v3.8.0

- print out Node.js and OS information

README.md

@@ -87,6 +87,7 @@ a double dash to prevent input files being used as option arguments:
                                 `wrap_iife`  Wrap IIFEs in parenthesis. Note: you may
                                              want to disable `negate_iife` under
                                              compressor options.
+    -O, --output-opts [options] Specify output options (`beautify` disabled by default).
     -o, --output <file>         Output file path (default STDOUT). Specify `ast` or
                                 `spidermonkey` to write UglifyJS or SpiderMonkey AST
                                 as JSON to STDOUT respectively.
@@ -735,6 +736,8 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
   annotation `/*@__PURE__*/` or `/*#__PURE__*/` immediately precedes the call. For
   example: `/*@__PURE__*/foo();`
 
+- `strings` (default: `true`) -- compact string concatenations.
+
 - `switches` (default: `true`) -- de-duplicate and remove unreachable `switch` branches
 
 - `toplevel` (default: `false`) -- drop unreferenced functions (`"funcs"`) and/or
@@ -845,8 +848,14 @@ can pass additional arguments that control the code output:
   statement.
 
 - `comments` (default `false`) -- pass `true` or `"all"` to preserve all
-  comments, `"some"` to preserve some comments, a regular expression string
-  (e.g. `/^!/`) or a function.
+  comments, `"some"` to preserve multi-line comments that contain `@cc_on`,
+  `@license`, or `@preserve` (case-insensitive), a regular expression string
+  (e.g. `/^!/`), or a function which returns `boolean`, e.g.
+  ```js
+  function(node, comment) {
+      return comment.value.indexOf("@type " + node.TYPE) >= 0;
+  }
+  ```
 
 - `indent_level` (default `4`)
 

bin/uglifyjs

@@ -36,6 +36,7 @@ program.option("-c, --compress [options]", "Enable compressor/specify compressor
 program.option("-m, --mangle [options]", "Mangle names/specify mangler options.", parse_js());
 program.option("--mangle-props [options]", "Mangle properties/specify mangler options.", parse_js());
 program.option("-b, --beautify [options]", "Beautify output/specify output options.", parse_js());
+program.option("-O, --output-opts [options]", "Output options (beautify disabled).", parse_js());
 program.option("-o, --output <file>", "Output file (default STDOUT).");
 program.option("--comments [filter]", "Preserve copyright comments in the output.");
 program.option("--config-file <file>", "Read minify() options from JSON file.");
@@ -53,6 +54,7 @@ program.option("--toplevel", "Compress and/or mangle variables in toplevel scope
 program.option("--verbose", "Print diagnostic messages.");
 program.option("--warn", "Print warning messages.");
 program.option("--wrap <name>", "Embed everything as a function with “exports” corresponding to “name” globally.");
+program.option("--reduce-test", "Reduce a standalone `console.log` based test case.");
 program.arguments("[files...]").parseArgv(process.argv);
 if (program.configFile) {
     options = JSON.parse(read_file(program.configFile));
@@ -93,6 +95,10 @@ if (program.beautify) {
         options.output.beautify = true;
     }
 }
+if (program.outputOpts) {
+    if (program.beautify) fatal("--beautify cannot be used with --output-opts");
+    options.output = typeof program.outputOpts == "object" ? program.outputOpts : {};
+}
 if (program.comments) {
     if (typeof options.output != "object") options.output = {};
     options.output.comments = typeof program.comments == "string" ? program.comments : "some";
@@ -210,7 +216,15 @@ function run() {
     } catch (ex) {
         fatal(ex);
     }
-    var result = UglifyJS.minify(files, options);
+    if (program.reduceTest) {
+        // load on demand - assumes dev tree checked out
+        var reduce_test = require("../test/reduce");
+        var testcase = files[0] || files[Object.keys(files)[0]];
+        var result = reduce_test(testcase, options, {verbose: true});
+    }
+    else {
+        var result = UglifyJS.minify(files, options);
+    }
     if (result.error) {
         var ex = result.error;
         if (ex.name == "SyntaxError") {

lib/ast.js

@@ -169,10 +169,7 @@ var AST_SimpleStatement = DEFNODE("SimpleStatement", "body", {
 }, AST_Statement);
 
 function walk_body(node, visitor) {
-    var body = node.body;
-    if (body instanceof AST_Statement) {
-        body._walk(visitor);
-    } else body.forEach(function(node) {
+    node.body.forEach(function(node) {
         node._walk(visitor);
     });
 }
@@ -351,7 +348,7 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
             filename: "wrap=" + JSON.stringify(name)
         }).transform(new TreeTransformer(function(node) {
             if (node instanceof AST_Directive && node.value == "$ORIG") {
-                return MAP.splice(body);
+                return List.splice(body);
             }
         }));
     },
@@ -370,7 +367,7 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
             filename: "enclose=" + JSON.stringify(args_values)
         }).transform(new TreeTransformer(function(node) {
             if (node instanceof AST_Directive && node.value == "$ORIG") {
-                return MAP.splice(body);
+                return List.splice(body);
             }
         }));
     }

lib/output.js

@@ -783,6 +783,8 @@ function OutputStream(options) {
         var p = output.parent();
         if (p instanceof AST_PropAccess && p.expression === this) {
             var value = this.value;
+            // https://github.com/mishoo/UglifyJS2/issues/115
+            // https://github.com/mishoo/UglifyJS2/pull/1009
             if (value < 0 || /^0/.test(make_num(value))) {
                 return true;
             }
@@ -1352,11 +1354,18 @@ function OutputStream(options) {
     DEFPRINT(AST_RegExp, function(self, output) {
         var regexp = self.value;
         var str = regexp.toString();
+        var end = str.lastIndexOf("/");
         if (regexp.raw_source) {
-            str = "/" + regexp.raw_source + str.slice(str.lastIndexOf("/"));
+            str = "/" + regexp.raw_source + str.slice(end);
+        } else if (end == 1) {
+            str = "/(?:)" + str.slice(end);
+        } else if (str.indexOf("/", 1) < end) {
+            str = "/" + str.slice(1, end).replace(/\\\\|[^/]?\//g, function(match) {
+                return match[0] == "\\" ? match : match.slice(0, -1) + "\\/";
+            }) + str.slice(end);
         }
-        output.print(output.to_utf8(str).replace(/\\(?:\0(?![0-9])|[^\0])/g, function(seq) {
-            switch (seq[1]) {
+        output.print(output.to_utf8(str).replace(/\\(?:\0(?![0-9])|[^\0])/g, function(match) {
+            switch (match[1]) {
               case "\n": return "\\n";
               case "\r": return "\\r";
               case "\t": return "\t";
@@ -1366,7 +1375,7 @@ function OutputStream(options) {
               case "\x0B": return "\v";
               case "\u2028": return "\\u2028";
               case "\u2029": return "\\u2029";
-              default: return seq;
+              default: return match;
             }
         }).replace(/[\n\r\u2028\u2029]/g, function(c) {
             switch (c) {

lib/transform.js

@@ -52,7 +52,7 @@ TreeTransformer.prototype = new TreeWalker;
 
 (function(DEF) {
     function do_list(list, tw) {
-        return MAP(list, function(node) {
+        return List(list, function(node) {
             return node.transform(tw, true);
         });
     }

lib/utils.js

@@ -113,8 +113,8 @@ function return_true() { return true; }
 function return_this() { return this; }
 function return_null() { return null; }
 
-var MAP = (function() {
-    function MAP(a, f, backwards) {
+var List = (function() {
+    function List(a, f, backwards) {
         var ret = [], top = [], i;
         function doit() {
             var val = f(a[i], i);
@@ -149,14 +149,14 @@ var MAP = (function() {
         }
         return top.concat(ret);
     }
-    MAP.at_top = function(val) { return new AtTop(val) };
-    MAP.splice = function(val) { return new Splice(val) };
-    MAP.last = function(val) { return new Last(val) };
-    var skip = MAP.skip = {};
-    function AtTop(val) { this.v = val }
-    function Splice(val) { this.v = val }
-    function Last(val) { this.v = val }
-    return MAP;
+    List.at_top = function(val) { return new AtTop(val); };
+    List.splice = function(val) { return new Splice(val); };
+    List.last = function(val) { return new Last(val); };
+    var skip = List.skip = {};
+    function AtTop(val) { this.v = val; }
+    function Splice(val) { this.v = val; }
+    function Last(val) { this.v = val; }
+    return List;
 })();
 
 function push_uniq(array, el) {

package.json

@@ -3,7 +3,7 @@
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.7.4",
+  "version": "3.8.0",
   "engines": {
     "node": ">=0.8.0"
   },

test/compress/arrays.js

@@ -16,6 +16,7 @@ holes_and_undefined: {
 constant_join: {
     options = {
         evaluate: true,
+        strings: true,
         unsafe: true,
     }
     input: {
@@ -65,6 +66,7 @@ constant_join: {
 constant_join_2: {
     options = {
         evaluate: true,
+        strings: true,
         unsafe: true,
     }
     input: {
@@ -94,9 +96,11 @@ constant_join_2: {
 constant_join_3: {
     options = {
         evaluate: true,
+        strings: true,
         unsafe: true,
     }
     input: {
+        var foo, bar, baz;
         var a = [ null ].join();
         var b = [ , ].join();
         var c = [ , 1, , 3 ].join();
@@ -111,6 +115,7 @@ constant_join_3: {
         var l = [ foo, bar + "baz" ].join("");
     }
     expect: {
+        var foo, bar, baz;
         var a = "";
         var b = "";
         var c = ",1,,3";

test/compress/booleans.js

@@ -131,3 +131,25 @@ issue_3658: {
     }
     expect_stdout: "PASS"
 }
+
+issue_3690: {
+    options = {
+        booleans: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            return function() {
+                return a = [ this ];
+            }() ? "PASS" : "FAIL";
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            return function() {
+                return 1;
+            }() ? "PASS" : "FAIL";
+        }());
+    }
+    expect_stdout: "PASS"
+}

test/compress/collapse_vars.js

@@ -7464,3 +7464,304 @@ issue_3651: {
     }
     expect_stdout: "PASS"
 }
+
+issue_3671: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 0;
+        try {
+            a++;
+            A += 0;
+            a = 1 + a;
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect: {
+        var a = 0;
+        try {
+            a++;
+            A += 0;
+            a = 1 + a;
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect_stdout: "1"
+}
+
+call_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        (function(a) {
+            a = console;
+            (function() {})();
+            a.log("PASS");
+        })();
+    }
+    expect: {
+        (function(a) {
+            (function() {})();
+            (a = console).log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+call_1_symbol: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            function f() {}
+            a = console;
+            f();
+            a.log(typeof f);
+        })();
+    }
+    expect: {
+        (function(a) {
+            function f() {}
+            f();
+            (a = console).log(typeof f);
+        })();
+    }
+    expect_stdout: "function"
+}
+
+call_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        (function(a) {
+            a = console;
+            (function() {
+                return 42;
+                console.log("FAIL");
+            })();
+            a.log("PASS");
+        })();
+    }
+    expect: {
+        (function(a) {
+            (function() {
+                return 42;
+                console.log("FAIL");
+            })();
+            (a = console).log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+call_2_symbol: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            function f() {
+                return 42;
+                console.log("FAIL");
+            }
+            a = console;
+            f();
+            a.log(typeof f);
+        })();
+    }
+    expect: {
+        (function(a) {
+            function f() {
+                return 42;
+                console.log("FAIL");
+            }
+            f();
+            (a = console).log(typeof f);
+        })();
+    }
+    expect_stdout: "function"
+}
+
+call_3: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        (function(a) {
+            a = console;
+            (function() {
+                a = {
+                    log: function() {
+                        console.log("PASS");
+                    }
+                }
+            })();
+            a.log("FAIL");
+        })();
+    }
+    expect: {
+        (function(a) {
+            a = console;
+            (function() {
+                a = {
+                    log: function() {
+                        console.log("PASS");
+                    }
+                }
+            })();
+            a.log("FAIL");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+call_3_symbol: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            function f() {
+                a = {
+                    log: function() {
+                        console.log(typeof f);
+                    }
+                }
+            }
+            a = console;
+            f();
+            a.log("FAIL");
+        })();
+    }
+    expect: {
+        (function(a) {
+            function f() {
+                a = {
+                    log: function() {
+                        console.log(typeof f);
+                    }
+                }
+            }
+            a = console;
+            f();
+            a.log("FAIL");
+        })();
+    }
+    expect_stdout: "function"
+}
+
+issue_3698_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var log = console.log;
+        var a, b = 0, c = 0;
+        (function() {
+            a = b;
+        })(b++, (b++, c++));
+        log(a, b, c);
+    }
+    expect: {
+        var log = console.log;
+        var a, b = 0, c = 0;
+        (function() {
+            a = b;
+        })(b++, (b++, c++));
+        log(a, b, c);
+    }
+    expect_stdout: "2 2 1"
+}
+
+issue_3698_2: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+    }
+    input: {
+        var log = console.log;
+        var a, b = 0, c = 0, d = 1;
+        (function f() {
+            a = b;
+            d-- && f();
+        })(b++, (b++, c++));
+        log(a, b, c, d);
+    }
+    expect: {
+        var log = console.log;
+        var a, b = 0, c = 0, d = 1;
+        (function f() {
+            a = b;
+            d-- && f();
+        })(b++, (b++, c++));
+        log(a, b, c, d);
+    }
+    expect_stdout: "2 2 1 -1"
+}
+
+issue_3698_3: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+    }
+    input: {
+        var a = 0, b = 0;
+        (function f(c) {
+            {
+                b++;
+                var bar_1 = (b = 1 + b, c = 0);
+                a-- && f();
+            }
+        })();
+        console.log(b);
+    }
+    expect: {
+        var a = 0, b = 0;
+        (function f(c) {
+            var bar_1 = (b = 1 + ++b, c = 0);
+            a-- && f();
+        })();
+        console.log(b);
+    }
+    expect_stdout: "2"
+}
+
+issue_3700: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            a = "PASS";
+            (function() {
+                throw 0;
+            })();
+            a = 1 + a;
+        } catch (e) {
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        try {
+            a = "PASS";
+            (function() {
+                throw 0;
+            })();
+            a = 1 + a;
+        } catch (e) {
+        }
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}

test/compress/concat-strings.js

@@ -26,7 +26,9 @@ concat_1: {
 }
 
 concat_2: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             1 + (2 + 3),
@@ -55,7 +57,9 @@ concat_2: {
 }
 
 concat_3: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             1 + 2 + (3 + 4 + 5),
@@ -84,7 +88,9 @@ concat_3: {
 }
 
 concat_4: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             1 + "2" + (3 + 4 + 5),
@@ -113,7 +119,9 @@ concat_4: {
 }
 
 concat_5: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             "1" + 2 + (3 + 4 + 5),
@@ -142,7 +150,9 @@ concat_5: {
 }
 
 concat_6: {
-    options = {}
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             "1" + "2" + (3 + 4 + 5),
@@ -171,6 +181,9 @@ concat_6: {
 }
 
 concat_7: {
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             "" + 1,
@@ -197,6 +210,9 @@ concat_7: {
 }
 
 concat_8: {
+    options = {
+        strings: true,
+    }
     input: {
         console.log(
             1 + "",
@@ -221,3 +237,20 @@ concat_8: {
     }
     expect_stdout: true
 }
+
+issue_3689: {
+    options = {
+        strings: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a + ("" + (a[0] = 0));
+        }([]));
+    }
+    expect: {
+        console.log(function(a) {
+            return a + ("" + (a[0] = 0));
+        }([]));
+    }
+    expect_stdout: "00"
+}

test/compress/conditionals.js

@@ -294,6 +294,45 @@ cond_5: {
     }
 }
 
+cond_6: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        x ? a : b;
+        x ? a : a;
+
+        x ? y ? a : b : c;
+        x ? y ? a : a : b;
+        x ? y ? a : b : b;
+        x ? y ? a : b : a;
+        x ? y ? a : a : a;
+
+        x ? a : y ? b : c;
+        x ? a : y ? a : b;
+        x ? a : y ? b : b;
+        x ? a : y ? b : a;
+        x ? a : y ? a : a;
+    }
+    expect: {
+        x ? a : b;
+        x, a;
+
+        x ? y ? a : b : c;
+        x ? (y, a) : b;
+        x && y ? a : b;
+        !x || y ? a : b;
+        x && y, a;
+
+        x ? a : y ? b : c;
+        x || y ? a : b;
+        x ? a : (y, b);
+        !x && y ? b : a;
+        !x && y, a;
+    }
+}
+
 cond_7: {
     options = {
         conditionals: true,
@@ -726,6 +765,24 @@ cond_11: {
     expect_stdout: "foo bar"
 }
 
+cond_12: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        x ? y && a : a;
+        x ? y || a : a;
+        x ? a : y && a;
+        x ? a : y || a;
+    }
+    expect: {
+        (!x || y) && a;
+        x && y || a;
+        (x || y) && a;
+        !x && y || a;
+    }
+}
+
 ternary_boolean_consequent: {
     options = {
         booleans: true,

test/compress/dead-code.js

@@ -830,6 +830,7 @@ issue_3552: {
 unreachable_assign: {
     options = {
         dead_code: true,
+        strings: true,
     }
     input: {
         console.log(A = "P" + (A = "A" + (B = "S" + (A = B = "S"))), A, B);

test/compress/drop-unused.js

@@ -1191,10 +1191,10 @@ issue_2105_1: {
     input: {
         !function(factory) {
             factory();
-        }( function() {
+        }(function() {
             return function(fn) {
                 fn()().prop();
-            }( function() {
+            }(function() {
                 function bar() {
                     var quux = function() {
                         console.log("PASS");
@@ -1205,7 +1205,7 @@ issue_2105_1: {
                     return { prop: foo };
                 }
                 return bar;
-            } );
+            });
         });
     }
     expect: {
@@ -1235,10 +1235,10 @@ issue_2105_2: {
     input: {
         !function(factory) {
             factory();
-        }( function() {
+        }(function() {
             return function(fn) {
                 fn()().prop();
-            }( function() {
+            }(function() {
                 function bar() {
                     var quux = function() {
                         console.log("PASS");
@@ -1249,7 +1249,7 @@ issue_2105_2: {
                     return { prop: foo };
                 }
                 return bar;
-            } );
+            });
         });
     }
     expect: {
@@ -1258,6 +1258,44 @@ issue_2105_2: {
     expect_stdout: "PASS"
 }
 
+issue_2105_3: {
+    options = {
+        inline: true,
+        passes: 2,
+        reduce_vars: 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 void {
+            prop: function() {
+                console.log;
+                void console.log("PASS");
+            }
+        }.prop();
+    }
+    expect_stdout: "PASS"
+}
+
 issue_2226_1: {
     options = {
         side_effects: true,
@@ -2330,7 +2368,7 @@ function_parameter_ie8: {
         (function() {
             (function f() {
                 console.log("PASS");
-            })(0);
+            })();
         })();
     }
     expect_stdout: "PASS"
@@ -2355,3 +2393,23 @@ issue_3664: {
     }
     expect_stdout: "PASS"
 }
+
+issue_3673: {
+    options = {
+        pure_getters: "strict",
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        (a = [ a ]).p = 42;
+        console.log("PASS");
+    }
+    expect: {
+        var a;
+        (a = [ a ]).p = 42;
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}

test/compress/functions.js

@@ -1276,7 +1276,7 @@ issue_2630_3: {
         (function() {
             (function f1(a) {
                 f2();
-                --x >= 0 && f1({});
+                --x >= 0 && f1();
             })(a++);
             function f2() {
                 a++;
@@ -2244,7 +2244,7 @@ issue_3076: {
         var c = "PASS";
         (function(b) {
             var n = 2;
-            while (--b + (e = void 0, e && (c = "FAIL"), e = 5, 1).toString() && --n > 0);
+            while (--b + (e = void 0, e && (c = "FAIL"), e = 5, 1..toString()) && --n > 0);
             var e;
         })(2),
         console.log(c);
@@ -3700,3 +3700,88 @@ pr_3595_4: {
     }
     expect_stdout: "PASS"
 }
+
+issue_3679_1: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var f = function() {};
+            f.g = function() {
+                console.log("PASS");
+            };
+            f.g();
+        })();
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3679_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            "use strict";
+            var f = function() {};
+            f.g = function() {
+                console.log("PASS");
+            };
+            f.g();
+        })();
+    }
+    expect: {
+        (function() {
+            "use strict";
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_3679_3: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        functions: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var f = function() {};
+            f.p = "PASS";
+            f.g = function() {
+                console.log(f.p);
+            };
+            f.g();
+        })();
+    }
+    expect: {
+        (function() {
+            function f() {};
+            f.p = "PASS";
+            (f.g = function() {
+                console.log(f.p);
+            })();
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/ie8.js

@@ -2361,3 +2361,40 @@ issue_3542: {
     }
     expect_stdout: "1"
 }
+
+issue_3703: {
+    options = {
+        ie8: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        function f() {
+            var b;
+            function g() {
+                a = "FAIL";
+            }
+            var c = g;
+            function h() {
+                f;
+            }
+            a ? b |= c : b.p;
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        (function() {
+            var b;
+            var c = function g() {
+                a = "FAIL";
+            };
+            a ? b |= c : b.p;
+        })();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}

test/compress/issue-1770.js

@@ -46,7 +46,7 @@ mangle_props: {
             obj[1/0],
             obj["Infinity"],
             obj[-1/0],
-            obj[-1/0],
+            obj[-(1/0)],
             obj["-Infinity"],
             obj[null],
             obj["null"]

test/compress/issue-269.js

@@ -1,98 +1,111 @@
 issue_269_1: {
-	options = {
+    options = {
         unsafe: true,
     }
-	input: {
-		f(
-			String(x),
-			Number(x),
-			Boolean(x),
+    input: {
+        var x = {};
+        console.log(
+            String(x),
+            Number(x),
+            Boolean(x),
 
-			String(),
-			Number(),
-			Boolean()
-		);
-	}
-	expect: {
-		f(
-			x + '', +x, !!x,
-			'', 0, false
-		);
-	}
+            String(),
+            Number(),
+            Boolean()
+        );
+    }
+    expect: {
+        var x = {};
+        console.log(
+            x + "", +x, !!x,
+            "", 0, false
+        );
+    }
+    expect_stdout: true
 }
 
 issue_269_dangers: {
-	options = {
+    options = {
         unsafe: true,
     }
-	input: {
-		f(
-			String(x, x),
-			Number(x, x),
-			Boolean(x, x)
-		);
-	}
-	expect: {
-		f(String(x, x), Number(x, x), Boolean(x, x));
-	}
+    input: {
+        var x = {};
+        console.log(
+            String(x, x),
+            Number(x, x),
+            Boolean(x, x)
+        );
+    }
+    expect: {
+        var x = {};
+        console.log(String(x, x), Number(x, x), Boolean(x, x));
+    }
+    expect_stdout: true
 }
 
 issue_269_in_scope: {
-	options = {
+    options = {
         unsafe: true,
     }
-	input: {
-		var String, Number, Boolean;
-		f(
-			String(x),
-			Number(x, x),
-			Boolean(x)
-		);
-	}
-	expect: {
-		var String, Number, Boolean;
-		f(String(x), Number(x, x), Boolean(x));
-	}
+    input: {
+        var String, Number, Boolean;
+        var x = {};
+        console.log(
+            String(x),
+            Number(x, x),
+            Boolean(x)
+        );
+    }
+    expect: {
+        var String, Number, Boolean;
+        var x = {};
+        console.log(String(x), Number(x, x), Boolean(x));
+    }
+    expect_stdout: true
 }
 
 strings_concat: {
-	options = {
+    options = {
+        strings: true,
         unsafe: true,
     }
-	input: {
-		f(
-			String(x + 'str'),
-			String('str' + x)
-		);
-	}
-	expect: {
-		f(
-			x + 'str',
-			'str' + x
-		);
-	}
+    input: {
+        var x = {};
+        console.log(
+            String(x + "str"),
+            String("str" + x)
+        );
+    }
+    expect: {
+        var x = {};
+        console.log(
+            x + "str",
+            "str" + x
+        );
+    }
+    expect_stdout: true
 }
 
 regexp: {
-	options = {
+    options = {
         evaluate: true,
         unsafe: true,
     }
-	input: {
-		RegExp("foo");
-		RegExp("bar", "ig");
-		RegExp(foo);
-		RegExp("bar", ig);
-		RegExp("should", "fail");
-	}
-	expect: {
-		/foo/;
-		/bar/ig;
-		RegExp(foo);
-		RegExp("bar", ig);
-		RegExp("should", "fail");
-	}
-	expect_warnings: [
-		'WARN: Error converting RegExp("should","fail") [test/compress/issue-269.js:5,2]',
-	]
+    input: {
+        RegExp("foo");
+        RegExp("bar", "ig");
+        RegExp(foo);
+        RegExp("bar", ig);
+        RegExp("should", "fail");
+    }
+    expect: {
+        /foo/;
+        /bar/ig;
+        RegExp(foo);
+        RegExp("bar", ig);
+        RegExp("should", "fail");
+    }
+    expect_warnings: [
+        'WARN: Error converting RegExp("should","fail") [test/compress/issue-269.js:5,8]',
+    ]
 }

test/compress/keep_fargs.js

@@ -728,7 +728,7 @@ issue_2630_3: {
         (function() {
             (function f1() {
                 f2();
-                --x >= 0 && f1({});
+                --x >= 0 && f1();
             })(a++);
             function f2() {
                 a++;
@@ -1369,7 +1369,7 @@ recursive_iife_1: {
     }
     expect: {
         console.log(function f(a, b) {
-            return b || f("FAIL", "PASS");
+            return b || f(0, "PASS");
         }());
     }
     expect_stdout: "PASS"
@@ -1388,7 +1388,7 @@ recursive_iife_2: {
     }
     expect: {
         console.log(function f(a, b) {
-            return b || f("FAIL", "PASS");
+            return b || f(0, "PASS");
         }(0, 0));
     }
     expect_stdout: "PASS"
@@ -1416,7 +1416,7 @@ recursive_iife_3: {
         var a = 1, c = "PASS";
         (function() {
             (function f(b, d, e) {
-                a-- && f(null, 42, 0);
+                a-- && f(0, 42, 0);
                 e && (c = "FAIL");
                 d && d.p;
             })();

test/compress/numbers.js

@@ -669,6 +669,9 @@ issue_1710: {
 }
 
 unary_binary_parenthesis: {
+    options = {
+        evaluate: true,
+    }
     input: {
         var v = [ 0, 1, NaN, Infinity, null, undefined, true, false, "", "foo", /foo/ ];
         v.forEach(function(x) {
@@ -1075,11 +1078,11 @@ issue_3653: {
     }
     expect: {
         console.log(0 - (console && 0));
-        console.log(0 - (console && 0) + 0);
+        console.log(0 - (console && 0));
         console.log(0 - (0 - (console && 0)));
         console.log(0 - (console && 0));
         console.log(1 / (0 - (console && 0)));
-        console.log(0 - (console && 0) + 0);
+        console.log(0 - (console && 0));
         console.log(0 - (console && 0));
         console.log(0 - (console && 0));
         console.log(0 - (console && 0));
@@ -1135,3 +1138,116 @@ issue_3655: {
         "0",
     ]
 }
+
+issue_3676_1: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        var a = [];
+        console.log(false - (a - (a[1] = 42)));
+    }
+    expect: {
+        var a = [];
+        console.log(false - (a - (a[1] = 42)));
+    }
+    expect_stdout: "NaN"
+}
+
+issue_3676_2: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        var a;
+        console.log(false - ((a = []) - (a[1] = 42)));
+    }
+    expect: {
+        var a;
+        console.log(false - ((a = []) - (a[1] = 42)));
+    }
+    expect_stdout: "NaN"
+}
+
+issue_3682_1: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        var a = -0;
+        console.log(1 / (a - 1 + 1));
+    }
+    expect: {
+        var a = -0;
+        console.log(1 / (a - 1 + 1));
+    }
+    expect_stdout: "Infinity"
+}
+
+issue_3682_2: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        var a = -0, b = 1;
+        console.log(1 / (a - (b - b)));
+    }
+    expect: {
+        var a = -0, b = 1;
+        console.log(1 / (a - (b - b)));
+    }
+    expect_stdout: "-Infinity"
+}
+
+issue_3682_3: {
+    options = {
+        evaluate: true,
+        unsafe_math: true,
+    }
+    input: {
+        var a = -0, b = 1, c = -1;
+        console.log(1 / (a - (+b + +c)));
+    }
+    expect: {
+        var a = -0, b = 1, c = -1;
+        console.log(1 / (a - (+b + +c)));
+    }
+    expect_stdout: "-Infinity"
+}
+
+issue_3684: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log(1 / (-1 * (0 & console) + 0));
+        console.log(1 / ((0 & console) / -1 + 0));
+    }
+    expect: {
+        console.log(1 / (-1 * (0 & console) + 0));
+        console.log(1 / ((0 & console) / -1 + 0));
+    }
+    expect_stdout: [
+        "Infinity",
+        "Infinity",
+    ]
+}
+
+issue_3695: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        var a = [];
+        console.log(+(a * (a[0] = false)));
+    }
+    expect: {
+        var a = [];
+        console.log(+(a * (a[0] = false)));
+    }
+    expect_stdout: "NaN"
+}

test/compress/properties.js

@@ -817,6 +817,29 @@ issue_2208_5: {
     expect_stdout: "42"
 }
 
+issue_2208_6: {
+    options = {
+        inline: true,
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        a = 42;
+        console.log(("FAIL", {
+            p: function() {
+                return this.a;
+            }
+        }.p)());
+    }
+    expect: {
+        a = 42;
+        console.log(function() {
+            return this.a;
+        }());
+    }
+    expect_stdout: "42"
+}
+
 issue_2256: {
     options = {
         side_effects: true,

test/compress/reduce_vars.js

@@ -2071,13 +2071,8 @@ issue_1670_6: {
     }
     expect: {
         (function(a) {
-            switch (1) {
-              case a = 1:
-                console.log(a);
-                break;
-              default:
-                console.log(2);
-            }
+            a = 1;
+            console.log(a);
         })(1);
     }
     expect_stdout: "1"

test/compress/regexp.js

@@ -186,3 +186,72 @@ issue_3434_3: {
         /\nfo\n[\n]o\bbb/;
     }
 }
+
+issue_3434_4: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        [
+            [ "", RegExp("") ],
+            [ "/", RegExp("/") ],
+            [ "//", RegExp("//") ],
+            [ "\/", RegExp("\\/") ],
+            [ "///", RegExp("///") ],
+            [ "/\/", RegExp("/\\/") ],
+            [ "\//", RegExp("\\//") ],
+            [ "\\/", RegExp("\\\\/") ],
+            [ "////", RegExp("////") ],
+            [ "//\/", RegExp("//\\/") ],
+            [ "/\//", RegExp("/\\//") ],
+            [ "/\\/", RegExp("/\\\\/") ],
+            [ "\///", RegExp("\\///") ],
+            [ "\/\/", RegExp("\\/\\/") ],
+            [ "\\//", RegExp("\\\\//") ],
+            [ "\\\/", RegExp("\\\\\\/") ],
+        ].forEach(function(test) {
+            console.log(test[1].test("\\"), test[1].test(test[0]));
+        });
+    }
+    expect: {
+        [
+            [ "", /(?:)/ ],
+            [ "/", /\// ],
+            [ "//", /\/\// ],
+            [ "/", /\// ],
+            [ "///", /\/\/\// ],
+            [ "//", /\/\// ],
+            [ "//", /\/\// ],
+            [ "\\/", /\\\// ],
+            [ "////", /\/\/\/\// ],
+            [ "///", /\/\/\// ],
+            [ "///", /\/\/\// ],
+            [ "/\\/", /\/\\\// ],
+            [ "///", /\/\/\// ],
+            [ "//", /\/\// ],
+            [ "\\//", /\\\/\// ],
+            [ "\\/", /\\\// ],
+        ].forEach(function(test) {
+            console.log(test[1].test("\\"), test[1].test(test[0]));
+        });
+    }
+    expect_stdout: [
+        "true true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+        "false true",
+    ]
+}

test/compress/sequences.js

@@ -910,15 +910,23 @@ call: {
             console.log(this === b ? "bar" : "baz");
         };
         (a, b)();
+        (a, b).c();
         (a, b.c)();
+        (a, b)["c"]();
+        (a, b["c"])();
         (a, function() {
             console.log(this === a);
         })();
         new (a, b)();
+        new (a, b).c();
         new (a, b.c)();
+        new (a, b)["c"]();
+        new (a, b["c"])();
         new (a, function() {
             console.log(this === a);
         })();
+        console.log(typeof (a, b).c);
+        console.log(typeof (a, b)["c"]);
     }
     expect: {
         var a = function() {
@@ -931,23 +939,39 @@ call: {
             console.log(this === b ? "bar" : "baz");
         },
         b(),
+        b.c(),
         (a, b.c)(),
+        b["c"](),
+        (a, b["c"])(),
         function() {
             console.log(this === a);
         }(),
         new b(),
         new b.c(),
+        new b.c(),
+        new b["c"](),
+        new b["c"](),
         new function() {
             console.log(this === a);
-        }();
+        }(),
+        console.log((a, typeof b.c)),
+        console.log((a, typeof b["c"]));
     }
     expect_stdout: [
         "foo",
+        "bar",
+        "baz",
+        "bar",
         "baz",
         "true",
         "foo",
         "baz",
+        "baz",
+        "baz",
+        "baz",
         "false",
+        "function",
+        "function",
     ]
 }
 
@@ -1069,3 +1093,22 @@ issue_3490_2: {
     }
     expect_stdout: "PASS 42"
 }
+
+issue_3703: {
+    options = {
+        evaluate: true,
+        sequences: true,
+        unsafe: true,
+    }
+    input: {
+        var a = "FAIL";
+        while ((a = "PASS", 0).foo = 0);
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        while (a = "PASS", (0).foo = 0);
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}

test/exports.js

@@ -1,6 +1,7 @@
 exports["Compressor"] = Compressor;
 exports["defaults"] = defaults;
 exports["JS_Parse_Error"] = JS_Parse_Error;
+exports["List"] = List;
 exports["mangle_properties"] = mangle_properties;
 exports["minify"] = minify;
 exports["OutputStream"] = OutputStream;

test/input/issue-1482/beautify.js

@@ -0,0 +1,17 @@
+if (x) foo();
+
+if (x) foo(); else baz();
+
+if (x) foo(); else if (y) bar(); else baz();
+
+if (x) if (y) foo(); else bar(); else baz();
+
+if (x) foo(); else if (y) bar(); else if (z) baz(); else moo();
+
+function f() {
+    if (x) foo();
+    if (x) foo(); else baz();
+    if (x) foo(); else if (y) bar(); else baz();
+    if (x) if (y) foo(); else bar(); else baz();
+    if (x) foo(); else if (y) bar(); else if (z) baz(); else moo();
+}

test/input/issue-1482/default.js

@@ -1,17 +1 @@
-if (x) foo();
-
-if (x) foo(); else baz();
-
-if (x) foo(); else if (y) bar(); else baz();
-
-if (x) if (y) foo(); else bar(); else baz();
-
-if (x) foo(); else if (y) bar(); else if (z) baz(); else moo();
-
-function f() {
-    if (x) foo();
-    if (x) foo(); else baz();
-    if (x) foo(); else if (y) bar(); else baz();
-    if (x) if (y) foo(); else bar(); else baz();
-    if (x) foo(); else if (y) bar(); else if (z) baz(); else moo();
-}
+if(x)foo();if(x)foo();else baz();if(x)foo();else if(y)bar();else baz();if(x)if(y)foo();else bar();else baz();if(x)foo();else if(y)bar();else if(z)baz();else moo();function f(){if(x)foo();if(x)foo();else baz();if(x)foo();else if(y)bar();else baz();if(x)if(y)foo();else bar();else baz();if(x)foo();else if(y)bar();else if(z)baz();else moo()}

test/input/reduce/label.js

@@ -0,0 +1,9 @@
+var o = this;
+
+for (var k in o) L17060: {
+    a++;
+}
+
+var a;
+
+console.log(k);

test/input/reduce/label.reduced.js

@@ -0,0 +1,16 @@
+var o = this;
+
+for (var k in o) {
+    0;
+}
+
+var a;
+
+console.log(k);
+// output: a
+// 
+// minify: k
+// 
+// options: {
+//   "mangle": false
+// }

test/input/reduce/unsafe_math.js

@@ -0,0 +1,18 @@
+var _calls_ = 10, a = 100, b = 10, c = 0;
+
+function f0(b_1, a, undefined_2) {
+    a++ + ++b;
+    {
+        var expr2 = (b + 1 - .1 - .1 - .1 || a || 3).toString();
+        L20778: for (var key2 in expr2) {
+            (c = c + 1) + [ --b + b_1, typeof f0 == "function" && --_calls_ >= 0 && f0(--b + typeof (undefined_2 = 1 === 1 ? a : b), --b + {
+                c: (c = c + 1) + null
+            }, a++ + (typeof f0 == "function" && --_calls_ >= 0 && f0(typeof (c = 1 + c, 3 / "a" * ("c" >>> 23..toString()) >= (b_1 && (b_1[(c = c + 1) + a--] = (- -0,
+            true + {})))), 3, 25))), 1 === 1 ? a : b ];
+        }
+    }
+}
+
+var a_1 = f0([ , 0 ].length === 2);
+
+console.log(null, a, b, c, Infinity, NaN, undefined);

test/input/reduce/unsafe_math.reduced.js

@@ -0,0 +1,19 @@
+var b = 0;
+
+var expr2 = (0 - 1 - .1 - .1).toString();
+
+for (var key2 in expr2) {
+    --b;
+}
+
+console.log(b);
+// output: -19
+// 
+// minify: -4
+// 
+// options: {
+//   "compress": {
+//     "unsafe_math": true
+//   },
+//   "mangle": false
+// }

test/mocha/cli.js

@@ -176,7 +176,7 @@ describe("bin/uglifyjs", function() {
         var command = uglifyjscmd + ' test/input/issue-1482/input.js -b';
         exec(command, function(err, stdout) {
             if (err) throw err;
-            assert.strictEqual(stdout, read("test/input/issue-1482/default.js"));
+            assert.strictEqual(stdout, read("test/input/issue-1482/beautify.js"));
             done();
         });
     });
@@ -188,6 +188,22 @@ describe("bin/uglifyjs", function() {
             done();
         });
     });
+    it("Should work with `--output-opts`", function(done) {
+        var command = uglifyjscmd + ' test/input/issue-1482/input.js -O';
+        exec(command, function(err, stdout) {
+            if (err) throw err;
+            assert.strictEqual(stdout, read("test/input/issue-1482/default.js"));
+            done();
+        });
+    });
+    it("Should fail when both --beautify & --output-opts are specified", function(done) {
+        var command = uglifyjscmd + " test/input/issue-520/input.js -bO";
+        exec(command, function(err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stderr, "ERROR: --beautify cannot be used with --output-opts\n");
+            done();
+        });
+    });
     it("Should process inline source map", function(done) {
         var command = [
             uglifyjscmd,

test/mocha/reduce.js

@@ -0,0 +1,167 @@
+var assert = require("assert");
+var exec = require("child_process").exec;
+var fs = require("fs");
+var reduce_test = require("../reduce");
+var semver = require("semver");
+
+function read(path) {
+    return fs.readFileSync(path, "utf8");
+}
+
+describe("test/reduce.js", function() {
+    this.timeout(60000);
+    it("Should reduce test case", function() {
+        var result = reduce_test(read("test/input/reduce/unsafe_math.js"), {
+            compress: {
+                unsafe_math: true,
+            },
+            mangle: false,
+        }, {
+            verbose: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, read("test/input/reduce/unsafe_math.reduced.js"));
+    });
+    it("Should eliminate unreferenced labels", function() {
+        var result = reduce_test(read("test/input/reduce/label.js"), {
+            mangle: false,
+        }, {
+            verbose: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, read("test/input/reduce/label.reduced.js"));
+    });
+    it("Should handle test cases with --toplevel", function() {
+        var result = reduce_test([
+            "var Infinity = 42;",
+            "console.log(Infinity);",
+        ].join("\n"), {
+            toplevel: true,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "// Can't reproduce test failure with minify options provided:",
+            "// {",
+            '//   "toplevel": true',
+            "// }",
+        ].join("\n"));
+    });
+    it("Should handle test result of NaN", function() {
+        var result = reduce_test("throw 0 / 0;");
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "// Can't reproduce test failure with minify options provided:",
+            "// {",
+            '//   "compress": {},',
+            '//   "mangle": false',
+            "// }",
+        ].join("\n"));
+    });
+    it("Should print correct output for irreducible test case", function() {
+        var result = reduce_test([
+            "console.log(function f(a) {",
+            "    return f.length;",
+            "}());",
+        ].join("\n"), {
+            compress: {
+                keep_fargs: false,
+            },
+            mangle: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "console.log(function f(a) {",
+            "    return f.length;",
+            "}());",
+            "// output: 1",
+            "// ",
+            "// minify: 0",
+            "// ",
+            "// options: {",
+            '//   "compress": {',
+            '//     "keep_fargs": false',
+            "//   },",
+            '//   "mangle": false',
+            "// }",
+        ].join("\n"));
+    });
+    it("Should fail when invalid option is supplied", function() {
+        var result = reduce_test("", {
+            compress: {
+                unsafe_regex: true,
+            },
+        });
+        var err = result.error;
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.stack.split(/\n/)[0], "DefaultsError: `unsafe_regex` is not a supported option");
+    });
+    it("Should report on test case with invalid syntax", function() {
+        var result = reduce_test("var 0 = 1;");
+        var err = result.error;
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.stack.split(/\n/)[0], "SyntaxError: Name expected");
+    });
+    it("Should format multi-line output correctly", function() {
+        var code = [
+            "var a = 0;",
+            "",
+            "for (var b in [ 1, 2, 3 ]) {",
+            "    a = +a + 1 - .2;",
+            "    console.log(a);",
+            "}",
+        ].join("\n");
+        var result = reduce_test(code, {
+            compress: {
+                unsafe_math: true,
+            },
+            mangle: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            code,
+            "// output: 0.8",
+            "// 1.6",
+            "// 2.4",
+            "// ",
+            "// minify: 0.8",
+            "// 1.6",
+            "// 2.4000000000000004",
+            "// ",
+            "// options: {",
+            '//   "compress": {',
+            '//     "unsafe_math": true',
+            "//   },",
+            '//   "mangle": false',
+            "// }",
+        ].join("\n"));
+    });
+    it("Should reduce infinite loops with reasonable performance", function() {
+        if (semver.satisfies(process.version, "0.10")) return;
+        this.timeout(120000);
+        var code = [
+            "var a = 9007199254740992, b = 1;",
+            "",
+            "while (a++ + (1 - b) < a) {",
+            "    0;",
+            "}",
+        ].join("\n");
+        var result = reduce_test(code, {
+            compress: {
+                unsafe_math: true,
+            },
+            mangle: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code.replace(/ timed out after [0-9]+ms/, " timed out."), [
+            code,
+            "// output: ",
+            "// minify: Error: Script execution timed out.",
+            "// options: {",
+            '//   "compress": {',
+            '//     "unsafe_math": true',
+            "//   },",
+            '//   "mangle": false',
+            "// }",
+        ].join("\n"));
+    });
+});

test/reduce.js

@@ -0,0 +1,564 @@
+var crypto = require("crypto");
+var U = require("./node");
+var List = U.List;
+var os = require("os");
+var sandbox = require("./sandbox");
+
+// Reduce a ufuzz-style `console.log` based test case by iteratively replacing
+// AST nodes with various permutations. Each AST_Statement in the tree is also
+// speculatively dropped to determine whether it is needed.  If the altered
+// tree and the last known good tree produce the same non-nil error-free output
+// after being run, then the permutation survives to the next generation and
+// is the basis for subsequent iterations.  The test case is reduced as a
+// consequence of complex expressions being replaced with simpler ones.
+// This function assumes that the testcase will not result in a parse or
+// runtime Error.  Note that a reduced test case will have different runtime
+// output - it is not functionally equivalent to the original. The only criteria
+// is that once the generated reduced test case is run without minification, it
+// will produce different output from the code minified with `minify_options`.
+// Returns a `minify` result object with an additonal boolean property `reduced`.
+
+module.exports = function reduce_test(testcase, minify_options, reduce_options) {
+    if (testcase instanceof U.AST_Node) testcase = testcase.print_to_string();
+    minify_options = minify_options || { compress: {}, mangle: false };
+    reduce_options = reduce_options || {};
+    var max_iterations = reduce_options.max_iterations || 1000;
+    var max_timeout = reduce_options.max_timeout || 10000;
+    var verbose = reduce_options.verbose;
+    var minify_options_json = JSON.stringify(minify_options, null, 2);
+    var result_cache = Object.create(null);
+    // the initial timeout to assess the viability of the test case must be large
+    var differs = producesDifferentResultWhenMinified(result_cache, testcase, minify_options, max_timeout);
+
+    if (verbose) {
+        console.error("// Node.js " + process.version + " on " + os.platform() + " " + os.arch());
+    }
+    if (!differs) {
+        // same stdout result produced when minified
+        return {
+            code: "// Can't reproduce test failure with minify options provided:"
+                + "\n// " + to_comment(minify_options_json)
+        };
+    } else if (differs.timed_out) {
+        return {
+            code: "// Can't reproduce test failure within " + max_timeout + "ms:"
+                + "\n// " + to_comment(minify_options_json)
+        };
+    } else if (differs.error) {
+        return differs;
+    } else {
+        max_timeout = Math.min(100 * differs.elapsed, max_timeout);
+        // Replace expressions with constants that will be parsed into
+        // AST_Nodes as required.  Each AST_Node has its own permutation count,
+        // so these replacements can't be shared.
+        // Although simpler replacements are generally faster and better,
+        // feel free to experiment with a different replacement set.
+        var REPLACEMENTS = [
+            // "null", "''", "false", "'foo'", "undefined", "9",
+            "1", "0",
+        ];
+
+        // There's a relationship between each node's _permute counter and
+        // REPLACEMENTS.length which is why fractional _permutes were needed.
+        // One could scale all _permute operations by a factor of `steps`
+        // to only deal with integer operations, but this works well enough.
+        var steps = 4;        // must be a power of 2
+        var step = 1 / steps; // 0.25 is exactly representable in floating point
+
+        var tt = new U.TreeTransformer(function(node, descend, in_list) {
+            if (CHANGED) return;
+
+            // quick ignores
+            if (node instanceof U.AST_Accessor) return;
+            if (node instanceof U.AST_Directive) return;
+            if (node instanceof U.AST_Label) return;
+            if (node instanceof U.AST_LabelRef) return;
+            if (!in_list && node instanceof U.AST_SymbolDeclaration) return;
+            if (node instanceof U.AST_Toplevel) return;
+
+            var parent = tt.parent();
+
+            // ensure that the _permute prop is a number.
+            // can not use `node.start._permute |= 0;` as it will erase fractional part.
+            if (typeof node.start._permute === "undefined") node.start._permute = 0;
+
+            // if node reached permutation limit - skip over it.
+            // no structural AST changes before this point.
+            if (node.start._permute >= REPLACEMENTS.length) return;
+
+            if (parent instanceof U.AST_Assign
+                    && parent.left === node
+                || parent instanceof U.AST_Unary
+                    && parent.expression === node
+                    && ["++", "--", "delete"].indexOf(parent.operator) >= 0) {
+                // ignore lvalues
+                return;
+            }
+            if ((parent instanceof U.AST_For || parent instanceof U.AST_ForIn)
+                && parent.init === node && node instanceof U.AST_Var) {
+                // preserve for (var ...)
+                return node;
+            }
+
+            // node specific permutations with no parent logic
+
+            if (node instanceof U.AST_Array) {
+                var expr = node.elements[0];
+                if (expr && !(expr instanceof U.AST_Hole)) {
+                    node.start._permute++;
+                    CHANGED = true;
+                    return expr;
+                }
+            }
+            else if (node instanceof U.AST_Binary) {
+                CHANGED = true;
+                return [
+                    node.left,
+                    node.right,
+                ][ ((node.start._permute += step) * steps | 0) % 2 ];
+            }
+            else if (node instanceof U.AST_Catch || node instanceof U.AST_Finally) {
+                // drop catch or finally block
+                node.start._permute++;
+                CHANGED = true;
+                return null;
+            }
+            else if (node instanceof U.AST_Conditional) {
+                CHANGED = true;
+                return [
+                    node.condition,
+                    node.consequent,
+                    node.alternative,
+                ][ ((node.start._permute += step) * steps | 0) % 3 ];
+            }
+            else if (node instanceof U.AST_BlockStatement) {
+                if (in_list) {
+                    node.start._permute++;
+                    CHANGED = true;
+                    return List.splice(node.body);
+                }
+            }
+            else if (node instanceof U.AST_Call) {
+                var expr = [
+                    node.expression,
+                    node.args[0],
+                    null,  // intentional
+                ][ ((node.start._permute += step) * steps | 0) % 3 ];
+                if (expr) {
+                    CHANGED = true;
+                    return expr;
+                }
+                if (node.expression instanceof U.AST_Function) {
+                    // hoist and return expressions from the IIFE function expression
+                    var body = node.expression.body;
+                    node.expression.body = [];
+                    var seq = [];
+                    body.forEach(function(node) {
+                        var expr = expr instanceof U.AST_Exit ? node.value : node.body;
+                        if (expr instanceof U.AST_Node && !is_statement(expr)) {
+                            // collect expressions from each statements' body
+                            seq.push(expr);
+                        }
+                    });
+                    CHANGED = true;
+                    return to_sequence(seq);
+                }
+            }
+            else if (node instanceof U.AST_Defun) {
+                switch (((node.start._permute += step) * steps | 0) % 2) {
+                  case 0:
+                    CHANGED = true;
+                    return List.skip;
+                  case 1:
+                    if (!has_exit(node)) {
+                        // hoist function declaration body
+                        var body = node.body;
+                        node.body = [];
+                        body.push(node); // retain function with empty body to be dropped later
+                        CHANGED = true;
+                        return List.splice(body);
+                    }
+                }
+            }
+            else if (node instanceof U.AST_DWLoop) {
+                var expr = [
+                    node.condition,
+                    node.body,
+                    null,  // intentional
+                ][ (node.start._permute * steps | 0) % 3 ];
+                node.start._permute += step;
+                if (!expr) {
+                    if (node.body[0] instanceof U.AST_Break) {
+                        if (node instanceof U.AST_Do) {
+                            CHANGED = true;
+                            return List.skip;
+                        }
+                        expr = node.condition; // AST_While - fall through
+                    }
+                }
+                if (expr && (expr !== node.body || !has_loopcontrol(expr, node, parent))) {
+                    CHANGED = true;
+                    return to_statement(expr);
+                }
+            }
+            else if (node instanceof U.AST_PropAccess) {
+                var expr = [
+                    node.expression,
+                    node.property instanceof U.AST_Node && node.property,
+                ][ node.start._permute++ % 2 ];
+                if (expr) {
+                    CHANGED = true;
+                    return expr;
+                }
+            }
+            else if (node instanceof U.AST_For) {
+                var expr = [
+                    node.init,
+                    node.condition,
+                    node.step,
+                    node.body,
+                ][ (node.start._permute * steps | 0) % 4 ];
+                node.start._permute += step;
+                if (expr && (expr !== node.body || !has_loopcontrol(expr, node, parent))) {
+                    CHANGED = true;
+                    return to_statement(expr);
+                }
+            }
+            else if (node instanceof U.AST_ForIn) {
+                var expr = [
+                    node.init,
+                    node.object,
+                    node.body,
+                ][ (node.start._permute * steps | 0) % 3 ];
+                node.start._permute += step;
+                if (expr && (expr !== node.body || !has_loopcontrol(expr, node, parent))) {
+                    CHANGED = true;
+                    return to_statement(expr);
+                }
+            }
+            else if (node instanceof U.AST_If) {
+                var expr = [
+                    node.condition,
+                    node.body,
+                    node.alternative,
+                ][ (node.start._permute * steps | 0) % 3 ];
+                node.start._permute += step;
+                if (expr) {
+                    // replace if statement with its condition, then block or else block
+                    CHANGED = true;
+                    return to_statement(expr);
+                }
+            }
+            else if (node instanceof U.AST_Object) {
+                // first property's value
+                var expr = node.properties[0] instanceof U.AST_ObjectKeyVal && node.properties[0].value;
+                if (expr) {
+                    node.start._permute++;
+                    CHANGED = true;
+                    return expr;
+                }
+            }
+            else if (node instanceof U.AST_SimpleStatement) {
+                if (node.body instanceof U.AST_Call && node.body.expression instanceof U.AST_Function) {
+                    // hoist simple statement IIFE function expression body
+                    node.start._permute++;
+                    if (!has_exit(node.body.expression)) {
+                        var body = node.body.expression.body;
+                        node.body.expression.body = [];
+                        CHANGED = true;
+                        return List.splice(body);
+                    }
+                }
+            }
+            else if (node instanceof U.AST_Switch) {
+                var expr = [
+                    node.expression,                         // switch expression
+                    node.body[0] && node.body[0].expression, // first case expression or undefined
+                    node.body[0] && node.body[0],            // first case body or undefined
+                ][ (node.start._permute * steps | 0) % 4 ];
+                node.start._permute += step;
+                if (expr && (!(expr instanceof U.AST_Statement) || !has_loopcontrol(expr, node, parent))) {
+                    CHANGED = true;
+                    return expr instanceof U.AST_SwitchBranch ? new U.AST_BlockStatement({
+                        body: expr.body.slice(),
+                        start: {},
+                    }) : to_statement(expr);
+                }
+            }
+            else if (node instanceof U.AST_Try) {
+                var body = [
+                    node.body,
+                    node.bcatch && node.bcatch.body,
+                    node.bfinally && node.bfinally.body,
+                    null,  // intentional
+                ][ (node.start._permute * steps | 0) % 4 ];
+                node.start._permute += step;
+                if (body) {
+                    // replace try statement with try block, catch block, or finally block
+                    CHANGED = true;
+                    return new U.AST_BlockStatement({
+                        body: body,
+                        start: {},
+                    });
+                } else {
+                    // replace try with a break or return if first in try statement
+                    if (node.body[0] instanceof U.AST_Break
+                        || node.body[0] instanceof U.AST_Return) {
+                        CHANGED = true;
+                        return node.body[0];
+                    }
+                }
+            }
+            else if (node instanceof U.AST_Unary) {
+                node.start._permute++;
+                CHANGED = true;
+                return node.expression;
+            }
+            else if (node instanceof U.AST_Var) {
+                if (node.definitions.length == 1 && node.definitions[0].value) {
+                    // first declaration value
+                    node.start._permute++;
+                    CHANGED = true;
+                    return to_statement(node.definitions[0].value);
+                }
+            }
+            else if (node instanceof U.AST_LabeledStatement) {
+                if (node.body instanceof U.AST_Statement
+                    && !has_loopcontrol(node.body, node.body, node)) {
+                    // replace labelled statement with its non-labelled body
+                    node.start._permute = REPLACEMENTS.length;
+                    CHANGED = true;
+                    return node.body;
+                }
+            }
+
+            if (in_list) {
+                // special case to drop object properties and switch branches
+                if (parent instanceof U.AST_Object
+                    || parent instanceof U.AST_Switch && parent.expression != node) {
+                    node.start._permute++;
+                    CHANGED = true;
+                    return List.skip;
+                }
+
+                // replace or skip statement
+                if (node instanceof U.AST_Statement) {
+                    node.start._permute++;
+                    CHANGED = true;
+                    return List.skip;
+                }
+
+                // remove this node unless its the sole element of a (transient) sequence
+                if (!(parent instanceof U.AST_Sequence) || parent.expressions.length > 1) {
+                    node.start._permute++;
+                    CHANGED = true;
+                    return List.skip;
+                }
+            }
+
+            // replace this node
+            var newNode = U.parse(REPLACEMENTS[node.start._permute % REPLACEMENTS.length | 0], {
+                expression: true,
+            });
+            if (is_statement(node)) {
+                newNode = new U.AST_SimpleStatement({
+                    body: newNode,
+                    start: {},
+                });
+            }
+            newNode.start._permute = ++node.start._permute;
+            CHANGED = true;
+            return newNode;
+        }, function(node, in_list) {
+            if (node instanceof U.AST_Sequence) {
+                // expand single-element sequence
+                if (node.expressions.length == 1) return node.expressions[0];
+            }
+            else if (node instanceof U.AST_Try) {
+                // expand orphaned try block
+                if (!node.bcatch && !node.bfinally) return new U.AST_BlockStatement({
+                    body: node.body,
+                    start: {},
+                });
+            }
+            else if (node instanceof U.AST_Var) {
+                // remove empty var statement
+                if (node.definitions.length == 0) return in_list ? List.skip : new U.AST_EmptyStatement({
+                    start: {},
+                });
+            }
+        });
+
+        for (var pass = 1; pass <= 3; ++pass) {
+            var testcase_ast = U.parse(testcase);
+            testcase_ast.walk(new U.TreeWalker(function(node) {
+                // unshare start props to retain visit data between iterations
+                node.start = JSON.parse(JSON.stringify(node.start));
+                node.start._permute = 0;
+            }));
+            for (var c = 0; c < max_iterations; ++c) {
+                if (verbose) {
+                    if (pass == 1 && c % 25 == 0) {
+                        console.error("// reduce test pass "
+                            + pass + ", iteration " + c + ": " + testcase.length + " bytes");
+                    }
+                }
+                var CHANGED = false;
+                var code_ast = testcase_ast.clone(true).transform(tt);
+                if (!CHANGED) break;
+                try {
+                    var code = code_ast.print_to_string();
+                } catch (ex) {
+                    // AST is not well formed.
+                    // no harm done - just log the error, ignore latest change and continue iterating.
+                    console.error("*** Error generating code from AST.");
+                    console.error(ex);
+                    console.error("*** Discarding permutation and continuing.");
+                    continue;
+                }
+                var diff = producesDifferentResultWhenMinified(result_cache, code, minify_options, max_timeout);
+                if (diff) {
+                    if (diff.timed_out) {
+                        // can't trust the validity of `code_ast` and `code` when timed out.
+                        // no harm done - just ignore latest change and continue iterating.
+                    } else if (diff.error) {
+                        // something went wrong during minify() - could be malformed AST or genuine bug.
+                        // no harm done - just log code & error, ignore latest change and continue iterating.
+                        console.error("*** Error during minification.");
+                        console.error(code);
+                        console.error(diff.error);
+                        console.error("*** Discarding permutation and continuing.");
+                    } else if (is_error(diff.unminified_result)
+                        && is_error(diff.minified_result)
+                        && diff.unminified_result.name == diff.minified_result.name) {
+                        // ignore difference in error messages caused by minification
+                    } else {
+                        // latest permutation is valid, so use it as the basis of new changes
+                        testcase_ast = code_ast;
+                        testcase = code;
+                        differs = diff;
+                    }
+                }
+            }
+            if (c == 0) break;
+            if (verbose) {
+                console.error("// reduce test pass " + pass + ": " + testcase.length + " bytes");
+            }
+        }
+        testcase = U.minify(testcase, {
+            compress: false,
+            mangle: false,
+            output: {
+                beautify: true,
+                braces: true,
+                comments: true,
+            },
+        });
+        testcase.code += [
+            "",
+            "// output: " + to_comment(differs.unminified_result),
+            "// minify: " + to_comment(differs.minified_result),
+            "// options: " + to_comment(minify_options_json),
+        ].join("\n").replace(/\u001b\[\d+m/g, "");
+        return testcase;
+    }
+};
+
+function to_comment(value) {
+    return ("" + value).replace(/\n/g, "\n// ");
+}
+
+function has_exit(fn) {
+    var found = false;
+    var tw = new U.TreeWalker(function(node) {
+        if (found) return found;
+        if (node instanceof U.AST_Exit) {
+            return found = true;
+        }
+        if (node instanceof U.AST_Scope && node !== fn) {
+            return true; // don't descend into nested functions
+        }
+    });
+    fn.walk(tw);
+    return found;
+}
+
+function has_loopcontrol(body, loop, label) {
+    var found = false;
+    var tw = new U.TreeWalker(function(node) {
+        if (found) return true;
+        if (node instanceof U.AST_LoopControl && this.loopcontrol_target(node) === loop) {
+            return found = true;
+        }
+    });
+    if (label instanceof U.AST_LabeledStatement) tw.push(label);
+    tw.push(loop);
+    body.walk(tw);
+    return found;
+}
+
+function is_error(result) {
+    return typeof result == "object" && typeof result.name == "string" && typeof result.message == "string";
+}
+
+function is_timed_out(result) {
+    return is_error(result) && /timed out/.test(result);
+}
+
+function is_statement(node) {
+    return node instanceof U.AST_Statement && !(node instanceof U.AST_Function);
+}
+
+function merge_sequence(array, node) {
+    if (node instanceof U.AST_Sequence) {
+        array.push.apply(array, node.expressions);
+    } else {
+        array.push(node);
+    }
+    return array;
+}
+
+function to_sequence(expressions) {
+    if (expressions.length == 0) return new U.AST_Number({value: 0, start: {}});
+    if (expressions.length == 1) return expressions[0];
+    return new U.AST_Sequence({
+        expressions: expressions.reduce(merge_sequence, []),
+        start: {},
+    });
+}
+
+function to_statement(node) {
+    return is_statement(node) ? node : new U.AST_SimpleStatement({
+        body: node,
+        start: {},
+    });
+}
+
+function run_code(result_cache, code, toplevel, timeout) {
+    var key = crypto.createHash("sha1").update(code).digest("base64");
+    return result_cache[key] || (result_cache[key] = sandbox.run_code(code, toplevel, timeout));
+}
+
+function producesDifferentResultWhenMinified(result_cache, code, minify_options, max_timeout) {
+    var minified = U.minify(code, minify_options);
+    if (minified.error) return minified;
+
+    var toplevel = minify_options.toplevel;
+    var elapsed = Date.now();
+    var unminified_result = run_code(result_cache, code, toplevel, max_timeout);
+    elapsed = Date.now() - elapsed;
+    var timeout = Math.min(100 * elapsed, max_timeout);
+    var minified_result = run_code(result_cache, minified.code, toplevel, timeout);
+
+    if (sandbox.same_stdout(unminified_result, minified_result)) {
+        return is_timed_out(unminified_result) && is_timed_out(minified_result) && {
+            timed_out: true,
+        };
+    }
+    return {
+        unminified_result: unminified_result,
+        minified_result: minified_result,
+        elapsed: elapsed,
+    };
+}
+Error.stackTraceLimit = Infinity;

test/sandbox.js

@@ -54,14 +54,15 @@ function createContext() {
     }
 }
 
-exports.run_code = function(code, toplevel) {
+exports.run_code = function(code, toplevel, timeout) {
+    timeout = timeout || 5000;
     var stdout = "";
     var original_write = process.stdout.write;
     process.stdout.write = function(chunk) {
         stdout += chunk;
     };
     try {
-        vm.runInContext(toplevel ? "(function(){" + code + "})()" : code, createContext(), { timeout: 5000 });
+        vm.runInContext(toplevel ? "(function(){" + code + "})()" : code, createContext(), { timeout: timeout });
         return stdout;
     } catch (ex) {
         return ex;
@@ -76,8 +77,9 @@ function strip_func_ids(text) {
 
 exports.same_stdout = semver.satisfies(process.version, "0.12") ? function(expected, actual) {
     if (typeof expected != typeof actual) return false;
-    if (typeof expected != "string") {
-        if (expected.name != actual.name) return false;
+    if (typeof expected == "object" && typeof expected.name == "string" && typeof expected.message == "string") {
+        if (expected.name !== actual.name) return false;
+        if (typeof actual.message != "string") return false;
         expected = expected.message.slice(expected.message.lastIndexOf("\n") + 1);
         actual = actual.message.slice(actual.message.lastIndexOf("\n") + 1);
     }

test/ufuzz/index.js

@@ -10,6 +10,7 @@ require("../../tools/exit");
 var UglifyJS = require("../..");
 var randomBytes = require("crypto").randomBytes;
 var sandbox = require("../sandbox");
+var reduce_test = require("../reduce");
 
 var MAX_GENERATED_TOPLEVELS_PER_RUN = 1;
 var MAX_GENERATION_RECURSION_DEPTH = 12;
@@ -1051,6 +1052,7 @@ function log_rename(options) {
 }
 
 function log(options) {
+    var options_copy = JSON.parse(options);
     options = JSON.parse(options);
     if (!ok) errorln("\n\n\n\n\n\n!!!!!!!!!!\n\n\n");
     errorln("//=============================================================");
@@ -1069,6 +1071,18 @@ function log(options) {
         errorln(original_result);
         errorln("uglified result:");
         errorln(uglify_result);
+        errorln("//-------------------------------------------------------------");
+        var reduced = reduce_test(original_code, options_copy, {
+            verbose: false,
+        }).code;
+        if (reduced) {
+            errorln();
+            errorln("// reduced test case (output will differ)");
+            errorln();
+            errorln(reduced);
+            errorln();
+            errorln("//-------------------------------------------------------------");
+        }
     } else {
         errorln("// !!! uglify failed !!!");
         errorln(uglify_code);

tools/exports.js

@@ -1,4 +1,5 @@
 exports["Dictionary"] = Dictionary;
+exports["List"] = List;
 exports["minify"] = minify;
 exports["parse"] = parse;
 exports["push_uniq"] = push_uniq;