support asynchronous test cases properly (#4529)

10 files changed, 347 insertions, 134 deletions

diff --git a/.github/workflows/ufuzz.yml b/.github/workflows/ufuzz.yml
index 48a3ba6c..beefd96a 100644
--- a/.github/workflows/ufuzz.yml
+++ b/.github/workflows/ufuzz.yml
@@ -32,6 +32,8 @@ jobs:
       - uses: actions/checkout@v2
       - name: Install GNU Core Utilities
         if: ${{ startsWith(matrix.os, 'macos') }}
+        env:
+          HOMEBREW_NO_INSTALL_CLEANUP: 1
         shell: bash
         run: |
           brew install coreutils
diff --git a/lib/compress.js b/lib/compress.js
index 21072f0c..4710b69f 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -382,6 +382,7 @@ merge(Compressor.prototype, {
         });
     }
 
+    var RE_POSITIVE_INTEGER = /^(0|[1-9][0-9]*)$/;
     (function(def) {
         def(AST_Node, noop);
 
@@ -603,7 +604,7 @@ merge(Compressor.prototype, {
             if (!is_arguments(def)) return;
             var key = node.property;
             if (key.is_constant()) key = key.value;
-            if (!(key instanceof AST_Node) && !/^[1-9]*[0-9]$/.test(key)) return;
+            if (!(key instanceof AST_Node) && !RE_POSITIVE_INTEGER.test(key)) return;
             def.reassigned = true;
             (key instanceof AST_Node ? def.scope.argnames : [ def.scope.argnames[key] ]).forEach(function(argname) {
                 if (argname instanceof AST_SymbolFunarg) argname.definition().fixed = false;
@@ -8160,7 +8161,7 @@ merge(Compressor.prototype, {
                 try {
                     var code = "n(function(" + self.args.slice(0, -1).map(function(arg) {
                         return arg.value;
-                    }).join(",") + "){" + self.args[self.args.length - 1].value + "})";
+                    }).join() + "){" + self.args[self.args.length - 1].value + "})";
                     var ast = parse(code);
                     var mangle = { ie8: compressor.option("ie8") };
                     ast.figure_out_scope(mangle);
@@ -8183,7 +8184,7 @@ merge(Compressor.prototype, {
                         make_node(AST_String, self, {
                             value: fun.argnames.map(function(arg) {
                                 return arg.print_to_string();
-                            }).join(",")
+                            }).join(),
                         }),
                         make_node(AST_String, self.args[self.args.length - 1], {
                             value: code.get().replace(/^\{|\}$/g, "")
@@ -10846,7 +10847,7 @@ merge(Compressor.prototype, {
                 flush();
                 values.push(prop);
             }
-            if (found && !generated && typeof key == "string" && /^[1-9]*[0-9]$/.test(key)) {
+            if (found && !generated && typeof key == "string" && RE_POSITIVE_INTEGER.test(key)) {
                 generated = true;
                 if (keys.has(key)) prop = keys.get(key)[0];
                 prop.key = make_node(AST_Number, prop, {
diff --git a/test/compress.js b/test/compress.js
index 29ea5a4f..b4dbaba6 100644
--- a/test/compress.js
+++ b/test/compress.js
@@ -209,7 +209,7 @@ function reminify(orig_options, input_code, input_formatted, stdout) {
         } else {
             var toplevel = sandbox.has_toplevel(options);
             var expected = stdout[toplevel ? 1 : 0];
-            var actual = run_code(result.code, toplevel);
+            var actual = sandbox.run_code(result.code, toplevel);
             if (typeof expected != "string" && typeof actual != "string" && expected.name == actual.name) {
                 actual = expected;
             }
@@ -244,11 +244,6 @@ function reminify(orig_options, input_code, input_formatted, stdout) {
     return true;
 }
 
-function run_code(code, toplevel) {
-    var result = sandbox.run_code(code, toplevel);
-    return typeof result == "string" ? result.replace(/\u001b\[\d+m/g, "") : result;
-}
-
 function test_case(test) {
     log("    Running test [{name}]", { name: test.name });
     U.AST_Node.enable_validation();
@@ -380,7 +375,7 @@ function test_case(test) {
         }
     }
     if (test.expect_stdout && (!test.node_version || semver.satisfies(process.version, test.node_version))) {
-        var stdout = [ run_code(input_code), run_code(input_code, true) ];
+        var stdout = [ sandbox.run_code(input_code), sandbox.run_code(input_code, true) ];
         var toplevel = sandbox.has_toplevel({
             compress: test.options,
             mangle: test.mangle
@@ -409,7 +404,7 @@ function test_case(test) {
             });
             return false;
         }
-        actual = run_code(output_code, toplevel);
+        actual = sandbox.run_code(output_code, toplevel);
         if (!sandbox.same_stdout(test.expect_stdout, actual)) {
             log([
                 "!!! failed",
diff --git a/test/compress/awaits.js b/test/compress/awaits.js
index 89d11bb9..4a90ca5e 100644
--- a/test/compress/awaits.js
+++ b/test/compress/awaits.js
@@ -612,22 +612,32 @@ issue_4340: {
 call_expression: {
     input: {
         console.log(typeof async function(log) {
-            (await log)("FAIL");
+            (await log)("foo");
         }(console.log).then);
+        console.log("bar");
     }
-    expect_exact: 'console.log(typeof async function(log){(await log)("FAIL")}(console.log).then);'
-    expect_stdout: "function"
+    expect_exact: 'console.log(typeof async function(log){(await log)("foo")}(console.log).then);console.log("bar");'
+    expect_stdout: [
+        "function",
+        "bar",
+        "foo",
+    ]
     node_version: ">=8"
 }
 
 property_access_expression: {
     input: {
         console.log(typeof async function(con) {
-            (await con).log("FAIL");
+            (await con).log("foo");
         }(console).then);
+        console.log("bar");
     }
-    expect_exact: 'console.log(typeof async function(con){(await con).log("FAIL")}(console).then);'
-    expect_stdout: "function"
+    expect_exact: 'console.log(typeof async function(con){(await con).log("foo")}(console).then);console.log("bar");'
+    expect_stdout: [
+        "function",
+        "bar",
+        "foo",
+    ]
     node_version: ">=8"
 }
 
@@ -685,20 +695,18 @@ reduce_iife_3: {
     input: {
         var a = "foo";
         (async function() {
-            console.log(a);
-            console.log(await a);
+            console.log(a, await a, a, await a);
         })();
         a = "bar";
     }
     expect: {
         var a = "foo";
         (async function() {
-            console.log(a);
-            console.log(await a);
+            console.log(a, await a, a, await a);
         })();
         a = "bar";
     }
-    expect_stdout: "foo"
+    expect_stdout: "foo foo bar bar"
     node_version: ">=8"
 }
 
diff --git a/test/compress/sandbox.js b/test/compress/sandbox.js
index 9356f6f3..338afd11 100644
--- a/test/compress/sandbox.js
+++ b/test/compress/sandbox.js
@@ -13,6 +13,23 @@ console_log: {
     ]
 }
 
+console_log_console: {
+    input: {
+        var log = console.log;
+        log(console);
+        log(typeof console.log);
+    }
+    expect: {
+        var log = console.log;
+        log(console);
+        log(typeof console.log);
+    }
+    expect_stdout: [
+        "{ log: 'function(){}' }",
+        "function",
+    ]
+}
+
 typeof_arguments: {
     options = {
         evaluate: true,
@@ -81,6 +98,38 @@ log_global: {
     expect_stdout: "[object global]"
 }
 
+timers: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var count = 0, interval = 1000, duration = 3210;
+        var timer = setInterval(function() {
+            console.log(++count);
+        }, interval);
+        setTimeout(function() {
+            clearInterval(timer);
+        }, duration);
+    }
+    expect: {
+        var count = 0;
+        var timer = setInterval(function() {
+            console.log(++count);
+        }, 1000);
+        setTimeout(function() {
+            clearInterval(timer);
+        }, 3210);
+    }
+    expect_stdout: [
+        "1",
+        "2",
+        "3",
+    ]
+    node_version: ">=0.12"
+}
+
 issue_4054: {
     input: {
         console.log({
diff --git a/test/mocha/cli.js b/test/mocha/cli.js
index c050b717..475eae65 100644
--- a/test/mocha/cli.js
+++ b/test/mocha/cli.js
@@ -56,7 +56,7 @@ describe("bin/uglifyjs", function() {
             "--source-map", [
                 "names=true",
                 "url=inline",
-            ].join(","),
+            ].join(),
         ].join(" "), function(err, stdout) {
             if (err) throw err;
             var expected = [
@@ -84,7 +84,7 @@ describe("bin/uglifyjs", function() {
             "--source-map", [
                 "names=false",
                 "url=inline",
-            ].join(","),
+            ].join(),
         ].join(" "), function(err, stdout) {
             if (err) throw err;
             var expected = [
@@ -171,7 +171,7 @@ describe("bin/uglifyjs", function() {
                 "content=" + mapFile,
                 "includeSources",
                 "url=inline",
-            ].join(","),
+            ].join(),
         ].join(" ");
 
         var child = exec(command, function(err, stdout) {
diff --git a/test/reduce.js b/test/reduce.js
index 91df8bce..9d5f053c 100644
--- a/test/reduce.js
+++ b/test/reduce.js
@@ -70,8 +70,8 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
     } else if (differs.error) {
         differs.warnings = warnings;
         return differs;
-    } else if (is_error(differs.unminified_result)
-        && is_error(differs.minified_result)
+    } else if (sandbox.is_error(differs.unminified_result)
+        && sandbox.is_error(differs.minified_result)
         && differs.unminified_result.name == differs.minified_result.name) {
         return {
             code: [
@@ -558,8 +558,8 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                         log(code);
                         log(diff.error.stack);
                         log("*** Discarding permutation and continuing.");
-                    } else if (is_error(diff.unminified_result)
-                        && is_error(diff.minified_result)
+                    } else if (sandbox.is_error(diff.unminified_result)
+                        && sandbox.is_error(diff.minified_result)
                         && diff.unminified_result.name == diff.minified_result.name) {
                         // ignore difference in error messages caused by minification
                         diff_error_message = testcase;
@@ -600,10 +600,10 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
         }
         var lines = [ "" ];
         if (isNaN(max_timeout)) {
-            lines.push("// minify error: " + to_comment(strip_color_codes(differs.minified_result.stack)));
+            lines.push("// minify error: " + to_comment(differs.minified_result.stack));
         } else {
-            var unminified_result = strip_color_codes(differs.unminified_result);
-            var minified_result = strip_color_codes(differs.minified_result);
+            var unminified_result = differs.unminified_result;
+            var minified_result = differs.minified_result;
             if (trim_trailing_whitespace(unminified_result) == trim_trailing_whitespace(minified_result)) {
                 lines.push(
                     "// (stringified)",
@@ -624,10 +624,6 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
     }
 };
 
-function strip_color_codes(value) {
-    return ("" + value).replace(/\u001b\[\d+m/g, "");
-}
-
 function to_comment(value) {
     return ("" + value).replace(/\n/g, "\n// ");
 }
@@ -665,12 +661,8 @@ function has_loopcontrol(body, loop, label) {
     return found;
 }
 
-function is_error(result) {
-    return result && typeof result.name == "string" && typeof result.message == "string";
-}
-
 function is_timed_out(result) {
-    return is_error(result) && /timed out/.test(result.message);
+    return sandbox.is_error(result) && /timed out/.test(result.message);
 }
 
 function is_statement(node) {
diff --git a/test/sandbox.js b/test/sandbox.js
index 78a3435e..540b2339 100644
--- a/test/sandbox.js
+++ b/test/sandbox.js
@@ -1,45 +1,174 @@
+var execSync = require("child_process").execSync;
 var semver = require("semver");
 var vm = require("vm");
 
-var setupContext = new vm.Script([
-    "[ Array, Boolean, Error, Function, Number, Object, RegExp, String ].forEach(function(f) {",
-    "    f.toString = Function.prototype.toString;",
-    "});",
-    "Function.prototype.toString = function() {",
-    "    var id = 100000;",
-    "    return function() {",
-    "        var n = this.name;",
-    "        if (!/^F[0-9]{6}N$/.test(n)) {",
-    '            n = "F" + ++id + "N";',
-].concat(Object.getOwnPropertyDescriptor(Function.prototype, "name").configurable ? [
-    '            Object.defineProperty(this, "name", {',
-    "                get: function() {",
-    "                    return n;",
-    "                }",
-    "            });",
-] : [], [
-    "        }",
-    '        return "function(){}";',
-    "    };",
-    "}();",
-    "this;",
-]).join("\n"));
+setup_log();
+var setup_code = "(" + setup + ")(this, " + setup_log + ", " + find_builtins() + ");";
+exports.has_toplevel = function(options) {
+    return options.toplevel
+        || options.mangle && options.mangle.toplevel
+        || options.compress && options.compress.toplevel;
+};
+exports.is_error = is_error;
+exports.run_code = semver.satisfies(process.version, "0.8") ? function(code, toplevel, timeout) {
+    var stdout = run_code_vm(code, toplevel, timeout);
+    if (typeof stdout != "string" || !/arguments/.test(code)) return stdout;
+    do {
+        var prev = stdout;
+        stdout = run_code_vm(code, toplevel, timeout);
+    } while (prev !== stdout);
+    return stdout;
+} : semver.satisfies(process.version, "<0.12") ? run_code_vm : function(code, toplevel, timeout) {
+    if (/\basync([ \t]+[^\s()[\]{},.&|!~=*%/+-]+|[ \t]*\([\s\S]*?\))[ \t]*=>|\b(async[ \t]+function|setInterval|setTimeout)\b/.test(code)) {
+        return run_code_exec(code, toplevel, timeout);
+    } else {
+        return run_code_vm(code, toplevel, timeout);
+    }
+};
+exports.same_stdout = semver.satisfies(process.version, "0.12") ? function(expected, actual) {
+    if (typeof expected != typeof actual) return false;
+    if (is_error(expected)) {
+        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);
+    }
+    return strip_func_ids(expected) == strip_func_ids(actual);
+} : function(expected, actual) {
+    return typeof expected == typeof actual && strip_func_ids(expected) == strip_func_ids(actual);
+};
+
+function is_error(result) {
+    return result && typeof result.name == "string" && typeof result.message == "string";
+}
+
+function strip_color_codes(value) {
+    return value.replace(/\u001b\[\d+m/g, "");
+}
 
-function createContext() {
-    var ctx = vm.createContext(Object.defineProperties({}, {
-        console: { value: { log: log } },
+function strip_func_ids(text) {
+    return ("" + text).replace(/F[0-9]{6}N/g, "<F<>N>");
+}
+
+function setup_log() {
+    var inspect = require("util").inspect;
+    if (inspect.defaultOptions) {
+        var log_options = {
+            breakLength: Infinity,
+            colors: false,
+            compact: true,
+            customInspect: false,
+            depth: Infinity,
+            maxArrayLength: Infinity,
+            maxStringLength: Infinity,
+            showHidden: false,
+        };
+        for (var name in log_options) {
+            if (name in inspect.defaultOptions) inspect.defaultOptions[name] = log_options[name];
+        }
+    }
+    return inspect;
+}
+
+function find_builtins() {
+    setup_code = "console.log(Object.keys(this));";
+    var builtins = run_code_vm("");
+    if (semver.satisfies(process.version, ">=0.12")) builtins += ".concat(" + run_code_exec("") + ")";
+    return builtins;
+}
+
+function setup(global, setup_log, builtins) {
+    [ Array, Boolean, Error, Function, Number, Object, RegExp, String ].forEach(function(f) {
+        f.toString = Function.prototype.toString;
+    });
+    Function.prototype.toString = function() {
+        var configurable = Object.getOwnPropertyDescriptor(Function.prototype, "name").configurable;
+        var id = 100000;
+        return function() {
+            var n = this.name;
+            if (!/^F[0-9]{6}N$/.test(n)) {
+                n = "F" + ++id + "N";
+                if (configurable) Object.defineProperty(this, "name", {
+                    get: function() {
+                        return n;
+                    }
+                });
+            }
+            return "function(){}";
+        };
+    }();
+    var process = global.process;
+    if (process) {
+        var inspect = setup_log();
+        process.on("uncaughtException", function(ex) {
+            var value = ex;
+            if (value instanceof Error) {
+                value = {};
+                for (var name in ex) value[name] = ex[name];
+            }
+            process.stderr.write(inspect(value) + "\n\n-----===== UNCAUGHT EXCEPTION =====-----\n\n");
+            throw ex;
+        }).on("unhandledRejection", function() {});
+    }
+    var log = console.log;
+    var safe_console = {
+        log: function(msg) {
+            if (arguments.length == 1 && typeof msg == "string") return log("%s", msg);
+            return log.apply(null, [].map.call(arguments, function(arg) {
+                return safe_log(arg, {
+                    level: 3,
+                    original: [],
+                    replaced: [],
+                });
+            }));
+        },
+    };
+    var props = {
+        // for Node.js v8
+        console: {
+            get: function() {
+                return safe_console;
+            },
+        },
         global: { get: self },
         self: { get: self },
         window: { get: self },
-    }));
-    var global = setupContext.runInContext(ctx);
-    return ctx;
+    };
+    [
+        // for Node.js v0.12
+        "Buffer",
+        "clearInterval",
+        "clearTimeout",
+        // for Node.js v0.12
+        "DTRACE_NET_STREAM_END",
+        // for Node.js v8
+        "process",
+        "setInterval",
+        "setTimeout",
+    ].forEach(function(name) {
+        var value = global[name];
+        props[name] = {
+            get: function() {
+                return value;
+            },
+        };
+    });
+    builtins.forEach(function(name) {
+        try {
+            delete global[name];
+        } catch (e) {}
+    });
+    Object.defineProperties(global, props);
+    // for Node.js v8+
+    global.toString = function() {
+        return "[object global]";
+    };
 
     function self() {
         return this;
     }
 
-    function safe_log(arg, level) {
+    function safe_log(arg, cache) {
         if (arg) switch (typeof arg) {
           case "function":
             return arg.toString();
@@ -48,23 +177,27 @@ function createContext() {
             if (/Error$/.test(arg.name)) return arg.toString();
             if (typeof arg.then == "function") return "[object Promise]";
             arg.constructor.toString();
-            if (level--) for (var key in arg) {
+            var index = cache.original.indexOf(arg);
+            if (index >= 0) return cache.replaced[index];
+            if (--cache.level < 0) break;
+            var value = {};
+            cache.original.push(arg);
+            cache.replaced.push(value);
+            for (var key in arg) {
                 var desc = Object.getOwnPropertyDescriptor(arg, key);
-                if (!desc || !desc.get && !desc.set) arg[key] = safe_log(arg[key], level);
+                if (desc && (desc.get || desc.set)) {
+                    Object.defineProperty(value, key, desc);
+                } else {
+                    value[key] = safe_log(arg[key], cache);
+                }
             }
+            return value;
         }
         return arg;
     }
-
-    function log(msg) {
-        if (arguments.length == 1 && typeof msg == "string") return console.log("%s", msg);
-        return console.log.apply(console, [].map.call(arguments, function(arg) {
-            return safe_log(arg, 3);
-        }));
-    }
 }
 
-function run_code(code, toplevel, timeout) {
+function run_code_vm(code, toplevel, timeout) {
     timeout = timeout || 5000;
     var stdout = "";
     var original_write = process.stdout.write;
@@ -72,8 +205,11 @@ function run_code(code, toplevel, timeout) {
         stdout += chunk;
     };
     try {
-        vm.runInContext(toplevel ? "(function(){" + code + "})()" : code, createContext(), { timeout: timeout });
-        return stdout;
+        var ctx = vm.createContext({ console: console });
+        // for Node.js v6
+        vm.runInContext(setup_code, ctx);
+        vm.runInContext(toplevel ? "(function(){" + code + "})();" : code, ctx, { timeout: timeout });
+        return strip_color_codes(stdout);
     } catch (ex) {
         return ex;
     } finally {
@@ -81,34 +217,35 @@ function run_code(code, toplevel, timeout) {
     }
 }
 
-exports.run_code = semver.satisfies(process.version, "0.8") ? function(code, toplevel, timeout) {
-    var stdout = run_code(code, toplevel, timeout);
-    if (typeof stdout != "string" || !/arguments/.test(code)) return stdout;
-    do {
-        var prev = stdout;
-        stdout = run_code(code, toplevel, timeout);
-    } while (prev !== stdout);
-    return stdout;
-} : run_code;
-
-function strip_func_ids(text) {
-    return ("" + text).replace(/F[0-9]{6}N/g, "<F<>N>");
-}
-
-exports.same_stdout = semver.satisfies(process.version, "0.12") ? function(expected, actual) {
-    if (typeof expected != typeof actual) 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);
+function run_code_exec(code, toplevel, timeout) {
+    if (toplevel) {
+        code = setup_code + "(function(){" + code + "})();";
+    } else {
+        code = code.replace(/^((["'])[^"']*\2(;|$))?/, function(directive) {
+            return directive + setup_code;
+        });
     }
-    return strip_func_ids(expected) == strip_func_ids(actual);
-} : function(expected, actual) {
-    return typeof expected == typeof actual && strip_func_ids(expected) == strip_func_ids(actual);
-};
-exports.has_toplevel = function(options) {
-    return options.toplevel
-        || options.mangle && options.mangle.toplevel
-        || options.compress && options.compress.toplevel;
-};
+    try {
+        return execSync('"' + process.argv[0] + '" --max-old-space-size=4096', {
+            encoding: "utf8",
+            input: code,
+            stdio: "pipe",
+            timeout: timeout || 5000,
+        });
+    } catch (ex) {
+        var msg = ex.message.replace(/\r\n/g, "\n");
+        if (/ETIMEDOUT/.test(msg)) return new Error("Script execution timed out.");
+        var value = msg.slice(msg.indexOf("\n") + 1, msg.indexOf("\n\n-----===== UNCAUGHT EXCEPTION =====-----\n\n"));
+        try {
+            value = vm.runInNewContext("(" + value.replace(/<([1-9][0-9]*) empty items?>/g, function(match, count) {
+                return new Array(+count).join();
+            }) + ")");
+        } catch (e) {}
+        var match = /\n([^:\s]*Error)(?:: ([\s\S]+?))?\n(    at [\s\S]+)\n$/.exec(msg);
+        if (!match) return value;
+        ex = new global[match[1]](match[2]);
+        ex.stack = ex.stack.slice(0, ex.stack.indexOf("    at ")) + match[3];
+        for (var name in value) ex[name] = value[name];
+        return ex;
+    }
+}
diff --git a/test/ufuzz/index.js b/test/ufuzz/index.js
index cb5da18d..a5275e5f 100644
--- a/test/ufuzz/index.js
+++ b/test/ufuzz/index.js
@@ -317,7 +317,6 @@ var VAR_NAMES = [
     "NaN",
     "Infinity",
     "arguments",
-    "Math",
     "parseInt",
     "async",
     "await",
@@ -1020,9 +1019,9 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
           case 0:
             return [
                 "[ ",
-                new Array(rng(3)).join(","),
+                new Array(rng(3)).join(),
                 getVarName(NO_CONST),
-                new Array(rng(3)).join(","),
+                new Array(rng(3)).join(),
                 " ] = ",
                 createArrayLiteral(recurmax, stmtDepth, canThrow),
             ].join("");
@@ -1743,24 +1742,49 @@ function log(options) {
 }
 
 function sort_globals(code) {
-    var globals = sandbox.run_code("throw Object.keys(this).sort();" + code);
+    var globals = sandbox.run_code("throw Object.keys(this).sort(" + function(global) {
+        return function(m, n) {
+            return (n == "toString") - (m == "toString")
+                || (typeof global[n] == "function") - (typeof global[m] == "function")
+                || (m < n ? -1 : m > n ? 1 : 0);
+        };
+    } + "(this));" + code);
+    if (!Array.isArray(globals)) {
+        errorln();
+        errorln();
+        errorln("//-------------------------------------------------------------");
+        errorln("// !!! sort_globals() failed !!!");
+        errorln("// expected Array, got:");
+        try {
+            errorln("// " + JSON.stringify(globals));
+        } catch (e) {
+            errorln("// " + globals);
+        }
+        errorln("//");
+        errorln(code);
+        errorln();
+        return code;
+    }
     return globals.length ? "var " + globals.map(function(name) {
         return name + "=" + name;
-    }).join(",") + ";" + code : code;
+    }).join() + ";" + code : code;
 }
 
 function fuzzy_match(original, uglified) {
-    uglified = uglified.split(" ");
-    var i = uglified.length;
-    original = original.split(" ", i);
-    while (--i >= 0) {
-        if (original[i] === uglified[i]) continue;
-        var a = +original[i];
-        var b = +uglified[i];
-        if (Math.abs((b - a) / a) < 1e-10) continue;
-        return false;
+    var m = [], n = [];
+    if (collect(original, m) !== collect(uglified, n)) return false;
+    for (var i = 0; i < m.length; i++) {
+        var a = m[i];
+        var b = n[i];
+        if (Math.abs((b - a) / a) > 1e-10) return false;
     }
     return true;
+
+    function collect(input, nums) {
+        return input.replace(/-?([1-9][0-9]*(\.[0-9]+)?|0\.[0-9]+)(e-?[1-9][0-9]*)?/ig, function(num) {
+            return "<|" + nums.push(+num) + "|>";
+        });
+    }
 }
 
 function is_error_in(ex) {
@@ -1768,7 +1792,7 @@ function is_error_in(ex) {
 }
 
 function is_error_spread(ex) {
-    return ex.name == "TypeError" && /Found non-callable @@iterator|is not iterable|undefined is not a function/.test(ex.message);
+    return ex.name == "TypeError" && /Found non-callable @@iterator| is not iterable| is not a function/.test(ex.message);
 }
 
 function is_error_recursion(ex) {
@@ -1782,6 +1806,7 @@ function patch_try_catch(orig, toplevel) {
         offset: 0,
         tries: [],
     } ];
+    var tail_throw = '\nif (typeof UFUZZ_ERROR == "object") throw UFUZZ_ERROR;\n';
     var re = /(?:(?:^|[\s{}):;])try|}\s*catch\s*\(([^)[{]+)\)|}\s*finally)\s*(?={)/g;
     while (stack.length) {
         var code = stack[0].code;
@@ -1798,7 +1823,7 @@ function patch_try_catch(orig, toplevel) {
             var insert;
             if (/}\s*finally\s*$/.test(match[0])) {
                 tries.shift();
-                insert = 'if (typeof UFUZZ_ERROR == "object") throw UFUZZ_ERROR;';
+                insert = tail_throw;
             } else {
                 while (tries.length && tries[0].catch) tries.shift();
                 tries[0].catch = index - offset;
@@ -1812,7 +1837,7 @@ function patch_try_catch(orig, toplevel) {
                     "throw " + match[1] + ";",
                 ].join("\n");
             }
-            var new_code = code.slice(0, index) + insert + code.slice(index);
+            var new_code = code.slice(0, index) + insert + code.slice(index) + tail_throw;
             var result = sandbox.run_code(new_code, toplevel);
             if (typeof result != "object" || typeof result.name != "string" || typeof result.message != "string") {
                 if (!stack.filled && match[1]) stack.push({
@@ -1904,8 +1929,12 @@ for (var round = 1; round <= num_iterations; round++) {
                 ok = sandbox.same_stdout(sandbox.run_code(sort_globals(original_code)), sandbox.run_code(sort_globals(uglify_code)));
             }
             // ignore numerical imprecision caused by `unsafe_math`
-            if (!ok && o.compress && o.compress.unsafe_math && typeof original_result == "string" && typeof uglify_result == "string") {
-                ok = fuzzy_match(original_result, uglify_result);
+            if (!ok && o.compress && o.compress.unsafe_math && typeof original_result == typeof uglify_result) {
+                if (typeof original_result == "string") {
+                    ok = fuzzy_match(original_result, uglify_result);
+                } else if (sandbox.is_error(original_result)) {
+                    ok = original_result.name == uglify_result.name && fuzzy_match(original_result.message, uglify_result.message);
+                }
                 if (!ok) {
                     var fuzzy_result = sandbox.run_code(original_code.replace(/( - 0\.1){3}/g, " - 0.3"), toplevel);
                     ok = sandbox.same_stdout(fuzzy_result, uglify_result);
diff --git a/test/ufuzz/job.js b/test/ufuzz/job.js
index 5cef23e9..6edfba53 100644
--- a/test/ufuzz/job.js
+++ b/test/ufuzz/job.js
@@ -2,7 +2,7 @@ var actions = require("./actions");
 var child_process = require("child_process");
 
 var args = [
-    "--max-old-space-size=2048",
+    "--max-old-space-size=4096",
     "test/ufuzz",
 ];
 var iterations;