator && !exp.async) {
+        if (is_func_expr(exp) && !exp.is_generator && !exp.async) {
             if (compressor.option("inline")
                 && !exp.name
-                && exp.body.length == 1
+                && (exp.body instanceof AST_Node || exp.body.length == 1)
                 && !exp.uses_arguments
                 && !exp.uses_eval
                 && simple_args
@@ -3385,6 +3402,13 @@ merge(Compressor.prototype, {
                         value: value
                     }));
                     var body = fn.transform(compressor).body;
+                    if (body instanceof AST_Node) {
+                        body = [
+                            make_node(AST_Return, body, {
+                                value: body
+                            })
+                        ];
+                    }
                     if (body.length == 0) return make_node(AST_Undefined, self);
                     if (body.length == 1 && body[0] instanceof AST_Return) {
                         value = body[0].value;
@@ -3411,7 +3435,7 @@ merge(Compressor.prototype, {
                     if (value !== self) return value;
                 }
             }
-            if (compressor.option("side_effects") && all(exp.body, is_empty)) {
+            if (compressor.option("side_effects") && !(exp.body instanceof AST_Node) && all(exp.body, is_empty)) {
                 var args = self.args.concat(make_node(AST_Undefined, self));
                 return make_sequence(self, args).transform(compressor);
             }
@@ -4085,7 +4109,7 @@ merge(Compressor.prototype, {
                 d.fixed = fixed = make_node(AST_Function, fixed, fixed);
             }
             if (compressor.option("unused")
-                && fixed instanceof AST_Function
+                && is_func_expr(fixed)
                 && d.references.length == 1
                 && !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
                 && !d.scope.uses_eval

test/compress/arrow.js

@@ -280,3 +280,261 @@ issue_27: {
         })(jQuery);
     }
 }
+
+issue_2105_1: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        !function(factory) {
+            factory();
+        }( function() {
+            return function(fn) {
+                fn()().prop();
+            }( function() {
+                function bar() {
+                    var quux = function() {
+                        console.log("PASS");
+                    }, foo = function() {
+                        console.log;
+                        quux();
+                    };
+                    return { prop: foo };
+                }
+                return bar;
+            } );
+        });
+    }
+    expect: {
+        !void (() => {
+            var quux = () => {
+                console.log("PASS");
+            };
+            return {
+                prop: () => {
+                    console.log;
+                    quux();
+                }
+            };
+        })().prop();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_2105_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        ((factory) => {
+            factory();
+        })( () => {
+            return ((fn) => {
+                fn()().prop();
+            })( () => {
+                let bar = () => {
+                    var quux = () => {
+                        console.log("PASS");
+                    }, foo = () => {
+                        console.log;
+                        quux();
+                    };
+                    return { prop: foo };
+                };
+                return bar;
+            } );
+        });
+    }
+    expect: {
+        !void (() => {
+            var quux = () => {
+                console.log("PASS");
+            };
+            return {
+                prop: () => {
+                    console.log;
+                    quux();
+                }
+            };
+        })().prop();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_2136_2: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        inline: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            console.log(x);
+        }
+        !function(a, ...b) {
+            f(b[0]);
+        }(1, 2, 3);
+    }
+    expect: {
+        function f(x) {
+            console.log(x);
+        }
+        f([2,3][0]);
+    }
+    expect_stdout: "2"
+    node_version: ">=6"
+}
+
+issue_2136_3: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        passes: 3,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            console.log(x);
+        }
+        !function(a, ...b) {
+            f(b[0]);
+        }(1, 2, 3);
+    }
+    expect: {
+        console.log(2);
+    }
+    expect_stdout: "2"
+    node_version: ">=6"
+}
+
+call_args: {
+    options = {
+        arrows: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+    }
+    input: {
+        const a = 1;
+        console.log(a);
+        +function(a) {
+            return a;
+        }(a);
+    }
+    expect: {
+        const a = 1;
+        console.log(1);
+        +(1, 1);
+    }
+    expect_stdout: true
+}
+
+call_args_drop_param: {
+    options = {
+        arrows: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        const a = 1;
+        console.log(a);
+        +function(a) {
+            return a;
+        }(a, b);
+    }
+    expect: {
+        const a = 1;
+        console.log(1);
+        +(b, 1);
+    }
+    expect_stdout: true
+}
+
+issue_485_crashing_1530: {
+    options = {
+        arrows: true,
+        conditionals: true,
+        dead_code: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+    }
+    input: {
+        (function(a) {
+            if (true) return;
+            var b = 42;
+        })(this);
+    }
+    expect: {
+        this, void 0;
+    }
+}
+
+issue_2084: {
+    options = {
+        arrows: true,
+        collapse_vars: true,
+        conditionals: true,
+        ecma: 6,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function() {
+            !function(c) {
+                c = 1 + c;
+                var c = 0;
+                function f14(a_1) {
+                    if (c = 1 + c, 0 !== 23..toString())
+                        c = 1 + c, a_1 && (a_1[0] = 0);
+                }
+                f14();
+            }(-1);
+        }();
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        !((c) => {
+            c = 1 + c,
+            c = 1 + (c = 0),
+            0 !== 23..toString() && (c = 1 + c);
+        })(-1),
+        console.log(c);
+    }
+    expect_stdout: "0"
+    node_version: ">=4"
+}

test/compress/issue-203.js

@@ -49,8 +49,8 @@ compress_new_function_with_destruct_arrows: {
         new Function("[[aa]], [{bb}]", 'return aa;');
     }
     expect: {
-        Function("aa, [bb]", 'return aa;');
+        Function("N", "[a]", 'return N');
-        Function("aa, {bb}", 'return aa;');
+        Function("b", "{bb:N}", 'return b');
-        Function("[[aa]], [{bb}]", 'return aa;');
+        Function("[[b]]", "[{bb:N}]", 'return b');
     }
 }