v3.17.3

minor clean-ups (#5701 )
fix corner case in varify (#5698 )
2022-10-06 02:14:42 +08:00 · 2022-10-06 02:06:21 +08:00 · 2022-10-04 16:03:24 +08:00 · 2022-10-04 12:58:55 +08:00 · 2022-10-03 22:47:15 +08:00 · 2022-10-03 08:01:56 +08:00
94 changed files with 13474 additions and 2114 deletions
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -50,7 +50,7 @@ jobs:
      OPTIONS: ${{ matrix.options }}
      SCRIPT: ${{ matrix.script }}
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
      - name: Perform uglify, build & test
        shell: bash
        run: |
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,9 +15,10 @@ jobs:
    env:
      NODE: ${{ matrix.node }}
      TYPE: ${{ matrix.script }}
+      UGLIFY_GITHUB_LAG: 10000
    steps:
-      - uses: actions/checkout@v2
-      - uses: actions/cache@v2
+      - uses: actions/checkout@v3
+      - uses: actions/cache@v3
        with:
          path: tmp
          key: tmp ${{ matrix.script }}
--- a/.github/workflows/ufuzz.yml
+++ b/.github/workflows/ufuzz.yml
@@ -17,13 +17,13 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - node: latest
+          - node: '16'
            os: macos-latest
-          - node: '8'
+          - node: '12'
            os: ubuntu-latest
          - node: '8'
            os: ubuntu-latest
-          - node: '8'
+          - node: '12'
            os: windows-latest
          - node: '8'
            os: windows-latest
@@ -32,7 +32,7 @@ jobs:
    env:
      NODE: ${{ matrix.node }}
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
      - name: Perform fuzzing
        shell: bash
        run: |
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -3,7 +3,7 @@ Contributing

 ## Documentation

-Every new feature and API change should be accompanied by a README additon.
+Every new feature and API change should be accompanied by a README addition.

 ## Testing

--- a/README.md
+++ b/README.md
@@ -54,8 +54,6 @@ a double dash to prevent input files being used as option arguments:
                                                modules and Userscripts that may
                                                be anonymous function wrapped (IIFE)
                                                by the .user.js engine `caller`.
-                                `expression`  Parse a single expression, rather than
-                                              a program (for parsing JSON).
                                `spidermonkey`  Assume input files are SpiderMonkey
                                                AST format (as JSON).
    -c, --compress [options]    Enable compressor/specify compressor options:
@@ -111,6 +109,8 @@ a double dash to prevent input files being used as option arguments:
    -d, --define <expr>[=value] Global definitions.
    -e, --enclose [arg[:value]] Embed everything in a big function, with configurable
                                argument(s) & value(s).
+    --expression                Parse a single expression, rather than a program
+                                (for parsing JSON).
    --ie                        Support non-standard Internet Explorer.
                                Equivalent to setting `ie: true` in `minify()`
                                for `compress`, `mangle` and `output` options.
@@ -118,6 +118,7 @@ a double dash to prevent input files being used as option arguments:
    --keep-fargs                Do not mangle/drop function arguments.
    --keep-fnames               Do not mangle/drop function names.  Useful for
                                code relying on Function.prototype.name.
+    --module                    Process input as ES module (implies --toplevel)
    --name-cache <file>         File to hold mangled name mappings.
    --self                      Build UglifyJS as a library (implies --wrap UglifyJS)
    --source-map [options]      Enable source map/specify source map options:
@@ -146,7 +147,7 @@ a double dash to prevent input files being used as option arguments:
    --warn                      Print warning messages.
    --webkit                    Support non-standard Safari/Webkit.
                                Equivalent to setting `webkit: true` in `minify()`
-                                for `mangle` and `output` options.
+                                for `compress`, `mangle` and `output` options.
                                By default UglifyJS will not try to be Safari-proof.
    --wrap <name>               Embed everything in a big function, making the
                                “exports” and “global” variables available. You
@@ -326,7 +327,7 @@ unquoted style (`o.foo`). Example:
 // stuff.js
 var o = {
    "foo": 1,
-    bar: 3
+    bar: 3,
 };
 o.foo += o.bar;
 console.log(o.foo);
@@ -338,6 +339,16 @@ $ uglifyjs stuff.js --mangle-props keep_quoted -c -m
 var o={foo:1,o:3};o.foo+=o.o,console.log(o.foo);
 ```

+If the minified output will be processed again by UglifyJS, consider specifying
+`keep_quoted_props` so the same property names are preserved:
+
+```bash
+$ uglifyjs stuff.js --mangle-props keep_quoted -c -m -O keep_quoted_props
+```
+```javascript
+var o={"foo":1,o:3};o.foo+=o.o,console.log(o.foo);
+```
+
 ### Debugging property name mangling

 You can also pass `--mangle-props debug` in order to mangle property names
@@ -503,6 +514,8 @@ if (result.error) throw result.error;
 - `compress` (default: `{}`) — pass `false` to skip compressing entirely.
  Pass an object to specify custom [compress options](#compress-options).

+- `expression` (default: `false`) — parse as a single expression, e.g. JSON.
+
 - `ie` (default: `false`) — enable workarounds for Internet Explorer bugs.

 - `keep_fargs` (default: `false`) — pass `true` to prevent discarding or mangling
@@ -517,6 +530,10 @@ if (result.error) throw result.error;
  - `mangle.properties` (default: `false`) — a subcategory of the mangle option.
    Pass an object to specify custom [mangle property options](#mangle-properties-options).

+- `module` (default: `false`) — set to `true` if you wish to process input as
+  ES module, i.e. implicit `"use strict";` and support for top-level `await`,
+  alongside with `toplevel` enabled.
+
 - `nameCache` (default: `null`) — pass an empty object `{}` or a previously
  used `nameCache` object if you wish to cache mangled variable and
  property names across multiple invocations of `minify()`. Note: this is
@@ -628,7 +645,11 @@ to be `false` and all symbol names will be omitted.

 - `bare_returns` (default: `false`) — support top level `return` statements

- `html5_comments` (default: `true`)
+- `html5_comments` (default: `true`) — process HTML comment as workaround for
+  browsers which do not recognize `<script>` tags
+
+- `module` (default: `false`) — set to `true` if you wish to process input as
+  ES module, i.e. implicit `"use strict";` and support for top-level `await`.

 - `shebang` (default: `true`) — support `#!command` as the first line

@@ -728,8 +749,11 @@ to be `false` and all symbol names will be omitted.

 - `merge_vars` (default: `true`) — combine and reuse variables.

+- `module` (default: `false`) — set to `true` if you wish to process input as
+  ES module, i.e. implicit `"use strict";` alongside with `toplevel` enabled.
+
 - `negate_iife` (default: `true`) — negate "Immediately-Called Function Expressions"
-  where the return value is discarded, to avoid the parens that the
+  where the return value is discarded, to avoid the parentheses that the
  code generator would insert.

 - `objects` (default: `true`) — compact duplicate keys in object literals.
@@ -804,8 +828,9 @@ to be `false` and all symbol names will be omitted.

 - `unsafe` (default: `false`) — apply "unsafe" transformations (discussion below)

- `unsafe_comps` (default: `false`) — compress expressions like `a <= b` assuming
-  none of the operands can be (coerced to) `NaN`.
+- `unsafe_comps` (default: `false`) — assume operands cannot be (coerced to) `NaN`
+  in numeric comparisons, e.g. `a <= b`. In addition, expressions involving `in`
+  or `instanceof` would never throw.

 - `unsafe_Function` (default: `false`) — compress and mangle `Function(args, code)`
  when both `args` and `code` are string literals.
@@ -826,7 +851,7 @@ to be `false` and all symbol names will be omitted.
 - `unused` (default: `true`) — drop unreferenced functions and variables (simple
  direct variable assignments do not count as references unless set to `"keep_assign"`)

- `varify` (default: `true`) — convert block-scoped declaractions into `var`
+- `varify` (default: `true`) — convert block-scoped declarations into `var`
  whenever safe to do so

 - `yields` (default: `true`) — apply optimizations to `yield` expressions
@@ -866,12 +891,15 @@ UglifyJS.minify(code, { mangle: { toplevel: true } }).code;

 ### Mangle properties options

- `builtins` (default: `false`) — Use `true` to allow the mangling of builtin
-  DOM properties. Not recommended to override this setting.
+- `builtins` (default: `false`) — Use `true` to allow the mangling of built-in
+  properties of JavaScript API. Not recommended to override this setting.

 - `debug` (default: `false`) — Mangle names with the original name still present.
  Pass an empty string `""` to enable, or a non-empty string to set the debug suffix.

+- `domprops` (default: `false`) — Use `true` to allow the mangling of properties
+  commonly found in Document Object Model. Not recommended to override this setting.
+
 - `keep_fargs` (default: `false`) — Use `true` to prevent mangling of function
  arguments.

@@ -915,6 +943,9 @@ can pass additional arguments that control the code output:
  }
  ```

+- `extendscript` (default: `false`) — enable workarounds for Adobe ExtendScript
+  bugs
+
 - `galio` (default: `false`) — enable workarounds for ANT Galio bugs

 - `indent_level` (default: `4`) — indent by specified number of spaces or the
@@ -1331,11 +1362,9 @@ To allow for better optimizations, the compiler makes various assumptions:
 - Later versions of JavaScript will throw `SyntaxError` with the following:
  ```javascript
  var await;
-  async function f() {
  class A {
      static p = await;
  }
-  }
  // SyntaxError: Unexpected reserved word
  ```
  UglifyJS may modify the input which in turn may suppress those errors.
@@ -1346,7 +1375,7 @@ To allow for better optimizations, the compiler makes various assumptions:
  // SyntaxError: The left-hand side of a for-of loop may not be 'async'.
  ```
  UglifyJS may modify the input which in turn may suppress those errors.
- Later versions of Chrome and Node.js will give incorrect results with the
+- Some versions of Chrome and Node.js will give incorrect results with the
  following:
  ```javascript
  console.log({
@@ -1355,9 +1384,15 @@ To allow for better optimizations, the compiler makes various assumptions:
          return "FAIL";
      },
      [42]: "PASS",
+  }[42], {
+      ...console,
+      get 42() {
+          return "FAIL";
+      },
+      42: "PASS",
  }[42]);
-  // Expected: "PASS"
-  // Actual:   "FAIL"
+  // Expected: "PASS PASS"
+  // Actual:   "PASS FAIL"
  ```
  UglifyJS may modify the input which in turn may suppress those errors.
 - Earlier versions of JavaScript will throw `TypeError` with the following:
@@ -1389,3 +1424,55 @@ To allow for better optimizations, the compiler makes various assumptions:
  // Actual:   "FAIL"
  ```
  UglifyJS may modify the input which in turn may suppress those errors.
+- Some versions of Chrome and Node.js will give incorrect results with the
+  following:
+  ```javascript
+  (async function(a) {
+      (function() {
+          var b = await => console.log("PASS");
+          b();
+      })();
+  })().catch(console.error);
+  // Expected: "PASS"
+  // Actual:   SyntaxError: Unexpected reserved word
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of Chrome and Node.js will give incorrect results with the
+  following:
+  ```javascript
+  try {
+      f();
+      function f() {
+          throw 42;
+      }
+  } catch (e) {
+      console.log(typeof f, e);
+  }
+  // Expected: "function 42"
+  // Actual:   "undefined 42"
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Later versions of JavaScript will throw `SyntaxError` with the following:
+  ```javascript
+  "use strict";
+  console.log(function f() {
+      return f = "PASS";
+  }());
+  // Expected: "PASS"
+  // Actual:   TypeError: invalid assignment to const 'f'
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Adobe ExtendScript will give incorrect results with the following:
+  ```javascript
+  alert(true ? "PASS" : false ? "FAIL" : null);
+  // Expected: "PASS"
+  // Actual:   "FAIL"
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
+- Adobe ExtendScript will give incorrect results with the following:
+  ```javascript
+  alert(42 ? null ? "FAIL" : "PASS" : "FAIL");
+  // Expected: "PASS"
+  // Actual:   SyntaxError: Expected: :
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.
--- a/bin/uglifyjs
+++ b/bin/uglifyjs
@@ -104,9 +104,11 @@ function process_option(name, no_value) {
                "  --config-file <file>                     Read minify() options from JSON file.",
                "  -d, --define <expr>[=value]              Global definitions.",
                "  -e, --enclose [arg[,...][:value[,...]]]  Embed everything in a big function, with configurable argument(s) & value(s).",
+                "  --expression                             Parse a single expression, rather than a program.",
                "  --ie                                     Support non-standard Internet Explorer.",
                "  --keep-fargs                             Do not mangle/drop function arguments.",
                "  --keep-fnames                            Do not mangle/drop function names. Useful for code relying on Function.prototype.name.",
+                "  --module                                 Process input as ES module (implies --toplevel)",
                "  --name-cache <file>                      File to hold mangled name mappings.",
                "  --rename                                 Force symbol expansion.",
                "  --no-rename                              Disable symbol expansion.",
@@ -150,8 +152,10 @@ function process_option(name, no_value) {
        options[name] = read_value();
        break;
      case "annotations":
+      case "expression":
      case "ie":
      case "ie8":
+      case "module":
      case "timings":
      case "toplevel":
      case "v8":
@@ -234,17 +238,6 @@ if (specified["beautify"] && specified["output-opts"]) fatal("--beautify cannot
 [ "compress", "mangle" ].forEach(function(name) {
    if (!(name in options)) options[name] = false;
 });
-if (options.mangle && options.mangle.properties) {
-    if (options.mangle.properties.domprops) {
-        delete options.mangle.properties.domprops;
-    } else {
-        if (typeof options.mangle.properties != "object") options.mangle.properties = {};
-        if (!Array.isArray(options.mangle.properties.reserved)) options.mangle.properties.reserved = [];
-        require("../tools/domprops").forEach(function(name) {
-            UglifyJS.push_uniq(options.mangle.properties.reserved, name);
-        });
-    }
-}
 if (/^ast|spidermonkey$/.test(output)) {
    if (typeof options.output != "object") options.output = {};
    options.output.ast = true;
@@ -274,6 +267,8 @@ if (specified["self"]) {
    if (paths.length) UglifyJS.AST_Node.warn("Ignoring input files since --self was passed");
    if (!options.wrap) options.wrap = "UglifyJS";
    paths = UglifyJS.FILES;
+} else if (paths.length) {
+    paths = simple_glob(paths);
 }
 if (specified["in-situ"]) {
    if (output && output != "spidermonkey" || specified["reduce-test"] || specified["self"]) {
@@ -288,7 +283,7 @@ if (specified["in-situ"]) {
        run();
    });
 } else if (paths.length) {
-    simple_glob(paths).forEach(function(name) {
+    paths.forEach(function(name) {
        files[convert_path(name)] = read_file(name);
    });
    run();
@@ -487,16 +482,20 @@ function fatal(message) {

 // A file glob function that only supports "*" and "?" wildcards in the basename.
 // Example: "foo/bar/*baz??.*.js"
-// Argument `glob` may be a string or an array of strings.
+// Argument `paths` must be an array of strings.
 // Returns an array of strings. Garbage in, garbage out.
-function simple_glob(glob) {
-    if (Array.isArray(glob)) {
-        return [].concat.apply([], glob.map(simple_glob));
-    }
-    if (glob.match(/\*|\?/)) {
+function simple_glob(paths) {
+    return paths.reduce(function(paths, glob) {
+        if (/\*|\?/.test(glob)) {
            var dir = path.dirname(glob);
            try {
-            var entries = fs.readdirSync(dir);
+                var entries = fs.readdirSync(dir).filter(function(name) {
+                    try {
+                        return fs.statSync(path.join(dir, name)).isFile();
+                    } catch (ex) {
+                        return false;
+                    }
+                });
            } catch (ex) {}
            if (entries) {
                var pattern = "^" + path.basename(glob)
@@ -505,15 +504,20 @@ function simple_glob(glob) {
                    .replace(/\?/g, "[^/\\\\]") + "$";
                var mod = process.platform === "win32" ? "i" : "";
                var rx = new RegExp(pattern, mod);
-            var results = entries.sort().filter(function(name) {
+                var results = entries.filter(function(name) {
                    return rx.test(name);
-            }).map(function(name) {
+                }).sort().map(function(name) {
                    return path.join(dir, name);
                });
-            if (results.length) return results;
+                if (results.length) {
+                    [].push.apply(paths, results);
+                    return paths;
                }
            }
-    return [ glob ];
+        }
+        paths.push(glob);
+        return paths;
+    }, []);
 }

 function read_file(path, default_value) {
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -109,6 +109,9 @@ var AST_Node = DEFNODE("Node", "start end", {
        start: "[AST_Token] The first token of this node",
        end: "[AST_Token] The last token of this node"
    },
+    equals: function(node) {
+        return this.TYPE == node.TYPE && this._equals(node);
+    },
    walk: function(visitor) {
        visitor.visit(this);
    },
@@ -125,12 +128,7 @@ var AST_Node = DEFNODE("Node", "start end", {
        var marker = {};
        this.walk(new TreeWalker(function(node) {
            if (node.validate_visited === marker) {
-                throw new Error(string_template("cannot reuse {type} from [{file}:{line},{col}]", {
-                    type: "AST_" + node.TYPE,
-                    file: node.start.file,
-                    line: node.start.line,
-                    col: node.start.col,
-                }));
+                throw new Error(string_template("cannot reuse AST_{TYPE} from [{start}]", node));
            }
            node.validate_visited = marker;
        }));
@@ -138,6 +136,7 @@ var AST_Node = DEFNODE("Node", "start end", {
 }, null);

 DEF_BITPROPS(AST_Node, [
+    // AST_Node
    "_optimized",
    "_squeezed",
    // AST_Call
@@ -172,6 +171,8 @@ DEF_BITPROPS(AST_Node, [
    "pure",
    // AST_Assign
    "redundant",
+    // AST_Node
+    "single_use",
    // AST_ClassProperty
    "static",
    // AST_Call
@@ -231,6 +232,24 @@ AST_Node.disable_validation = function() {
    while (restore = restore_transforms.pop()) restore();
 };

+function all_equals(k, l) {
+    return k.length == l.length && all(k, function(m, i) {
+        return m.equals(l[i]);
+    });
+}
+
+function list_equals(s, t) {
+    return s.length == t.length && all(s, function(u, i) {
+        return u == t[i];
+    });
+}
+
+function prop_equals(u, v) {
+    if (u === v) return true;
+    if (u == null) return v == null;
+    return u instanceof AST_Node && v instanceof AST_Node && u.equals(v);
+}
+
 /* -----[ statements ]----- */

 var AST_Statement = DEFNODE("Statement", null, {
@@ -242,6 +261,7 @@ var AST_Statement = DEFNODE("Statement", null, {

 var AST_Debugger = DEFNODE("Debugger", null, {
    $documentation: "Represents a debugger statement",
+    _equals: return_true,
 }, AST_Statement);

 var AST_Directive = DEFNODE("Directive", "quote value", {
@@ -250,6 +270,9 @@ var AST_Directive = DEFNODE("Directive", "quote value", {
        quote: "[string?] the original quote character",
        value: "[string] The value of this directive as a plain string (it's not an AST_String!)",
    },
+    _equals: function(node) {
+        return this.value == node.value;
+    },
    _validate: function() {
        if (this.quote != null) {
            if (typeof this.quote != "string") throw new Error("quote must be string");
@@ -260,7 +283,8 @@ var AST_Directive = DEFNODE("Directive", "quote value", {
 }, AST_Statement);

 var AST_EmptyStatement = DEFNODE("EmptyStatement", null, {
-    $documentation: "The empty statement (empty block or simply a semicolon)"
+    $documentation: "The empty statement (empty block or simply a semicolon)",
+    _equals: return_true,
 }, AST_Statement);

 function is_statement(node) {
@@ -291,6 +315,9 @@ var AST_SimpleStatement = DEFNODE("SimpleStatement", "body", {
    $propdoc: {
        body: "[AST_Node] an expression node (should not be instanceof AST_Statement)",
    },
+    _equals: function(node) {
+        return this.body.equals(node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -305,7 +332,7 @@ var AST_SimpleStatement = DEFNODE("SimpleStatement", "body", {
 var AST_BlockScope = DEFNODE("BlockScope", "_var_names enclosed functions make_def parent_scope variables", {
    $documentation: "Base class for all statements introducing a lexical scope",
    $propdoc: {
-        enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any subscopes",
+        enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any inner scopes",
        functions: "[Dictionary/S] like `variables`, but only lists function declarations",
        parent_scope: "[AST_Scope?/S] link to the parent scope",
        variables: "[Dictionary/S] a map of name ---> SymbolDef for all variables/functions defined in this scope",
@@ -342,6 +369,9 @@ var AST_Block = DEFNODE("Block", "body", {
    $propdoc: {
        body: "[AST_Statement*] an array of statements"
    },
+    _equals: function(node) {
+        return all_equals(this.body, node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -376,6 +406,10 @@ var AST_LabeledStatement = DEFNODE("LabeledStatement", "label", {
    $propdoc: {
        label: "[AST_Label] a label definition"
    },
+    _equals: function(node) {
+        return this.label.equals(node.label)
+            && this.body.equals(node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -417,6 +451,10 @@ var AST_DWLoop = DEFNODE("DWLoop", "condition", {
    $propdoc: {
        condition: "[AST_Node] the loop condition.  Should not be instanceof AST_Statement"
    },
+    _equals: function(node) {
+        return this.body.equals(node.body)
+            && this.condition.equals(node.condition);
+    },
    _validate: function() {
        if (this.TYPE == "DWLoop") throw new Error("should not instantiate AST_DWLoop");
        must_be_expression(this, "condition");
@@ -431,7 +469,7 @@ var AST_Do = DEFNODE("Do", null, {
            node.body.walk(visitor);
            node.condition.walk(visitor);
        });
-    }
+    },
 }, AST_DWLoop);

 var AST_While = DEFNODE("While", null, {
@@ -442,7 +480,7 @@ var AST_While = DEFNODE("While", null, {
            node.condition.walk(visitor);
            node.body.walk(visitor);
        });
-    }
+    },
 }, AST_DWLoop);

 var AST_For = DEFNODE("For", "init condition step", {
@@ -452,6 +490,12 @@ var AST_For = DEFNODE("For", "init condition step", {
        condition: "[AST_Node?] the `for` termination clause, or null if empty",
        step: "[AST_Node?] the `for` update clause, or null if empty"
    },
+    _equals: function(node) {
+        return prop_equals(this.init, node.init)
+            && prop_equals(this.condition, node.condition)
+            && prop_equals(this.step, node.step)
+            && this.body.equals(node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -479,6 +523,11 @@ var AST_ForEnumeration = DEFNODE("ForEnumeration", "init object", {
        init: "[AST_Node] the assignment target during iteration",
        object: "[AST_Node] the object to iterate over"
    },
+    _equals: function(node) {
+        return this.init.equals(node.init)
+            && this.object.equals(node.object)
+            && this.body.equals(node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -519,6 +568,10 @@ var AST_With = DEFNODE("With", "expression", {
    $propdoc: {
        expression: "[AST_Node] the `with` expression"
    },
+    _equals: function(node) {
+        return this.expression.equals(node.expression)
+            && this.body.equals(node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -534,7 +587,7 @@ var AST_With = DEFNODE("With", "expression", {
 /* -----[ scope and functions ]----- */

 var AST_Scope = DEFNODE("Scope", "fn_defs may_call_this uses_eval uses_with", {
-    $documentation: "Base class for all statements introducing a lexical scope",
+    $documentation: "Base class for all statements introducing a lambda scope",
    $propdoc: {
        uses_eval: "[boolean/S] tells whether this scope contains a direct call to the global `eval`",
        uses_with: "[boolean/S] tells whether this scope uses the `with` statement",
@@ -592,6 +645,10 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
    }
 }, AST_Scope);

+var AST_ClassInitBlock = DEFNODE("ClassInitBlock", null, {
+    $documentation: "Value for `class` static initialization blocks",
+}, AST_Scope);
+
 var AST_Lambda = DEFNODE("Lambda", "argnames length_read rest safe_ids uses_arguments", {
    $documentation: "Base class for functions",
    $propdoc: {
@@ -617,6 +674,13 @@ var AST_Lambda = DEFNODE("Lambda", "argnames length_read rest safe_ids uses_argu
        });
        if (this.rest) this.rest.walk(tw);
    },
+    _equals: function(node) {
+        return prop_equals(this.rest, node.rest)
+            && prop_equals(this.name, node.name)
+            && prop_equals(this.value, node.value)
+            && all_equals(this.argnames, node.argnames)
+            && all_equals(this.body, node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -827,6 +891,14 @@ var AST_Class = DEFNODE("Class", "extends name properties", {
        extends: "[AST_Node?] the super class, or null if not specified",
        properties: "[AST_ClassProperty*] array of class properties",
    },
+    _equals: function(node) {
+        return prop_equals(this.name, node.name)
+            && prop_equals(this.extends, node.extends)
+            && all_equals(this.properties, node.properties);
+    },
+    resolve: function(def_class) {
+        return def_class ? this : this.parent_scope.resolve();
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -851,9 +923,6 @@ var AST_DefClass = DEFNODE("DefClass", null, {
    $propdoc: {
        name: "[AST_SymbolDefClass] the name of this class",
    },
-    resolve: function(def_class) {
-        return def_class ? this : this.parent_scope.resolve();
-    },
    _validate: function() {
        if (!(this.name instanceof AST_SymbolDefClass)) throw new Error("name must be AST_SymbolDefClass");
    },
@@ -874,11 +943,17 @@ var AST_ClassExpression = DEFNODE("ClassExpression", null, {
 var AST_ClassProperty = DEFNODE("ClassProperty", "key private static value", {
    $documentation: "Base class for `class` properties",
    $propdoc: {
-        key: "[string|AST_Node] property name (AST_Node for computed property)",
+        key: "[string|AST_Node?] property name (AST_Node for computed property, null for initialization block)",
        private: "[boolean] whether this is a private property",
        static: "[boolean] whether this is a static property",
        value: "[AST_Node?] property value (AST_Accessor for getters/setters, AST_LambdaExpression for methods, null if not specified for fields)",
    },
+    _equals: function(node) {
+        return !this.private == !node.private
+            && !this.static == !node.static
+            && prop_equals(this.key, node.key)
+            && prop_equals(this.value, node.value);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -888,7 +963,9 @@ var AST_ClassProperty = DEFNODE("ClassProperty", "key private static value", {
    },
    _validate: function() {
        if (this.TYPE == "ClassProperty") throw new Error("should not instantiate AST_ClassProperty");
-        if (typeof this.key != "string") {
+        if (this instanceof AST_ClassInit) {
+            if (this.key != null) throw new Error("key must be null");
+        } else if (typeof this.key != "string") {
            if (!(this.key instanceof AST_Node)) throw new Error("key must be string or AST_Node");
            must_be_expression(this, "key");
        }
@@ -928,6 +1005,17 @@ var AST_ClassMethod = DEFNODE("ClassMethod", null, {
    },
 }, AST_ClassProperty);

+var AST_ClassInit = DEFNODE("ClassInit", null, {
+    $documentation: "A `class` static initialization block",
+    _validate: function() {
+        if (!this.static) throw new Error("static must be true");
+        if (!(this.value instanceof AST_ClassInitBlock)) throw new Error("value must be AST_ClassInitBlock");
+    },
+    initialize: function() {
+        this.static = true;
+    },
+}, AST_ClassProperty);
+
 /* -----[ JUMPS ]----- */

 var AST_Jump = DEFNODE("Jump", null, {
@@ -942,6 +1030,9 @@ var AST_Exit = DEFNODE("Exit", "value", {
    $propdoc: {
        value: "[AST_Node?] the value returned or thrown by this statement; could be null for AST_Return"
    },
+    _equals: function(node) {
+        return prop_equals(this.value, node.value);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -972,6 +1063,9 @@ var AST_LoopControl = DEFNODE("LoopControl", "label", {
    $propdoc: {
        label: "[AST_LabelRef?] the label, or null if none",
    },
+    _equals: function(node) {
+        return prop_equals(this.label, node.label);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1002,6 +1096,11 @@ var AST_If = DEFNODE("If", "condition alternative", {
        condition: "[AST_Node] the `if` condition",
        alternative: "[AST_Statement?] the `else` part, or null if not present"
    },
+    _equals: function(node) {
+        return this.body.equals(node.body)
+            && this.condition.equals(node.condition)
+            && prop_equals(this.alternative, node.alternative);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1025,6 +1124,10 @@ var AST_Switch = DEFNODE("Switch", "expression", {
    $propdoc: {
        expression: "[AST_Node] the `switch` “discriminant”"
    },
+    _equals: function(node) {
+        return this.expression.equals(node.expression)
+            && all_equals(this.body, node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1056,6 +1159,10 @@ var AST_Case = DEFNODE("Case", "expression", {
    $propdoc: {
        expression: "[AST_Node] the `case` expression"
    },
+    _equals: function(node) {
+        return this.expression.equals(node.expression)
+            && all_equals(this.body, node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1076,6 +1183,11 @@ var AST_Try = DEFNODE("Try", "bcatch bfinally", {
        bcatch: "[AST_Catch?] the catch block, or null if not present",
        bfinally: "[AST_Finally?] the finally block, or null if not present"
    },
+    _equals: function(node) {
+        return all_equals(this.body, node.body)
+            && prop_equals(this.bcatch, node.bcatch)
+            && prop_equals(this.bfinally, node.bfinally);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1099,6 +1211,10 @@ var AST_Catch = DEFNODE("Catch", "argname", {
    $propdoc: {
        argname: "[(AST_Destructured|AST_SymbolCatch)?] symbol for the exception, or null if not present",
    },
+    _equals: function(node) {
+        return prop_equals(this.argname, node.argname)
+            && all_equals(this.body, node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1124,6 +1240,9 @@ var AST_Definitions = DEFNODE("Definitions", "definitions", {
    $propdoc: {
        definitions: "[AST_VarDef*] array of variable definitions"
    },
+    _equals: function(node) {
+        return all_equals(this.definitions, node.definitions);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1180,6 +1299,10 @@ var AST_VarDef = DEFNODE("VarDef", "name value", {
        name: "[AST_Destructured|AST_SymbolVar] name of the variable",
        value: "[AST_Node?] initializer, or null of there's no initializer",
    },
+    _equals: function(node) {
+        return this.name.equals(node.name)
+            && prop_equals(this.value, node.value);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1199,6 +1322,9 @@ var AST_ExportDeclaration = DEFNODE("ExportDeclaration", "body", {
    $propdoc: {
        body: "[AST_DefClass|AST_Definitions|AST_LambdaDefinition] the statement to export",
    },
+    _equals: function(node) {
+        return this.body.equals(node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1219,6 +1345,9 @@ var AST_ExportDefault = DEFNODE("ExportDefault", "body", {
    $propdoc: {
        body: "[AST_Node] the default export",
    },
+    _equals: function(node) {
+        return this.body.equals(node.body);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1232,29 +1361,29 @@ var AST_ExportDefault = DEFNODE("ExportDefault", "body", {
    },
 }, AST_Statement);

-var AST_ExportForeign = DEFNODE("ExportForeign", "aliases keys path quote", {
+var AST_ExportForeign = DEFNODE("ExportForeign", "aliases keys path", {
    $documentation: "An `export ... from '...'` statement",
    $propdoc: {
-        aliases: "[string*] array of aliases to export",
-        keys: "[string*] array of keys to import",
-        path: "[string] the path to import module",
-        quote: "[string?] the original quote character",
+        aliases: "[AST_String*] array of aliases to export",
+        keys: "[AST_String*] array of keys to import",
+        path: "[AST_String] the path to import module",
+    },
+    _equals: function(node) {
+        return this.path.equals(node.path)
+            && all_equals(this.aliases, node.aliases)
+            && all_equals(this.keys, node.keys);
    },
    _validate: function() {
        if (this.aliases.length != this.keys.length) {
            throw new Error("aliases:key length mismatch: " + this.aliases.length + " != " + this.keys.length);
        }
        this.aliases.forEach(function(name) {
-            if (typeof name != "string") throw new Error("aliases must contain string");
+            if (!(name instanceof AST_String)) throw new Error("aliases must contain AST_String");
        });
        this.keys.forEach(function(name) {
-            if (typeof name != "string") throw new Error("keys must contain string");
+            if (!(name instanceof AST_String)) throw new Error("keys must contain AST_String");
        });
-        if (typeof this.path != "string") throw new Error("path must be string");
-        if (this.quote != null) {
-            if (typeof this.quote != "string") throw new Error("quote must be string");
-            if (!/^["']$/.test(this.quote)) throw new Error("invalid quote: " + this.quote);
-        }
+        if (!(this.path instanceof AST_String)) throw new Error("path must be AST_String");
    },
 }, AST_Statement);

@@ -1263,6 +1392,9 @@ var AST_ExportReferences = DEFNODE("ExportReferences", "properties", {
    $propdoc: {
        properties: "[AST_SymbolExport*] array of aliases to export",
    },
+    _equals: function(node) {
+        return all_equals(this.properties, node.properties);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1278,14 +1410,20 @@ var AST_ExportReferences = DEFNODE("ExportReferences", "properties", {
    },
 }, AST_Statement);

-var AST_Import = DEFNODE("Import", "all default path properties quote", {
+var AST_Import = DEFNODE("Import", "all default path properties", {
    $documentation: "An `import` statement",
    $propdoc: {
        all: "[AST_SymbolImport?] the imported namespace, or null if not specified",
        default: "[AST_SymbolImport?] the alias for default `export`, or null if not specified",
-        path: "[string] the path to import module",
+        path: "[AST_String] the path to import module",
        properties: "[(AST_SymbolImport*)?] array of aliases, or null if not specified",
-        quote: "[string?] the original quote character",
+    },
+    _equals: function(node) {
+        return this.path.equals(node.path)
+            && prop_equals(this.all, node.all)
+            && prop_equals(this.default, node.default)
+            && !this.properties == !node.properties
+            && (!this.properties || all_equals(this.properties, node.properties));
    },
    walk: function(visitor) {
        var node = this;
@@ -1304,16 +1442,12 @@ var AST_Import = DEFNODE("Import", "all default path properties quote", {
        }
        if (this.default != null) {
            if (!(this.default instanceof AST_SymbolImport)) throw new Error("default must be AST_SymbolImport");
-            if (this.default.key !== "") throw new Error("invalid default key: " + this.default.key);
+            if (this.default.key.value !== "") throw new Error("invalid default key: " + this.default.key.value);
        }
-        if (typeof this.path != "string") throw new Error("path must be string");
+        if (!(this.path instanceof AST_String)) throw new Error("path must be AST_String");
        if (this.properties != null) this.properties.forEach(function(node) {
            if (!(node instanceof AST_SymbolImport)) throw new Error("properties must contain AST_SymbolImport");
        });
-        if (this.quote != null) {
-            if (typeof this.quote != "string") throw new Error("quote must be string");
-            if (!/^["']$/.test(this.quote)) throw new Error("invalid quote: " + this.quote);
-        }
    },
 }, AST_Statement);

@@ -1323,6 +1457,10 @@ var AST_DefaultValue = DEFNODE("DefaultValue", "name value", {
        name: "[AST_Destructured|AST_SymbolDeclaration] name of the variable",
        value: "[AST_Node] value to assign if variable is `undefined`",
    },
+    _equals: function(node) {
+        return this.name.equals(node.name)
+            && this.value.equals(node.value);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1350,6 +1488,11 @@ var AST_Call = DEFNODE("Call", "args expression optional pure terminal", {
        pure: "[boolean/S] marker for side-effect-free call expression",
        terminal: "[boolean] whether the chain has ended",
    },
+    _equals: function(node) {
+        return !this.optional == !node.optional
+            && this.expression.equals(node.expression)
+            && all_equals(this.args, node.args);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1376,7 +1519,10 @@ var AST_New = DEFNODE("New", null, {
 var AST_Sequence = DEFNODE("Sequence", "expressions", {
    $documentation: "A sequence expression (comma-separated expressions)",
    $propdoc: {
-        expressions: "[AST_Node*] array of expressions (at least two)"
+        expressions: "[AST_Node*] array of expressions (at least two)",
+    },
+    _equals: function(node) {
+        return all_equals(this.expressions, node.expressions);
    },
    walk: function(visitor) {
        var node = this;
@@ -1405,6 +1551,11 @@ var AST_PropAccess = DEFNODE("PropAccess", "expression optional property termina
        property: "[AST_Node|string] the property to access.  For AST_Dot this is always a plain string, while for AST_Sub it's an arbitrary AST_Node",
        terminal: "[boolean] whether the chain has ended",
    },
+    _equals: function(node) {
+        return !this.optional == !node.optional
+            && prop_equals(this.property, node.property)
+            && this.expression.equals(node.expression);
+    },
    get_property: function() {
        var p = this.property;
        if (p instanceof AST_Constant) return p.value;
@@ -1417,8 +1568,11 @@ var AST_PropAccess = DEFNODE("PropAccess", "expression optional property termina
    },
 });

-var AST_Dot = DEFNODE("Dot", null, {
+var AST_Dot = DEFNODE("Dot", "quoted", {
    $documentation: "A dotted property access expression",
+    $propdoc: {
+        quoted: "[boolean] whether property is transformed from a quoted string",
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1449,6 +1603,9 @@ var AST_Spread = DEFNODE("Spread", "expression", {
    $propdoc: {
        expression: "[AST_Node] expression to be expanded",
    },
+    _equals: function(node) {
+        return this.expression.equals(node.expression);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1464,7 +1621,11 @@ var AST_Unary = DEFNODE("Unary", "operator expression", {
    $documentation: "Base class for unary expressions",
    $propdoc: {
        operator: "[string] the operator",
-        expression: "[AST_Node] expression that this unary operator applies to"
+        expression: "[AST_Node] expression that this unary operator applies to",
+    },
+    _equals: function(node) {
+        return this.operator == node.operator
+            && this.expression.equals(node.expression);
    },
    walk: function(visitor) {
        var node = this;
@@ -1494,6 +1655,11 @@ var AST_Binary = DEFNODE("Binary", "operator left right", {
        operator: "[string] the operator",
        right: "[AST_Node] right-hand side expression"
    },
+    _equals: function(node) {
+        return this.operator == node.operator
+            && this.left.equals(node.left)
+            && this.right.equals(node.right);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1515,6 +1681,11 @@ var AST_Conditional = DEFNODE("Conditional", "condition consequent alternative",
        consequent: "[AST_Node]",
        alternative: "[AST_Node]"
    },
+    _equals: function(node) {
+        return this.condition.equals(node.condition)
+            && this.consequent.equals(node.consequent)
+            && this.alternative.equals(node.alternative);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1556,6 +1727,9 @@ var AST_Await = DEFNODE("Await", "expression", {
    $propdoc: {
        expression: "[AST_Node] expression with Promise to resolve on",
    },
+    _equals: function(node) {
+        return this.expression.equals(node.expression);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1573,6 +1747,10 @@ var AST_Yield = DEFNODE("Yield", "expression nested", {
        expression: "[AST_Node?] return value for iterator, or null if undefined",
        nested: "[boolean] whether to iterate over expression as generator",
    },
+    _equals: function(node) {
+        return !this.nested == !node.nested
+            && prop_equals(this.expression, node.expression);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1595,6 +1773,9 @@ var AST_Array = DEFNODE("Array", "elements", {
    $propdoc: {
        elements: "[AST_Node*] array of elements"
    },
+    _equals: function(node) {
+        return all_equals(this.elements, node.elements);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1637,6 +1818,10 @@ var AST_DestructuredArray = DEFNODE("DestructuredArray", "elements", {
    $propdoc: {
        elements: "[(AST_DefaultValue|AST_Destructured|AST_SymbolDeclaration|AST_SymbolRef)*] array of elements",
    },
+    _equals: function(node) {
+        return prop_equals(this.rest, node.rest)
+            && all_equals(this.elements, node.elements);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1654,6 +1839,10 @@ var AST_DestructuredKeyVal = DEFNODE("DestructuredKeyVal", "key value", {
        key: "[string|AST_Node] property name.  For computed property this is an AST_Node.",
        value: "[AST_DefaultValue|AST_Destructured|AST_SymbolDeclaration|AST_SymbolRef] property value",
    },
+    _equals: function(node) {
+        return prop_equals(this.key, node.key)
+            && this.value.equals(node.value);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1675,6 +1864,10 @@ var AST_DestructuredObject = DEFNODE("DestructuredObject", "properties", {
    $propdoc: {
        properties: "[AST_DestructuredKeyVal*] array of properties",
    },
+    _equals: function(node) {
+        return prop_equals(this.rest, node.rest)
+            && all_equals(this.properties, node.properties);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1696,6 +1889,9 @@ var AST_Object = DEFNODE("Object", "properties", {
    $propdoc: {
        properties: "[(AST_ObjectProperty|AST_Spread)*] array of properties"
    },
+    _equals: function(node) {
+        return all_equals(this.properties, node.properties);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1719,6 +1915,10 @@ var AST_ObjectProperty = DEFNODE("ObjectProperty", "key value", {
        key: "[string|AST_Node] property name.  For computed property this is an AST_Node.",
        value: "[AST_Node] property value.  For getters and setters this is an AST_Accessor.",
    },
+    _equals: function(node) {
+        return prop_equals(this.key, node.key)
+            && this.value.equals(node.value);
+    },
    walk: function(visitor) {
        var node = this;
        visitor.visit(node, function() {
@@ -1773,6 +1973,9 @@ var AST_Symbol = DEFNODE("Symbol", "scope name thedef", {
        scope: "[AST_Scope/S] the current scope (not necessarily the definition scope)",
        thedef: "[SymbolDef/S] the definition of this symbol"
    },
+    _equals: function(node) {
+        return this.thedef ? this.thedef === node.thedef : this.name == node.name;
+    },
    _validate: function() {
        if (this.TYPE == "Symbol") throw new Error("should not instantiate AST_Symbol");
        if (typeof this.name != "string") throw new Error("name must be string");
@@ -1790,10 +1993,14 @@ var AST_SymbolConst = DEFNODE("SymbolConst", null, {
 var AST_SymbolImport = DEFNODE("SymbolImport", "key", {
    $documentation: "Symbol defined by an `import` statement",
    $propdoc: {
-        key: "[string] the original `export` name",
+        key: "[AST_String] the original `export` name",
+    },
+    _equals: function(node) {
+        return this.name == node.name
+            && this.key.equals(node.key);
    },
    _validate: function() {
-        if (typeof this.key != "string") throw new Error("key must be string");
+        if (!(this.key instanceof AST_String)) throw new Error("key must be AST_String");
    },
 }, AST_SymbolConst);

@@ -1837,7 +2044,7 @@ var AST_Label = DEFNODE("Label", "references", {
    initialize: function() {
        this.references = [];
        this.thedef = this;
-    }
+    },
 }, AST_Symbol);

 var AST_SymbolRef = DEFNODE("SymbolRef", "fixed in_arg redef", {
@@ -1847,10 +2054,14 @@ var AST_SymbolRef = DEFNODE("SymbolRef", "fixed in_arg redef", {
 var AST_SymbolExport = DEFNODE("SymbolExport", "alias", {
    $documentation: "Reference in an `export` statement",
    $propdoc: {
-        alias: "[string] the `export` alias",
+        alias: "[AST_String] the `export` alias",
+    },
+    _equals: function(node) {
+        return this.name == node.name
+            && this.alias.equals(node.alias);
    },
    _validate: function() {
-        if (typeof this.alias != "string") throw new Error("alias must be string");
+        if (!(this.alias instanceof AST_String)) throw new Error("alias must be AST_String");
    },
 }, AST_SymbolRef);

@@ -1860,6 +2071,7 @@ var AST_LabelRef = DEFNODE("LabelRef", null, {

 var AST_ObjectIdentity = DEFNODE("ObjectIdentity", null, {
    $documentation: "Base class for `super` & `this`",
+    _equals: return_true,
    _validate: function() {
        if (this.TYPE == "ObjectIdentity") throw new Error("should not instantiate AST_ObjectIdentity");
    },
@@ -1894,7 +2106,12 @@ var AST_Template = DEFNODE("Template", "expressions strings tag", {
    $propdoc: {
        expressions: "[AST_Node*] the placeholder expressions",
        strings: "[string*] the raw text segments",
-        tag: "[AST_Node] tag function, or null if absent",
+        tag: "[AST_Node?] tag function, or null if absent",
+    },
+    _equals: function(node) {
+        return prop_equals(this.tag, node.tag)
+            && list_equals(this.strings, node.strings)
+            && all_equals(this.expressions, node.expressions);
    },
    walk: function(visitor) {
        var node = this;
@@ -1919,6 +2136,9 @@ var AST_Template = DEFNODE("Template", "expressions strings tag", {

 var AST_Constant = DEFNODE("Constant", null, {
    $documentation: "Base class for all constants",
+    _equals: function(node) {
+        return this.value === node.value;
+    },
    _validate: function() {
        if (this.TYPE == "Constant") throw new Error("should not instantiate AST_Constant");
    },
@@ -1967,6 +2187,9 @@ var AST_RegExp = DEFNODE("RegExp", "value", {
    $propdoc: {
        value: "[RegExp] the actual regexp"
    },
+    _equals: function(node) {
+        return "" + this.value == "" + node.value;
+    },
    _validate: function() {
        if (!(this.value instanceof RegExp)) throw new Error("value must be RegExp");
    },
@@ -1974,6 +2197,7 @@ var AST_RegExp = DEFNODE("RegExp", "value", {

 var AST_Atom = DEFNODE("Atom", null, {
    $documentation: "Base class for atoms",
+    _equals: return_true,
    _validate: function() {
        if (this.TYPE == "Atom") throw new Error("should not instantiate AST_Atom");
    },
@@ -2039,16 +2263,21 @@ TreeWalker.prototype = {
        return this.stack[this.stack.length - 2 - (n || 0)];
    },
    push: function(node) {
-        if (node instanceof AST_Lambda) {
+        var value;
+        if (node instanceof AST_Class) {
+            this.directives = Object.create(this.directives);
+            value = "use strict";
+        } else if (node instanceof AST_Directive) {
+            value = node.value;
+        } else if (node instanceof AST_Lambda) {
            this.directives = Object.create(this.directives);
-        } else if (node instanceof AST_Directive && !this.directives[node.value]) {
-            this.directives[node.value] = node;
        }
+        if (value && !this.directives[value]) this.directives[value] = node;
        this.stack.push(node);
    },
    pop: function() {
        var node = this.stack.pop();
-        if (node instanceof AST_Lambda) {
+        if (node instanceof AST_Class || node instanceof AST_Lambda) {
            this.directives = Object.getPrototypeOf(this.directives);
        }
    },
--- a/lib/compress.js
+++ b/lib/compress.js
--- a/lib/minify.js
+++ b/lib/minify.js
@@ -76,18 +76,20 @@ function minify(files, options) {
            annotations: undefined,
            compress: {},
            enclose: false,
+            expression: false,
            ie: false,
            ie8: false,
            keep_fargs: false,
            keep_fnames: false,
            mangle: {},
+            module: false,
            nameCache: null,
            output: {},
            parse: {},
            rename: undefined,
            sourceMap: false,
            timings: false,
-            toplevel: false,
+            toplevel: !!(options && options["module"]),
            v8: false,
            validate: false,
            warnings: false,
@@ -97,10 +99,12 @@ function minify(files, options) {
        if (options.validate) AST_Node.enable_validation();
        var timings = options.timings && { start: Date.now() };
        if (options.annotations !== undefined) set_shorthand("annotations", options, [ "compress", "output" ]);
+        if (options.expression) set_shorthand("expression", options, [ "compress", "parse" ]);
        if (options.ie8) options.ie = options.ie || options.ie8;
        if (options.ie) set_shorthand("ie", options, [ "compress", "mangle", "output", "rename" ]);
        if (options.keep_fargs) set_shorthand("keep_fargs", options, [ "compress", "mangle", "rename" ]);
        if (options.keep_fnames) set_shorthand("keep_fnames", options, [ "compress", "mangle", "rename" ]);
+        if (options.module) set_shorthand("module", options, [ "compress", "parse" ]);
        if (options.toplevel) set_shorthand("toplevel", options, [ "compress", "mangle", "rename" ]);
        if (options.v8) set_shorthand("v8", options, [ "mangle", "output", "rename" ]);
        if (options.webkit) set_shorthand("webkit", options, [ "compress", "mangle", "output", "rename" ]);
@@ -151,13 +155,11 @@ function minify(files, options) {
        }, options.warnings == "verbose");
        if (timings) timings.parse = Date.now();
        var toplevel;
-        if (files instanceof AST_Toplevel) {
+        options.parse = options.parse || {};
+        if (files instanceof AST_Node) {
            toplevel = files;
        } else {
-            if (typeof files == "string") {
-                files = [ files ];
-            }
-            options.parse = options.parse || {};
+            if (typeof files == "string") files = [ files ];
            options.parse.toplevel = null;
            var source_map_content = options.sourceMap && options.sourceMap.content;
            if (typeof source_map_content == "string" && source_map_content != "inline") {
@@ -169,17 +171,14 @@ function minify(files, options) {
                options.parse.toplevel = toplevel = parse(files[name], options.parse);
                if (source_map_content == "inline") {
                    var inlined_content = read_source_map(name, toplevel);
-                    if (inlined_content) {
-                        options.sourceMap.orig[name] = parse_source_map(inlined_content);
-                    }
+                    if (inlined_content) options.sourceMap.orig[name] = parse_source_map(inlined_content);
                } else if (source_map_content) {
                    options.sourceMap.orig[name] = source_map_content;
                }
            }
        }
-        if (quoted_props) {
-            reserve_quoted_keys(toplevel, quoted_props);
-        }
+        if (options.parse.expression) toplevel = toplevel.wrap_expression();
+        if (quoted_props) reserve_quoted_keys(toplevel, quoted_props);
        [ "enclose", "wrap" ].forEach(function(action) {
            var option = options[action];
            if (!option) return;
@@ -206,7 +205,9 @@ function minify(files, options) {
            toplevel.mangle_names(options.mangle);
        }
        if (timings) timings.properties = Date.now();
+        if (quoted_props) reserve_quoted_keys(toplevel, quoted_props);
        if (options.mangle && options.mangle.properties) mangle_properties(toplevel, options.mangle.properties);
+        if (options.parse.expression) toplevel = toplevel.unwrap_expression();
        if (timings) timings.output = Date.now();
        var result = {};
        var output = defaults(options.output, {
--- a/lib/mozilla-ast.js
+++ b/lib/mozilla-ast.js
@@ -192,6 +192,19 @@
                value: from_moz(M.value),
            });
        },
+        StaticBlock: function(M) {
+            var start = my_start_token(M);
+            var end = my_end_token(M);
+            return new AST_ClassInit({
+                start: start,
+                end: end,
+                value: new AST_ClassInitBlock({
+                    start: start,
+                    end: end,
+                    body: normalize_directives(M.body.map(from_moz)),
+                }),
+            });
+        },
        ForOfStatement: function(M) {
            return new (M.await ? AST_ForAwaitOf : AST_ForOf)({
                start: my_start_token(M),
@@ -303,13 +316,22 @@
            });
        },
        ExportAllDeclaration: function(M) {
-            var alias = M.exported ? read_name(M.exported) : "*";
+            var start = my_start_token(M);
+            var end = my_end_token(M);
            return new AST_ExportForeign({
-                start: my_start_token(M),
-                end: my_end_token(M),
-                aliases: [ alias ],
-                keys: [ "*" ],
-                path: M.source.value,
+                start: start,
+                end: end,
+                aliases: [ M.exported ? from_moz_alias(M.exported) : new AST_String({
+                    start: start,
+                    value: "*",
+                    end: end,
+                }) ],
+                keys: [ new AST_String({
+                    start: start,
+                    value: "*",
+                    end: end,
+                }) ],
+                path: from_moz(M.source),
            });
        },
        ExportDefaultDeclaration: function(M) {
@@ -346,15 +368,15 @@
            if (M.source) {
                var aliases = [], keys = [];
                M.specifiers.forEach(function(prop) {
-                    aliases.push(read_name(prop.exported));
-                    keys.push(read_name(prop.local));
+                    aliases.push(from_moz_alias(prop.exported));
+                    keys.push(from_moz_alias(prop.local));
                });
                return new AST_ExportForeign({
                    start: my_start_token(M),
                    end: my_end_token(M),
                    aliases: aliases,
                    keys: keys,
-                    path: M.source.value,
+                    path: from_moz(M.source),
                });
            }
            return new AST_ExportReferences({
@@ -362,38 +384,48 @@
                end: my_end_token(M),
                properties: M.specifiers.map(function(prop) {
                    var sym = new AST_SymbolExport(from_moz(prop.local));
-                    sym.alias = read_name(prop.exported);
+                    sym.alias = from_moz_alias(prop.exported);
                    return sym;
                }),
            });
        },
        ImportDeclaration: function(M) {
+            var start = my_start_token(M);
+            var end = my_end_token(M);
            var all = null, def = null, props = null;
            M.specifiers.forEach(function(prop) {
                var sym = new AST_SymbolImport(from_moz(prop.local));
                switch (prop.type) {
                  case "ImportDefaultSpecifier":
                    def = sym;
-                    def.key = "";
+                    def.key = new AST_String({
+                        start: start,
+                        value: "",
+                        end: end,
+                    });
                    break;
                  case "ImportNamespaceSpecifier":
                    all = sym;
-                    all.key = "*";
+                    all.key = new AST_String({
+                        start: start,
+                        value: "*",
+                        end: end,
+                    });
                    break;
                  default:
-                    sym.key = prop.imported.name || syn.name;
+                    sym.key = from_moz_alias(prop.imported);
                    if (!props) props = [];
                    props.push(sym);
                    break;
                }
            });
            return new AST_Import({
-                start: my_start_token(M),
-                end: my_end_token(M),
+                start: start,
+                end: end,
                all: all,
                default: def,
                properties: props,
-                path: M.source.value,
+                path: from_moz(M.source),
            });
        },
        ImportExpression: function(M) {
@@ -714,6 +746,10 @@
        };
    });

+    def_to_moz(AST_ClassInit, function To_Moz_StaticBlock(M) {
+        return to_moz_scope("StaticBlock", M.value);
+    });
+
    function To_Moz_ForOfStatement(is_await) {
        return function(M) {
            return {
@@ -780,38 +816,26 @@
    });

    def_to_moz(AST_ExportForeign, function To_Moz_ExportAllDeclaration_ExportNamedDeclaration(M) {
-        if (M.keys[0] == "*") return {
+        if (M.keys[0].value == "*") return {
            type: "ExportAllDeclaration",
-            exported: M.aliases[0] == "*" ? null : {
-                type: "Identifier",
-                name: M.aliases[0],
-            },
-            source: {
-                type: "Literal",
-                value: M.path,
-            },
+            exported: M.aliases[0].value == "*" ? null : to_moz_alias(M.aliases[0]),
+            source: to_moz(M.path),
        };
        var specifiers = [];
        for (var i = 0; i < M.aliases.length; i++) {
-            specifiers.push({
+            specifiers.push(set_moz_loc({
+                start: M.keys[i].start,
+                end: M.aliases[i].end,
+            }, {
                type: "ExportSpecifier",
-                exported: {
-                    type: "Identifier",
-                    name: M.aliases[i],
-                },
-                local: {
-                    type: "Identifier",
-                    name: M.keys[i],
-                },
-            });
+                local: to_moz_alias(M.keys[i]),
+                exported: to_moz_alias(M.aliases[i]),
+            }));
        }
        return {
            type: "ExportNamedDeclaration",
            specifiers: specifiers,
-            source: {
-                type: "Literal",
-                value: M.path,
-            },
+            source: to_moz(M.path),
        };
    });

@@ -819,44 +843,41 @@
        return {
            type: "ExportNamedDeclaration",
            specifiers: M.properties.map(function(prop) {
-                return {
+                return set_moz_loc({
+                    start: prop.start,
+                    end: prop.alias.end,
+                }, {
                    type: "ExportSpecifier",
                    local: to_moz(prop),
-                    exported: {
-                        type: "Identifier",
-                        name: prop.alias,
-                    },
-                };
+                    exported: to_moz_alias(prop.alias),
+                });
            }),
        };
    });

    def_to_moz(AST_Import, function To_Moz_ImportDeclaration(M) {
        var specifiers = M.properties ? M.properties.map(function(prop) {
-            return {
+            return set_moz_loc({
+                start: prop.key.start,
+                end: prop.end,
+            }, {
                type: "ImportSpecifier",
                local: to_moz(prop),
-                imported: {
-                    type: "Identifier",
-                    name: prop.key,
-                },
-            };
+                imported: to_moz_alias(prop.key),
+            });
        }) : [];
-        if (M.all) specifiers.unshift({
+        if (M.all) specifiers.unshift(set_moz_loc(M.all, {
            type: "ImportNamespaceSpecifier",
            local: to_moz(M.all),
-        });
-        if (M.default) specifiers.unshift({
+        }));
+        if (M.default) specifiers.unshift(set_moz_loc(M.default, {
            type: "ImportDefaultSpecifier",
            local: to_moz(M.default),
-        });
+        }));
        return {
            type: "ImportDeclaration",
            specifiers: specifiers,
-            source: {
-                type: "Literal",
-                value: M.path,
-            },
+            source: to_moz(M.path),
        };
    });

@@ -1203,6 +1224,14 @@
        return node;
    }

+    function from_moz_alias(moz) {
+        return new AST_String({
+            start: my_start_token(moz),
+            value: read_name(moz),
+            end: my_end_token(moz),
+        });
+    }
+
    AST_Node.from_mozilla_ast = function(node) {
        var save_stack = FROM_MOZ_STACK;
        FROM_MOZ_STACK = [];
@@ -1254,6 +1283,13 @@
        return node != null ? node.to_mozilla_ast() : null;
    }

+    function to_moz_alias(alias) {
+        return is_identifier_string(alias.value) ? set_moz_loc(alias, {
+            type: "Identifier",
+            name: alias.value,
+        }) : to_moz(alias);
+    }
+
    function to_moz_block(node) {
        return {
            type: "BlockStatement",
--- a/lib/output.js
+++ b/lib/output.js
@@ -55,6 +55,7 @@ function OutputStream(options) {
        beautify         : false,
        braces           : false,
        comments         : false,
+        extendscript     : false,
        galio            : false,
        ie               : false,
        indent_level     : 4,
@@ -75,7 +76,7 @@ function OutputStream(options) {
        wrap_iife        : false,
    }, true);

-    // Convert comment option to RegExp if neccessary and set up comments filter
+    // Convert comment option to RegExp if necessary and set up comments filter
    var comment_filter = return_false; // Default case, throw all comments away
    if (options.comments) {
        var comments = options.comments;
@@ -260,6 +261,15 @@ function OutputStream(options) {

    var require_semicolon = makePredicate("( [ + * / - , .");

+    function require_space(prev, ch, str) {
+        return is_identifier_char(prev) && (is_identifier_char(ch) || ch == "\\")
+            || (ch == "/" && ch == prev)
+            || ((ch == "+" || ch == "-") && ch == last)
+            || last == "--" && ch == ">"
+            || last == "!" && str == "--"
+            || prev == "/" && (str == "in" || str == "instanceof");
+    }
+
    var print = options.beautify
        || options.comments
        || options.max_line_len
@@ -312,12 +322,7 @@ function OutputStream(options) {
        }

        if (might_need_space) {
-            if (is_identifier_char(prev) && (is_identifier_char(ch) || ch == "\\")
-                || (ch == "/" && ch == prev)
-                || ((ch == "+" || ch == "-") && ch == last)
-                || str == "--" && last == "!"
-                || str == "in" && prev == "/"
-                || last == "--" && ch == ">") {
+            if (require_space(prev, ch, str)) {
                output += " ";
                current_col++;
            }
@@ -355,14 +360,7 @@ function OutputStream(options) {
            }
        }
        if (might_need_space) {
-            if (is_identifier_char(prev) && (is_identifier_char(ch) || ch == "\\")
-                || (ch == "/" && ch == prev)
-                || ((ch == "+" || ch == "-") && ch == last)
-                || str == "--" && last == "!"
-                || str == "in" && prev == "/"
-                || last == "--" && ch == ">") {
-                output += " ";
-            }
+            if (require_space(prev, ch, str)) output += " ";
            if (prev != "<" || str != "!") might_need_space = false;
        }
        output += str;
@@ -409,10 +407,11 @@ function OutputStream(options) {
        print(";");
    }

-    function with_block(cont) {
+    function with_block(cont, end) {
        print("{");
        newline();
        with_indent(cont);
+        add_mapping(end);
        indent();
        print("}");
    }
@@ -702,6 +701,7 @@ function OutputStream(options) {
        if (p instanceof AST_Class) return true;
        // (x++)[y]
        // (typeof x).y
+        // https://github.com/mishoo/UglifyJS/issues/115
        if (p instanceof AST_PropAccess) return p.expression === this;
        // (~x)`foo`
        if (p instanceof AST_Template) return p.tag === this;
@@ -877,7 +877,9 @@ function OutputStream(options) {
        return needs_parens_assign_cond(this, output);
    });
    PARENS(AST_Conditional, function(output) {
-        return needs_parens_assign_cond(this, output);
+        return needs_parens_assign_cond(this, output)
+            // https://github.com/mishoo/UglifyJS/issues/1144
+            || output.option("extendscript") && output.parent() instanceof AST_Conditional;
    });
    PARENS(AST_Yield, function(output) {
        return needs_parens_assign_cond(this, output);
@@ -956,7 +958,7 @@ function OutputStream(options) {
        if (self.body.length > 0) {
            output.with_block(function() {
                display_body(self.body, false, output, allow_directives);
-            });
+            }, self.end);
        } else print_braced_empty(self, output);
    }
    DEFPRINT(AST_BlockStatement, function(output) {
@@ -995,7 +997,7 @@ function OutputStream(options) {
                if (self.init instanceof AST_Definitions) {
                    self.init.print(output);
                } else {
-                    parenthesize_for_noin(self.init, output, true);
+                    parenthesize_for_no_in(self.init, output, true);
                }
                output.print(";");
                output.space();
@@ -1064,6 +1066,14 @@ function OutputStream(options) {
        }
        output.semicolon();
    });
+    function print_alias(alias, output) {
+        var value = alias.value;
+        if (value == "*" || is_identifier_string(value)) {
+            output.print_name(value);
+        } else {
+            output.print_string(value, alias.quote);
+        }
+    }
    DEFPRINT(AST_ExportForeign, function(output) {
        var self = this;
        output.print("export");
@@ -1071,7 +1081,7 @@ function OutputStream(options) {
        var len = self.keys.length;
        if (len == 0) {
            print_braced_empty(self, output);
-        } else if (self.keys[0] == "*") {
+        } else if (self.keys[0].value == "*") {
            print_entry(0);
        } else output.with_block(function() {
            output.indent();
@@ -1083,22 +1093,22 @@ function OutputStream(options) {
                print_entry(i);
            }
            output.newline();
-        });
+        }, self.end);
        output.space();
        output.print("from");
        output.space();
-        output.print_string(self.path, self.quote);
+        self.path.print(output);
        output.semicolon();

        function print_entry(index) {
            var alias = self.aliases[index];
            var key = self.keys[index];
-            output.print_name(key);
-            if (alias != key) {
+            print_alias(key, output);
+            if (alias.value != key.value) {
                output.space();
                output.print("as");
                output.space();
-                output.print_name(alias);
+                print_alias(alias, output);
            }
        }
    });
@@ -1127,7 +1137,7 @@ function OutputStream(options) {
            output.print("from");
            output.space();
        }
-        output.print_string(self.path, self.quote);
+        self.path.print(output);
        output.semicolon();
    });

@@ -1257,6 +1267,11 @@ function OutputStream(options) {
        }
        print_method(self, output);
    });
+    DEFPRINT(AST_ClassInit, function(output) {
+        output.print("static");
+        output.space();
+        print_braced(this.value, output);
+    });

    /* -----[ jumps ]----- */
    function print_jump(kind, prop) {
@@ -1342,7 +1357,7 @@ function OutputStream(options) {
                if (i < last && branch.body.length > 0)
                    output.newline();
            });
-        });
+        }, self.end);
    });
    function print_branch_body(self, output) {
        output.newline();
@@ -1398,7 +1413,7 @@ function OutputStream(options) {
        print_braced(this, output);
    });

-    function print_definitinos(type) {
+    function print_definitions(type) {
        return function(output) {
            var self = this;
            output.print(type);
@@ -1411,15 +1426,15 @@ function OutputStream(options) {
            if (!(p instanceof AST_IterationStatement && p.init === self)) output.semicolon();
        };
    }
-    DEFPRINT(AST_Const, print_definitinos("const"));
-    DEFPRINT(AST_Let, print_definitinos("let"));
-    DEFPRINT(AST_Var, print_definitinos("var"));
+    DEFPRINT(AST_Const, print_definitions("const"));
+    DEFPRINT(AST_Let, print_definitions("let"));
+    DEFPRINT(AST_Var, print_definitions("var"));

-    function parenthesize_for_noin(node, output, noin) {
+    function parenthesize_for_no_in(node, output, no_in) {
        var parens = false;
        // need to take some precautions here:
        //    https://github.com/mishoo/UglifyJS/issues/60
-        if (noin) node.walk(new TreeWalker(function(node) {
+        if (no_in) node.walk(new TreeWalker(function(node) {
            if (parens) return true;
            if (node instanceof AST_Binary && node.operator == "in") return parens = true;
            if (node instanceof AST_Scope && !(is_arrow(node) && node.value)) return true;
@@ -1435,8 +1450,8 @@ function OutputStream(options) {
            output.print("=");
            output.space();
            var p = output.parent(1);
-            var noin = p instanceof AST_For || p instanceof AST_ForEnumeration;
-            parenthesize_for_noin(self.value, output, noin);
+            var no_in = p instanceof AST_For || p instanceof AST_ForEnumeration;
+            parenthesize_for_no_in(self.value, output, no_in);
        }
    });

@@ -1462,14 +1477,12 @@ function OutputStream(options) {
        output.print("/*@__PURE__*/");
    }
    function print_call_args(self, output) {
-        if (self.expression instanceof AST_Call || self.expression instanceof AST_Lambda) {
-            output.add_mapping(self.start);
-        }
        output.with_parens(function() {
            self.args.forEach(function(expr, i) {
                if (i) output.comma();
                expr.print(output);
            });
+            output.add_mapping(self.end);
        });
    }
    DEFPRINT(AST_Call, function(output) {
@@ -1504,11 +1517,12 @@ function OutputStream(options) {
        var expr = self.expression;
        expr.print(output);
        var prop = self.property;
-        if (output.option("ie") && RESERVED_WORDS[prop]) {
-            output.print(self.optional ? "?.[" : "[");
+        if (output.option("ie") && RESERVED_WORDS[prop] || self.quoted && output.option("keep_quoted_props")) {
+            if (self.optional) output.print("?.");
+            output.with_square(function() {
                output.add_mapping(self.end);
                output.print_string(prop);
-            output.print("]");
+            });
        } else {
            if (expr instanceof AST_Number && !/[ex.)]/i.test(output.last())) output.print(".");
            output.print(self.optional ? "?." : ".");
@@ -1520,9 +1534,10 @@ function OutputStream(options) {
    DEFPRINT(AST_Sub, function(output) {
        var self = this;
        self.expression.print(output);
-        output.print(self.optional ? "?.[" : "[");
+        if (self.optional) output.print("?.");
+        output.with_square(function() {
            self.property.print(output);
-        output.print("]");
+        });
    });
    DEFPRINT(AST_Spread, function(output) {
        output.print("...");
@@ -1541,8 +1556,10 @@ function OutputStream(options) {
        exp.print(output);
    });
    DEFPRINT(AST_UnaryPostfix, function(output) {
-        this.expression.print(output);
-        output.print(this.operator);
+        var self = this;
+        self.expression.print(output);
+        output.add_mapping(self.end);
+        output.print(self.operator);
    });
    DEFPRINT(AST_Binary, function(output) {
        var self = this;
@@ -1635,7 +1652,8 @@ function OutputStream(options) {
        value.print(output);
    });
    DEFPRINT(AST_DestructuredObject, function(output) {
-        var props = this.properties, len = props.length, rest = this.rest;
+        var self = this;
+        var props = self.properties, len = props.length, rest = self.rest;
        if (len || rest) output.with_block(function() {
            props.forEach(function(prop, i) {
                if (i) {
@@ -1655,8 +1673,8 @@ function OutputStream(options) {
                rest.print(output);
            }
            output.newline();
-        });
-        else print_braced_empty(this, output);
+        }, self.end);
+        else print_braced_empty(self, output);
    });
    function print_properties(self, output, no_comma) {
        var props = self.properties;
@@ -1670,7 +1688,7 @@ function OutputStream(options) {
                prop.print(output);
            });
            output.newline();
-        });
+        }, self.end);
        else print_braced_empty(self, output);
    }
    DEFPRINT(AST_Object, function(output) {
@@ -1732,19 +1750,19 @@ function OutputStream(options) {
        var name = get_symbol_name(self);
        output.print_name(name);
        var alias = self.alias;
-        if (alias != name) {
+        if (alias.value != name) {
            output.space();
            output.print("as");
            output.space();
-            output.print_name(alias);
+            print_alias(alias, output);
        }
    });
    DEFPRINT(AST_SymbolImport, function(output) {
        var self = this;
        var name = get_symbol_name(self);
        var key = self.key;
-        if (key && key != name) {
-            output.print_name(key);
+        if (key.value && key.value != name) {
+            print_alias(key, output);
            output.space();
            output.print("as");
            output.space();
@@ -1814,9 +1832,6 @@ function OutputStream(options) {
              case "\u2029": return "\\u2029";
            }
        }));
-        var p = output.parent();
-        if (p instanceof AST_Binary && /^in/.test(p.operator) && p.left === this)
-            output.print(" ");
    });

    function force_statement(stat, output) {
@@ -1883,7 +1898,7 @@ function OutputStream(options) {
            output.indent();
            stmt.print(output);
            output.newline();
-        });
+        }, stmt.end);
    }

    /* -----[ source map generators ]----- */
@@ -1906,22 +1921,27 @@ function OutputStream(options) {
    // or if we should add even more.
    DEFMAP([
        AST_Array,
+        AST_Await,
        AST_BlockStatement,
        AST_Catch,
        AST_Constant,
        AST_Debugger,
        AST_Definitions,
        AST_Destructured,
+        AST_Directive,
        AST_Finally,
        AST_Jump,
        AST_Lambda,
        AST_New,
        AST_Object,
+        AST_Spread,
        AST_StatementWithBody,
        AST_Symbol,
        AST_Switch,
        AST_SwitchBranch,
        AST_Try,
+        AST_UnaryPrefix,
+        AST_Yield,
    ], function(output) {
        output.add_mapping(this.start);
    });
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -237,8 +237,7 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
        newline_before  : false,
        regex_allowed   : false,
        comments_before : [],
-        directives      : {},
-        directive_stack : [],
+        directives      : Object.create(null),
        read_template   : with_eof_error("Unterminated template literal", function(strings) {
            var s = "";
            for (;;) {
@@ -553,16 +552,8 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {

    function handle_dot() {
        next();
-        var ch = peek();
-        if (ch == ".") {
-            var op = ".";
-            do {
-                op += ".";
-                next();
-            } while (peek() == ".");
-            return token("operator", op);
-        }
-        return is_digit(ch.charCodeAt(0)) ? read_num(".") : token("punc", ".");
+        if (looking_at("..")) return token("operator", "." + next() + next());
+        return is_digit(peek().charCodeAt(0)) ? read_num(".") : token("punc", ".");
    }

    function read_word() {
@@ -635,24 +626,19 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
    };

    next_token.add_directive = function(directive) {
-        S.directive_stack[S.directive_stack.length - 1].push(directive);
-        if (S.directives[directive]) S.directives[directive]++;
-        else S.directives[directive] = 1;
+        S.directives[directive] = true;
    }

    next_token.push_directives_stack = function() {
-        S.directive_stack.push([]);
+        S.directives = Object.create(S.directives);
    }

    next_token.pop_directives_stack = function() {
-        var directives = S.directive_stack.pop();
-        for (var i = directives.length; --i >= 0;) {
-            S.directives[directives[i]]--;
-        }
+        S.directives = Object.getPrototypeOf(S.directives);
    }

    next_token.has_directive = function(directive) {
-        return S.directives[directive] > 0;
+        return !!S.directives[directive];
    }

    return next_token;
@@ -699,6 +685,7 @@ function parse($TEXT, options) {
        expression     : false,
        filename       : null,
        html5_comments : true,
+        module         : false,
        shebang        : true,
        strict         : false,
        toplevel       : null,
@@ -795,7 +782,7 @@ function parse($TEXT, options) {
        else if (!optional && !can_insert_semicolon()) expect(";");
    }

-    function parenthesised() {
+    function parenthesized() {
        expect("(");
        var exp = expression();
        expect(")");
@@ -820,7 +807,7 @@ function parse($TEXT, options) {
        }
    }

-    var statement = embed_tokens(function() {
+    var statement = embed_tokens(function(toplevel) {
        handle_regexp();
        switch (S.token.type) {
          case "string":
@@ -859,15 +846,15 @@ function parse($TEXT, options) {
                if (S.in_async) return simple_statement();
                break;
              case "export":
+                if (!toplevel && options.module !== "") unexpected();
                next();
                return export_();
              case "import":
                var token = peek();
-                if (!(token.type == "punc" && /^[(.]$/.test(token.value))) {
+                if (token.type == "punc" && /^[(.]$/.test(token.value)) break;
+                if (!toplevel && options.module !== "") unexpected();
                next();
                return import_();
-                }
-                break;
              case "let":
                if (is_vardefs()) {
                    next();
@@ -933,18 +920,18 @@ function parse($TEXT, options) {
                next();
                var body = in_loop(statement);
                expect_token("keyword", "while");
-                var condition = parenthesised();
+                var condition = parenthesized();
                semicolon(true);
                return new AST_Do({
                    body      : body,
-                    condition : condition
+                    condition : condition,
                });

              case "while":
                next();
                return new AST_While({
-                    condition : parenthesised(),
-                    body      : in_loop(statement)
+                    condition : parenthesized(),
+                    body      : in_loop(statement),
                });

              case "for":
@@ -972,15 +959,13 @@ function parse($TEXT, options) {
                    value = expression();
                    semicolon();
                }
-                return new AST_Return({
-                    value: value
-                });
+                return new AST_Return({ value: value });

              case "switch":
                next();
                return new AST_Switch({
-                    expression : parenthesised(),
-                    body       : in_loop(switch_body_)
+                    expression : parenthesized(),
+                    body       : in_loop(switch_body_),
                });

              case "throw":
@@ -989,9 +974,7 @@ function parse($TEXT, options) {
                    croak("Illegal newline after 'throw'");
                var value = expression();
                semicolon();
-                return new AST_Throw({
-                    value: value
-                });
+                return new AST_Throw({ value: value });

              case "try":
                next();
@@ -1009,8 +992,8 @@ function parse($TEXT, options) {
                }
                next();
                return new AST_With({
-                    expression : parenthesised(),
-                    body       : statement()
+                    expression : parenthesized(),
+                    body       : statement(),
                });
            }
        }
@@ -1069,13 +1052,13 @@ function parse($TEXT, options) {
        return stat;
    }

-    function has_modifier(name) {
+    function has_modifier(name, no_nlb) {
        if (!is("name", name)) return;
        var token = peek();
        if (!token) return;
        if (is_token(token, "operator", "=")) return;
        if (token.type == "punc" && /^[(;}]$/.test(token.value)) return;
-        if (has_newline_before(token)) return;
+        if (no_nlb && has_newline_before(token)) return;
        return next();
    }

@@ -1105,7 +1088,7 @@ function parse($TEXT, options) {
            }
            var start = S.token;
            var fixed = !!has_modifier("static");
-            var async = has_modifier("async");
+            var async = has_modifier("async", true);
            if (is("operator", "*")) {
                next();
                var internal = is("name") && /^#/.test(S.token.value);
@@ -1124,6 +1107,18 @@ function parse($TEXT, options) {
                }));
                continue;
            }
+            if (fixed && is("punc", "{")) {
+                props.push(new AST_ClassInit({
+                    start: start,
+                    value: new AST_ClassInitBlock({
+                        start: start,
+                        body: block_(),
+                        end: prev(),
+                    }),
+                    end: prev(),
+                }));
+                continue;
+            }
            var internal = is("name") && /^#/.test(S.token.value);
            var key = as_property_key();
            if (is("punc", "(")) {
@@ -1340,11 +1335,11 @@ function parse($TEXT, options) {
        var loop = S.in_loop;
        var labels = S.labels;
        ++S.in_function;
-        S.in_directives = true;
        S.input.push_directives_stack();
        S.in_loop = 0;
        S.labels = [];
        if (is("punc", "{")) {
+            S.in_directives = true;
            body = block_();
            value = null;
        } else {
@@ -1412,7 +1407,7 @@ function parse($TEXT, options) {
            name: name,
            argnames: argnames,
            rest: argnames.rest || null,
-            body: body
+            body: body,
        });
        if (is_strict) {
            if (name) strict_verify_symbol(name);
@@ -1422,41 +1417,54 @@ function parse($TEXT, options) {
    };

    function if_() {
-        var cond = parenthesised(), body = statement(), belse = null;
+        var cond = parenthesized(), body = statement(), alt = null;
        if (is("keyword", "else")) {
            next();
-            belse = statement();
+            alt = statement();
        }
        return new AST_If({
            condition   : cond,
            body        : body,
-            alternative : belse
+            alternative : alt,
        });
    }

    function is_alias() {
-        return is("name") || is_identifier_string(S.token.value);
+        return is("name") || is("string") || is_identifier_string(S.token.value);
+    }
+
+    function make_string(token) {
+        return new AST_String({
+            start: token,
+            quote: token.quote,
+            value: token.value,
+            end: token,
+        });
+    }
+
+    function as_path() {
+        var path = S.token;
+        expect_token("string");
+        semicolon();
+        return make_string(path);
    }

    function export_() {
        if (is("operator", "*")) {
+            var key = S.token;
+            var alias = key;
            next();
-            var alias = "*";
            if (is("name", "as")) {
                next();
                if (!is_alias()) expect_token("name");
-                alias = S.token.value;
+                alias = S.token;
                next();
            }
            expect_token("name", "from");
-            var path = S.token;
-            expect_token("string");
-            semicolon();
            return new AST_ExportForeign({
-                aliases: [ alias ],
-                keys: [ "*" ],
-                path: path.value,
-                quote: path.quote,
+                aliases: [ make_string(alias) ],
+                keys: [ make_string(key) ],
+                path: as_path(),
            });
        }
        if (is("punc", "{")) {
@@ -1470,26 +1478,20 @@ function parse($TEXT, options) {
                if (is("name", "as")) {
                    next();
                    if (!is_alias()) expect_token("name");
-                    aliases.push(S.token.value);
+                    aliases.push(S.token);
                    next();
                } else {
-                    aliases.push(key.value);
+                    aliases.push(key);
                }
                if (!is("punc", "}")) expect(",");
            }
            expect("}");
            if (is("name", "from")) {
                next();
-                var path = S.token;
-                expect_token("string");
-                semicolon();
                return new AST_ExportForeign({
-                    aliases: aliases,
-                    keys: keys.map(function(token) {
-                        return token.value;
-                    }),
-                    path: path.value,
-                    quote: path.quote,
+                    aliases: aliases.map(make_string),
+                    keys: keys.map(make_string),
+                    path: as_path(),
                });
            }
            semicolon();
@@ -1497,7 +1499,7 @@ function parse($TEXT, options) {
                properties: keys.map(function(token, index) {
                    if (!is_token(token, "name")) token_error(token, "Name expected");
                    var sym = _make_symbol(AST_SymbolExport, token);
-                    sym.alias = aliases[index];
+                    sym.alias = make_string(aliases[index]);
                    return sym;
                }),
            });
@@ -1587,26 +1589,42 @@ function parse($TEXT, options) {
        var all = null;
        var def = as_symbol(AST_SymbolImport, true);
        var props = null;
-        if (def ? (def.key = "", is("punc", ",") && next()) : !is("string")) {
+        var cont;
+        if (def) {
+            def.key = new AST_String({
+                start: def.start,
+                value: "",
+                end: def.end,
+            });
+            if (cont = is("punc", ",")) next();
+        } else {
+            cont = !is("string");
+        }
+        if (cont) {
            if (is("operator", "*")) {
+                var key = S.token;
                next();
                expect_token("name", "as");
                all = as_symbol(AST_SymbolImport);
-                all.key = "*";
+                all.key = make_string(key);
            } else {
                expect("{");
                props = [];
                while (is_alias()) {
                    var alias;
                    if (is_token(peek(), "name", "as")) {
-                        var key = S.token.value;
+                        var key = S.token;
                        next();
                        next();
                        alias = as_symbol(AST_SymbolImport);
-                        alias.key = key;
+                        alias.key = make_string(key);
                    } else {
                        alias = as_symbol(AST_SymbolImport);
-                        alias.key = alias.name;
+                        alias.key = new AST_String({
+                            start: alias.start,
+                            value: alias.name,
+                            end: alias.end,
+                        });
                    }
                    props.push(alias);
                    if (!is("punc", "}")) expect(",");
@@ -1615,15 +1633,11 @@ function parse($TEXT, options) {
            }
        }
        if (all || def || props) expect_token("name", "from");
-        var path = S.token;
-        expect_token("string");
-        semicolon();
        return new AST_Import({
            all: all,
            default: def,
-            path: path.value,
+            path: as_path(),
            properties: props,
-            quote: path.quote,
        });
    }

@@ -1801,7 +1815,7 @@ function parse($TEXT, options) {
            ret = new AST_BigInt({ value: value });
            break;
          case "string":
-            ret = new AST_String({ value : value, quote : tok.quote });
+            ret = new AST_String({ value: value, quote: tok.quote });
            break;
          case "regexp":
            ret = new AST_RegExp({ value: value });
@@ -2153,9 +2167,9 @@ function parse($TEXT, options) {
            token_error(sym.start, "Unexpected " + sym.name + " in strict mode");
    }

-    function as_symbol(type, noerror) {
+    function as_symbol(type, no_error) {
        if (!is("name")) {
-            if (!noerror) croak("Name expected");
+            if (!no_error) croak("Name expected");
            return null;
        }
        var sym = _make_symbol(type, S.token);
@@ -2391,20 +2405,20 @@ function parse($TEXT, options) {
        return new ctor({ operator: op, expression: expr });
    }

-    var expr_op = function(left, min_prec, no_in) {
+    var expr_op = function(left, min_precision, no_in) {
        var op = is("operator") ? S.token.value : null;
        if (op == "in" && no_in) op = null;
-        var prec = op != null ? PRECEDENCE[op] : null;
-        if (prec != null && prec > min_prec) {
+        var precision = op != null ? PRECEDENCE[op] : null;
+        if (precision != null && precision > min_precision) {
            next();
-            var right = expr_op(maybe_unary(no_in), op == "**" ? prec - 1 : prec, no_in);
+            var right = expr_op(maybe_unary(no_in), op == "**" ? precision - 1 : precision, no_in);
            return expr_op(new AST_Binary({
                start    : left.start,
                left     : left,
                operator : op,
                right    : right,
-                end      : right.end
-            }), min_prec, no_in);
+                end      : right.end,
+            }), min_precision, no_in);
        }
        return left;
    };
@@ -2550,9 +2564,13 @@ function parse($TEXT, options) {
    return function() {
        var start = S.token;
        var body = [];
+        if (options.module) {
+            S.in_async = true;
+            S.input.add_directive("use strict");
+        }
        S.input.push_directives_stack();
        while (!is("eof"))
-            body.push(statement());
+            body.push(statement(true));
        S.input.pop_directives_stack();
        var end = prev() || start;
        var toplevel = options.toplevel;
--- a/lib/propmangle.js
+++ b/lib/propmangle.js
@@ -43,10 +43,11 @@

 "use strict";

-var builtins = function() {
+function get_builtins() {
    var names = new Dictionary();
-    // NaN will be included due to Number.NaN
+    // constants
    [
+        "NaN",
        "null",
        "true",
        "false",
@@ -54,37 +55,85 @@ var builtins = function() {
        "-Infinity",
        "undefined",
    ].forEach(add);
+    // global functions
    [
-        Array,
-        Boolean,
-        Date,
-        Error,
-        Function,
-        Math,
-        Number,
-        Object,
-        RegExp,
-        String,
-    ].forEach(function(ctor) {
+        "encodeURI",
+        "encodeURIComponent",
+        "escape",
+        "eval",
+        "decodeURI",
+        "decodeURIComponent",
+        "isFinite",
+        "isNaN",
+        "parseFloat",
+        "parseInt",
+        "unescape",
+    ].forEach(add);
+    // global constructors & objects
+    var global = Function("return this")();
+    [
+        "Array",
+        "ArrayBuffer",
+        "Atomics",
+        "BigInt",
+        "Boolean",
+        "console",
+        "DataView",
+        "Date",
+        "Error",
+        "Function",
+        "Int8Array",
+        "Intl",
+        "JSON",
+        "Map",
+        "Math",
+        "Number",
+        "Object",
+        "Promise",
+        "Proxy",
+        "Reflect",
+        "RegExp",
+        "Set",
+        "String",
+        "Symbol",
+        "WebAssembly",
+    ].forEach(function(name) {
+        add(name);
+        var ctor = global[name];
+        if (!ctor) return;
        Object.getOwnPropertyNames(ctor).map(add);
-        if (ctor.prototype) {
+        if (typeof ctor != "function") return;
+        if (ctor.__proto__) Object.getOwnPropertyNames(ctor.__proto__).map(add);
+        if (ctor.prototype) Object.getOwnPropertyNames(ctor.prototype).map(add);
+        try {
            Object.getOwnPropertyNames(new ctor()).map(add);
-            Object.getOwnPropertyNames(ctor.prototype).map(add);
+        } catch (e) {
+            try {
+                Object.getOwnPropertyNames(ctor()).map(add);
+            } catch (e) {}
        }
    });
-    return names;
+    return (get_builtins = function() {
+        return names.clone();
+    })();

    function add(name) {
        names.set(name, true);
    }
-}();
+}

 function reserve_quoted_keys(ast, reserved) {
    ast.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_ClassProperty) {
-            if (node.start && node.start.quote) add(node.key);
-        } else if (node instanceof AST_ObjectProperty) {
-            if (node.start && node.start.quote) add(node.key);
+        if (node instanceof AST_ClassProperty
+            || node instanceof AST_DestructuredKeyVal
+            || node instanceof AST_ObjectProperty) {
+            if (node.key instanceof AST_Node) {
+                addStrings(node.key, add);
+            } else if (node.start && node.start.quote) {
+                add(node.key);
+            }
+        } else if (node instanceof AST_Dot) {
+            if (node.quoted) add(node.property);
        } else if (node instanceof AST_Sub) {
            addStrings(node.property, add);
        }
@@ -111,12 +160,16 @@ function mangle_properties(ast, options) {
        builtins: false,
        cache: null,
        debug: false,
+        domprops: false,
        keep_quoted: false,
        regex: null,
        reserved: null,
    }, true);

-    var reserved = options.builtins ? new Dictionary() : builtins.clone();
+    var reserved = options.builtins ? new Dictionary() : get_builtins();
+    if (!options.domprops && typeof domprops !== "undefined") domprops.forEach(function(name) {
+        reserved.set(name, true);
+    });
    if (Array.isArray(options.reserved)) options.reserved.forEach(function(name) {
        reserved.set(name, true);
    });
@@ -135,7 +188,7 @@ function mangle_properties(ast, options) {
    var regex = options.regex;

    // note debug is either false (disabled), or a string of the debug suffix to use (enabled).
-    // note debug may be enabled as an empty string, which is falsey. Also treat passing 'true'
+    // note debug may be enabled as an empty string, which is falsy. Also treat passing 'true'
    // the same as passing an empty string.
    var debug = options.debug !== false;
    var debug_suffix;
@@ -146,9 +199,7 @@ function mangle_properties(ast, options) {

    // step 1: find candidates to mangle
    ast.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_Binary) {
-            if (node.operator == "in") addStrings(node.left, add);
-        } else if (node.TYPE == "Call") {
+        if (node.TYPE == "Call") {
            var exp = node.expression;
            if (exp instanceof AST_Dot) switch (exp.property) {
              case "defineProperty":
@@ -165,14 +216,18 @@ function mangle_properties(ast, options) {
                addStrings(node.args[0], add);
                break;
            }
-        } else if (node instanceof AST_ClassProperty) {
-            if (typeof node.key == "string") add(node.key);
+        } else if (node instanceof AST_ClassProperty
+            || node instanceof AST_DestructuredKeyVal
+            || node instanceof AST_ObjectProperty) {
+            if (node.key instanceof AST_Node) {
+                addStrings(node.key, add);
+            } else {
+                add(node.key);
+            }
        } else if (node instanceof AST_Dot) {
-            add(node.property);
-        } else if (node instanceof AST_ObjectProperty) {
-            if (typeof node.key == "string") add(node.key);
+            if (is_lhs(node, this.parent())) add(node.property);
        } else if (node instanceof AST_Sub) {
-            addStrings(node.property, add);
+            if (is_lhs(node, this.parent())) addStrings(node.property, add);
        }
    }));

@@ -197,12 +252,16 @@ function mangle_properties(ast, options) {
                mangleStrings(node.args[0]);
                break;
            }
-        } else if (node instanceof AST_ClassProperty) {
-            if (typeof node.key == "string") node.key = mangle(node.key);
+        } else if (node instanceof AST_ClassProperty
+            || node instanceof AST_DestructuredKeyVal
+            || node instanceof AST_ObjectProperty) {
+            if (node.key instanceof AST_Node) {
+                mangleStrings(node.key);
+            } else {
+                node.key = mangle(node.key);
+            }
        } else if (node instanceof AST_Dot) {
            node.property = mangle(node.property);
-        } else if (node instanceof AST_ObjectProperty) {
-            if (typeof node.key == "string") node.key = mangle(node.key);
        } else if (node instanceof AST_Sub) {
            if (!options.keep_quoted) mangleStrings(node.property);
        }
@@ -217,8 +276,14 @@ function mangle_properties(ast, options) {
    }

    function should_mangle(name) {
-        if (reserved.has(name)) return false;
-        if (regex && !regex.test(name)) return false;
+        if (reserved.has(name)) {
+            AST_Node.info("Preserving reserved property {this}", name);
+            return false;
+        }
+        if (regex && !regex.test(name)) {
+            AST_Node.info("Preserving excluded property {this}", name);
+            return false;
+        }
        return cache.has(name) || names_to_mangle.has(name);
    }

@@ -243,12 +308,16 @@ function mangle_properties(ast, options) {
            if (/^#/.test(name)) mangled = "#" + mangled;
            cache.set(name, mangled);
        }
+        AST_Node.info("Mapping property {name} to {mangled}", {
+            mangled: mangled,
+            name: name,
+        });
        return mangled;
    }

    function mangleStrings(node) {
        if (node instanceof AST_Sequence) {
-            mangleStrings(node.expressions.tail_node());
+            mangleStrings(node.tail_node());
        } else if (node instanceof AST_String) {
            node.value = mangle(node.value);
        } else if (node instanceof AST_Conditional) {
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -64,19 +64,20 @@ SymbolDef.prototype = {
        this.references.forEach(fn);
    },
    mangle: function(options) {
-        var cache = options.cache && options.cache.props;
-        if (this.global && cache && cache.has(this.name)) {
+        if (this.mangled_name) return;
+        var cache = this.global && options.cache && options.cache.props;
+        if (cache && cache.has(this.name)) {
            this.mangled_name = cache.get(this.name);
-        } else if (!this.mangled_name && !this.unmangleable(options)) {
+        } else if (this.unmangleable(options)) {
+            names_in_use(this.scope, options).set(this.name, true);
+        } else {
            var def = this.redefined();
            if (def) {
                this.mangled_name = def.mangled_name || def.name;
            } else {
                this.mangled_name = next_mangled_name(this, options);
            }
-            if (this.global && cache) {
-                cache.set(this.name, this.mangled_name);
-            }
+            if (cache) cache.set(this.name, this.mangled_name);
        }
    },
    redefined: function() {
@@ -285,7 +286,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
                // ensure mangling works if `catch` reuses a scope variable
                var redef = def.redefined();
                if (redef) for (var s = node.scope; s; s = s.parent_scope) {
-                    push_uniq(s.enclosed, redef);
+                    if (!push_uniq(s.enclosed, redef)) break;
                    if (s === redef.scope) break;
                }
            } else if (node instanceof AST_SymbolConst) {
@@ -368,8 +369,9 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
    // pass 3: fix up any scoping issue with IE8
    if (options.ie) self.walk(new TreeWalker(function(node) {
        if (node instanceof AST_SymbolCatch) {
-            var scope = node.thedef.defun;
-            if (scope.name instanceof AST_SymbolLambda && scope.name.name == node.name) {
+            var def = node.thedef;
+            var scope = def.defun;
+            if (def.name != "arguments" && scope.name instanceof AST_SymbolLambda && scope.name.name == def.name) {
                scope = scope.parent_scope.resolve();
            }
            redefine(node, scope);
@@ -479,7 +481,7 @@ AST_Lambda.DEFMETHOD("init_vars", function(parent_scope) {
 AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
    var def = this.definition();
    for (var s = this.scope; s; s = s.parent_scope) {
-        push_uniq(s.enclosed, def);
+        if (!push_uniq(s.enclosed, def)) break;
        if (!options) {
            s._var_names = undefined;
        } else {
@@ -621,14 +623,10 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
    var lname = -1;
    var redefined = [];
    var tw = new TreeWalker(function(node, descend) {
-        if (node instanceof AST_LabeledStatement) {
-            // `lname` is incremented when we get to the `AST_Label`
-            var save_nesting = lname;
-            descend();
-            if (!options.v8 || !in_label(tw)) lname = save_nesting;
-            return true;
-        }
+        var save_nesting;
        if (node instanceof AST_BlockScope) {
+            // `lname` is incremented when we get to the `AST_Label`
+            if (node instanceof AST_LabeledStatement) save_nesting = lname;
            if (options.webkit && node instanceof AST_IterationStatement && node.init instanceof AST_Let) {
                node.init.definitions.forEach(function(defn) {
                    defn.name.match_symbol(function(sym) {
@@ -674,6 +672,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
                }));
            }
            to_mangle.forEach(mangle);
+            if (node instanceof AST_LabeledStatement && !(options.v8 && in_label(tw))) lname = save_nesting;
            return true;
        }
        if (node instanceof AST_Label) {
@@ -706,7 +705,12 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
        }
        redefined.push(def);
        def.references.forEach(reference);
-        if (sym instanceof AST_SymbolCatch || sym instanceof AST_SymbolConst) reference(sym);
+        if (sym instanceof AST_SymbolCatch || sym instanceof AST_SymbolConst) {
+            reference(sym);
+            def.redefined = function() {
+                return redef;
+            };
+        }
        return true;

        function reference(sym) {
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -127,8 +127,10 @@ function push_uniq(array, el) {

 function string_template(text, props) {
    return text.replace(/\{([^{}]+)\}/g, function(str, p) {
-        var value = props[p];
-        return value instanceof AST_Node ? value.print_to_string() : value;
+        var value = p == "this" ? props : props[p];
+        if (value instanceof AST_Node) return value.print_to_string();
+        if (value instanceof AST_Token) return value.file + ":" + value.line + "," + value.col;
+        return value;
    });
 }

--- a/package.json
+++ b/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": "3.15.5",
+  "version": "3.17.3",
  "engines": {
    "node": ">=0.8.0"
  },
@@ -23,7 +23,7 @@
    "LICENSE"
  ],
  "devDependencies": {
-    "acorn": "~8.2.1",
+    "acorn": "~8.7.1",
    "semver": "~6.3.0"
  },
  "scripts": {
--- a/test/compress.js
+++ b/test/compress.js
@@ -60,8 +60,9 @@ function log() {
    console.log("%s", tmpl.apply(null, arguments));
 }

-function make_code(ast, options) {
+function make_code(ast, options, expression) {
    var stream = U.OutputStream(options);
+    if (expression) ast = ast.clone(true).unwrap_expression();
    ast.print(stream);
    return stream.get();
 }
@@ -69,9 +70,7 @@ function make_code(ast, options) {
 function parse_test(file) {
    var script = fs.readFileSync(file, "utf8");
    try {
-        var ast = U.parse(script, {
-            filename: file
-        });
+        var ast = U.parse(script, { filename: file, module: "" });
    } catch (e) {
        console.error("Caught error while parsing tests in " + file);
        console.error(e);
@@ -98,14 +97,14 @@ function parse_test(file) {
            file: file,
            line: node.start.line,
            col: node.start.col,
-            code: make_code(node, { beautify: false })
+            code: make_code(node, { beautify: false }),
        }));
    }

    function read_string(stat) {
        if (stat.TYPE == "SimpleStatement") {
            var body = stat.body;
-            switch(body.TYPE) {
+            switch (body.TYPE) {
              case "String":
                return body.value;
              case "Array":
@@ -127,6 +126,17 @@ function parse_test(file) {
                    croak(node);
                }
                var name = node.left.name;
+                assert.ok([
+                    "beautify",
+                    "expression",
+                    "mangle",
+                    "options",
+                    "rename",
+                ].indexOf(name) >= 0, tmpl("Unsupported setting {name} [{line},{col}]", {
+                    name: name,
+                    line: node.start.line,
+                    col: node.start.col,
+                }));
                test[name] = evaluate(node.right);
                return true;
            }
@@ -142,7 +152,7 @@ function parse_test(file) {
                ].indexOf(label.name) >= 0, tmpl("Unsupported label {name} [{line},{col}]", {
                    name: label.name,
                    line: label.start.line,
-                    col: label.start.col
+                    col: label.start.col,
                }));
                var stat = node.body;
                if (label.name == "expect_exact" || label.name == "node_version") {
@@ -155,12 +165,12 @@ function parse_test(file) {
                        var ctor = global[body.expression.name];
                        assert.ok(ctor === Error || ctor.prototype instanceof Error, tmpl("Unsupported expect_stdout format [{line},{col}]", {
                            line: label.start.line,
-                            col: label.start.col
+                            col: label.start.col,
                        }));
                        test[label.name] = ctor.apply(null, body.args.map(function(node) {
                            assert.ok(node instanceof U.AST_Constant, tmpl("Unsupported expect_stdout format [{line},{col}]", {
                                line: label.start.line,
-                                col: label.start.col
+                                col: label.start.col,
                            }));
                            return node.value;
                        }));
@@ -180,9 +190,18 @@ function parse_test(file) {

 // Try to reminify original input with standard options
 // to see if it matches expect_stdout.
-function reminify(orig_options, input_code, input_formatted, stdout) {
+function reminify(expression, orig_options, input_code, input_formatted, stdout) {
    for (var i = 0; i < minify_options.length; i++) {
        var options = JSON.parse(minify_options[i]);
+        if (expression) {
+            if (!options.parse || typeof options.parse != "object") options.parse = {};
+            options.parse.expression = true;
+            if (options.compress == null) options.compress = {};
+            if (options.compress) {
+                if (typeof options.compress != "object") options.compress = {};
+                options.compress.expression = true;
+            }
+        }
        [
            "keep_fargs",
            "keep_fnames",
@@ -212,7 +231,7 @@ function reminify(orig_options, input_code, input_formatted, stdout) {
        } else {
            var toplevel = sandbox.has_toplevel(options);
            var expected = stdout[toplevel ? 1 : 0];
-            var actual = sandbox.run_code(result.code, toplevel);
+            var actual = run_code(expression, result.code, toplevel);
            if (typeof expected != "string" && typeof actual != "string" && expected.name == actual.name) {
                actual = expected;
            }
@@ -247,18 +266,25 @@ function reminify(orig_options, input_code, input_formatted, stdout) {
    return true;
 }

+function run_code(expression, code, toplevel) {
+    return sandbox.run_code(expression ? "console.log(" + code + ");" : code, toplevel);
+}
+
 function test_case(test) {
    log("    Running test [{name}]", { name: test.name });
    U.AST_Node.enable_validation();
    var output_options = test.beautify || {};
    var expect;
    if (test.expect) {
-        expect = make_code(to_toplevel(test.expect, test.mangle), output_options);
+        expect = to_toplevel(test.expect, test.mangle, test.expression);
+        expect = make_code(expect, output_options, test.expression);
    } else {
        expect = test.expect_exact;
    }
-    var input = to_toplevel(test.input, test.mangle);
-    var input_code = make_code(input);
+    var input = to_toplevel(test.input, test.mangle, test.expression);
+    var input_code = make_code(input, {
+        keep_quoted_props: true,
+    }, test.expression);
    var input_formatted = make_code(test.input, {
        annotations: true,
        beautify: true,
@@ -268,7 +294,7 @@ function test_case(test) {
    });
    try {
        input.validate_ast();
-        U.parse(input_code);
+        U.parse(input_code, { expression: test.expression });
    } catch (ex) {
        log([
            "!!! Cannot parse input",
@@ -294,8 +320,9 @@ function test_case(test) {
            warnings_emitted.push(text);
        }, /"INFO: /.test(expected_warnings));
    }
+    var quoted_props;
    if (test.mangle && test.mangle.properties && test.mangle.properties.keep_quoted) {
-        var quoted_props = test.mangle.properties.reserved;
+        quoted_props = test.mangle.properties.reserved;
        if (!Array.isArray(quoted_props)) quoted_props = [];
        test.mangle.properties.reserved = quoted_props;
        U.reserve_quoted_keys(input, quoted_props);
@@ -310,9 +337,10 @@ function test_case(test) {
    if (test.mangle) {
        output.compute_char_frequency(test.mangle);
        output.mangle_names(test.mangle);
+        if (quoted_props) U.reserve_quoted_keys(input, quoted_props);
        if (test.mangle.properties) U.mangle_properties(output, test.mangle.properties);
    }
-    var output_code = make_code(output, output_options);
+    var output_code = make_code(output, output_options, test.expression);
    U.AST_Node.log_function();
    if (expect != output_code) {
        log([
@@ -335,7 +363,7 @@ function test_case(test) {
    // expect == output
    try {
        output.validate_ast();
-        U.parse(output_code);
+        U.parse(output_code, { expression: test.expression });
    } catch (ex) {
        log([
            "!!! Test matched expected result but cannot parse output",
@@ -379,7 +407,7 @@ function test_case(test) {
        }
    }
    if (test.expect_stdout && (!test.node_version || semver.satisfies(process.version, test.node_version))) {
-        var stdout = [ sandbox.run_code(input_code), sandbox.run_code(input_code, true) ];
+        var stdout = [ run_code(test.expression, input_code), run_code(test.expression, input_code, true) ];
        var toplevel = sandbox.has_toplevel({
            compress: test.options,
            mangle: test.mangle
@@ -408,7 +436,7 @@ function test_case(test) {
            });
            return false;
        }
-        actual = sandbox.run_code(output_code, toplevel);
+        actual = run_code(test.expression, output_code, toplevel);
        if (!sandbox.same_stdout(test.expect_stdout, actual)) {
            log([
                "!!! failed",
@@ -429,7 +457,7 @@ function test_case(test) {
            });
            return false;
        }
-        if (!reminify(test.options, input_code, input_formatted, stdout)) {
+        if (!reminify(test.expression, test.options, input_code, input_formatted, stdout)) {
            return false;
        }
    }
@@ -440,20 +468,30 @@ function tmpl() {
    return U.string_template.apply(null, arguments);
 }

-function to_toplevel(input, mangle_options) {
+function to_toplevel(input, mangle_options, expression) {
    if (!(input instanceof U.AST_BlockStatement)) throw new Error("Unsupported input syntax");
-    var directive = true;
    var offset = input.start.line;
    var tokens = [];
-    var toplevel = new U.AST_Toplevel(input.transform(new U.TreeTransformer(function(node) {
+    input.walk(new U.TreeWalker(function(node) {
        if (U.push_uniq(tokens, node.start)) node.start.line -= offset;
-        if (!directive || node === input) return;
+        if (U.push_uniq(tokens, node.end)) node.end.line -= offset;
+    }));
+    var toplevel;
+    if (!expression) {
+        var directive = true;
+        toplevel = new U.AST_Toplevel(input.transform(new U.TreeTransformer(function(node) {
+            if (!directive) return node;
+            if (node === input) return;
            if (node instanceof U.AST_SimpleStatement && node.body instanceof U.AST_String) {
                return new U.AST_Directive(node.body);
-        } else {
-            directive = false;
            }
+            directive = false;
        })));
+    } else if (input.body.length == 1) {
+        toplevel = input.body[0].wrap_expression();
+    } else {
+        throw new Error("Invalid expression");
+    }
    toplevel.figure_out_scope(mangle_options);
    return toplevel;
 }
--- a/test/compress/arrows.js
+++ b/test/compress/arrows.js
@@ -668,6 +668,28 @@ single_use_recursive: {
    node_version: ">=4"
 }

+inline_iife_within_arrow: {
+    options = {
+        arrows: true,
+        inline: true,
+    }
+    input: {
+        var f = () => console.log(function(a) {
+            return Math.ceil(a);
+        }(Math.random()));
+        f();
+    }
+    expect: {
+        var f = () => {
+            return console.log((a = Math.random(), Math.ceil(a)));
+            var a;
+        };
+        f();
+    }
+    expect_stdout: "1"
+    node_version: ">=4"
+}
+
 issue_4388: {
    options = {
        inline: true,
@@ -1073,7 +1095,7 @@ issue_5414_2: {
    node_version: ">=4"
 }

-issue_5416: {
+issue_5416_1: {
    options = {
        dead_code: true,
        evaluate: true,
@@ -1095,10 +1117,11 @@ issue_5416: {
    expect: {
        var f = () => {
            {
-                arguments = void 0;
                console;
+                arguments = void 0,
                console.log(arguments);
                var arguments;
+                return;
            }
        };
        f();
@@ -1106,3 +1129,133 @@ issue_5416: {
    expect_stdout: "undefined"
    node_version: ">=4"
 }
+
+issue_5416_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        inline: true,
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var f = () => {
+            while ((() => {
+                console;
+                var a = function g(arguments) {
+                    while (console.log(arguments));
+                }();
+            })());
+        };
+        f();
+    }
+    expect: {
+        var f = () => {
+            {
+                console;
+                var arguments = void 0;
+                for (; console.log(arguments););
+                return;
+            }
+        };
+        f();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_5416_3: {
+    options = {
+        inline: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var f = () => {
+            (() => {
+                var a = function g(arguments) {
+                    console.log(arguments);
+                }();
+            })();
+        };
+        f();
+    }
+    expect: {
+        var f = () => {
+            arguments = void 0,
+            console.log(arguments);
+            var arguments;
+        };
+        f();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_5416_4: {
+    options = {
+        arrows: true,
+        inline: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var f = () => {
+            (() => {
+                var a = function g(arguments) {
+                    while (console.log(arguments));
+                }();
+            })();
+        };
+        f();
+    }
+    expect: {
+        var f = () => {
+            var arguments = void 0;
+            while (console.log(arguments));
+            return;
+        };
+        f();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_5495: {
+    input: {
+        console.log((() => {
+            "use strict";
+            return function() {
+                return this;
+            }();
+        })());
+    }
+    expect_exact: 'console.log((()=>{"use strict";return function(){return this}()})());'
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_5653: {
+    options = {
+        arrows: true,
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        console.log((a => {
+            a = { p: console };
+            return a++;
+        })());
+    }
+    expect: {
+        console.log((a => {
+            return console, +{};
+        })());
+    }
+    expect_stdout: "NaN"
+    node_version: ">=4"
+}
--- a/test/compress/assignments.js
+++ b/test/compress/assignments.js
@@ -290,6 +290,45 @@ increment_decrement_2: {
    expect_stdout: "42"
 }

+lazily_chained_assignments: {
+    options = {
+        assignments: true,
+        collapse_vars: true,
+        conditionals: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            if (a = console.log("foo"))
+                a = console.log("bar");
+            return a;
+        }
+        function g(b) {
+            if (b = console.log("baz"))
+                ;
+            else
+                b = console.log("moo");
+            return b;
+        }
+        console.log(f(), g());
+    }
+    expect: {
+        function f(a) {
+            return console.log("foo") && console.log("bar");
+        }
+        function g(b) {
+            return console.log("baz") || console.log("moo");
+        }
+        console.log(f(), g());
+    }
+    expect_stdout: [
+        "foo",
+        "baz",
+        "moo",
+        "undefined undefined",
+    ]
+}
+
 issue_3375_1: {
    options = {
        assignments: true,
@@ -803,3 +842,23 @@ issue_4924_2: {
    expect_stdout: "PASS"
    node_version: ">=15"
 }
+
+issue_5670: {
+    options = {
+        assignments: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a, b) {
+            a && a && (a = b += "") || console.log("PASS");
+        })();
+    }
+    expect: {
+        (function(a, b) {
+            a = a,
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/awaits.js
+++ b/test/compress/awaits.js
@@ -529,6 +529,7 @@ inline_block_await: {

 inline_block_await_async: {
    options = {
+        awaits: true,
        inline: true,
    }
    input: {
@@ -1046,6 +1047,60 @@ collapse_vars_3: {
    node_version: ">=8"
 }

+collapse_funarg_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        A = "FAIL";
+        var a = "PASS";
+        (async function({}, b) {
+            return b;
+        })(null, A = a);
+        console.log(A);
+    }
+    expect: {
+        A = "FAIL";
+        var a = "PASS";
+        (async function({}, b) {
+            return b;
+        })(null, A = a);
+        console.log(A);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+collapse_funarg_2: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        A = "FAIL";
+        B = "PASS";
+        (async function() {
+            console.log(function({}, a) {
+                return a;
+            }(null, A = B));
+        })();
+        console.log(A);
+    }
+    expect: {
+        A = "FAIL";
+        B = "PASS";
+        (async function() {
+            console.log(function({}, a) {
+                return a;
+            }(null, A = B));
+        })();
+        console.log(A);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
 collapse_property_lambda: {
    options = {
        collapse_vars: true,
@@ -1293,6 +1348,21 @@ functions_inner_var: {
    node_version: ">=8"
 }

+instanceof_lambda: {
+    options = {
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(42 instanceof async function() {});
+    }
+    expect: {
+        console.log(false);
+    }
+    expect_stdout: "false"
+    node_version: ">=8"
+}
+
 issue_4335_1: {
    options = {
        inline: true,
@@ -1748,8 +1818,8 @@ issue_4454_2: {
    expect: {
        function f(a) {
            (async function(c = console.log(a)) {})();
-            var a = 42..toString();
-            console.log(a);
+            var b = 42..toString();
+            console.log(b);
        }
        f("PASS");
    }
@@ -2427,80 +2497,6 @@ issue_5023_2: {
    node_version: ">=8"
 }

-issue_5032_normal: {
-    options = {
-        merge_vars: true,
-        webkit: false,
-    }
-    input: {
-        function log(value) {
-            console.log(value);
-            return value;
-        }
-        async function f(a) {
-            var b = log(a), c = b;
-            log(b);
-            log(c);
-        }
-        f("PASS");
-    }
-    expect: {
-        function log(value) {
-            console.log(value);
-            return value;
-        }
-        async function f(a) {
-            var a = log(a), c = a;
-            log(a);
-            log(c);
-        }
-        f("PASS");
-    }
-    expect_stdout: [
-        "PASS",
-        "PASS",
-        "PASS",
-    ]
-    node_version: ">=8"
-}
-
-issue_5032_webkit: {
-    options = {
-        merge_vars: true,
-        webkit: true,
-    }
-    input: {
-        function log(value) {
-            console.log(value);
-            return value;
-        }
-        async function f(a) {
-            var b = log(a), c = b;
-            log(b);
-            log(c);
-        }
-        f("PASS");
-    }
-    expect: {
-        function log(value) {
-            console.log(value);
-            return value;
-        }
-        async function f(a) {
-            var b = log(a), c = b;
-            log(b);
-            log(c);
-        }
-        f("PASS");
-    }
-    expect_stdout: [
-        "PASS",
-        "PASS",
-        "PASS",
-    ]
-    node_version: ">=8"
-}
-
 issue_5034: {
    options = {
        functions: true,
@@ -2752,6 +2748,7 @@ issue_5177: {

 issue_5250: {
    options = {
+        awaits: true,
        inline: true,
    }
    input: {
@@ -2860,6 +2857,7 @@ issue_5298: {

 issue_5305_1: {
    options = {
+        awaits: true,
        inline: true,
    }
    input: {
@@ -2893,6 +2891,7 @@ issue_5305_1: {

 issue_5305_2: {
    options = {
+        awaits: true,
        inline: true,
    }
    input: {
@@ -2959,3 +2958,643 @@ issue_5305_3: {
    expect_stdout: "PASS"
    node_version: ">=8"
 }
+
+issue_5456: {
+    options = {
+        inline: true,
+        merge_vars: true,
+    }
+    input: {
+        var a = true;
+        (function() {
+            (function(b, c) {
+                var d = async function() {
+                    c = await null;
+                }();
+                var e = function() {
+                    if (c)
+                        console.log(typeof d);
+                    while (b);
+                }();
+            })(function(i) {
+                return console.log("foo") && i;
+            }(a));
+        })();
+    }
+    expect: {
+        var a = true;
+        (function() {
+            b = (i = a, console.log("foo") && i),
+            d = async function() {
+                c = await null;
+            }(),
+            e = function() {
+                if (c) console.log(typeof d);
+                while (b);
+            }(),
+            void 0;
+            var b, c, d, e;
+            var i;
+        })();
+    }
+    expect_stdout: "foo"
+    node_version: ">=8"
+}
+
+issue_5478: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        A = {
+            get then() {
+                a = "FAIL";
+            },
+        };
+        var a = "PASS";
+        (async function() {
+            for (var b in "foo")
+                return void A;
+        })();
+        console.log(a);
+    }
+    expect: {
+        A = {
+            get then() {
+                a = "FAIL";
+            },
+        };
+        var a = "PASS";
+        (async function() {
+            for (var b in "foo")
+                return !A;
+        })();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+issue_5493: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+    }
+    input: {
+        (async function(a) {
+            var b = await [ 42 || b, a = b ];
+            console.log(a);
+        })();
+    }
+    expect: {
+        (async function(a) {
+            var b = await [ 42 || b, a = b ];
+            console.log(a);
+        })();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=8"
+}
+
+issue_5506: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        console.log(function(a) {
+            (async function() {
+                a = null in (a = "PASS");
+            })();
+            return a;
+        }("FAIL"));
+    }
+    expect: {
+        console.log(function(a) {
+            (async function() {
+                a = null in (a = "PASS");
+            })();
+            return a;
+        }("FAIL"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8"
+}
+
+issue_5528_1: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        (async function() {
+            await function() {
+                try {
+                    return;
+                } finally {
+                    console.log("foo");
+                }
+            }();
+        })();
+        console.log("bar");
+    }
+    expect: {
+        (async function() {
+            await function() {
+                try {
+                    return;
+                } finally {
+                    console.log("foo");
+                }
+            }();
+        })();
+        console.log("bar");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    node_version: ">=8"
+}
+
+issue_5528_2: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        (async function() {
+            await function() {
+                try {
+                    return 42;
+                } finally {
+                    console.log("foo");
+                }
+            }();
+        })();
+        console.log("bar");
+    }
+    expect: {
+        (async function() {
+            await function() {
+                try {
+                    return 42;
+                } finally {
+                    console.log("foo");
+                }
+            }();
+        })();
+        console.log("bar");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    node_version: ">=8"
+}
+
+issue_5528_3: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        (async function() {
+            await function() {
+                try {
+                    FAIL;
+                } catch (e) {
+                    return console.log("foo");
+                } finally {
+                    console.log("bar");
+                }
+            }();
+        })();
+        console.log("baz");
+    }
+    expect: {
+        (async function() {
+            await function() {
+                try {
+                    FAIL;
+                } catch (e) {
+                    return console.log("foo");
+                } finally {
+                    console.log("bar");
+                }
+            }();
+        })();
+        console.log("baz");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=8"
+}
+
+issue_5528_4: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        (async function() {
+            await function() {
+                try {
+                    return {
+                        then() {
+                            console.log("foo");
+                        },
+                    };
+                } finally {
+                    console.log("bar");
+                }
+            }();
+        })();
+        console.log("baz");
+    }
+    expect: {
+        (async function() {
+            await function() {
+                try {
+                    return {
+                        then() {
+                            console.log("foo");
+                        },
+                    };
+                } finally {
+                    console.log("bar");
+                }
+            }();
+        })();
+        console.log("baz");
+    }
+    expect_stdout: [
+        "bar",
+        "baz",
+        "foo",
+    ]
+    node_version: ">=8"
+}
+
+issue_5634_1: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        var a = "foo";
+        (async function() {
+            (async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            })();
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "foo";
+        (async function() {
+            (async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            })();
+        })();
+        console.log(a);
+    }
+    expect_stdout: [
+        "moo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=8"
+}
+
+issue_5634_1_side_effects: {
+    options = {
+        awaits: true,
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        var a = "foo";
+        (async function() {
+            (async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            })();
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "foo";
+        (async function() {
+            try {
+                return {
+                    then(resolve) {
+                        console.log("bar");
+                        resolve();
+                        console.log("baz");
+                    },
+                };
+            } finally {
+                a = "moo";
+            }
+        })();
+        console.log(a);
+    }
+    expect_stdout: [
+        "moo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=8"
+}
+
+issue_5634_2: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        var a = "foo";
+        (async function() {
+            await async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            }();
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "foo";
+        (async function() {
+            await async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            }();
+        })();
+        console.log(a);
+    }
+    expect_stdout: [
+        "moo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=8"
+}
+
+issue_5634_2_side_effects: {
+    options = {
+        awaits: true,
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        var a = "foo";
+        (async function() {
+            await async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            }();
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "foo";
+        (async function() {
+            try {
+                return {
+                    then(resolve) {
+                        console.log("bar");
+                        resolve();
+                        console.log("baz");
+                    },
+                };
+            } finally {
+                a = "moo";
+            }
+        })();
+        console.log(a);
+    }
+    expect_stdout: [
+        "moo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=8"
+}
+
+issue_5634_3: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        var a = "foo";
+        (async function() {
+            return async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            }();
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "foo";
+        (async function() {
+            return async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            }();
+        })();
+        console.log(a);
+    }
+    expect_stdout: [
+        "moo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=8"
+}
+
+issue_5634_3_side_effects: {
+    options = {
+        awaits: true,
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        var a = "foo";
+        (async function() {
+            return async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            console.log("bar");
+                            resolve();
+                            console.log("baz");
+                        },
+                    };
+                } finally {
+                    a = "moo";
+                }
+            }();
+        })();
+        console.log(a);
+    }
+    expect: {
+        var a = "foo";
+        (async function() {
+            try {
+                return {
+                    then(resolve) {
+                        console.log("bar");
+                        resolve();
+                        console.log("baz");
+                    },
+                };
+            } finally {
+                a = "moo";
+            }
+        })();
+        console.log(a);
+    }
+    expect_stdout: [
+        "moo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=8"
+}
+
+issue_5692_1: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        (async function() {
+            (async function() {
+                for await (var k of []);
+            })();
+            console.log("foo");
+        })();
+        console.log("bar");
+    }
+    expect: {
+        (async function() {
+            (async function() {
+                for await (var k of []);
+            })();
+            console.log("foo");
+        })();
+        console.log("bar");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    node_version: ">=10"
+}
+
+issue_5692_2: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        (async function() {
+            (async function() {
+                for (var k of []);
+            })();
+            console.log("foo");
+        })();
+        console.log("bar");
+    }
+    expect: {
+        (async function() {
+            for (var k of []);
+            console.log("foo");
+        })();
+        console.log("bar");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    node_version: ">=8"
+}
--- a/test/compress/booleans.js
+++ b/test/compress/booleans.js
@@ -80,6 +80,25 @@ de_morgan_1c: {
    expect_stdout: "true"
 }

+de_morgan_1d: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        function f(a) {
+            return (a = false) || a;
+        }
+        console.log(f(null), f(42));
+    }
+    expect: {
+        function f(a) {
+            return a = !1;
+        }
+        console.log(f(null), f(42));
+    }
+    expect_stdout: "false false"
+}
+
 de_morgan_2a: {
    options = {
        booleans: true,
@@ -181,6 +200,31 @@ de_morgan_2d: {
    ]
 }

+de_morgan_2e: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        function f(a, b) {
+            return (a && b) && b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect: {
+        function f(a, b) {
+            return a && b;
+        }
+        console.log(f(null), f(null, {}));
+        console.log(f(42), f(42, {}));
+    }
+    expect_stdout: [
+        "null null",
+        "undefined {}",
+    ]
+}
+
 de_morgan_3a: {
    options = {
        booleans: true,
@@ -762,3 +806,61 @@ issue_5228: {
    }
    expect_stdout: "true"
 }
+
+issue_5469: {
+    options = {
+        assignments: true,
+        booleans: true,
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        pure_getters: "strict",
+        side_effects: true,
+    }
+    input: {
+        console.log(function f(a) {
+            a && 42[a = A && null];
+        }());
+    }
+    expect: {
+        console.log(function f(a) {
+            a && A,
+            0;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5694_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var Infinity;
+        // Node.js v0.12~6 (vm): 42
+        console.log((Infinity = 42) && Infinity);
+    }
+    expect: {
+        var Infinity;
+        console.log((Infinity = 42) && Infinity);
+    }
+    expect_stdout: true
+}
+
+issue_5694_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+    }
+    input: {
+        var undefined;
+        // Node.js v0.12~6 (vm): NaN
+        console.log(("foo", ++undefined) || undefined);
+    }
+    expect: {
+        var undefined;
+        console.log(("foo", ++undefined) || undefined);
+    }
+    expect_stdout: true
+}
--- a/test/compress/classes.js
+++ b/test/compress/classes.js
--- a/test/compress/collapse_vars.js
+++ b/test/compress/collapse_vars.js
@@ -9321,12 +9321,11 @@ issue_4874: {
        })(a = 42);
    }
    expect: {
-        var a;
        null;
        (function(b) {
-            for (var c in a && a[console.log("PASS")])
+            for (var c in 42, 42[console.log("PASS")])
                console;
-        })(a = 42);
+        })();
    }
    expect_stdout: "PASS"
 }
@@ -9979,3 +9978,146 @@ issue_5396: {
    }
    expect_stdout: "PASS"
 }
+
+issue_5568: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        A = "FAIL";
+        var a = (A = "PASS", !1);
+        for (var b in a);
+        console.log(A);
+    }
+    expect: {
+        A = "FAIL";
+        for (var b in !(A = "PASS"));
+        console.log(A);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5638_1: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a;
+        console;
+        a = [ 42 ];
+        console || FAIL(a);
+        console.log(a++);
+    }
+    expect: {
+        var a;
+        console;
+        a = [ 42 ];
+        console || FAIL(a);
+        console.log(a++);
+    }
+    expect_stdout: "42"
+}
+
+issue_5638_2: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a;
+        console;
+        a = [ 6 ];
+        console || FAIL(a);
+        console.log(a *= 7);
+    }
+    expect: {
+        var a;
+        console;
+        a = [ 6 ];
+        console || FAIL(a);
+        console.log(a *= 7);
+    }
+    expect_stdout: "42"
+}
+
+issue_5638_3: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var log = console.log;
+        var a = { foo: 42 }, b;
+        for (var k in a) {
+            b = a[k];
+            log(k || b, b++);
+        }
+    }
+    expect: {
+        var log = console.log;
+        var a = { foo: 42 }, b;
+        for (var k in a) {
+            b = a[k];
+            log(k || b, b++);
+        }
+    }
+    expect_stdout: "foo 42"
+}
+
+issue_5638_4: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var log = console.log;
+        var a = { foo: 6 }, b;
+        for (var k in a) {
+            b = a[k];
+            log(k || b, b *= 7);
+        }
+    }
+    expect: {
+        var log = console.log;
+        var a = { foo: 6 }, b;
+        for (var k in a) {
+            b = a[k];
+            log(k || b, b *= 7);
+        }
+    }
+    expect_stdout: "foo 42"
+}
+
+issue_5643: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 3, b;
+        a *= 7;
+        b = !!this;
+        console || console.log(b);
+        console.log(a * ++b);
+    }
+    expect: {
+        var a = 3, b;
+        a *= 7;
+        b = !!this;
+        console || console.log(b);
+        console.log(a * ++b);
+    }
+    expect_stdout: "42"
+}
--- a/test/compress/comparisons.js
+++ b/test/compress/comparisons.js
@@ -40,6 +40,22 @@ unsafe_comps: {
    }
 }

+unsafe_in_instanceof: {
+    options = {
+        side_effects: true,
+        unsafe_comps: true,
+    }
+    input: {
+        var a;
+        42 in a;
+        f() instanceof "foo";
+    }
+    expect: {
+        var a;
+        f();
+    }
+}
+
 dont_change_in_or_instanceof_expressions: {
    input: {
        1 in 1;
@@ -259,6 +275,7 @@ issue_2857_3: {
 issue_2857_4: {
    options = {
        comparisons: true,
+        conditionals: true,
    }
    input: {
        function f(a, p) {
@@ -289,6 +306,7 @@ issue_2857_4: {
 issue_2857_5: {
    options = {
        comparisons: true,
+        conditionals: true,
    }
    input: {
        function f(a, p) {
@@ -512,6 +530,7 @@ nullish_assign: {
 nullish_chain: {
    options = {
        comparisons: true,
+        conditionals: true,
    }
    input: {
        var a;
--- a/test/compress/concat-strings.js
+++ b/test/compress/concat-strings.js
@@ -12,7 +12,7 @@ concat_1: {

        var e = 1 + x() + 2 + "X" + 3 + "boo";

-        // be careful with concatentation with "\0" with octal-looking strings.
+        // be careful with concatenation with "\0" with octal-looking strings.
        var f = "\0" + 360 + "\0" + 8 + "\0";
    }
    expect: {
--- a/test/compress/conditionals.js
+++ b/test/compress/conditionals.js
--- a/test/compress/const.js
+++ b/test/compress/const.js
@@ -142,6 +142,80 @@ if_dead_branch: {
    expect_stdout: "undefined"
 }

+retain_tail_1: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function f(a) {
+            var b = "foo";
+            if (a) {
+                const b = "bar";
+                while (console.log("baz"));
+                console.log(b);
+            } else {
+                while (console.log("moo"));
+                console.log(b);
+            }
+        }
+        f();
+        f(42);
+    }
+    expect: {
+        function f(a) {
+            var b = "foo";
+            if (a) {
+                const b = "bar";
+                while (console.log("baz"));
+                console.log(b);
+            } else {
+                while (console.log("moo"));
+                console.log(b);
+            }
+        }
+        f();
+        f(42);
+    }
+    expect_stdout: true
+}
+
+retain_tail_2: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function f(a) {
+            var b = "foo";
+            if (a) {
+                while (console.log("bar"));
+                console.log(b);
+            } else {
+                const b = "baz";
+                while (console.log("moo"));
+                console.log(b);
+            }
+        }
+        f();
+        f(42);
+    }
+    expect: {
+        function f(a) {
+            var b = "foo";
+            if (a) {
+                while (console.log("bar"));
+                console.log(b);
+            } else {
+                const b = "baz";
+                while (console.log("moo"));
+                console.log(b);
+            }
+        }
+        f();
+        f(42);
+    }
+    expect_stdout: true
+}
+
 merge_vars_1: {
    options = {
        merge_vars: true,
@@ -579,6 +653,37 @@ dead_block_after_return: {
    expect_stdout: true
 }

+if_return_3: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        var a = "PASS";
+        function f(b) {
+            if (console) {
+                const b = a;
+                return b;
+            } else
+                while (console.log("FAIL 1"));
+            return b;
+        }
+        console.log(f("FAIL 2"));
+    }
+    expect: {
+        var a = "PASS";
+        function f(b) {
+            if (console) {
+                const b = a;
+                return b;
+            } else
+                while (console.log("FAIL 1"));
+            return b;
+        }
+        console.log(f("FAIL 2"));
+    }
+    expect_stdout: true
+}
+
 do_if_continue_1: {
    options = {
        if_return: true,
@@ -1855,3 +1960,247 @@ issue_5338: {
    }
    expect_stdout: true
 }
+
+issue_5476: {
+    mangle = {
+        keep_fargs: true,
+    }
+    input: {
+        console.log(function(n) {
+            const a = 42;
+        }());
+    }
+    expect: {
+        console.log(function(n) {
+            const o = 42;
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5516: {
+    options = {
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(typeof function() {
+            try {} catch (a) {
+                (function f() {
+                    a;
+                })();
+            }
+            {
+                const a = function() {};
+                return a;
+            }
+        }());
+    }
+    expect: {
+        console.log(typeof function() {
+            try {} catch (a) {
+                void a;
+            }
+            {
+                const a = function() {};
+                return a;
+            }
+        }());
+    }
+    expect_stdout: "function"
+}
+
+issue_5580_1: {
+    mangle = {}
+    input: {
+        "use strict";
+        console.log(function(a, b, c) {
+            try {
+                FAIL;
+            } catch (e) {
+                return function() {
+                    var d = e, i, j;
+                    {
+                        const e = j;
+                    }
+                    return a;
+                }();
+            } finally {
+                const e = 42;
+            }
+        }("PASS"));
+    }
+    expect: {
+        "use strict";
+        console.log(function(r, n, t) {
+            try {
+                FAIL;
+            } catch (o) {
+                return function() {
+                    var n = o, t, c;
+                    {
+                        const o = c;
+                    }
+                    return r;
+                }();
+            } finally {
+                const c = 42;
+            }
+        }("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_5580_2: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        (function() {
+            try {
+                throw "PASS";
+            } catch (e) {
+                return function() {
+                    console.log(e);
+                    {
+                        const e = "FAIL 1";
+                    }
+                }();
+            } finally {
+                const e = "FAIL 2";
+            }
+        })();
+    }
+    expect: {
+        "use strict";
+        (function() {
+            try {
+                throw "PASS";
+            } catch (e) {
+                console.log(e);
+                {
+                    const e = "FAIL 1";
+                }
+                return;
+            } finally {
+                var e = "FAIL 2";
+            }
+        })();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_5591: {
+    options = {
+        dead_code: true,
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console.log("baz"))
+                    return;
+                else {
+                    const a = 42;
+                    return;
+                }
+                break;
+              case null:
+                FAIL;
+            }
+        }
+        f();
+    }
+    expect: {
+        "use strict";
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console.log("baz"))
+                    return;
+                else {
+                    const a = 42;
+                    return;
+                }
+              case null:
+                FAIL;
+            }
+        }
+        f();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=4"
+}
+
+issue_5656: {
+    options = {
+        collapse_vars: true,
+        merge_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            var b = a;
+            b++;
+            {
+                const a = b;
+            }
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            var b = a;
+            {
+                const a = ++b;
+            }
+        }());
+    }
+    expect_stdout: true
+}
+
+issue_5660: {
+    options = {
+        merge_vars: true,
+        side_effects: true,
+    }
+    input: {
+        function f() {
+            try {
+                a;
+                var b;
+                return b;
+            } catch (e) {
+                var a = "FAIL";
+                const b = null;
+                return a;
+            }
+        }
+        console.log(f());
+    }
+    expect: {
+        function f() {
+            try {
+                var b;
+                return b;
+            } catch (e) {
+                var a = "FAIL";
+                const b = null;
+                return a;
+            }
+        }
+        console.log(f());
+    }
+    expect_stdout: true
+}
--- a/test/compress/dead-code.js
+++ b/test/compress/dead-code.js
@@ -1485,8 +1485,6 @@ self_assignments_5: {
    }
    expect: {
        var i = 0, l = [ "FAIL", "PASS" ];
-        l[0];
-        l[0];
        l[0] = l[1];
        console.log(l[0], 2);
    }
@@ -1669,3 +1667,66 @@ issue_5106_2: {
    }
    expect_stdout: "PASS"
 }
+
+issue_5506: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        try {
+            (function(a) {
+                var b = 1;
+                (function f() {
+                    try {
+                        b-- && f();
+                    } catch (c) {}
+                    console.log(a);
+                    a = 42 in (a = "bar");
+                })();
+            })("foo");
+        } catch (e) {}
+    }
+    expect: {
+        try {
+            (function(a) {
+                var b = 1;
+                (function f() {
+                    try {
+                        b-- && f();
+                    } catch (c) {}
+                    console.log(a);
+                    a = 42 in (a = "bar");
+                })();
+            })("foo");
+        } catch (e) {}
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+}
+
+issue_5641: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        dead_code: true,
+    }
+    input: {
+        function f(a) {
+            if (a || b) {
+                var b = "PASS", c = b && console.log(b);
+            } else
+                var d = a || b;
+        }
+        f(42);
+    }
+    expect: {
+        function f(a) {
+            var b, c, d;
+            (a || b) && (b = "PASS") && console.log(b);
+        }
+        f(42);
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/default-values.js
+++ b/test/compress/default-values.js
@@ -180,6 +180,26 @@ collapse_arg_sequence: {
    node_version: ">=6"
 }

+collapse_in_arg: {
+    options = {
+        collapse_vars: true,
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        (function(a, b = a) {
+            b("PASS");
+        })(console.log);
+    }
+    expect: {
+        (function(a) {
+            a("PASS");
+        })(console.log);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
 collapse_value_1: {
    options = {
        collapse_vars: true,
@@ -541,7 +561,7 @@ inline_side_effects_2: {
    }
    expect: {
        var a = 42;
-        [ [].e = --a ] = [ console ];
+        [ [][0] = --a ] = [ console ];
        console.log(a);
    }
    expect_stdout: "42"
@@ -648,6 +668,8 @@ drop_fargs: {
 hoist_vars: {
    options = {
        hoist_vars: true,
+        join_vars: true,
+        unused: true,
    }
    input: {
        var a = "PASS";
@@ -655,8 +677,7 @@ hoist_vars: {
        console.log(a, b);
    }
    expect: {
-        var a = "PASS";
-        var [ b = 42 ] = [];
+        var a = "PASS", [ b = 42 ] = [];
        console.log(a, b);
    }
    expect_stdout: "PASS 42"
@@ -1170,6 +1191,49 @@ mangle_arrow_2_toplevel: {
    node_version: ">=6.9.3"
 }

+collapse_preceding_simple_arg: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = "foo";
+        console.log(function(b, c = "bar") {
+            return b + c;
+        }(a, a));
+    }
+    expect: {
+        var a = "foo";
+        console.log(function(b, c = "bar") {
+            return a + c;
+        }(0, a));
+    }
+    expect_stdout: "foofoo"
+    node_version: ">=6"
+}
+
+drop_preceding_simple_arg: {
+    options = {
+        collapse_vars: true,
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        var a = "foo";
+        console.log(function(b, c = "bar") {
+            return b + c;
+        }(a, a));
+    }
+    expect: {
+        var a = "foo";
+        console.log(function(c = "bar") {
+            return a + c;
+        }(a));
+    }
+    expect_stdout: "foofoo"
+    node_version: ">=6"
+}
+
 issue_4444: {
    options = {
        collapse_vars: true,
@@ -1558,7 +1622,7 @@ issue_4502_4: {
        (function(a, b = console.log("FAIL")) {})(..."" + console.log(42));
    }
    expect: {
-        [ , [].e = console.log("FAIL") ] = [ ..."" + console.log(42) ];
+        [ , [][0] = console.log("FAIL") ] = [ ..."" + console.log(42) ];
    }
    expect_stdout: "42"
    node_version: ">=6"
@@ -1655,7 +1719,7 @@ issue_4540: {
    node_version: ">=6"
 }

-issue_4548: {
+issue_4548_1: {
    options = {
        merge_vars: true,
        toplevel: true,
@@ -1681,6 +1745,32 @@ issue_4548: {
    node_version: ">=6"
 }

+issue_4548_2: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        A = "foo";
+        var a = A;
+        var [ b = c = "bar" ] = [ console, console.log(a) ];
+        console.log(c);
+        var c;
+    }
+    expect: {
+        A = "foo";
+        var a = A;
+        var [ b = c = "bar" ] = [ console, console.log(a) ];
+        console.log(c);
+        var c;
+    }
+    expect_stdout: [
+        "foo",
+        "undefined",
+    ]
+    node_version: ">=6"
+}
+
 issue_4588_1_unused: {
    options = {
        unused: true,
@@ -2023,7 +2113,7 @@ issue_5246_1: {
    }
    expect_stdout: "PASS"
    expect_warnings: [
-        "INFO: Dropping unused default argument {}=42 [test/compress/default-values.js:1,29]",
+        "INFO: Dropping unused default argument {} [test/compress/default-values.js:1,29]",
    ]
    node_version: ">=6"
 }
@@ -2183,7 +2273,7 @@ issue_5340_2: {
    }
    expect: {
        var a;
-        [ [].e = 0 ] = [ ({ p: a } = true).q ];
+        [ [][0] = 0 ] = [ ({ p: a } = true).q ];
        console.log(a);
    }
    expect_stdout: "undefined"
@@ -2239,3 +2329,743 @@ issue_5407: {
    ]
    node_version: ">=6"
 }
+
+issue_5444_1: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 42;
+        var b = function({} = setImmediate(function() {
+            console.log(a++);
+        })) {
+            return this;
+        }();
+        console.log(typeof b);
+    }
+    expect: {
+        var a = 42;
+        var b = function({} = setImmediate(function() {
+            console.log(a++);
+        })) {
+            return this;
+        }();
+        console.log(typeof b);
+    }
+    expect_stdout: [
+        "object",
+        "42",
+    ]
+    node_version: ">=6"
+}
+
+issue_5444_2: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a, b = a++) {
+            return b;
+        }
+        console.log(f("FAIL") || "PASS");
+    }
+    expect: {
+        function f(a, b = a++) {
+            return b;
+        }
+        console.log(f("FAIL") || "PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5444_3: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a, b = function(c = a *= this) {
+            return c;
+        }()) {
+            return b;
+        }
+        console.log(f("FAIL") || "PASS");
+    }
+    expect: {
+        function f(a, b = function(c = a *= this) {
+            return c;
+        }()) {
+            return b;
+        }
+        console.log(f("FAIL") || "PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5448_1: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a = typeof console.log) {
+            do {
+                var b = [ ...a ];
+            } while (console.log("PASS"));
+        })();
+    }
+    expect: {
+        (function(a = console.log) {
+            do {} while (console.log("PASS"));
+        })();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5448_2: {
+    options = {
+        keep_fargs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a = typeof console) {
+            do {
+                var b = [ ...a ];
+            } while (console.log("PASS"));
+        })();
+    }
+    expect: {
+        (function(a = 0) {
+            do {} while (console.log("PASS"));
+        })();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5448_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var [ a = typeof console ] = [ void console.log("PASS") ];
+        var b = [ ...a ];
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5448_4: {
+    options = {
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var { p: a = typeof console } = { p: void console.log("PASS") };
+        var b = [ ...a ];
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5463: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        if (console.log("PASS"))
+            var a = void 0,
+                b = void 0,
+                b = ([ a = FAIL ] = b && b);
+    }
+    expect: {
+        var a, b, b;
+        console.log("PASS") && (
+            b = a = void 0,
+            b = [a = FAIL] = a
+        );
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5465: {
+    options = {
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            (function(c = b = "FAIL 2") {
+                this && console.log(b || "PASS");
+            })(42 - a && a);
+        }
+        f("FAIL 1");
+    }
+    expect: {
+        a = "FAIL 1",
+        void function(c = b = "FAIL 2") {
+            this && console.log(b || "PASS");
+        }(42 - a && a);
+        var a, b;
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5485: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        (function f(f, a = console.log(void 0 === f ? "PASS" : "FAIL")) {})();
+    }
+    expect: {
+        (function f(f, a = console.log(void 0 === f ? "PASS" : "FAIL")) {})();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_1_keep_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(b = 42) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_1_drop_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: false,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(b = 42) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_2_keep_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f([ b ] = []) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;) {
+                    var [ [] = [] ] = [];
+                    throw "PASS";
+                }
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_2_drop_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: false,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f([ b ] = []) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;) {
+                    var [ [ , ] = [] ] = [];
+                    throw "PASS";
+                }
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_3_keep_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(b = 42, c = null) {
+                            c;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_3_drop_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: false,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(b = 42, c = null) {
+                            c;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_4_keep_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(b = 42, [ c ] = []) {
+                            c;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;) {
+                    var [ [] = [] ] = [];
+                    throw "PASS";
+                }
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_4_drop_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: false,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(b = 42, [ c ] = []) {
+                            c;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;) {
+                    var [ [] = [] ] = [];
+                    throw "PASS";
+                }
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5536: {
+    options = {
+        inline: true,
+        keep_fargs: true,
+        unused: true,
+    }
+    input: {
+        (function*() {
+            (([], a = 42) => {})([]);
+            console.log(typeof a);
+        })().next();
+    }
+    expect: {
+        (function*() {
+            [ , [][0] = 0 ] = [ [] ],
+            void 0;
+            console.log(typeof a);
+        })().next();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=6"
+}
+
+issue_5566_1: {
+    options = {
+        unused: true,
+    }
+    input: {
+        (function(a, f = function() {
+            return a;
+        }) {
+            var a = "foo";
+            console.log(a, f());
+        })("bar");
+    }
+    expect: {
+        (function(a, f = function() {
+            return a;
+        }) {
+            var a = "foo";
+            console.log(a, f());
+        })("bar");
+    }
+    expect_stdout: "foo bar"
+    node_version: ">=6"
+}
+
+issue_5566_2: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a, f = function() {
+            return a;
+        }) {
+            function a() {}
+            console.log(typeof a, typeof f());
+        })(42);
+    }
+    expect: {
+        (function(a, f = function() {
+            return a;
+        }) {
+            function a() {}
+            console.log(typeof a, typeof f());
+        })(42);
+    }
+    expect_stdout: "function number"
+    node_version: ">=6"
+}
+
+issue_5566_3: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a, f = function() {
+            return a;
+        }) {
+            function a() {}
+            console.log(typeof a, typeof f());
+        })(42);
+    }
+    expect: {
+        (function(a, f = function() {
+            return a;
+        }) {
+            function a() {}
+            console.log(typeof a, typeof f());
+        })(42);
+    }
+    expect_stdout: "function number"
+    node_version: ">=6"
+}
+
+issue_5566_4: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a, b = function() {
+            return a;
+        }) {
+            var a = 0;
+            b()("PASS");
+        })(console.log);
+    }
+    expect: {
+        (function(a, b = function() {
+            return a;
+        }) {
+            var a = 0;
+            b()("PASS");
+        })(console.log);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5566_5: {
+    options = {
+        hoist_vars: true,
+    }
+    input: {
+        (function(a, f = function() {
+            return a;
+        }) {
+            var a = "foo";
+            var b;
+            console.log(a, f());
+        })("bar");
+    }
+    expect: {
+        (function(a, f = function() {
+            return a;
+        }) {
+            var a, b;
+            a = "foo";
+            console.log(a, f());
+        })("bar");
+    }
+    expect_stdout: "foo bar"
+    node_version: ">=6"
+}
+
+issue_5651: {
+    options = {
+        ie: true,
+        unused: true,
+    }
+    input: {
+        console.log(function arguments(a = "FAIL") {
+            try {} catch (arguments) {
+                var arguments;
+            }
+            return arguments[0];
+        }());
+    }
+    expect: {
+        console.log(function arguments(a = "FAIL") {
+            try {} catch (arguments) {
+                var arguments;
+            }
+            return arguments[0];
+        }());
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
--- a/test/compress/destructured.js
+++ b/test/compress/destructured.js
@@ -472,6 +472,93 @@ funarg_collapse_vars_3: {
    node_version: ">=6"
 }

+funarg_collapse_vars_4: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        (function(b, { log: c }) {
+            c(b);
+        })(a, console);
+    }
+    expect: {
+        var a = "PASS";
+        (function(b, { log: c }) {
+            c(a);
+        })(0, console);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+funarg_collapse_vars_5: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        A = "FAIL";
+        B = "PASS";
+        try {
+            console.log(function({}, a) {
+                return a;
+            }(null, A = B));
+        } catch (e) {}
+        console.log(A);
+    }
+    expect: {
+        A = "FAIL";
+        B = "PASS";
+        try {
+            console.log(function({}, a) {
+                return a;
+            }(null, A = B));
+        } catch (e) {}
+        console.log(A);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+funarg_collapse_vars_6: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        A = "FAIL";
+        B = "PASS";
+        function f() {
+            console.log(function({}, a) {
+                return a;
+            }(null, A = B));
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log(A);
+        }
+    }
+    expect: {
+        A = "FAIL";
+        B = "PASS";
+        function f() {
+            console.log(function({}, a) {
+                return a;
+            }(null, A = B));
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log(A);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
 funarg_reduce_vars_1: {
    options = {
        reduce_vars: true,
@@ -1219,7 +1306,7 @@ keep_reference: {
    }
    expect: {
        var a = [ {}, 42 ];
-        var [ b ] = a;
+        var b = a[0];
        console.log(a[0] === b ? "PASS" : "FAIL");
    }
    expect_stdout: "PASS"
@@ -1565,6 +1652,8 @@ fn_name_unused: {
 hoist_vars: {
    options = {
        hoist_vars: true,
+        join_vars: true,
+        unused: true,
    }
    input: {
        var a = "PASS";
@@ -1572,8 +1661,7 @@ hoist_vars: {
        console.log(a, b);
    }
    expect: {
-        var a = "PASS";
-        var [ b ] = [ 42 ];
+        var a = "PASS", b = [ 42 ][0];
        console.log(a, b);
    }
    expect_stdout: "PASS 42"
@@ -1649,6 +1737,23 @@ singleton_side_effects: {
    node_version: ">=6"
 }

+mangle_properties: {
+    mangle = {
+        properties: {
+            domprops: true,
+        },
+    }
+    input: {
+        function f({ p: a }) {
+            return a;
+        }
+        console.log(f({ p: "PASS" }));
+    }
+    expect_exact: 'function f({n}){return n}console.log(f({n:"PASS"}));'
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
 issue_4280: {
    options = {
        evaluate: true,
@@ -1815,8 +1920,8 @@ issue_4288: {
                console.log(typeof b);
            }()]: a,
        }) {
-            var b = a;
-            b++;
+            var a = a;
+            a++;
        }
        f(0);
    }
@@ -1848,8 +1953,8 @@ issue_4294: {
            }) {}({
                [a]: 0,
            });
-            var a = A;
-            console.log(a);
+            var b = A;
+            console.log(b);
        })();
    }
    expect_stdout: "PASS"
@@ -1989,17 +2094,16 @@ issue_4312: {
        console.log(a);
    }
    expect: {
-        var a;
        b = "PASS",
        c = "FAIL",
        [
            {
-                [a = b]: d,
+                [c = b]: d,
            },
        ] = [ c && c ],
        void 0;
        var b, c, d;
-        console.log(a);
+        console.log(c);
    }
    expect_stdout: "PASS"
    node_version: ">=6"
@@ -3020,6 +3124,7 @@ issue_5074_method_pure_getters: {
 issue_5085_1: {
    options = {
        evaluate: true,
+        passes: 2,
        reduce_vars: true,
        toplevel: true,
        unsafe: true,
@@ -3032,8 +3137,7 @@ issue_5085_1: {
    }
    expect: {
        var a = "PASS";
-        var b = [ 42 ][0];
-        b;
+        42;
        console.log(a);
    }
    expect_stdout: "PASS"
@@ -3043,6 +3147,7 @@ issue_5085_1: {
 issue_5085_2: {
    options = {
        evaluate: true,
+        passes: 2,
        reduce_vars: true,
        side_effects: true,
        unsafe: true,
@@ -3059,7 +3164,7 @@ issue_5085_2: {
    expect: {
        var a = "PASS";
        (function(b) {
-            b = [ 42 ][0];
+            0;
        })();
        console.log(a);
    }
@@ -3400,7 +3505,7 @@ issue_5222: {
    node_version: ">=6"
 }

-issue_5288: {
+issue_5288_1: {
    options = {
        conditionals: true,
        inline: true,
@@ -3420,7 +3525,37 @@ issue_5288: {
        }() ]));
    }
    expect: {
-        while (console ? console.log("PASS") : 0, void 0);
+        while (function() {
+            if (console)
+                console.log("PASS");
+        }(), void 0);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5288_2: {
+    options = {
+        conditionals: true,
+        inline: true,
+        keep_fargs: false,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        while (function([]) {}([ function f() {
+            if (console)
+                return console.log("PASS");
+            else {
+                let a = 0;
+            }
+        }() ]));
+    }
+    expect: {
+        while (console && console.log("PASS"), void 0);
    }
    expect_stdout: "PASS"
    node_version: ">=6"
@@ -3466,7 +3601,7 @@ issue_5314_2: {
        A = this;
        new function() {
            [ {
-                [console.log(this === A ? "FAIL" : "PASS")]: [].e,
+                [console.log(this === A ? "FAIL" : "PASS")]: [][0],
            } ] = [ 42 ];
        }();
    }
@@ -3566,3 +3701,188 @@ issue_5423: {
    expect_stdout: "function"
    node_version: ">=6"
 }
+
+issue_5454: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var a = 42, a = {
+                p: [ a ] = [],
+            };
+            return "PASS";
+        }
+        console.log(f());
+    }
+    expect: {
+        console.log(function(a) {
+            a = 42, a = {
+                p: [ a ] = [],
+            };
+            return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5485: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        (function f({
+            p: f,
+            [console.log(void 0 === f ? "PASS" : "FAIL")]: a,
+        }) {})(42);
+    }
+    expect: {
+        (function f({
+            p: f,
+            [console.log(void 0 === f ? "PASS" : "FAIL")]: a,
+        }) {})(42);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_keep_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f([ b ]) {
+                            b;
+                            throw "PASS";
+                        })([]);
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_drop_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: false,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f([ b ]) {
+                            b;
+                            throw "PASS";
+                        })([]);
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5573: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var log = console.log;
+        var a = "FAIL";
+        (function([ { [log(a)]: b } ]) {
+            A = 42;
+        })((a = "PASS", [ {} ]));
+        log(a, A);
+    }
+    expect: {
+        var log = console.log;
+        var a = "FAIL";
+        (function([ { [log(a)]: b } ]) {
+            A = 42;
+        })((a = "PASS", [ {} ]));
+        log(a, A);
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS 42",
+    ]
+    node_version: ">=6"
+}
+
+issue_5651: {
+    options = {
+        ie: true,
+        unused: true,
+    }
+    input: {
+        console.log(function arguments({}) {
+            try {} catch (arguments) {
+                var arguments;
+            }
+            return arguments[0];
+        }("PASS"));
+    }
+    expect: {
+        console.log(function arguments({}) {
+            try {} catch (arguments) {
+                var arguments;
+            }
+            return arguments[0];
+        }("PASS"));
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
--- a/test/compress/directives.js
+++ b/test/compress/directives.js
@@ -131,19 +131,34 @@ valid_after_invalid_2: {
 }

 issue_5368_1: {
+    expression = true
    options = {
        directives: true,
        expression: true,
    }
    input: {
-        "foo";
-    }
-    expect: {
-        "foo";
+        "foo"
    }
+    expect_exact: '"foo"'
+    expect_stdout: "foo"
 }

 issue_5368_2: {
+    expression = true
+    options = {
+        directives: true,
+        expression: true,
+    }
+    input: {
+        (function() {
+            "foo";
+        })()
+    }
+    expect_exact: "function(){}()"
+    expect_stdout: "undefined"
+}
+
+issue_5368_3: {
    options = {
        directives: true,
        expression: true,
--- a/test/compress/drop-unused.js
+++ b/test/compress/drop-unused.js
@@ -409,6 +409,15 @@ drop_toplevel_retain: {
        a = 2;
        console.log(3);
    }
+    expect_stdout: "3"
+    expect_warnings: [
+        "INFO: Retaining variable a",
+        "INFO: Retaining variable f",
+        "INFO: Dropping unused variable b [test/compress/drop-unused.js:1,15]",
+        "INFO: Dropping unused variable c [test/compress/drop-unused.js:1,22]",
+        "INFO: Dropping unused function g [test/compress/drop-unused.js:8,17]",
+        "WARN: Dropping unused function h [test/compress/drop-unused.js:9,17]",
+    ]
 }

 drop_toplevel_retain_array: {
@@ -442,6 +451,15 @@ drop_toplevel_retain_array: {
        a = 2;
        console.log(3);
    }
+    expect_stdout: "3"
+    expect_warnings: [
+        "INFO: Retaining variable a",
+        "INFO: Retaining variable f",
+        "INFO: Dropping unused variable b [test/compress/drop-unused.js:1,15]",
+        "INFO: Dropping unused variable c [test/compress/drop-unused.js:1,22]",
+        "INFO: Dropping unused function g [test/compress/drop-unused.js:8,17]",
+        "WARN: Dropping unused function h [test/compress/drop-unused.js:9,17]",
+    ]
 }

 drop_toplevel_retain_regex: {
@@ -471,6 +489,15 @@ drop_toplevel_retain_regex: {
        a = 2;
        console.log(3);
    }
+    expect_stdout: "3"
+    expect_warnings: [
+        "INFO: Retaining variable a",
+        "INFO: Retaining variable f",
+        "INFO: Dropping unused variable b [test/compress/drop-unused.js:1,15]",
+        "INFO: Dropping unused variable c [test/compress/drop-unused.js:1,22]",
+        "INFO: Dropping unused function g [test/compress/drop-unused.js:8,17]",
+        "WARN: Dropping unused function h [test/compress/drop-unused.js:9,17]",
+    ]
 }

 drop_toplevel_all_retain: {
@@ -501,6 +528,15 @@ drop_toplevel_all_retain: {
        a = 2;
        console.log(3);
    }
+    expect_stdout: "3"
+    expect_warnings: [
+        "INFO: Retaining variable a",
+        "INFO: Retaining variable f",
+        "INFO: Dropping unused variable b [test/compress/drop-unused.js:1,15]",
+        "INFO: Dropping unused variable c [test/compress/drop-unused.js:1,22]",
+        "INFO: Dropping unused function g [test/compress/drop-unused.js:8,17]",
+        "WARN: Dropping unused function h [test/compress/drop-unused.js:9,17]",
+    ]
 }

 drop_toplevel_funcs_retain: {
@@ -532,6 +568,12 @@ drop_toplevel_funcs_retain: {
        function g() {}
        console.log(b = 3);
    }
+    expect_stdout: "3"
+    expect_warnings: [
+        "INFO: Retaining variable a",
+        "INFO: Retaining variable f",
+        "WARN: Dropping unused function h [test/compress/drop-unused.js:9,17]",
+    ]
 }

 drop_toplevel_vars_retain: {
@@ -564,6 +606,13 @@ drop_toplevel_vars_retain: {
        function h() {}
        console.log(3);
    }
+    expect_stdout: "3"
+    expect_warnings: [
+        "INFO: Retaining variable a",
+        "INFO: Retaining variable f",
+        "INFO: Dropping unused variable b [test/compress/drop-unused.js:1,15]",
+        "INFO: Dropping unused variable c [test/compress/drop-unused.js:1,22]",
+    ]
 }

 drop_toplevel_keep_assign: {
@@ -671,6 +720,76 @@ iife: {
    }
 }

+drop_instanceof: {
+    options = {
+        booleans: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {}
+        console.log({} instanceof f, Math instanceof f);
+    }
+    expect: {
+        console.log(!1, (Math, !1));
+    }
+    expect_stdout: "false false"
+}
+
+keep_instanceof_1: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {}
+        var f;
+        console.log({} instanceof f, Math instanceof f);
+    }
+    expect: {
+        function f() {}
+        var f;
+        console.log({} instanceof f, Math instanceof f);
+    }
+    expect_stdout: "false false"
+}
+
+keep_instanceof_2: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {}
+        var f = Object;
+        console.log({} instanceof f, Math instanceof f);
+    }
+    expect: {
+        function f() {}
+        var f = Object;
+        console.log({} instanceof f, Math instanceof f);
+    }
+    expect_stdout: "true true"
+}
+
+keep_instanceof_3: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        f = Object;
+        function f() {}
+        console.log({} instanceof f, Math instanceof f);
+    }
+    expect: {
+        f = Object;
+        function f() {}
+        console.log({} instanceof f, Math instanceof f);
+    }
+    expect_stdout: "true true"
+}
+
 issue_1539: {
    options = {
        collapse_vars: true,
@@ -1759,7 +1878,7 @@ issue_2846: {
        var c = function(a, b) {
            a = 0;
            b && b(a);
-            return a++;
+            return +a;
        }();
        console.log(c);
    }
@@ -2857,14 +2976,12 @@ issue_4025: {
        console.log(a, b, d);
    }
    expect: {
-        var c = 0;
        try {
-            console.log(c);
+            console.log(0);
        } finally {
-            var d = c + 1;
-            c = 0;
+            0;
        }
-        console.log(1, 1, d);
+        console.log(1, 1, 1);
    }
    expect_stdout: [
        "0",
@@ -3577,7 +3694,7 @@ issue_5224: {
                (function() {
                    var a = "FAIL 1";
                    null;
-                    a = console.log(a);
+                    console.log(a);
                })(function() {
                    console.log(1 / 0);
                    a;
@@ -3615,3 +3732,85 @@ issue_5271: {
    }
    expect_stdout: "42"
 }
+
+issue_5533_keep_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(b) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5533_drop_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: false,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(b) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/evaluate.js
+++ b/test/compress/evaluate.js
@@ -907,6 +907,20 @@ chained_side_effects: {
    ]
 }

+instanceof_lambda: {
+    options = {
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(42 instanceof function() {});
+    }
+    expect: {
+        console.log(false);
+    }
+    expect_stdout: "false"
+}
+
 issue_1649: {
    options = {
        evaluate: true,
@@ -3376,3 +3390,29 @@ issue_5380: {
    }
    expect_stdout: "PASS"
 }
+
+issue_5558: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        sequences: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 99, b = 0;
+        a++;
+        b++;
+        b += a;
+        b *= a;
+        b += a;
+        console.log(a);
+    }
+    expect: {
+        var a = 99, b = 0;
+        b++,
+        b = (b += ++a) * a + a,
+        console.log(a);
+    }
+    expect_stdout: "100"
+}
--- a/test/compress/exports.js
+++ b/test/compress/exports.js
@@ -109,6 +109,17 @@ foreign: {
    expect_exact: 'export*from"foo";export{}from"bar";export*as a from"baz";export{default}from"moo";export{b,c as case,default as delete,d}from"moz";'
 }

+non_identifiers: {
+    beautify = {
+        quote_style: 3,
+    }
+    input: {
+        export * as "42" from 'foo';
+        export { '42', "delete" as 'foo' } from "bar";
+    }
+    expect_exact: "export*as\"42\"from'foo';export{'42',delete as foo}from\"bar\";"
+}
+
 same_quotes: {
    beautify = {
        beautify: true,
@@ -417,6 +428,46 @@ hoist_funs: {
    expect_exact: "export function f(){}export default async function*g(){}"
 }

+instanceof_default_class: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class A {
+            f(a) {
+                return a instanceof A;
+            }
+        }
+    }
+    expect: {
+        export default class A {
+            f(a) {
+                return a instanceof A;
+            }
+        }
+    }
+}
+
+instanceof_default_function: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f() {
+            if (!(this instanceof f))
+                throw new Error("must instantiate");
+        }
+    }
+    expect: {
+        export default function f() {
+            if (!(this instanceof f))
+                throw new Error("must instantiate");
+        }
+    }
+}
+
 issue_4742_join_vars_1: {
    options = {
        join_vars: true,
@@ -496,3 +547,36 @@ issue_4766: {
        export var a = "bar";
    }
 }
+
+issue_5444: {
+    options = {
+        unused: true,
+    }
+    input: {
+        export var a = (console, console);
+    }
+    expect: {
+        console;
+        export var a = console;
+    }
+}
+
+issue_5628: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a;
+        export default function f() {
+            for (a in 42);
+        }
+        console.log(a);
+    }
+    expect: {
+        var a;
+        export default function f() {
+            for (a in 42);
+        }
+        console.log(a);
+    }
+}
--- a/test/compress/functions.js
+++ b/test/compress/functions.js
@@ -629,7 +629,7 @@ inline_binary_and: {
                return void "moo";
                return;
            } else
-                return;
+                return void 0;
        }());
    }
    expect_stdout: [
@@ -5512,6 +5512,40 @@ substitute_use_strict: {
    ]
 }

+substitute_assignment: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b, c) {
+            a[b] = c;
+        }
+        var o = {};
+        f(o, 42, null);
+        f(o, "foo", "bar");
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect: {
+        var o = {};
+        o[42] = null;
+        o.foo = "bar";
+        for (var k in o)
+            console.log(k, o[k]);
+    }
+    expect_stdout: [
+        "42 null",
+        "foo bar",
+    ]
+}
+
 issue_3833_1: {
    options = {
        inline: 3,
@@ -5582,7 +5616,7 @@ issue_3835: {
            return f();
        })();
    }
-    expect_stdout: true
+    expect_stdout: RangeError("Maximum call stack size exceeded")
 }

 issue_3836_1: {
@@ -7835,7 +7869,7 @@ issue_5249_1: {
                while (console.log("FAIL 2"));
                return;
            } else
-                return;
+                return void 0;
            throw "FAIL 3";
        }());
    }
@@ -8398,3 +8432,311 @@ issue_5409: {
    }
    expect_stdout: "undefined"
 }
+
+mixed_mode_inline_1: {
+    options = {
+        directives: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return this;
+        }
+        console.log(function() {
+            return f();
+        }() ? "PASS" : "FAIL");
+    }
+    expect: {
+        console.log(function() {
+            return this;
+        }() ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+mixed_mode_inline_1_strict: {
+    options = {
+        directives: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function f() {
+            return this;
+        }
+        console.log(function() {
+            return f();
+        }() ? "FAIL" : "PASS");
+    }
+    expect: {
+        "use strict";
+        console.log(function() {
+            return this;
+        }() ? "FAIL" : "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+mixed_mode_inline_2: {
+    options = {
+        directives: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            "use strict";
+            return this;
+        }
+        console.log(function() {
+            return f();
+        }() ? "FAIL" : "PASS");
+    }
+    expect: {
+        console.log(function() {
+            "use strict";
+            return this;
+        }() ? "FAIL" : "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+mixed_mode_inline_2_strict: {
+    options = {
+        directives: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function f() {
+            "use strict";
+            return this;
+        }
+        console.log(function() {
+            return f();
+        }() ? "FAIL" : "PASS");
+    }
+    expect: {
+        "use strict";
+        console.log(function() {
+            return this;
+        }() ? "FAIL" : "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+mixed_mode_inline_3: {
+    options = {
+        directives: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return this;
+        }
+        console.log(function() {
+            "use strict";
+            return f();
+        }() ? "PASS" : "FAIL");
+    }
+    expect: {
+        function f() {
+            return this;
+        }
+        console.log(function() {
+            "use strict";
+            return f();
+        }() ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+mixed_mode_inline_3_strict: {
+    options = {
+        directives: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function f() {
+            return this;
+        }
+        console.log(function() {
+            "use strict";
+            return f();
+        }() ? "FAIL" : "PASS");
+    }
+    expect: {
+        "use strict";
+        console.log(function() {
+            return this;
+        }() ? "FAIL" : "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+mixed_mode_inline_4: {
+    options = {
+        directives: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            "use strict";
+            return this;
+        }
+        console.log(function() {
+            "use strict";
+            return f();
+        }() ? "FAIL" : "PASS");
+    }
+    expect: {
+        console.log(function() {
+            "use strict";
+            return function() {
+                "use strict";
+                return this;
+            }();
+        }() ? "FAIL" : "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+mixed_mode_inline_4_strict: {
+    options = {
+        directives: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        function f() {
+            "use strict";
+            return this;
+        }
+        console.log(function() {
+            "use strict";
+            return f();
+        }() ? "FAIL" : "PASS");
+    }
+    expect: {
+        "use strict";
+        console.log(function() {
+            return this;
+        }() ? "FAIL" : "PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+module_inline: {
+    options = {
+        inline: true,
+        module: true,
+        reduce_vars: true,
+    }
+    input: {
+        var a = f;
+        function f() {
+            return a;
+        }
+        console.log(f() === a);
+    }
+    expect: {
+        var a = f;
+        function f() {
+            return a;
+        }
+        console.log(a === a);
+    }
+    expect_stdout: "true"
+}
+
+single_use_inline_collision: {
+    options = {
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        (function() {
+            var f = function() {
+                while (console.log(a));
+            };
+            (function() {
+                (function() {
+                    f();
+                })();
+                (function(a) {
+                    a || a("FAIL");
+                })(console.log);
+            })();
+        })();
+    }
+    expect: {
+        var a = "PASS";
+        (function() {
+            (function() {
+                while (console.log(a));
+                return;
+            })();
+            (function(a) {
+                a || a("FAIL");
+            })(console.log);
+            return;
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5692: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (function() {
+            while (console.log("PASS"))
+                if (console)
+                    return;
+        })();
+    }
+    expect: {
+        (function() {
+            while (console.log("PASS"))
+                if (console)
+                    return;
+        })();
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/hoist_props.js
+++ b/test/compress/hoist_props.js
@@ -462,6 +462,11 @@ issue_2473_1: {
        var x = {};
        var y = [];
    }
+    expect_warnings: [
+        "INFO: Retaining variable x",
+        "INFO: Retaining variable y",
+        "WARN: Dropping unused variable z [test/compress/hoist_props.js:3,12]",
+    ]
 }

 issue_2473_2: {
@@ -484,6 +489,11 @@ issue_2473_2: {
        var x = {};
        var y = [];
    }
+    expect_warnings: [
+        "INFO: Retaining variable x",
+        "INFO: Retaining variable y",
+        "WARN: Dropping unused variable z [test/compress/hoist_props.js:3,12]",
+    ]
 }

 issue_2473_3: {
@@ -509,6 +519,9 @@ issue_2473_3: {
        console.log(o.a, o.b);
    }
    expect_stdout: "1 2"
+    expect_warnings: [
+        "INFO: Retaining variable o",
+    ]
 }

 issue_2473_4: {
@@ -535,6 +548,9 @@ issue_2473_4: {
        })();
    }
    expect_stdout: "1 2"
+    expect_warnings: [
+        "INFO: Dropping unused variable o [test/compress/hoist_props.js:2,16]",
+    ]
 }

 issue_2508_1: {
@@ -1176,3 +1192,51 @@ issue_5182: {
        "42",
    ]
 }
+
+issue_5441: {
+    options = {
+        hoist_props: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(function(a) {
+            (function() {
+                a = { p: this };
+            })();
+            return typeof a;
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            (function() {
+                a_p = this;
+            })();
+            var a_p;
+            return typeof {};
+        }());
+    }
+    expect_stdout: "object"
+}
+
+issue_5498: {
+    options = {
+        hoist_props: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var o = {
+            __proto__: 42,
+        };
+        while (console.log(typeof o.__proto__));
+    }
+    expect: {
+        var o = {
+            __proto__: 42,
+        };
+        while (console.log(typeof o.__proto__));
+    }
+    expect_stdout: "object"
+}
--- a/test/compress/hoist_vars.js
+++ b/test/compress/hoist_vars.js
@@ -2,6 +2,8 @@ statements: {
    options = {
        hoist_funs: false,
        hoist_vars: true,
+        join_vars: true,
+        unused: true,
    }
    input: {
        function f() {
@@ -25,6 +27,8 @@ statements_funs: {
    options = {
        hoist_funs: true,
        hoist_vars: true,
+        join_vars: true,
+        unused: true,
    }
    input: {
        function f() {
@@ -48,6 +52,8 @@ sequences: {
    options = {
        hoist_funs: false,
        hoist_vars: true,
+        join_vars: true,
+        unused: true,
    }
    input: {
        function f() {
@@ -71,6 +77,8 @@ sequences_funs: {
    options = {
        hoist_funs: true,
        hoist_vars: true,
+        join_vars: true,
+        unused: true,
    }
    input: {
        function f() {
@@ -108,7 +116,8 @@ catch_var: {
        console.log(a);
    }
    expect: {
-        var a = "PASS";
+        a = "PASS";
+        var a;
        console.log(a);
    }
    expect_stdout: "PASS"
@@ -118,6 +127,8 @@ issue_2295: {
    options = {
        collapse_vars: true,
        hoist_vars: true,
+        join_vars: true,
+        unused: true,
    }
    input: {
        function foo(o) {
@@ -139,6 +150,7 @@ issue_4487_1: {
    options = {
        functions: true,
        hoist_vars: true,
+        join_vars: true,
        keep_fnames: true,
        reduce_vars: true,
        toplevel: true,
@@ -163,6 +175,7 @@ issue_4487_2: {
    options = {
        functions: true,
        hoist_vars: true,
+        join_vars: true,
        keep_fnames: true,
        passes: 2,
        reduce_vars: true,
@@ -188,6 +201,7 @@ issue_4487_3: {
    options = {
        functions: true,
        hoist_vars: true,
+        join_vars: true,
        keep_fnames: true,
        passes: 3,
        reduce_vars: true,
@@ -248,8 +262,7 @@ issue_4517: {
    }
    expect: {
        console.log(function() {
-            var a = 2;
-            return (A = a) + typeof !1;
+            return (A = 2) + typeof !1;
        }());
    }
    expect_stdout: "2boolean"
@@ -260,6 +273,7 @@ issue_4736: {
        collapse_vars: true,
        evaluate: true,
        hoist_vars: true,
+        join_vars: true,
        merge_vars: true,
        reduce_vars: true,
        toplevel: true,
@@ -279,7 +293,7 @@ issue_4736: {
    expect: {
        (function() {
            (function() {
-                0,
+                0;
                console.log(1 << 30);
            })();
        })();
@@ -291,6 +305,7 @@ issue_4839: {
    options = {
        evaluate: true,
        hoist_vars: true,
+        join_vars: true,
        keep_fargs: false,
        reduce_vars: true,
        toplevel: true,
@@ -317,6 +332,7 @@ issue_4859: {
    options = {
        evaluate: true,
        hoist_vars: true,
+        join_vars: true,
        keep_infinity: true,
        merge_vars: true,
        reduce_vars: true,
@@ -441,7 +457,7 @@ issue_4898: {
    expect_stdout: "PASS"
 }

-issue_5187: {
+issue_5187_1: {
    options = {
        hoist_props: true,
        hoist_vars: true,
@@ -459,6 +475,37 @@ issue_5187: {
        }
        f();
    }
+    expect: {
+        (function() {
+            var a, b;
+            a = 42;
+            do {
+                b = { 0: a++ };
+            } while (console.log(b[b ^= 0]));
+        })();
+    }
+    expect_stdout: "42"
+}
+
+issue_5187_2: {
+    options = {
+        hoist_props: true,
+        hoist_vars: true,
+        join_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a = 42;
+            do {
+                var b = { 0: a++ };
+            } while (console.log(b[b ^= 0]));
+        }
+        f();
+    }
    expect: {
        (function() {
            var b, a = 42;
@@ -547,9 +594,9 @@ issue_5411_1: {
        console.log(b);
    }
    expect: {
-        var b, c, a = "PASS";
+        var a, b, c;
        b++;
-        b = a;
+        b = a = "PASS";
        c = c && c[b];
        console.log(b);
    }
@@ -577,7 +624,7 @@ issue_5411_2: {
        var b, c;
        b++;
        b = "PASS",
-        c = c && c[b];
+        c;
        console.log(b);
    }
    expect_stdout: "PASS"
@@ -596,6 +643,30 @@ issue_5411_3: {
        var a = A = a;
        console.log(A);
    }
+    expect: {
+        var a;
+        a = console;
+        a = A = ++a;
+        console.log(A);
+    }
+    expect_stdout: "NaN"
+}
+
+issue_5411_4: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        join_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = console;
+        a++;
+        var a = A = a;
+        console.log(A);
+    }
    expect: {
        var a = console;
        a = A = ++a;
@@ -603,3 +674,130 @@ issue_5411_3: {
    }
    expect_stdout: "NaN"
 }
+
+issue_5626: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function() {
+            return console.log(arguments[0]), 42;
+        }("PASS") ? null : "foo";
+        for (var b in a)
+            FAIL;
+    }
+    expect: {
+        (function() {
+            console.log(arguments[0]);
+        }("PASS"));
+        for (var b in null)
+            FAIL;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5638_1: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        var a = [ 42 ];
+        console || FAIL(a);
+        console.log(a++);
+    }
+    expect: {
+        var a;
+        a = "FAIL";
+        a = [ 42 ];
+        console || FAIL(a);
+        console.log(a++);
+    }
+    expect_stdout: "42"
+}
+
+issue_5638_2: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        var a = [ 6 ];
+        console || FAIL(a);
+        console.log(a *= 7);
+    }
+    expect: {
+        var a;
+        a = "FAIL";
+        a = [ 6 ];
+        console || FAIL(a);
+        console.log(a *= 7);
+    }
+    expect_stdout: "42"
+}
+
+issue_5638_3: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var log = console.log;
+        var o = { foo: 42 };
+        for (var k in o) {
+            var v = o[k];
+            log(k || v, v++);
+        }
+    }
+    expect: {
+        var log, o, k, v;
+        log = console.log;
+        for (k in o = { foo: 42 }) {
+            v = o[k];
+            log(k || v, v++);
+        }
+    }
+    expect_stdout: "foo 42"
+}
+
+issue_5638_4: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var log = console.log;
+        var o = { foo: 6 };
+        for (var k in o) {
+            var v = o[k];
+            log(k || v, v *= 7);
+        }
+    }
+    expect: {
+        var log, o, k, v;
+        log = console.log;
+        for (k in o = { foo: 6 }) {
+            v = o[k];
+            log(k || v, v *= 7);
+        }
+    }
+    expect_stdout: "foo 42"
+}
--- a/test/compress/if_return.js
+++ b/test/compress/if_return.js
--- a/test/compress/imports.js
+++ b/test/compress/imports.js
@@ -40,6 +40,17 @@ default_keys: {
    expect_exact: 'import foo,{bar}from"baz";'
 }

+non_identifiers: {
+    beautify = {
+        quote_style: 3,
+    }
+    input: {
+        import { '42' as foo } from "bar";
+        import { "foo" as bar } from 'baz';
+    }
+    expect_exact: "import{'42'as foo}from\"bar\";import{foo as bar}from'baz';"
+}
+
 dynamic: {
    input: {
        (async a => await import(a))("foo").then(bar);
@@ -129,12 +140,12 @@ mangle: {
    }
    input: {
        import foo, { bar } from "baz";
-        consoe.log(moo);
+        console.log(moo);
        import * as moo from "moz";
    }
    expect: {
        import o, { bar as m } from "baz";
-        consoe.log(r);
+        console.log(r);
        import * as r from "moz";
    }
 }
@@ -146,12 +157,12 @@ rename_mangle: {
    }
    input: {
        import foo, { bar } from "baz";
-        consoe.log(moo);
+        console.log(moo);
        import * as moo from "moz";
    }
    expect: {
        import o, { bar as m } from "baz";
-        consoe.log(r);
+        console.log(r);
        import * as r from "moz";
    }
 }
@@ -227,3 +238,33 @@ issue_4708_2: {
        import a from "foo";
    }
 }
+
+pr_5550_1: {
+    input: {
+        if (console)
+            import("foo");
+        else
+            import.meta.url.replace(/bar/g, console.log);
+    }
+    expect: {
+        if (console)
+            import("foo");
+        else
+            import.meta.url.replace(/bar/g, console.log);
+    }
+}
+
+pr_5550_2: {
+    input: {
+        L: {
+            import("foo");
+            import.meta.url.replace(/bar/g, console.log);
+        }
+    }
+    expect: {
+        L: {
+            import("foo");
+            import.meta.url.replace(/bar/g, console.log);
+        }
+    }
+}
--- a/test/compress/issue-1321.js
+++ b/test/compress/issue-1321.js
@@ -1,6 +1,7 @@
 issue_1321_no_debug: {
    mangle = {
        properties: {
+            domprops: true,
            keep_quoted: true,
        },
    }
@@ -23,6 +24,7 @@ issue_1321_debug: {
    mangle = {
        properties: {
            debug: "",
+            domprops: true,
            keep_quoted: true,
        },
    }
@@ -44,6 +46,7 @@ issue_1321_debug: {
 issue_1321_with_quoted: {
    mangle = {
        properties: {
+            domprops: true,
            keep_quoted: false,
        },
    }
--- a/test/compress/issue-143.js
+++ b/test/compress/issue-143.js
@@ -1,5 +1,5 @@
 /**
- * There was an incorrect sort behaviour documented in issue #143:
+ * There was an incorrect sort behavior documented in issue #143:
 * (x = f(…)) <= x → x >= (x = f(…))
 *
 * For example, let the equation be:
@@ -12,37 +12,54 @@
 * a >= (a = parseInt('100')) → 99 >= 100 → false
 */

-tranformation_sort_order_equal: {
+transformation_sort_order_equal: {
    options = {
        comparisons: true,
    }
-
-    input: { (a = parseInt('100')) == a }
-    expect: { (a = parseInt('100')) == a }
+    input: {
+        console.log((a = parseInt("100")) == a);
+    }
+    expect: {
+        console.log((a = parseInt("100")) == a);
+    }
+    expect_stdout: "true"
 }

-tranformation_sort_order_unequal: {
+transformation_sort_order_unequal: {
    options = {
        comparisons: true,
    }
-
-    input: { (a = parseInt('100')) != a }
-    expect: { (a = parseInt('100')) != a }
+    input: {
+        console.log((a = parseInt("100")) != a);
+    }
+    expect: {
+        console.log((a = parseInt("100")) != a);
+    }
+    expect_stdout: "false"
 }

-tranformation_sort_order_lesser_or_equal: {
+transformation_sort_order_lesser_or_equal: {
    options = {
        comparisons: true,
    }
-
-    input: { (a = parseInt('100')) <= a }
-    expect: { (a = parseInt('100')) <= a }
+    input: {
+        console.log((a = parseInt("100")) <= a);
+    }
+    expect: {
+        console.log((a = parseInt("100")) <= a);
+    }
+    expect_stdout: "true"
 }
-tranformation_sort_order_greater_or_equal: {
+
+transformation_sort_order_greater_or_equal: {
    options = {
        comparisons: true,
    }
-
-    input: { (a = parseInt('100')) >= a }
-    expect: { (a = parseInt('100')) >= a }
+    input: {
+        console.log((a = parseInt("100")) >= a);
+    }
+    expect: {
+        console.log((a = parseInt("100")) >= a);
+    }
+    expect_stdout: "true"
 }
--- a/test/compress/issue-1770.js
+++ b/test/compress/issue-1770.js
@@ -53,11 +53,21 @@ mangle_props: {
        );
    }
    expect_stdout: "1 1 1 2 2 2 3 3 3 4 4 4 5 5"
+    expect_warnings: [
+        "INFO: Preserving reserved property undefined",
+        "INFO: Preserving reserved property NaN",
+        "INFO: Preserving reserved property Infinity",
+        "INFO: Preserving reserved property -Infinity",
+        "INFO: Preserving reserved property null",
+        "INFO: Preserving reserved property log",
+    ]
 }

 numeric_literal: {
    mangle = {
-        properties: true,
+        properties: {
+            domprops: true,
+        },
    }
    beautify = {
        beautify: true,
@@ -106,11 +116,19 @@ numeric_literal: {
        "4 5 4 4",
        "8 7 8",
    ]
+    expect_warnings: [
+        "INFO: Mapping property 0x25 to o",
+        "INFO: Mapping property 1E42 to b",
+        "INFO: Preserving reserved property log",
+    ]
 }

 identifier: {
    mangle = {
-        properties: true,
+        properties: {
+            builtins: true,
+            domprops: true,
+        },
    }
    input: {
        var obj = {
@@ -209,37 +227,37 @@ identifier: {
            B: 28,
            C: 29,
            D: 30,
-            F: 31,
-            G: 32,
-            false: 33,
-            null: 34,
-            true: 35,
-            H: 36,
-            I: 37,
-            J: 38,
-            K: 39,
-            L: 40,
-            M: 41,
-            N: 42,
-            O: 43,
-            P: 44,
-            Q: 45,
-            R: 46,
-            S: 47,
-            T: 48,
-            U: 49,
-            V: 50,
-            W: 51,
-            X: 52,
-            Y: 53,
-            Z: 54,
-            $: 55,
-            _: 56,
-            ee: 57,
-            te: 58,
-            ne: 59,
-            ae: 60,
-            ie: 61,
+            E: 31,
+            F: 32,
+            G: 33,
+            H: 34,
+            I: 35,
+            J: 36,
+            K: 37,
+            L: 38,
+            M: 39,
+            N: 40,
+            O: 41,
+            P: 42,
+            Q: 43,
+            R: 44,
+            S: 45,
+            T: 46,
+            U: 47,
+            V: 48,
+            W: 49,
+            X: 50,
+            Y: 51,
+            Z: 52,
+            $: 53,
+            _: 54,
+            ee: 55,
+            te: 56,
+            ne: 57,
+            ae: 58,
+            ie: 59,
+            oe: 60,
+            re: 61,
        };
    }
 }
--- a/test/compress/issue-281.js
+++ b/test/compress/issue-281.js
@@ -108,6 +108,7 @@ safe_undefined: {
 }

 negate_iife_3: {
+    expression = true
    options = {
        conditionals: true,
        expression: true,
@@ -123,6 +124,7 @@ negate_iife_3: {
 }

 negate_iife_3_off: {
+    expression = true
    options = {
        conditionals: true,
        expression: true,
@@ -203,6 +205,7 @@ negate_iife_5_off: {
 }

 issue_1254_negate_iife_true: {
+    expression = true
    options = {
        expression: true,
        inline: true,
@@ -215,11 +218,12 @@ issue_1254_negate_iife_true: {
            };
        })()();
    }
-    expect_exact: 'void console.log("test");'
+    expect_exact: 'void console.log("test")'
    expect_stdout: true
 }

 issue_1254_negate_iife_nested: {
+    expression = true
    options = {
        expression: true,
        inline: true,
@@ -232,7 +236,7 @@ issue_1254_negate_iife_nested: {
            };
        })()()()()();
    }
-    expect_exact: '(void console.log("test"))()()();'
+    expect_exact: '(void console.log("test"))()()()'
 }

 negate_iife_issue_1073: {
--- a/test/compress/issue-368.js
+++ b/test/compress/issue-368.js
@@ -15,7 +15,7 @@ collapse: {
            var a;
            b = c();
            a = typeof b === 'function' ? b() : b;
-            return 'stirng' == typeof a && d();
+            return 'string' == typeof a && d();
        }
        function f3(c) {
            var a;
@@ -41,7 +41,7 @@ collapse: {
            return void 0 !== ('function' === typeof b ? b() : b) && c();
        }
        function f2(b) {
-            return 'stirng' == typeof ('function' === typeof (b = c()) ? b() : b) && d();
+            return 'string' == typeof ('function' === typeof (b = c()) ? b() : b) && d();
        }
        function f3(c) {
            var a;
--- a/test/compress/issue-5614.js
+++ b/test/compress/issue-5614.js
@@ -0,0 +1,195 @@
+record_update: {
+    options = {
+        loops: true,
+        passes: 3,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var value = { a: 42, b: "PASS" };
+        var unused = _Utils_update(value, { b: "FAIL" });
+        function _Utils_update(oldRecord, updatedFields) {
+            var newRecord = {};
+            for (var key in oldRecord)
+                newRecord[key] = oldRecord[key];
+            for (var key in updatedFields)
+                newRecord[key] = updatedFields[key];
+            return newRecord;
+        }
+    }
+    expect: {}
+}
+
+currying: {
+    options = {
+        inline: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function F(arity, fun, wrapper) {
+            wrapper.a = arity;
+            wrapper.f = fun;
+            return wrapper;
+        }
+        function F2(fun) {
+            return F(2, fun, function(a) {
+                return function(b) {
+                    return fun(a, b);
+                };
+            });
+        }
+        function _Utils_eq(x, y) {
+            var pair, stack = [], isEqual = _Utils_eqHelp(x, y, 0, stack);
+            while (isEqual && (pair = stack.pop()))
+                isEqual = _Utils_eqHelp(pair.a, pair.b, 0, stack);
+            return isEqual;
+        }
+        var _Utils_equal = F2(_Utils_eq);
+    }
+    expect: {}
+}
+
+conditional_property_write: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var o = {};
+            if (a)
+                o.p = console.log("foo");
+            else
+                o.q = console.log("bar");
+            o.r = console.log("baz");
+        }
+        f(42);
+        f(null);
+    }
+    expect: {
+        function f(a) {
+            if (a)
+                console.log("foo");
+            else
+                console.log("bar");
+            console.log("baz");
+        }
+        f(42);
+        f(null);
+    }
+    expect_stdout: [
+        "foo",
+        "baz",
+        "bar",
+        "baz",
+    ]
+}
+
+reassign_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS", b = "FAIL";
+        (b = a).toString();
+        console.log(b);
+    }
+    expect: {
+        var b = "FAIL";
+        (b = "PASS").toString();
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+reassign_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        if (false) {
+            a = null + 0;
+            a();
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        if (false) {
+            a = 0;
+            a();
+        }
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+reassign_3: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 0;
+        (a = a || "PASS").toString();
+        console.log(a);
+    }
+    expect: {
+        var a = 0;
+        (a = (0, "PASS")).toString();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}
+
+retain_instance_write: {
+    options = {
+        pure_getters: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            return a;
+        }
+        function g() {
+            var o = {};
+            var b = new f(o);
+            if (console)
+                b.p = "PASS";
+            return o;
+        }
+        console.log(g().p);
+    }
+    expect: {
+        function f(a) {
+            return a;
+        }
+        function g() {
+            var o = {};
+            var b = new f(o);
+            if (console)
+                b.p = "PASS";
+            return o;
+        }
+        console.log(g().p);
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/issue-640.js
+++ b/test/compress/issue-640.js
@@ -68,6 +68,7 @@ drop_console_2: {
 }

 drop_value: {
+    expression = true
    options = {
        expression: true,
        side_effects: true,
@@ -106,6 +107,7 @@ wrongly_optimized: {
 }

 negate_iife_1: {
+    expression = true
    options = {
        expression: true,
        negate_iife: true,
@@ -119,6 +121,7 @@ negate_iife_1: {
 }

 negate_iife_3: {
+    expression = true
    options = {
        conditionals: true,
        expression: true,
@@ -133,6 +136,7 @@ negate_iife_3: {
 }

 negate_iife_3_off: {
+    expression = true
    options = {
        conditionals: true,
        expression: true,
@@ -215,6 +219,7 @@ negate_iife_5_off: {
 }

 issue_1254_negate_iife_true: {
+    expression = true
    options = {
        expression: true,
        negate_iife: true,
@@ -226,11 +231,12 @@ issue_1254_negate_iife_true: {
            };
        })()();
    }
-    expect_exact: '(function(){return function(){console.log("test")}})()();'
+    expect_exact: 'function(){return function(){console.log("test")}}()()'
    expect_stdout: true
 }

 issue_1254_negate_iife_nested: {
+    expression = true
    options = {
        expression: true,
        negate_iife: true,
@@ -242,7 +248,7 @@ issue_1254_negate_iife_nested: {
            };
        })()()()()();
    }
-    expect_exact: '(function(){return function(){console.log("test")}})()()()()();'
+    expect_exact: 'function(){return function(){console.log("test")}}()()()()()'
    expect_stdout: true
 }

--- a/test/compress/issue-747.js
+++ b/test/compress/issue-747.js
@@ -1,6 +1,7 @@
 dont_reuse_prop: {
    mangle = {
        properties: {
+            domprops: true,
            regex: /asd/,
        },
    }
@@ -19,11 +20,17 @@ dont_reuse_prop: {
        console.log(obj.a);
    }
    expect_stdout: "123"
+    expect_warnings: [
+        "INFO: Preserving excluded property a",
+        "INFO: Mapping property asd to b",
+        "INFO: Preserving reserved property log",
+    ]
 }

 unmangleable_props_should_always_be_reserved: {
    mangle = {
        properties: {
+            domprops: true,
            regex: /asd/,
        },
    }
@@ -42,4 +49,9 @@ unmangleable_props_should_always_be_reserved: {
        console.log(obj.a);
    }
    expect_stdout: "123"
+    expect_warnings: [
+        "INFO: Preserving excluded property a",
+        "INFO: Mapping property asd to b",
+        "INFO: Preserving reserved property log",
+    ]
 }
--- a/test/compress/issue-913.js
+++ b/test/compress/issue-913.js
@@ -1,17 +1,18 @@
 keep_var_for_in: {
    options = {
        hoist_vars: true,
+        join_vars: true,
        unused: true,
    }
    input: {
-        (function(obj){
+        (function(obj) {
            var foo = 5;
            for (var i in obj)
                return foo;
        })();
    }
    expect: {
-        (function(obj){
+        (function(obj) {
            var i, foo = 5;
            for (i in obj)
                return foo;
--- a/test/compress/join_vars.js
+++ b/test/compress/join_vars.js
@@ -570,7 +570,7 @@ inlined_assignments: {
    expect_stdout: "PASS"
 }

-inilne_for: {
+inline_for: {
    options = {
        inline: true,
        join_vars: true,
@@ -590,7 +590,7 @@ inilne_for: {
    expect_stdout: "PASS"
 }

-inilne_var: {
+inline_var: {
    options = {
        inline: true,
        join_vars: true,
--- a/test/compress/labels.js
+++ b/test/compress/labels.js
@@ -111,6 +111,7 @@ labels_5: {
 labels_6: {
    options = {
        dead_code: true,
+        unused: true,
    }
    input: {
        out: break out;
@@ -208,6 +209,59 @@ labels_10: {
    expect_stdout: "PASS"
 }

+labels_11: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unused: true,
+    }
+    input: {
+        L: if (console.log("PASS"))
+            break L;
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+labels_12: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        if_return: true,
+    }
+    input: {
+        L: try {
+            if (console.log("foo"))
+                break L;
+            throw "bar";
+        } catch (e) {
+            console.log(e);
+            break L;
+        } finally {
+            if (console.log("baz"))
+                break L;
+        }
+    }
+    expect: {
+        L: try {
+            if (!console.log("foo"))
+                throw "bar";
+        } catch (e) {
+            console.log(e);
+        } finally {
+            if (console.log("baz"))
+                break L;
+        }
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
 issue_4466_1: {
    mangle = {
        v8: false,
@@ -327,3 +381,53 @@ issue_4466_2_toplevel_v8: {
    }
    expect_stdout: "PASS"
 }
+
+issue_5522: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        console.log(function() {
+            L: try {
+                return "FAIL";
+            } finally {
+                break L;
+            }
+            return "PASS";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            L: try {
+                return "FAIL";
+            } finally {
+                break L;
+            }
+            return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5524: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        L: try {
+            FAIL;
+        } finally {
+            break L;
+        }
+        console.log("PASS");
+    }
+    expect: {
+        L: try {
+            FAIL;
+        } finally {
+            break L;
+        }
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/let.js
+++ b/test/compress/let.js
@@ -190,6 +190,96 @@ if_dead_branch: {
    node_version: ">=4"
 }

+retain_tail_1: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        "use strict";
+        function f(a) {
+            var b = "foo";
+            if (a) {
+                let b = "bar";
+                while (console.log("baz"));
+                console.log(b);
+            } else {
+                while (console.log("moo"));
+                console.log(b);
+            }
+        }
+        f();
+        f(42);
+    }
+    expect: {
+        "use strict";
+        function f(a) {
+            var b = "foo";
+            if (a) {
+                let b = "bar";
+                while (console.log("baz"));
+                console.log(b);
+            } else {
+                while (console.log("moo"));
+                console.log(b);
+            }
+        }
+        f();
+        f(42);
+    }
+    expect_stdout: [
+        "moo",
+        "foo",
+        "baz",
+        "bar",
+    ]
+    node_version: ">=4"
+}
+
+retain_tail_2: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        "use strict";
+        function f(a) {
+            var b = "foo";
+            if (a) {
+                while (console.log("bar"));
+                console.log(b);
+            } else {
+                let b = "baz";
+                while (console.log("moo"));
+                console.log(b);
+            }
+        }
+        f();
+        f(42);
+    }
+    expect: {
+        "use strict";
+        function f(a) {
+            var b = "foo";
+            if (a) {
+                while (console.log("bar"));
+                console.log(b);
+            } else {
+                let b = "baz";
+                while (console.log("moo"));
+                console.log(b);
+            }
+        }
+        f();
+        f(42);
+    }
+    expect_stdout: [
+        "moo",
+        "baz",
+        "bar",
+        "foo",
+    ]
+    node_version: ">=4"
+}
+
 merge_vars_1: {
    options = {
        merge_vars: true,
@@ -892,6 +982,40 @@ if_return_2: {
    node_version: ">=4"
 }

+if_return_3: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        var a = "PASS";
+        function f(b) {
+            if (console) {
+                let b = a;
+                return b;
+            } else
+                while (console.log("FAIL 1"));
+            return b;
+        }
+        console.log(f("FAIL 2"));
+    }
+    expect: {
+        "use strict";
+        var a = "PASS";
+        function f(b) {
+            if (console) {
+                let b = a;
+                return b;
+            } else
+                while (console.log("FAIL 1"));
+            return b;
+        }
+        console.log(f("FAIL 2"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
 do_if_continue_1: {
    options = {
        if_return: true,
@@ -1604,48 +1728,6 @@ issue_4305_2: {
    node_version: ">=4"
 }

-issue_1753: {
-    mangle = {
-        toplevel: false,
-        webkit: true,
-    }
-    input: {
-        "use strict";
-        let l = null;
-        for (let i = 0; i < 1; i++)
-            console.log(i);
-    }
-    expect: {
-        "use strict";
-        let l = null;
-        for (let i = 0; i < 1; i++)
-            console.log(i);
-    }
-    expect_stdout: "0"
-    node_version: ">=4"
-}
-
-issue_1753_toplevel: {
-    mangle = {
-        toplevel: true,
-        webkit: true,
-    }
-    input: {
-        "use strict";
-        let l = null;
-        for (let i = 0; i < 1; i++)
-            console.log(i);
-    }
-    expect: {
-        "use strict";
-        let l = null;
-        for (let e = 0; e < 1; e++)
-            console.log(e);
-    }
-    expect_stdout: "0"
-    node_version: ">=4"
-}
-
 issue_4438: {
    options = {
        if_return: true,
@@ -1667,7 +1749,7 @@ issue_4438: {
        function f() {
            if (console) {
                let a = console.log;
-                void a("PASS");
+                a("PASS");
            }
        }
        f();
@@ -2020,3 +2102,71 @@ issue_5338: {
    expect_stdout: ReferenceError("a is not defined")
    node_version: ">=4"
 }
+
+issue_5476: {
+    mangle = {
+        keep_fargs: true,
+    }
+    input: {
+        "use strict";
+        console.log(function(n) {
+            let a;
+        }());
+    }
+    expect: {
+        "use strict";
+        console.log(function(n) {
+            let o;
+        }());
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_5591: {
+    options = {
+        dead_code: true,
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console.log("baz"))
+                    return;
+                else {
+                    let a;
+                    return;
+                }
+                break;
+              case null:
+                FAIL;
+            }
+        }
+        f();
+    }
+    expect: {
+        "use strict";
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console.log("baz"))
+                    return;
+                else {
+                    let a;
+                    return;
+                }
+              case null:
+                FAIL;
+            }
+        }
+        f();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=4"
+}
--- a/test/compress/merge_vars.js
+++ b/test/compress/merge_vars.js
@@ -3732,3 +3732,116 @@ issue_5420: {
    }
    expect_stdout: "PASS"
 }
+
+issue_5451: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        A = 1;
+        var a = 1, b;
+        console.log(function f() {
+            return a-- && f(b = A, b);
+        }());
+    }
+    expect: {
+        A = 1;
+        var a = 1, b;
+        console.log(function f() {
+            return a-- && f(b = A, b);
+        }());
+    }
+    expect_stdout: "0"
+}
+
+issue_5471_1: {
+    options = {
+        conditionals: true,
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL 1";
+        function f(b, c) {
+            function g() {
+                if (console)
+                    return 42;
+                else
+                    c = "FAIL 2";
+            }
+            var d = g();
+            console.log(c || "PASS");
+            var e = function h() {
+                while (b && e);
+            }();
+        }
+        f(a++) && a;
+    }
+    expect: {
+        var a = "FAIL 1";
+        var b, c, e;
+        b = +a,
+        function() {
+            if (console)
+                return;
+            c = "FAIL 2";
+        }(),
+        console.log(c || "PASS"),
+        e = function() {
+            while (b && e);
+        }();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5471_2: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL 1";
+        function f(b, c) {
+            function g() {
+                if (console)
+                    return 42;
+                else
+                    c = "FAIL 2";
+            }
+            var d = g();
+            console.log(c || "PASS");
+            var e = function h() {
+                while (b && e);
+            }();
+        }
+        f(a++) && a;
+    }
+    expect: {
+        var a = "FAIL 1";
+        var b, c, e;
+        b = +a,
+        function() {
+            if (console)
+                return;
+            c = "FAIL 2";
+        }(),
+        console.log(c || "PASS"),
+        e = function() {
+            while (b && e);
+        }(),
+        void 0;
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/nullish.js
+++ b/test/compress/nullish.js
@@ -308,6 +308,7 @@ issue_4679: {
 issue_5266: {
    options = {
        inline: true,
+        side_effects: true,
    }
    input: {
        [
--- a/test/compress/objects.js
+++ b/test/compress/objects.js
@@ -173,7 +173,9 @@ numeric_literal: {
        side_effects: true,
    }
    mangle = {
-        properties: true,
+        properties: {
+            domprops: true,
+        },
    }
    beautify = {
        beautify: true,
--- a/test/compress/properties.js
+++ b/test/compress/properties.js
@@ -133,6 +133,7 @@ evaluate_string_length: {
 mangle_properties_1: {
    mangle = {
        properties: {
+            domprops: true,
            keep_quoted: false,
        },
    }
@@ -147,17 +148,18 @@ mangle_properties_1: {
        a["a"] = "bar";
        a.b = "red";
        x = {o: 10};
-        a.r(x.o, a.a);
-        a['r']({b: "blue", a: "baz"});
+        a.run(x.o, a.a);
+        a['run']({b: "blue", a: "baz"});
    }
 }

 mangle_properties_2: {
    mangle = {
        properties: {
+            domprops: true,
            reserved: [
                "value",
-            ]
+            ],
        },
    }
    input: {
@@ -199,6 +201,24 @@ mangle_properties_2: {
    ]
 }

+mangle_properties_3: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        console.log({
+            [(console, "foo")]: "PASS",
+        }.foo);
+    }
+    expect: {
+        console.log({
+            [(console, "o")]: "PASS",
+        }.o);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
 mangle_unquoted_properties: {
    options = {
        evaluate: true,
@@ -206,6 +226,8 @@ mangle_unquoted_properties: {
    }
    mangle = {
        properties: {
+            builtins: true,
+            domprops: true,
            keep_quoted: true,
        },
    }
@@ -305,7 +327,9 @@ mangle_debug_suffix_keep_quoted: {
    }
    mangle = {
        properties: {
+            builtins: true,
            debug: "XYZ",
+            domprops: true,
            keep_quoted: true,
            reserved: [],
        },
@@ -351,6 +375,68 @@ mangle_debug_suffix_keep_quoted: {
    }
 }

+keep_substituted_property: {
+    options = {
+        evaluate: true,
+        properties: true,
+        reduce_vars: true,
+    }
+    mangle = {
+        properties: {
+            keep_quoted: true,
+        },
+    }
+    input: {
+        var o = { p: [] };
+        function f(b) {
+            return o[b];
+        }
+        function g() {
+            var a = "p";
+            return o[a] === f(a);
+        }
+        console.log(g() ? "PASS" : "FAIL");
+    }
+    expect: {
+        var o = { p: [] };
+        function f(n) {
+            return o[n];
+        }
+        function g() {
+            var n = "p";
+            return o.p === f(n);
+        }
+        console.log(g() ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+keep_substituted_property_quotes: {
+    options = {
+        evaluate: true,
+        properties: true,
+        reduce_vars: true,
+    }
+    beautify = {
+        keep_quoted_props: true,
+    }
+    input: {
+        function f(o) {
+            var a = "p";
+            return o[a];
+        }
+        console.log(f({ p: "PASS" }));
+    }
+    expect: {
+        function f(o) {
+            var a = "p";
+            return o["p"];
+        }
+        console.log(f({ p: "PASS" }));
+    }
+    expect_stdout: "PASS"
+}
+
 first_256_chars_as_properties: {
    beautify = {
        ascii_only: true,
@@ -897,12 +983,15 @@ issue_2256: {
        },
    }
    input: {
-        ({ "keep": 1 });
-        g.keep = g.change;
+        ({ "keep": 42 });
+        global.keep = global.change = "PASS";
+        console.log(keep);
    }
    expect: {
-        g.keep = g.g;
+        global.keep = global.l = "PASS";
+        console.log(keep);
    }
+    expect_stdout: "PASS"
 }

 lhs_prop_1: {
@@ -1578,3 +1667,163 @@ issue_5177: {
    expect_stdout: "PASS"
    node_version: ">=4"
 }
+
+issue_5682_in_1: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        function f(a) {
+            return "foo" in a;
+        }
+        var o = {};
+        var p = "foo";
+        o[p] = 42;
+        console.log(f(o) ? "PASS" : "FAIL");
+    }
+    expect: {
+        function f(o) {
+            return "foo" in o;
+        }
+        var o = {};
+        var p = "foo";
+        o[p] = 42;
+        console.log(f(o) ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5682_in_2: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        function f(a) {
+            return "foo" in a;
+        }
+        var o = { foo: 42 };
+        console.log(f(o) ? "PASS" : "FAIL");
+    }
+    expect: {
+        function f(o) {
+            return "o" in o;
+        }
+        var o = { o: 42 };
+        console.log(f(o) ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5682_dot_1: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        function f(a) {
+            return a.foo;
+        }
+        var o = {};
+        var p = "foo";
+        o[p] = "PASS";
+        console.log(f(o));
+    }
+    expect: {
+        function f(o) {
+            return o.foo;
+        }
+        var o = {};
+        var p = "foo";
+        o[p] = "PASS";
+        console.log(f(o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5682_dot_2: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        function f(a) {
+            return a.foo;
+        }
+        var o = { foo: "PASS" };
+        console.log(f(o));
+    }
+    expect: {
+        function f(o) {
+            return o.o;
+        }
+        var o = { o: "PASS" };
+        console.log(f(o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5682_dot_2_computed: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        function f(a) {
+            return a.foo;
+        }
+        var o = { ["foo"]: "PASS" };
+        console.log(f(o));
+    }
+    expect: {
+        function f(o) {
+            return o.o;
+        }
+        var o = { ["o"]: "PASS" };
+        console.log(f(o));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_5682_sub_1: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        function f(a) {
+            return a["foo"];
+        }
+        var o = {};
+        var p = "foo";
+        o[p] = "PASS";
+        console.log(f(o));
+    }
+    expect: {
+        function f(o) {
+            return o["foo"];
+        }
+        var o = {};
+        var p = "foo";
+        o[p] = "PASS";
+        console.log(f(o));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5682_sub_2: {
+    mangle = {
+        properties: true,
+    }
+    input: {
+        function f(a) {
+            return a["foo"];
+        }
+        var o = { foo: "PASS" };
+        console.log(f(o));
+    }
+    expect: {
+        function f(o) {
+            return o["o"];
+        }
+        var o = { o: "PASS" };
+        console.log(f(o));
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/pure_funcs.js
+++ b/test/compress/pure_funcs.js
@@ -147,7 +147,7 @@ relational: {
        "bar" >= "bar";
    }
    expect: {
-        bar();
+        0 instanceof bar();
        bar();
        bar(), bar();
        bar();
--- a/test/compress/pure_getters.js
+++ b/test/compress/pure_getters.js
@@ -1540,10 +1540,12 @@ this_toString: {
 issue_4803: {
    options = {
        hoist_vars: true,
+        join_vars: true,
        pure_getters: "strict",
        reduce_vars: true,
        side_effects: true,
        toplevel: true,
+        unused: true,
    }
    input: {
        var o = {
--- a/test/compress/reduce_vars.js
+++ b/test/compress/reduce_vars.js
@@ -2488,7 +2488,7 @@ side_effects_assign: {
        console.log(a);
    }
    expect: {
-        var a = typeof void (a && a.in);
+        var a = "undefined";
        console.log(a);
    }
    expect_stdout: "undefined"
@@ -2530,7 +2530,8 @@ pure_getters_2: {
        var a = a && a.b;
    }
    expect: {
-        var a = a && a.b;
+        var a;
+        a && a.b;
    }
 }

@@ -5424,7 +5425,7 @@ issue_2774: {
            get a() {
                var b;
                (b = true) && b.c;
-                b = void 0;
+                void 0;
            }
        }.a);
    }
@@ -7896,3 +7897,33 @@ issue_5434: {
    }
    expect_stdout: "PASS"
 }
+
+issue_5623: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        passes: 2,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 0;
+        function f() {
+            var b = a;
+            a = b;
+        }
+        f && f((a++ && a).toString());
+        console.log(a);
+    }
+    expect: {
+        var a = 0;
+        function f() {
+            var b;
+            a = a;
+        }
+        f((a++ && a).toString());
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
--- a/test/compress/regexp.js
+++ b/test/compress/regexp.js
@@ -50,6 +50,22 @@ regexp_properties: {
    expect_stdout: "abc true false 0 false"
 }

+instanceof_1: {
+    input: {
+        console.log(/foo/ instanceof RegExp);
+    }
+    expect_exact: "console.log(/foo/ instanceof RegExp);"
+    expect_stdout: "true"
+}
+
+instanceof_2: {
+    input: {
+        console.log(42 + /foo/ instanceof Object);
+    }
+    expect_exact: "console.log(42+/foo/ instanceof Object);"
+    expect_stdout: "false"
+}
+
 issue_3434_1: {
    options = {
        evaluate: true,
--- a/test/compress/rests.js
+++ b/test/compress/rests.js
@@ -648,7 +648,7 @@ drop_new_function: {
    }
    expect: {
        void ([ ... {
-            [console.log("PASS")]: [].e,
+            [console.log("PASS")]: [][0],
        }] = []);
    }
    expect_stdout: "PASS"
@@ -1363,3 +1363,264 @@ issue_5391: {
    expect_stdout: "NaN"
    node_version: ">=8.3.0"
 }
+
+issue_5533_1_keep_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(...b) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_1_drop_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: false,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(...b) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_2_keep_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: true,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(...[ b ]) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5533_2_drop_fargs: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        keep_fargs: false,
+        loops: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        try {
+            (function() {
+                var a;
+                for (; 1;)
+                    a = function() {
+                        (function f(...[ b ]) {
+                            b;
+                            throw "PASS";
+                        })();
+                    }();
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        "use strict";
+        try {
+            (function() {
+                for (;;)
+                    throw "PASS";
+            })();
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5552_1: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var log = console.log;
+        var a = f, b = log();
+        function f(...[ c = a = "PASS" ]) {}
+        f((a = "FAIL", b));
+        log(a);
+    }
+    expect: {
+        var log = console.log;
+        var a = f, b = log();
+        function f(...[ c = a = "PASS" ]) {}
+        f((a = "FAIL", b));
+        log(a);
+    }
+    expect_stdout: [
+        "",
+        "PASS",
+    ]
+    node_version: ">=6"
+}
+
+issue_5552_2: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var log = console.log;
+        var a = f;
+        function f(...{ [a = "PASS"]: b }) {}
+        f((a = "FAIL", 42));
+        log(a);
+    }
+    expect: {
+        var log = console.log;
+        var a = f;
+        function f(...{ [a = "PASS"]: b }) {}
+        f((a = "FAIL", 42));
+        log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5552_3: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = [ "FAIL", "PASS" ];
+        console.log(function(b, ...[ c = a.pop() ]) {
+            return b;
+        }(a.pop()));
+    }
+    expect: {
+        var a = [ "FAIL", "PASS" ];
+        console.log(function(b, ...[ c = a.pop() ]) {
+            return b;
+        }(a.pop()));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5552_4: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = [ "FAIL", "PASS" ];
+        console.log(function(b, ...{ [a.pop()]: c }) {
+            return b;
+        }(a.pop()));
+    }
+    expect: {
+        var a = [ "FAIL", "PASS" ];
+        console.log(function(b, ...{ [a.pop()]: c }) {
+            return b;
+        }(a.pop()));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
--- a/test/compress/side_effects.js
+++ b/test/compress/side_effects.js
@@ -318,6 +318,32 @@ unsafe_string_replace: {
    expect_stdout: "PASS"
 }

+unsafe_Object_call: {
+    options = {
+        side_effects: true,
+        unsafe: true,
+    }
+    input: {
+        var o = {
+            f: function(a) {
+                console.log(a ? this.p : "FAIL 1");
+            },
+            p: "FAIL 2",
+        }, p = "PASS";
+        Object(o.f)(42);
+    }
+    expect: {
+        var o = {
+            f: function(a) {
+                console.log(a ? this.p : "FAIL 1");
+            },
+            p: "FAIL 2",
+        }, p = "PASS";
+        (0, o.f)(42);
+    }
+    expect_stdout: "PASS"
+}
+
 drop_value: {
    options = {
        side_effects: true,
@@ -645,3 +671,56 @@ issue_4751: {
    }
    expect_stdout: "PASS"
 }
+
+drop_instanceof: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        42 instanceof function() {};
+        console.log("PASS");
+    }
+    expect: {
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+drop_instanceof_reference: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        function f() {}
+        42 instanceof f;
+        console.log("PASS");
+    }
+    expect: {
+        function f() {}
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+retain_instanceof: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        try {
+            42 instanceof "foo";
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try {
+            0 instanceof "foo";
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/spreads.js
+++ b/test/compress/spreads.js
@@ -1,15 +1,24 @@
+decimal: {
+    input: {
+        console.log({... 0.42});
+    }
+    expect_exact: "console.log({....42});"
+    expect_stdout: "{}"
+    node_version: ">=8.3.0"
+}
+
 collapse_vars_1: {
    options = {
        collapse_vars: true,
    }
    input: {
        var a;
-        [ ...a = "PASS", "PASS"].slice();
+        [ ...a = "PASS", "PASS" ].slice();
        console.log(a);
    }
    expect: {
        var a;
-        [ ...a = "PASS", "PASS"].slice();
+        [ ...a = "PASS", "PASS" ].slice();
        console.log(a);
    }
    expect_stdout: "PASS"
@@ -24,7 +33,7 @@ collapse_vars_2: {
        var a = "FAIL";
        try {
            a = "PASS";
-            [ ...42, "PASS"].slice();
+            [ ...42, "PASS" ].slice();
        } catch (e) {
            console.log(a);
        }
@@ -33,7 +42,7 @@ collapse_vars_2: {
        var a = "FAIL";
        try {
            a = "PASS";
-            [ ...42, "PASS"].slice();
+            [ ...42, "PASS" ].slice();
        } catch (e) {
            console.log(a);
        }
@@ -49,7 +58,7 @@ collapse_vars_3: {
    input: {
        var a = "FAIL";
        try {
-            [ ...(a = "PASS", 42), "PASS"].slice();
+            [ ...(a = "PASS", 42), "PASS" ].slice();
        } catch (e) {
            console.log(a);
        }
@@ -57,7 +66,7 @@ collapse_vars_3: {
    expect: {
        var a = "FAIL";
        try {
-            [ ...(a = "PASS", 42), "PASS"].slice();
+            [ ...(a = "PASS", 42), "PASS" ].slice();
        } catch (e) {
            console.log(a);
        }
@@ -1194,3 +1203,53 @@ issue_5382: {
    expect_stdout: "PASS"
    node_version: ">=8.3.0"
 }
+
+issue_5602: {
+    options = {
+        collapse_vars: true,
+        conditionals: true,
+        evaluate: true,
+        if_return: true,
+        inline: true,
+        passes: 2,
+        sequences: true,
+        spreads: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            try {
+                var b = function(c) {
+                    if (c)
+                        return FAIL;
+                    var d = 42;
+                }(...[ null, A = 0 ]);
+            } catch (e) {
+                b();
+            }
+        })();
+        console.log(A);
+    }
+    expect: {
+        (function() {
+            try {
+                var b = void (A = 0);
+            } catch (e) {
+                b();
+            }
+        })(),
+        console.log(A);
+    }
+    expect_stdout: "0"
+    expect_warnings: [
+        "INFO: Dropping unused variable d [test/compress/spreads.js:6,24]",
+        "INFO: Collapsing c [test/compress/spreads.js:4,24]",
+        "INFO: Dropping unused variable c [test/compress/spreads.js:3,33]",
+        "INFO: pass 0: last_count: Infinity, count: 27",
+        "WARN: Condition always false [test/compress/spreads.js:4,20]",
+        "INFO: Collapsing null [test/compress/spreads.js:7,23]",
+        "INFO: Collapsing 0 [test/compress/spreads.js:3,24]",
+        "INFO: pass 1: last_count: 27, count: 22",
+    ]
+    node_version: ">=6"
+}
--- a/test/compress/switches.js
+++ b/test/compress/switches.js
@@ -1608,3 +1608,83 @@ issue_5012: {
    }
    expect_stdout: "PASS"
 }
+
+issue_5543_1: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        var a;
+        switch (a) {
+          default:
+            switch (42) {
+              case a:
+              case console.log("PASS"):
+            }
+            break;
+          case null:
+            switch (false) {
+              case a:
+              case console.log("FAIL"):
+            }
+        }
+    }
+    expect: {
+        var a;
+        switch (a) {
+          default:
+            switch (42) {
+              case a:
+              case console.log("PASS"):
+            }
+            break;
+          case null:
+            switch (false) {
+              case a:
+              case console.log("FAIL"):
+            }
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5543_2: {
+    options = {
+        dead_code: true,
+        switches: true,
+    }
+    input: {
+        var a;
+        switch (a) {
+          default:
+            switch (42) {
+              case a:
+              case console.log("PASS"):
+            }
+            break;
+          case null:
+            switch (42) {
+              case a:
+              case console.log("FAIL"):
+            }
+        }
+    }
+    expect: {
+        var a;
+        switch (a) {
+          default:
+            switch (42) {
+              case a:
+              case console.log("PASS"):
+            }
+            break;
+          case null:
+            switch (42) {
+              case a:
+              case console.log("FAIL"):
+            }
+        }
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/transform.js
+++ b/test/compress/transform.js
@@ -127,7 +127,7 @@ if_return: {
                if (w) {
                    if (y) return;
                } else if (z) return;
-                return x == y || (x && w(), y && z()), !0;
+                return x != y && (x && w(), y && z()), !0;
            }
        }
    }
--- a/test/compress/varify.js
+++ b/test/compress/varify.js
@@ -111,7 +111,7 @@ hoist_props_const: {
        }
    }
    expect: {
-        var o = 0, o_p = "PASS";
+        var o, o_p = "PASS";
        console.log(o_p);
    }
    expect_stdout: "PASS"
@@ -194,6 +194,43 @@ scope_adjustment_let: {
    node_version: ">=4"
 }

+escaped_const: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        const log = console.log;
+        log("PASS");
+    }
+    expect: {
+        var log = console.log;
+        log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+escaped_let: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        let log = console.log;
+        log("PASS");
+    }
+    expect: {
+        "use strict";
+        var log = console.log;
+        log("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
 issue_4191_const: {
    options = {
        functions: true,
@@ -613,3 +650,197 @@ issue_4954: {
    ]
    node_version: ">=4"
 }
+
+issue_5516: {
+    options = {
+        reduce_funcs: true,
+        reduce_vars: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        console.log(typeof function() {
+            {
+                let a;
+            }
+            {
+                const a = function() {};
+                return a;
+            }
+        }());
+    }
+    expect: {
+        "use strict";
+        console.log(typeof function() {
+            {
+                const a = function() {};
+                return a;
+            }
+        }());
+    }
+    expect_stdout: "function"
+    node_version: ">=4"
+}
+
+issue_5697_1: {
+    options = {
+        if_return: true,
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        console.log(function() {
+            f();
+            return typeof a;
+            function f() {
+                (function() {
+                    for (var k in { foo: 42 }) {
+                        const a = k;
+                        console.log(a);
+                    }
+                })();
+            }
+        }());
+    }
+    expect: {
+        console.log(function() {
+            (function() {
+                for (var k in { foo: 42 }) {
+                    var a = k;
+                    console.log(a);
+                }
+            })();
+            return typeof a;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "undefined",
+    ]
+}
+
+issue_5697_2: {
+    options = {
+        if_return: true,
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        console.log(function() {
+            f();
+            return typeof a;
+            function f() {
+                (function() {
+                    for (var k in { foo: 42 }) {
+                        let a = k;
+                        console.log(a);
+                    }
+                })();
+            }
+        }());
+    }
+    expect: {
+        "use strict";
+        console.log(function() {
+            (function() {
+                for (var k in { foo: 42 }) {
+                    var a = k;
+                    console.log(a);
+                }
+            })();
+            return typeof a;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "undefined",
+    ]
+    node_version: ">=4"
+}
+
+issue_5697_3: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        console.log(function() {
+            f();
+            return typeof a;
+            function f() {
+                (function() {
+                    for (var k in { foo: 42 }) {
+                        const a = k;
+                        console.log(a);
+                    }
+                })();
+            }
+        }());
+    }
+    expect: {
+        console.log(function() {
+            (function() {
+                for (var k in { foo: 42 }) {
+                    var a = k;
+                    console.log(a);
+                }
+            })();
+            return typeof a;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "undefined",
+    ]
+}
+
+issue_5697_4: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+        varify: true,
+    }
+    input: {
+        "use strict";
+        console.log(function() {
+            f();
+            return typeof a;
+            function f() {
+                (function() {
+                    for (var k in { foo: 42 }) {
+                        let a = k;
+                        console.log(a);
+                    }
+                })();
+            }
+        }());
+    }
+    expect: {
+        "use strict";
+        console.log(function() {
+            (function() {
+                for (var k in { foo: 42 }) {
+                    var a = k;
+                    console.log(a);
+                }
+            })();
+            return typeof a;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "undefined",
+    ]
+    node_version: ">=4"
+}
--- a/test/compress/webkit.js
+++ b/test/compress/webkit.js
@@ -107,3 +107,209 @@ function_name_mangle_ie8: {
    expect_exact: "(function(){console.log(typeof function n(o){})})();"
    expect_stdout: "function"
 }
+
+issue_1753: {
+    mangle = {
+        toplevel: false,
+        webkit: true,
+    }
+    input: {
+        "use strict";
+        let l = null;
+        for (let i = 0; i < 1; i++)
+            console.log(i);
+    }
+    expect: {
+        "use strict";
+        let l = null;
+        for (let i = 0; i < 1; i++)
+            console.log(i);
+    }
+    expect_stdout: "0"
+    node_version: ">=4"
+}
+
+issue_1753_toplevel: {
+    mangle = {
+        toplevel: true,
+        webkit: true,
+    }
+    input: {
+        "use strict";
+        let l = null;
+        for (let i = 0; i < 1; i++)
+            console.log(i);
+    }
+    expect: {
+        "use strict";
+        let l = null;
+        for (let e = 0; e < 1; e++)
+            console.log(e);
+    }
+    expect_stdout: "0"
+    node_version: ">=4"
+}
+
+issue_5032_await: {
+    options = {
+        merge_vars: true,
+        webkit: false,
+    }
+    input: {
+        function log(value) {
+            console.log(value);
+            return value;
+        }
+        async function f(a) {
+            var b = log(a), c = b;
+            log(b);
+            log(c);
+        }
+        f("PASS");
+    }
+    expect: {
+        function log(value) {
+            console.log(value);
+            return value;
+        }
+        async function f(a) {
+            var a = log(a), c = a;
+            log(a);
+            log(c);
+        }
+        f("PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+    node_version: ">=8"
+}
+
+issue_5032_await_webkit: {
+    options = {
+        merge_vars: true,
+        webkit: true,
+    }
+    input: {
+        function log(value) {
+            console.log(value);
+            return value;
+        }
+        async function f(a) {
+            var b = log(a), c = b;
+            log(b);
+            log(c);
+        }
+        f("PASS");
+    }
+    expect: {
+        function log(value) {
+            console.log(value);
+            return value;
+        }
+        async function f(a) {
+            var b = log(a), c = b;
+            log(b);
+            log(c);
+        }
+        f("PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+    node_version: ">=8"
+}
+
+issue_5032_yield: {
+    options = {
+        merge_vars: true,
+        webkit: false,
+    }
+    input: {
+        function log(value) {
+            console.log(value);
+            return value;
+        }
+        function *f(a) {
+            var b = log(a), c = b;
+            log(b);
+            log(c);
+        }
+        f("PASS").next();
+    }
+    expect: {
+        function log(value) {
+            console.log(value);
+            return value;
+        }
+        function *f(a) {
+            var a = log(a), c = a;
+            log(a);
+            log(c);
+        }
+        f("PASS").next();
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+    node_version: ">=4"
+}
+
+issue_5032_yield_webkit: {
+    options = {
+        merge_vars: true,
+        webkit: true,
+    }
+    input: {
+        function log(value) {
+            console.log(value);
+            return value;
+        }
+        function *f(a) {
+            var b = log(a), c = b;
+            log(b);
+            log(c);
+        }
+        f("PASS").next();
+    }
+    expect: {
+        function log(value) {
+            console.log(value);
+            return value;
+        }
+        function *f(a) {
+            var b = log(a), c = b;
+            log(b);
+            log(c);
+        }
+        f("PASS").next();
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+    node_version: ">=4"
+}
+
+issue_5480: {
+    mangle = {
+        webkit: true,
+    }
+    input: {
+        "use strict";
+        L: for (let a in console.log("PASS"));
+    }
+    expect: {
+        "use strict";
+        o: for (let o in console.log("PASS"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
--- a/test/compress/yields.js
+++ b/test/compress/yields.js
@@ -907,7 +907,7 @@ drop_body: {
        })([ console.log("baz") ]);
    }
    expect: {
-        [ [ , [].e = console.log("foo") ] ] = [ [ console.log("baz") ] ];
+        [ [ , [][0] = console.log("foo") ] ] = [ [ console.log("baz") ] ];
    }
    expect_stdout: [
        "baz",
@@ -934,6 +934,21 @@ drop_unused_call: {
    node_version: ">=4"
 }

+instanceof_lambda: {
+    options = {
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(42 instanceof function*() {});
+    }
+    expect: {
+        console.log(false);
+    }
+    expect_stdout: "false"
+    node_version: ">=4"
+}
+
 issue_4454_1: {
    rename = false
    options = {
@@ -978,8 +993,8 @@ issue_4454_2: {
    expect: {
        function f(a) {
            (function*(c = console.log(a)) {})();
-            var a = 42..toString();
-            console.log(a);
+            var b = 42..toString();
+            console.log(b);
        }
        f("PASS");
    }
@@ -1168,6 +1183,35 @@ issue_4641_2: {
    node_version: ">=10"
 }

+issue_4641_3: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        console.log(typeof async function*() {
+            try {
+                return void "FAIL";
+            } finally {
+                console.log("PASS");
+            }
+        }().next().then);
+    }
+    expect: {
+        console.log(typeof async function*() {
+            try {
+                return void "FAIL";
+            } finally {
+                console.log("PASS");
+            }
+        }().next().then);
+    }
+    expect_stdout: [
+        "function",
+        "PASS",
+    ]
+    node_version: ">=10"
+}
+
 issue_4769_1: {
    options = {
        side_effects: true,
@@ -1267,80 +1311,6 @@ issue_5019_2: {
    node_version: ">=4"
 }

-issue_5032_normal: {
-    options = {
-        merge_vars: true,
-        webkit: false,
-    }
-    input: {
-        function log(value) {
-            console.log(value);
-            return value;
-        }
-        function *f(a) {
-            var b = log(a), c = b;
-            log(b);
-            log(c);
-        }
-        f("PASS").next();
-    }
-    expect: {
-        function log(value) {
-            console.log(value);
-            return value;
-        }
-        function *f(a) {
-            var a = log(a), c = a;
-            log(a);
-            log(c);
-        }
-        f("PASS").next();
-    }
-    expect_stdout: [
-        "PASS",
-        "PASS",
-        "PASS",
-    ]
-    node_version: ">=4"
-}
-
-issue_5032_webkit: {
-    options = {
-        merge_vars: true,
-        webkit: true,
-    }
-    input: {
-        function log(value) {
-            console.log(value);
-            return value;
-        }
-        function *f(a) {
-            var b = log(a), c = b;
-            log(b);
-            log(c);
-        }
-        f("PASS").next();
-    }
-    expect: {
-        function log(value) {
-            console.log(value);
-            return value;
-        }
-        function *f(a) {
-            var b = log(a), c = b;
-            log(b);
-            log(c);
-        }
-        f("PASS").next();
-    }
-    expect_stdout: [
-        "PASS",
-        "PASS",
-        "PASS",
-    ]
-    node_version: ">=4"
-}
-
 issue_5034: {
    options = {
        functions: true,
@@ -1526,6 +1496,80 @@ issue_5385_2: {
    node_version: ">=10"
 }

+issue_5385_3: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (async function*() {
+            return function() {
+                try {
+                    throw console.log("foo");
+                } catch (e) {
+                    return console.log("bar");
+                }
+            }();
+        })().next();
+        console.log("moo");
+    }
+    expect: {
+        (async function*() {
+            try {
+                throw console.log("foo");
+            } catch (e) {
+                return console.log("bar");
+            }
+            return void 0;
+        })().next();
+        console.log("moo");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "moo",
+    ]
+    node_version: ">=10"
+}
+
+issue_5385_4: {
+    options = {
+        awaits: true,
+        inline: true,
+    }
+    input: {
+        (async function*() {
+            return async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            resolve(console.log("FAIL"));
+                        },
+                    };
+                } finally {
+                    return "PASS";
+                }
+            }();
+        })().next().then(o => console.log(o.value, o.done));
+    }
+    expect: {
+        (async function*() {
+            return async function() {
+                try {
+                    return {
+                        then(resolve) {
+                            resolve(console.log("FAIL"));
+                        },
+                    };
+                } finally {
+                    return "PASS";
+                }
+            }();
+        })().next().then(o => console.log(o.value, o.done));
+    }
+    expect_stdout: "PASS true"
+    node_version: ">=10"
+}
+
 issue_5425: {
    options = {
        assignments: true,
@@ -1547,3 +1591,430 @@ issue_5425: {
    expect_stdout: "PASS undefined"
    node_version: ">=4"
 }
+
+issue_5456: {
+    options = {
+        inline: true,
+        merge_vars: true,
+    }
+    input: {
+        var a = true;
+        (function() {
+            (function(b, c) {
+                var d = function*() {
+                    c = null;
+                }();
+                var e = function() {
+                    if (c)
+                        console.log(typeof d);
+                    while (b);
+                }();
+            })(function(i) {
+                return console.log("foo") && i;
+            }(a));
+        })();
+    }
+    expect: {
+        var a = true;
+        (function() {
+            b = (i = a, console.log("foo") && i),
+            d = function*() {
+                c = null;
+            }(),
+            e = function() {
+                if (c) console.log(typeof d);
+                while (b);
+            }(),
+            void 0;
+            var b, c, d, e;
+            var i;
+        })();
+    }
+    expect_stdout: "foo"
+    node_version: ">=4"
+}
+
+issue_5506: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        console.log(function(a) {
+            var b = function*() {
+                a = null in (a = "PASS");
+            }();
+            try {
+                b.next();
+            } catch (e) {
+                return a;
+            }
+        }("FAIL"));
+    }
+    expect: {
+        console.log(function(a) {
+            var b = function*() {
+                a = null in (a = "PASS");
+            }();
+            try {
+                b.next();
+            } catch (e) {
+                return a;
+            }
+        }("FAIL"));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_5526: {
+    options = {
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        (async function*() {
+            try {
+                return function() {
+                    while (console.log("foo"));
+                }();
+            } finally {
+                console.log("bar");
+            }
+        })().next();
+        console.log("baz");
+    }
+    expect: {
+        (async function*() {
+            try {
+                while (console.log("foo"));
+                return void 0;
+            } finally {
+                console.log("bar");
+            }
+        })().next();
+        console.log("baz");
+    }
+    expect_stdout: [
+        "foo",
+        "baz",
+        "bar",
+    ]
+    node_version: ">=10"
+}
+
+issue_5576: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (async function*() {
+            try {
+                (function() {
+                    while (console.log("foo"));
+                })();
+            } finally {
+                console.log("bar");
+            }
+        })().next();
+        console.log("baz");
+    }
+    expect: {
+        (async function*() {
+            try {
+                while (console.log("foo"));
+            } finally {
+                console.log("bar");
+            }
+        })().next();
+        console.log("baz");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=10"
+}
+
+issue_5663: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var [ , a ] = function*() {
+            console.log("foo");
+            yield console.log("bar");
+            console.log("baz");
+            yield console.log("moo");
+            console.log("moz");
+            yield FAIL;
+        }();
+    }
+    expect: {
+        var [ , , ] = function*() {
+            console.log("foo");
+            yield console.log("bar");
+            console.log("baz");
+            yield console.log("moo");
+            console.log("moz");
+            yield FAIL;
+        }();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+        "moo",
+    ]
+    node_version: ">=6"
+}
+
+issue_5679_1: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a = "FAIL";
+        async function* f(b) {
+            try {
+                if (b)
+                    return;
+                else
+                    return;
+            } finally {
+                a = "PASS";
+            }
+        }
+        f().next();
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        async function* f(b) {
+            try {
+                b;
+                return;
+            } finally {
+                a = "PASS";
+            }
+        }
+        f().next();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}
+
+issue_5679_2: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a = "FAIL";
+        async function* f(b) {
+            try {
+                if (b)
+                    return undefined;
+                else
+                    return;
+            } finally {
+                a = "PASS";
+            }
+        }
+        f().next();
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        async function* f(b) {
+            try {
+                if (b)
+                    return void 0;
+                return;
+            } finally {
+                a = "PASS";
+            }
+        }
+        f().next();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}
+
+issue_5679_3: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a = "FAIL";
+        async function* f(b) {
+            try {
+                if (b)
+                    return;
+                else
+                    return undefined;
+            } finally {
+                a = "PASS";
+            }
+        }
+        f(42).next();
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        async function* f(b) {
+            try {
+                if (b)
+                    return;
+                return void 0;
+            } finally {
+                a = "PASS";
+            }
+        }
+        f(42).next();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}
+
+issue_5679_4: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a = "PASS";
+        async function* f(b) {
+            try {
+                if (b)
+                    return undefined;
+                else
+                    return undefined;
+            } finally {
+                a = "FAIL";
+            }
+        }
+        f(null).next();
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        async function* f(b) {
+            try {
+                return b, void 0;
+            } finally {
+                a = "FAIL";
+            }
+        }
+        f(null).next();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}
+
+issue_5679_5: {
+    options = {
+        conditionals: true,
+        if_return: true,
+    }
+    input: {
+        var a = "FAIL";
+        async function* f(b) {
+            try {
+                if (b)
+                    return console;
+                else
+                    return;
+            } finally {
+                a = "PASS";
+            }
+        }
+        f().next();
+        console.log(a);
+    }
+    expect: {
+        var a = "FAIL";
+        async function* f(b) {
+            try {
+                if (b)
+                    return console;
+                return;
+            } finally {
+                a = "PASS";
+            }
+        }
+        f().next();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}
+
+issue_5679_6: {
+    options = {
+        conditionals: true,
+        if_return: true,
+    }
+    input: {
+        var a = "PASS";
+        async function* f(b) {
+            try {
+                if (b)
+                    return;
+                else
+                    return console;
+            } finally {
+                a = "FAIL";
+            }
+        }
+        f().next();
+        console.log(a);
+    }
+    expect: {
+        var a = "PASS";
+        async function* f(b) {
+            try {
+                if (!b)
+                    return console;
+            } finally {
+                a = "FAIL";
+            }
+        }
+        f().next();
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}
+
+issue_5684: {
+    options = {
+        conditionals: true,
+        if_return: true,
+    }
+    input: {
+        (async function*() {
+            switch (42) {
+              default:
+                if (console.log("PASS"))
+                    return;
+                return null;
+              case false:
+            }
+        })().next();
+    }
+    expect: {
+        (async function*() {
+            switch (42) {
+              default:
+                return console.log("PASS") ? void 0 : null;
+              case false:
+            }
+        })().next();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=10"
+}
--- a/test/input/issue-3040/expect.js
+++ b/test/input/issue-3040/expect.js
@@ -38,4 +38,4 @@ var _require = require("bar"), foo = _require.foo;
 var _require2 = require("world"), hello = _require2.hello;

 foo.x.apply(foo, _toConsumableArray(foo.y(hello.z)));
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,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
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImlucHV0LmpzIl0sInNvdXJjZXNDb250ZW50IjpbImNvbnN0IHtmb299ID0gcmVxdWlyZShcImJhclwiKTtcbmNvbnN0IHtoZWxsb30gPSByZXF1aXJlKFwid29ybGRcIik7XG5cbmZvby54KC4uLmZvby55KGhlbGxvLnopKTtcbiJdLCJuYW1lcyI6WyJyZXF1aXJlIiwiZm9vIiwiaGVsbG8iLCJ4IiwiYXBwbHkiLCJfdG9Db25zdW1hYmxlQXJyYXkiLCJ5IiwieiJdLCJtYXBwaW5ncyI6Ijs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7ZUFBY0EsUUFBUSxLQUFELEdBQWRDLE0sU0FBQUE7O0EsZ0JBQ1NELFFBQVEsT0FBRCxHQUFoQkUsUSxVQUFBQTs7QUFFUEQsSUFBSUUsRUFBSkMsTUFBQUgsS0FBR0ksbUJBQU1KLElBQUlLLEVBQUVKLE1BQU1LLENBQVosQ0FBTixDQUFBIn0=
--- a/test/input/issue-3294/output.js
+++ b/test/input/issue-3294/output.js
@@ -1,2 +1,2 @@
 console.log(3);
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUEwQkEsUUFBUUMsSUFBSSJ9
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUEwQkEsUUFBUUMsSUFBSSxDQUFHIn0=
--- a/test/input/issue-505/output.js
+++ b/test/input/issue-505/output.js
@@ -2,4 +2,4 @@ function test(a){
 "aaaaaaaaaaaaaaaa";
 a(err,data),a(err,
 data)}
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsidGVzdCIsImNhbGxiYWNrIiwiZXJyIiwiZGF0YSJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0E7SEFBS0M7QUFFVkE7aEJBQVNDLElBQUtDLE1BQ2RGLEVBQVNDLElBQUtDIn0=
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsidGVzdCIsImNhbGxiYWNrIiwiZXJyIiwiZGF0YSJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0E7SEFBS0MsR0FDVjtBQUNBQTtoQkFBU0MsSUFBS0MsSUFBSSxFQUNsQkYsRUFBU0MsSUFBS0MsSUFBSSxDQUN0QiJ9
--- a/test/input/issue-520/output.js
+++ b/test/input/issue-520/output.js
@@ -1,2 +1,2 @@
 console.log(3);
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUEwQkEsUUFBUUMsSUFBSSJ9
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUEwQkEsUUFBUUMsSUFBSSxDQUFHIn0=
--- a/test/input/module/expect.js
+++ b/test/input/module/expect.js
@@ -0,0 +1 @@
+function n(){return this||arguments[0]+arguments[1]}function o(){return this||arguments[0]+arguments[1]}console.log(n(n(1,3),5)),console.log(o(o(2,4),6));
--- a/test/input/module/input.js
+++ b/test/input/module/input.js
@@ -0,0 +1,13 @@
+console.log(function() {
+    function sum(...params) {
+        return this || arguments[0] + arguments[1];
+    }
+    return sum(sum(1, 3), 5);
+}());
+console.log(function() {
+    "use strict";
+    function sum(...params) {
+        return this || arguments[0] + arguments[1];
+    }
+    return sum(sum(2, 4), 6);
+}());
--- a/test/jetstream.js
+++ b/test/jetstream.js
@@ -62,6 +62,7 @@ if (typeof phantom == "undefined") {
        var cmd = process.platform == "win32" ? "npm.cmd" : "npm";

        function npm(args, done) {
+            args.push("--loglevel=error");
            child_process.spawn(cmd, args, { stdio: [ "ignore", 1, 2 ] }).on("exit", done);
        }

@@ -72,9 +73,12 @@ if (typeof phantom == "undefined") {
                "is-my-json-valid@2.20.5",
                "phantomjs-prebuilt@2.1.14",
                "--no-audit",
+                "--no-fund",
                "--no-optional",
                "--no-save",
+                "--no-strict-ssl",
                "--no-update-notifier",
+                "--production",
            ], function(code) {
                if (code) {
                    console.log("npm install failed with code", code);
--- a/test/mocha.js
+++ b/test/mocha.js
@@ -1,13 +1,14 @@
 var fs = require("fs");

 var config = {
-    limit: 10000,
    timeout: function(limit) {
-        this.limit = limit;
-    }
+        this.limit = limit + lag;
+    },
 };
+var lag = +process.env["UGLIFY_GITHUB_LAG"] || 0;
 var tasks = [];
 var titles = [];
+config.timeout(10000);
 describe = function(title, fn) {
    config = Object.create(config);
    titles.push(title);
@@ -21,10 +22,11 @@ it = function(title, fn) {
    fn.titles.push(title);
    tasks.push(fn);
 };
-
-fs.readdirSync("test/mocha").filter(function(file) {
+(function(arg) {
+    return arg ? [ arg ] : fs.readdirSync("test/mocha").filter(function(file) {
        return /\.js$/.test(file);
-}).forEach(function(file) {
+    });
+})(process.argv[2]).forEach(function(file) {
    require("./mocha/" + file);
 });

@@ -66,12 +68,13 @@ process.nextTick(function run() {
        if (task.length) {
            task.timeout = function(limit) {
                clearTimeout(timer);
+                limit += lag;
                task.limit = limit;
                timer = setTimeout(function() {
                    raise(new Error("Timed out: exceeds " + limit + "ms"));
                }, limit);
            };
-            task.timeout(task.limit);
+            task.timeout(task.limit - lag);
            process.on("uncaughtException", raise);
            task.call(task, done);
        } else {
--- a/test/mocha/cli.js
+++ b/test/mocha/cli.js
@@ -53,6 +53,23 @@ describe("bin/uglifyjs", function() {
            done();
        });
    });
+    it("Should work with --expression", function(done) {
+        exec([
+            uglifyjscmd,
+            "--expression",
+            "--compress",
+            "--mangle",
+        ].join(" "), function(err, stdout) {
+            if (err) throw err;
+            assert.strictEqual(stdout, "function(n){for(;n(););return 42}(A)\n");
+            done();
+        }).stdin.end([
+            "function(x) {",
+            "    while (x()) {}",
+            "    return 42;",
+            "}(A)",
+        ].join("\n"));
+    });
    it("Should work with --source-map names=true", function(done) {
        exec([
            uglifyjscmd,
@@ -69,7 +86,7 @@ describe("bin/uglifyjs", function() {
                "    q: b",
                "};",
                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,",
-            ].join("\n")
+            ].join("\n");
            assert.strictEqual(stdout.slice(0, expected.length), expected);
            var map = JSON.parse(to_ascii(stdout.slice(expected.length).trim()));
            assert.deepEqual(map.names, [ "obj", "p", "a", "q", "b" ]);
@@ -97,7 +114,7 @@ describe("bin/uglifyjs", function() {
                "    q: b",
                "};",
                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,",
-            ].join("\n")
+            ].join("\n");
            assert.strictEqual(stdout.slice(0, expected.length), expected);
            var map = JSON.parse(to_ascii(stdout.slice(expected.length).trim()));
            assert.deepEqual(map.names, []);
@@ -126,7 +143,7 @@ describe("bin/uglifyjs", function() {
            if (err) throw err;
            assert.strictEqual(stdout, [
                "var bar=function(){function foo(bar){return bar}return foo}();",
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInRlc3QvaW5wdXQvaXNzdWUtMTMyMy9zYW1wbGUuanMiXSwibmFtZXMiOlsiYmFyIiwiZm9vIl0sIm1hcHBpbmdzIjoiQUFBQSxJQUFJQSxJQUFNLFdBQ04sU0FBU0MsSUFBS0QsS0FDVixPQUFPQSxJQUdYLE9BQU9DLElBTEQifQ==",
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInRlc3QvaW5wdXQvaXNzdWUtMTMyMy9zYW1wbGUuanMiXSwibmFtZXMiOlsiYmFyIiwiZm9vIl0sIm1hcHBpbmdzIjoiQUFBQSxJQUFJQSxJQUFNLFdBQ04sU0FBU0MsSUFBS0QsS0FDVixPQUFPQSxHQUNYLENBRUEsT0FBT0MsR0FDVixFQUFFIn0=",
                "",
            ].join("\n"));
            done();
@@ -313,7 +330,7 @@ describe("bin/uglifyjs", function() {
            if (err) throw err;
            assert.strictEqual(stdout, [
                "var bar=function(){function foo(bar){return bar}return foo}();",
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInRlc3QvaW5wdXQvaXNzdWUtMTMyMy9zYW1wbGUuanMiXSwibmFtZXMiOlsiYmFyIiwiZm9vIl0sIm1hcHBpbmdzIjoiQUFBQSxJQUFJQSxJQUFNLFdBQ04sU0FBU0MsSUFBS0QsS0FDVixPQUFPQSxJQUdYLE9BQU9DLElBTEQifQ==",
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInRlc3QvaW5wdXQvaXNzdWUtMTMyMy9zYW1wbGUuanMiXSwibmFtZXMiOlsiYmFyIiwiZm9vIl0sIm1hcHBpbmdzIjoiQUFBQSxJQUFJQSxJQUFNLFdBQ04sU0FBU0MsSUFBS0QsS0FDVixPQUFPQSxHQUNYLENBRUEsT0FBT0MsR0FDVixFQUFFIn0=",
                "",
            ].join("\n"));
            var stderrLines = stderr.split("\n");
@@ -333,7 +350,7 @@ describe("bin/uglifyjs", function() {
            if (err) throw err;
            assert.strictEqual(stdout, [
                "var Foo=function Foo(){console.log(1+2)};new Foo;var bar=function(){function foo(bar){return bar}return foo}();",
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIiwidGVzdC9pbnB1dC9pc3N1ZS0xMzIzL3NhbXBsZS5qcyJdLCJuYW1lcyI6WyJGb28iLCJjb25zb2xlIiwibG9nIiwiYmFyIiwiZm9vIl0sIm1hcHBpbmdzIjoiQUFBQSxJQUFNQSxJQUFJLFNBQUVBLE1BQWNDLFFBQVFDLElBQUksRUFBRSxJQUFPLElBQUlGLElDQW5ELElBQUlHLElBQU0sV0FDTixTQUFTQyxJQUFLRCxLQUNWLE9BQU9BLElBR1gsT0FBT0MsSUFMRCJ9",
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIiwidGVzdC9pbnB1dC9pc3N1ZS0xMzIzL3NhbXBsZS5qcyJdLCJuYW1lcyI6WyJGb28iLCJjb25zb2xlIiwibG9nIiwiYmFyIiwiZm9vIl0sIm1hcHBpbmdzIjoiQUFBQSxJQUFNQSxJQUFJLFNBQUVBLE1BQWNDLFFBQVFDLElBQUksRUFBRSxDQUFDLENBQUUsRUFBSSxJQUFJRixJQ0FuRCxJQUFJRyxJQUFNLFdBQ04sU0FBU0MsSUFBS0QsS0FDVixPQUFPQSxHQUNYLENBRUEsT0FBT0MsR0FDVixFQUFFIn0=",
                "",
            ].join("\n"));
            var stderrLines = stderr.split("\n");
@@ -774,7 +791,7 @@ describe("bin/uglifyjs", function() {
            if (err) throw err;
            assert.strictEqual(stdout, [
                '"use strict";var foo=function foo(x){return"foo "+x};console.log(foo("bar"));',
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImluZGV4LmpzIl0sIm5hbWVzIjpbImZvbyIsIngiLCJjb25zb2xlIiwibG9nIl0sIm1hcHBpbmdzIjoiYUFBQSxJQUFJQSxJQUFNLFNBQU5BLElBQU1DLEdBQUEsTUFBSyxPQUFTQSxHQUN4QkMsUUFBUUMsSUFBSUgsSUFBSSJ9",
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImluZGV4LmpzIl0sIm5hbWVzIjpbImZvbyIsIngiLCJjb25zb2xlIiwibG9nIl0sIm1hcHBpbmdzIjoiYUFBQSxJQUFJQSxJQUFNLFNBQU5BLElBQU1DLEdBQUEsTUFBSyxPQUFTQSxDQUFkLEVBQ1ZDLFFBQVFDLElBQUlILElBQUksS0FBSixDQUFaIn0=",
                ""
            ].join("\n"));
            done();
@@ -797,7 +814,7 @@ describe("bin/uglifyjs", function() {
            if (err) throw err;
            assert.strictEqual(stdout, [
                'function foo(){return function(){console.log("PASS")}}foo()();',
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInRlc3QvaW5wdXQvaXNzdWUtMjMxMC9pbnB1dC5qcyJdLCJuYW1lcyI6WyJmb28iLCJjb25zb2xlIiwibG9nIiwiZiJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0EsTUFDTCxPQUFPLFdBQ0hDLFFBQVFDLElBQUksU0FLUkYsS0FDUkcifQ==",
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInRlc3QvaW5wdXQvaXNzdWUtMjMxMC9pbnB1dC5qcyJdLCJuYW1lcyI6WyJmb28iLCJjb25zb2xlIiwibG9nIl0sIm1hcHBpbmdzIjoiQUFBQSxTQUFTQSxNQUNMLE9BQU8sV0FDSEMsUUFBUUMsSUFBSSxNQUFNLENBQ3RCLENBQ0osQ0FHWUYsSUFBSSxFQUNWIn0=",
                ""
            ].join("\n"));
            done();
@@ -928,6 +945,14 @@ describe("bin/uglifyjs", function() {
            done();
        });
    });
+    it("Should work with --module", function(done) {
+        var command = uglifyjscmd + " test/input/module/input.js --module -mc";
+        exec(command, function(err, stdout, stderr) {
+            if (err) throw err;
+            assert.strictEqual(stdout, read("test/input/module/expect.js"));
+            done();
+        });
+    });
    it("Should compress swarm of unused variables with reasonable performance", function(done) {
        var code = [
            "console.log(function() {",
--- a/test/mocha/comments.js
+++ b/test/mocha/comments.js
@@ -400,7 +400,7 @@ describe("comments", function() {
            assert.strictEqual(ast.print_to_string({comments: "all"}), "/*!test1*/\n/*test2*/\n//!test3\n//test4\n//test5\n//!test6\n//test7\n//!test8");
        });

-        it("Should be able to filter commments with the 'some' option", function() {
+        it("Should be able to filter comments with the 'some' option", function() {
            var ast = UglifyJS.parse("// foo\n/*@preserve*/\n// bar\n/*@license*/\n//@license with the wrong comment type\n/*@cc_on something*/");
            assert.strictEqual(ast.print_to_string({comments: "some"}), "/*@preserve*/\n/*@license*/\n/*@cc_on something*/");
        });
--- a/test/mocha/directives.js
+++ b/test/mocha/directives.js
@@ -348,7 +348,7 @@ describe("Directives", function() {
                '"use strict";doSomething("foo");'
            ],
            [
-                // Nothing gets optimised in the compressor because "use asm" is the first statement
+                // Nothing gets optimized in the compressor because "use asm" is the first statement
                '"use asm";"use\\x20strict";1+1;',
                '"use asm";"use\\x20strict";1+1;'
            ],
--- a/test/mocha/exports.js
+++ b/test/mocha/exports.js
@@ -1,3 +1,4 @@
+var acorn = require("acorn");
 var assert = require("assert");
 var UglifyJS = require("../node");

@@ -25,6 +26,7 @@ describe("export", function() {
            "export { * };",
            "export { * as A };",
            "export { 42 as A };",
+            "export { 'A' as B };",
            "export { A as B-C };",
            "export { default as A };",
        ].forEach(function(code) {
@@ -51,8 +53,11 @@ describe("export", function() {
    it("Should reject invalid `export ... from ...` statement syntax", function() {
        [
            "export from 'path';",
+            "export A from 'path';",
            "export * from `path`;",
+            "export 'A' from 'path';",
            "export A as B from 'path';",
+            "export 'A' as B from 'path';",
            "export default from 'path';",
            "export { A }, B from 'path';",
            "export * as A, B from 'path';",
@@ -68,4 +73,109 @@ describe("export", function() {
            }, code);
        });
    });
+    it("Should reject `export` statement not under top-level scope", function() {
+        [
+            "{ export {}; }",
+            "if (0) export var A;",
+            "function f() { export default 42; }",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
+    it("Should compare `export` statements correctly", function() {
+        var stats = {
+            Declaration: [
+                "export let A;",
+                "export const A = 42;",
+                "export var { A, B: [] } = C;",
+                "export function A() { return B(A); }",
+                "export async function* A({}, ...[]) { return B(A); }",
+            ],
+            Default: [
+                "export default 42;",
+                "export default A => A(B);",
+                "export default class A extends B {}",
+                "export default (class A extends B {});",
+                "export default class A { static C = 42; }",
+                "export default class A extends B { static C = 42; }",
+            ],
+            Foreign: [
+                "export * from 'path';",
+                "export {} from 'path';",
+                "export * as A from 'path';",
+                "export { default } from 'path';",
+                "export { A, B as C } from 'path';",
+                "export { A, default as C } from 'path';",
+            ],
+            References: [
+                "export {};",
+                "export { A };",
+                "export { A as B };",
+                "export { A, B as C };",
+                "export { A as default };",
+            ],
+        };
+        for (var k in stats) stats[k].forEach(function(c, i) {
+            var s = UglifyJS.parse(c);
+            assert.ok(s instanceof UglifyJS.AST_Toplevel, c);
+            assert.strictEqual(s.body.length, 1, c);
+            assert.strictEqual(s.body[0].TYPE, "Export" + k, c);
+            for (var l in stats) stats[l].forEach(function(d, j) {
+                var t = UglifyJS.parse(d);
+                assert.ok(t instanceof UglifyJS.AST_Toplevel, d);
+                assert.strictEqual(t.body.length, 1, d);
+                assert.strictEqual(t.body[0].TYPE, "Export" + l, d);
+                assert.strictEqual(s.equals(t), k === l && i === j, c + "\n" + d);
+            });
+        });
+    });
+    it("Should interoperate with ESTree correctly", function() {
+        [
+            "export var A = 42;",
+            "export default (class A {});",
+            "var A; export { A as '42' };",
+            "export { '42' } from 'path';",
+            "export * as '42' from 'path';",
+        ].forEach(function(code) {
+            var ast = UglifyJS.parse(code);
+            try {
+                var spidermonkey = ast.to_mozilla_ast();
+            } catch (ex) {
+                assert.fail("[to_mozilla_ast] " + ex.stack);
+            }
+            try {
+                var ast2 = UglifyJS.AST_Node.from_mozilla_ast(spidermonkey);
+            } catch (ex) {
+                assert.fail("[from_mozilla_ast] " + ex.stack);
+            }
+            assert.strictEqual(ast2.print_to_string(), ast.print_to_string(), [
+                "spidermonkey:",
+                ast.print_to_string(),
+                ast2.print_to_string(),
+            ].join("\n"));
+            try {
+                var acorn_est = acorn.parse(code, {
+                    ecmaVersion: "latest",
+                    locations: true,
+                    sourceType: "module",
+                });
+            } catch (ex) {
+                assert.fail("[acorn.parse] " + ex.stack);
+            }
+            try {
+                var ast3 = UglifyJS.AST_Node.from_mozilla_ast(acorn_est);
+            } catch (ex) {
+                assert.fail("[from_acorn] " + ex.stack);
+            }
+            assert.strictEqual(ast3.print_to_string(), ast.print_to_string(), [
+                "acorn:",
+                ast.print_to_string(),
+                ast3.print_to_string(),
+            ].join("\n"));
+        });
+    });
 });
--- a/test/mocha/imports.js
+++ b/test/mocha/imports.js
@@ -1,3 +1,4 @@
+var acorn = require("acorn");
 var assert = require("assert");
 var UglifyJS = require("../node");

@@ -8,15 +9,25 @@ describe("import", function() {
            "import A;",
            "import {};",
            "import `path`;",
+            "{ import 'path'; }",
            "import from 'path';",
+            "if (0) import 'path';",
            "import * from 'path';",
+            "import 'A' from 'path';",
+            "import A-B from 'path';",
            "import A as B from 'path';",
            "import { A }, B from 'path';",
+            "import * as 'A' from 'path';",
+            "import * as A-B from 'path';",
            "import * as A, B from 'path';",
            "import * as A, {} from 'path';",
            "import { * as A } from 'path';",
+            "import { * as 'A' } from 'path';",
+            "import { * as A-B } from 'path';",
+            "function f() { import 'path'; }",
            "import { 42 as A } from 'path';",
            "import { A-B as C } from 'path';",
+            "import { 'A' as 'B' } from 'path';",
        ].forEach(function(code) {
            assert.throws(function() {
                UglifyJS.parse(code);
@@ -25,4 +36,74 @@ describe("import", function() {
            }, code);
        });
    });
+    it("Should compare `import` statements correctly", function() {
+        [
+            "import 'foo';",
+            "import 'path';",
+            "import A from 'path';",
+            "import { A } from 'path';",
+            "import * as A from 'path';",
+            "import A, { B } from 'path';",
+            "import A, * as B from 'path';",
+            "import { A as B } from 'path';",
+            "import A, { B, C as D } from 'path';",
+        ].forEach(function(c, i, stats) {
+            var s = UglifyJS.parse(c);
+            assert.ok(s instanceof UglifyJS.AST_Toplevel, c);
+            assert.strictEqual(s.body.length, 1, c);
+            assert.ok(s.body[0] instanceof UglifyJS.AST_Import, c);
+            stats.forEach(function(d, j) {
+                var t = UglifyJS.parse(d);
+                assert.ok(t instanceof UglifyJS.AST_Toplevel, d);
+                assert.strictEqual(t.body.length, 1, d);
+                assert.ok(t.body[0] instanceof UglifyJS.AST_Import, d);
+                assert.strictEqual(s.equals(t), i === j, c + "\n" + d);
+            });
+        });
+    });
+    it("Should interoperate with ESTree correctly", function() {
+        [
+            "import A from 'path';",
+            "import * as A from 'path';",
+            "import A, * as B from 'path';",
+            "import { '42' as A, B } from 'path';",
+            "import A, { '42' as B } from 'path';",
+        ].forEach(function(code) {
+            var ast = UglifyJS.parse(code);
+            try {
+                var spidermonkey = ast.to_mozilla_ast();
+            } catch (ex) {
+                assert.fail("[to_mozilla_ast] " + ex.stack);
+            }
+            try {
+                var ast2 = UglifyJS.AST_Node.from_mozilla_ast(spidermonkey);
+            } catch (ex) {
+                assert.fail("[from_mozilla_ast] " + ex.stack);
+            }
+            assert.strictEqual(ast2.print_to_string(), ast.print_to_string(), [
+                "spidermonkey:",
+                ast.print_to_string(),
+                ast2.print_to_string(),
+            ].join("\n"));
+            try {
+                var acorn_est = acorn.parse(code, {
+                    ecmaVersion: "latest",
+                    locations: true,
+                    sourceType: "module",
+                });
+            } catch (ex) {
+                assert.fail("[acorn.parse] " + ex.stack);
+            }
+            try {
+                var ast3 = UglifyJS.AST_Node.from_mozilla_ast(acorn_est);
+            } catch (ex) {
+                assert.fail("[from_acorn] " + ex.stack);
+            }
+            assert.strictEqual(ast3.print_to_string(), ast.print_to_string(), [
+                "acorn:",
+                ast.print_to_string(),
+                ast3.print_to_string(),
+            ].join("\n"));
+        });
+    });
 });
--- a/test/mocha/let.js
+++ b/test/mocha/let.js
@@ -12,17 +12,16 @@ describe("let", function() {
        s += '}';
        var result = UglifyJS.minify(s, {
            compress: false,
-        }).code;
-
+        });
+        if (result.error) throw result.error;
        // Verify that select keywords and reserved keywords not produced
        [
            "do",
            "let",
            "var",
        ].forEach(function(name) {
-            assert.strictEqual(result.indexOf("var " + name + "="), -1);
+            assert.strictEqual(result.code.indexOf("var " + name + "="), -1);
        });
-
        // Verify that the variable names that appeared immediately before
        // and after the erroneously generated variable name still exist
        // to show the test generated enough symbols.
@@ -31,27 +30,29 @@ describe("let", function() {
            "eet", "fet",
            "rar", "oar",
        ].forEach(function(name) {
-            assert.notStrictEqual(result.indexOf("var " + name + "="), -1);
+            assert.notStrictEqual(result.code.indexOf("var " + name + "="), -1);
        });
    });
    it("Should quote mangled properties that are reserved keywords", function() {
        var s = '"rrrrrnnnnniiiiiaaaaa";';
        for (var i = 0; i < 18000; i++) {
-            s += "v.b" + i + ";";
+            s += "v.b" + i + "=v;";
        }
        var result = UglifyJS.minify(s, {
            compress: false,
            ie: true,
            mangle: {
-                properties: true,
-            }
-        }).code;
+                properties: {
+                    domprops: true,
+                },
+            },
+        });
+        if (result.error) throw result.error;
        [
            "in",
            "var",
        ].forEach(function(name) {
-            assert.notStrictEqual(result.indexOf(name), -1);
-            assert.notStrictEqual(result.indexOf('v["' + name + '"]'), -1);
+            assert.notStrictEqual(result.code.indexOf('v["' + name + '"]'), -1);
        });
    });
    it("Should parse `let` as name correctly", function() {
--- a/test/mocha/minify.js
+++ b/test/mocha/minify.js
@@ -1,6 +1,7 @@
 var assert = require("assert");
 var readFileSync = require("fs").readFileSync;
 var run_code = require("../sandbox").run_code;
+var semver = require("semver");
 var UglifyJS = require("../..");

 function read(path) {
@@ -109,10 +110,12 @@ describe("minify", function() {
            var result = UglifyJS.minify(code, {
                compress: false,
                mangle: {
-                    properties: true,
-                    toplevel: true
+                    properties: {
+                        domprops: true,
                    },
-                nameCache: cache
+                    toplevel: true,
+                },
+                nameCache: cache,
            });
            if (result.error) throw result.error;
            original += code;
@@ -187,32 +190,30 @@ describe("minify", function() {
        it("Shouldn't mangle quoted properties", function() {
            var js = 'a["foo"] = "bar"; a.color = "red"; x = {"bar": 10};';
            var result = UglifyJS.minify(js, {
-                compress: {
-                    properties: false
-                },
+                compress: true,
                mangle: {
                    properties: {
-                        keep_quoted: true
-                    }
+                        domprops: true,
+                        keep_quoted: true,
+                    },
                },
                output: {
                    keep_quoted_props: true,
-                    quote_style: 3
-                }
+                    quote_style: 3,
+                },
            });
-            assert.strictEqual(result.code,
-                    'a["foo"]="bar",a.a="red",x={"bar":10};');
+            assert.strictEqual(result.code, 'a["foo"]="bar",a.a="red",x={"bar":10};');
        });
        it("Should not mangle quoted property within dead code", function() {
-            var result = UglifyJS.minify('({ "keep": 1 }); g.keep = g.change;', {
+            var result = UglifyJS.minify('({ "keep": 1 }); g.keep = g.change = 42;', {
                mangle: {
                    properties: {
-                        keep_quoted: true
-                    }
-                }
+                        keep_quoted: true,
+                    },
+                },
            });
            if (result.error) throw result.error;
-            assert.strictEqual(result.code, "g.keep=g.g;");
+            assert.strictEqual(result.code, "g.keep=g.g=42;");
        });
    });

@@ -320,6 +321,24 @@ describe("minify", function() {
        });
    });

+    describe("module", function() {
+        it("Should not inline `await` variables", function() {
+            if (semver.satisfies(process.version, "<8")) return;
+            var code = [
+                "console.log(function() {",
+                "    return typeof await;",
+                "}());",
+            ].join("\n");
+            assert.strictEqual(run_code("(async function(){" + code + "})();"), "undefined\n");
+            var result = UglifyJS.minify(code, {
+                module: true,
+            });
+            if (result.error) throw result.error;
+            assert.strictEqual(result.code, "console.log(function(){return typeof await}());");
+            assert.strictEqual(run_code("(async function(){" + result.code + "})();"), "undefined\n");
+        });
+    });
+
    describe("rename", function() {
        it("Should be repeatable", function() {
            var code = "!function(x){return x(x)}(y);";
--- a/test/mocha/number-literal.js
+++ b/test/mocha/number-literal.js
@@ -50,12 +50,10 @@ describe("Number literals", function() {
            "0.000_000_004_2e+1_0-0B101_010+0x2_A-0o5_2+4_2",
        ].forEach(function(code) {
            var result = UglifyJS.minify(code, {
-                compress: {
                expression: true,
-                },
            });
            if (result.error) throw result.error;
-            assert.strictEqual(result.code, "42;");
+            assert.strictEqual(result.code, "42");
        });
    });
    it("Should reject invalid use of underscore", function() {
--- a/test/mocha/reduce.js
+++ b/test/mocha/reduce.js
@@ -449,6 +449,27 @@ describe("test/reduce.js", function() {
        ].join("\n"));
    });
    it("Should transform `export default function` correctly", function() {
+        if (semver.satisfies(process.version, "<8")) return;
+        var code = [
+            "export default function f(a) {",
+            "    for (var k in a)",
+            "        console.log(k);",
+            "    (async function() {})();",
+            "}",
+            "f(this);",
+        ].join("\n");
+        var result = reduce_test(code, {
+            mangle: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "// Can't reproduce test failure",
+            "// minify options: {",
+            '//   "mangle": false',
+            "// }",
+        ].join("\n"));
+    });
+    it("Should transform `export default (function)` correctly", function() {
        var code = [
            "for (var k in this)",
            "    console.log(k);",
--- a/test/mocha/sourcemaps.js
+++ b/test/mocha/sourcemaps.js
@@ -19,11 +19,11 @@ function source_map(code) {
 function get_map() {
    return {
        "version": 3,
-        "sources": ["index.js"],
+        "sources": [ "index.js" ],
        "names": [],
        "mappings": ";;AAAA,IAAI,MAAM,SAAN,GAAM;AAAA,SAAK,SAAS,CAAd;AAAA,CAAV;AACA,QAAQ,GAAR,CAAY,IAAI,KAAJ,CAAZ",
        "file": "bundle.js",
-        "sourcesContent": ["let foo = x => \"foo \" + x;\nconsole.log(foo(\"bar\"));"]
+        "sourcesContent": [ "let foo = x => \"foo \" + x;\nconsole.log(foo(\"bar\"));" ],
    };
 }

@@ -42,7 +42,7 @@ function prepare_map(sourceMap) {
        sourceMap: {
            content: sourceMap,
            includeSources: true,
-        }
+        },
    });
    if (result.error) throw result.error;
    return JSON.parse(result.map);
@@ -112,7 +112,7 @@ describe("sourcemaps", function() {
        });
        if (result.error) throw result.error;
        assert.strictEqual(result.code, "class A{static P=42;set#q(s){}}");
-        assert.strictEqual(result.map, '{"version":3,"sources":["0"],"names":["A","P","#q","v"],"mappings":"MAAMA,EACFC,SAAW,GACXC,MAAOC"}');
+        assert.strictEqual(result.map, '{"version":3,"sources":["0"],"names":["A","P","#q","v"],"mappings":"MAAMA,EACFC,SAAW,GACXC,MAAOC,IACX"}');
    });
    it("Should mark array/object literals", function() {
        var result = UglifyJS.minify([
@@ -124,7 +124,7 @@ describe("sourcemaps", function() {
        });
        if (result.error) throw result.error;
        assert.strictEqual(result.code, "({}).wat([]);");
-        assert.strictEqual(result.map, '{"version":3,"sources":["0"],"names":["wat"],"mappings":"CAAU,IACNA,IAAI"}');
+        assert.strictEqual(result.map, '{"version":3,"sources":["0"],"names":["wat"],"mappings":"CAAU,IACNA,IAAI,EAAE"}');
    });
    it("Should give correct sourceRoot", function() {
        var code = "console.log(42);";
@@ -135,7 +135,7 @@ describe("sourcemaps", function() {
        });
        if (result.error) throw result.error;
        assert.strictEqual(result.code, code);
-        assert.strictEqual(result.map, '{"version":3,"sourceRoot":"//foo.bar/","sources":["0"],"names":["console","log"],"mappings":"AAAAA,QAAQC,IAAI"}');
+        assert.strictEqual(result.map, '{"version":3,"sourceRoot":"//foo.bar/","sources":["0"],"names":["console","log"],"mappings":"AAAAA,QAAQC,IAAI,EAAE"}');
    });
    it("Should produce same source map with DOS or UNIX line endings", function() {
        var code = [
@@ -160,8 +160,8 @@ describe("sourcemaps", function() {
                sourceMap: {
                    content: read("test/input/issue-1236/simple.js.map"),
                    filename: "simple.min.js",
-                    includeSources: true
-                }
+                    includeSources: true,
+                },
            });
            if (result.error) throw result.error;
            var map = JSON.parse(result.map);
@@ -175,8 +175,8 @@ describe("sourcemaps", function() {
                sourceMap: {
                    content: "inline",
                    includeSources: true,
-                    url: "inline"
-                }
+                    url: "inline",
+                },
            });
            if (result.error) throw result.error;
            assert.strictEqual(result.code + "\n", read("test/input/issue-520/output.js"));
@@ -185,7 +185,7 @@ describe("sourcemaps", function() {
            var result = UglifyJS.minify(read("test/input/issue-1323/sample.js"), {
                mangle: false,
                sourceMap: {
-                    content: "inline"
+                    content: "inline",
                },
                warnings: true,
            });
@@ -206,7 +206,7 @@ describe("sourcemaps", function() {
            if (result.error) throw result.error;
            assert.strictEqual(result.code, [
                "var Foo=function(){console.log(3)},bar=(new Foo,function(o){return o});",
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIiwiMSJdLCJuYW1lcyI6WyJGb28iLCJjb25zb2xlIiwibG9nIiwiYmFyIl0sIm1hcHBpbmdzIjoiQUFBQSxJQUFNQSxJQUFJLFdBQWdCQyxRQUFRQyxJQUFJLElDQWxDQyxLREEyQyxJQUFJSCxJQ0MvQyxTQUFjRyxHQUNWLE9BQU9BIn0=",
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIiwiMSJdLCJuYW1lcyI6WyJGb28iLCJjb25zb2xlIiwibG9nIiwiYmFyIl0sIm1hcHBpbmdzIjoiQUFBQSxJQUFNQSxJQUFJLFdBQWdCQyxRQUFRQyxJQUFJLENBQUcsQ0FBRSxFQ0F2Q0MsS0RBMkMsSUFBSUgsSUNDL0MsU0FBY0csR0FDVixPQUFPQSxDQUNYIn0=",
            ].join("\n"));
            assert.deepEqual(result.warnings, [ "WARN: inline source map not found: 1" ]);
        });
@@ -239,13 +239,13 @@ describe("sourcemaps", function() {
                sourceMap: {
                    content: "inline",
                    includeSources: true,
-                    url: "inline"
-                }
+                    url: "inline",
+                },
            });
            if (result.error) throw result.error;
            assert.strictEqual(result.code + "\n", read("test/input/issue-3294/output.js"));
        });
-        it("Should work in presence of unrecognised annotations", function() {
+        it("Should work in presence of unrecognized annotations", function() {
            var result = UglifyJS.minify(read("test/input/issue-3441/input.js"), {
                compress: false,
                mangle: false,
@@ -255,7 +255,7 @@ describe("sourcemaps", function() {
            });
            if (result.error) throw result.error;
            assert.strictEqual(result.code, '(function(){console.log("hello")}).call(this);');
-            assert.strictEqual(result.map, '{"version":3,"sources":["main.coffee"],"names":["console","log"],"mappings":"CAAA,WAAAA,QAAQC,IAAI"}');
+            assert.strictEqual(result.map, '{"version":3,"sources":["main.coffee"],"names":["console","log"],"mappings":"CAAA,WAAAA,QAAQC,IAAI,OAAZ"}');
        });
        it("Should not overwrite existing sourcesContent", function() {
            var result = UglifyJS.minify({
@@ -302,7 +302,7 @@ describe("sourcemaps", function() {
            if (result.error) throw result.error;
            var code = result.code;
            assert.strictEqual(code, "var a=function(n){return n};\n" +
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsiYSIsImZvbyJdLCJtYXBwaW5ncyI6IkFBQUEsSUFBSUEsRUFBSSxTQUFTQyxHQUFPLE9BQU9BIn0=");
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsiYSIsImZvbyJdLCJtYXBwaW5ncyI6IkFBQUEsSUFBSUEsRUFBSSxTQUFTQyxHQUFPLE9BQU9BLENBQUsifQ==");
        });
        it("Should not append source map to output js when sourceMapInline is not enabled", function() {
            var result = UglifyJS.minify('var a = function(foo) { return foo; };');
--- a/test/mozilla-ast.js
+++ b/test/mozilla-ast.js
@@ -9,19 +9,22 @@ function beautify(ast) {
    var beautified = UglifyJS.minify(ast, {
        compress: false,
        mangle: false,
+        module: ufuzz.module,
        output: {
+            ast: true,
            beautify: true,
            braces: true,
        },
    });
-    if (beautified.error) return beautified;
-    return UglifyJS.minify(beautified.code, {
+    if (!beautified.error) {
+        var verify = UglifyJS.minify(beautified.code, {
            compress: false,
            mangle: false,
-        output: {
-            ast: true,
-        },
+            module: ufuzz.module,
        });
+        if (verify.error) return verify;
+    }
+    return beautified;
 }

 function validate(ast) {
@@ -35,6 +38,7 @@ function validate(ast) {
    return UglifyJS.minify(ast, {
        compress: false,
        mangle: false,
+        module: ufuzz.module,
        output: {
            ast: true,
        },
@@ -57,12 +61,12 @@ function test(input, to_moz, description, skip_on_error, beautified) {
        var ast = UglifyJS.AST_Node.from_mozilla_ast(to_moz(input));
    } catch (e) {
        if (skip_on_error) return true;
-        console.log("//=============================================================");
-        console.log("//", description, "failed... round", round);
-        console.log(e);
-        console.log("// original code");
-        if (beautified === true) console.log("// (beautified)");
-        console.log(input.code);
+        console.error("//=============================================================");
+        console.error("//", description, "failed... round", round);
+        console.error(e);
+        console.error("// original code");
+        if (beautified === true) console.error("// (beautified)");
+        console.error(input.code);
        return false;
    }
    var transformed = validate(ast);
@@ -74,34 +78,34 @@ function test(input, to_moz, description, skip_on_error, beautified) {
                if (!test(beautified, to_moz, description, skip_on_error, true)) return false;
            }
        }
-        console.log("//=============================================================");
-        console.log("// !!!!!! Failed... round", round);
-        console.log("// original code");
+        console.error("//=============================================================");
+        console.error("// !!!!!! Failed... round", round);
+        console.error("// original code");
        if (beautified.error) {
-            console.log("// !!! beautify failed !!!");
-            console.log(beautified.error.stack);
+            console.error("// !!! beautify failed !!!");
+            console.error(beautified.error.stack);
        } else if (beautified === true) {
-            console.log("// (beautified)");
+            console.error("// (beautified)");
        }
-        console.log(input.raw);
-        console.log();
-        console.log();
-        console.log("//-------------------------------------------------------------");
-        console.log("//", description);
+        console.error(input.raw);
+        console.error();
+        console.error();
+        console.error("//-------------------------------------------------------------");
+        console.error("//", description);
        if (transformed.error) {
-            console.log(transformed.error.stack);
+            console.error(transformed.error.stack);
        } else {
            beautified = beautify(transformed.ast);
            if (beautified.error) {
-                console.log("// !!! beautify failed !!!");
-                console.log(beautified.error.stack);
-                console.log(transformed.code);
+                console.error("// !!! beautify failed !!!");
+                console.error(beautified.error.stack);
+                console.error(transformed.code);
            } else {
-                console.log("// (beautified)");
-                console.log(beautified.code);
+                console.error("// (beautified)");
+                console.error(beautified.code);
            }
        }
-        console.log("!!!!!! Failed... round", round);
+        console.error("!!!!!! Failed... round", round);
        return false;
    }
    return true;
@@ -115,9 +119,29 @@ for (var round = 1; round <= num_iterations; round++) {
    var code = ufuzz.createTopLevelCode();
    minify_options.forEach(function(options) {
        var ok = true;
-        var input = UglifyJS.minify(options ? UglifyJS.minify(code, JSON.parse(options)).code : code, {
+        var minified;
+        if (options) {
+            var o = JSON.parse(options);
+            o.module = ufuzz.module;
+            minified = UglifyJS.minify(code, o);
+            if (minified.error) {
+                console.log("//=============================================================");
+                console.log("// minify() failed... round", round);
+                console.log("// original code");
+                console.log(code);
+                console.log();
+                console.log();
+                console.log("//-------------------------------------------------------------");
+                console.log("minify(options):");
+                console.log(JSON.stringify(o, null, 2));
+                return;
+            }
+            minified = minified.code;
+        }
+        var input = UglifyJS.minify(minified || code, {
            compress: false,
            mangle: false,
+            module: ufuzz.module,
            output: {
                ast: true,
            },
@@ -125,11 +149,27 @@ for (var round = 1; round <= num_iterations; round++) {
        input.raw = options ? input.code : code;
        if (input.error) {
            ok = false;
-            console.log("//=============================================================");
-            console.log("// minify() failed... round", round);
-            console.log(input.error);
-            console.log("// original code");
-            console.log(code);
+            console.error("//=============================================================");
+            console.error("// parse() failed... round", round);
+            console.error("// original code");
+            console.error(code);
+            console.error();
+            console.error();
+            if (options) {
+                console.error("//-------------------------------------------------------------");
+                console.error("// minified code");
+                console.error(minified);
+                console.error();
+                console.error();
+                console.error("//-------------------------------------------------------------");
+                console.error("minify(options):");
+                console.error(JSON.stringify(o, null, 2));
+                console.error();
+                console.error();
+            }
+            console.error("//-------------------------------------------------------------");
+            console.error("// parse() error");
+            console.error(input.error);
        }
        if (ok) ok = test(input, function(input) {
            return input.ast.to_mozilla_ast();
@@ -141,7 +181,10 @@ for (var round = 1; round <= num_iterations; round++) {
                sourceType: "module",
            });
        }, "acorn.parse()", !ufuzz.verbose);
-        if (!ok) process.exit(1);
+        if (!ok && isFinite(num_iterations)) {
+            console.log();
+            process.exit(1);
+        }
    });
 }
 console.log();
--- a/test/node.js
+++ b/test/node.js
@@ -1,6 +1,6 @@
 var fs = require("fs");

-new Function("exports", require("../tools/node").FILES.map(function(file) {
+new Function("domprops", "exports", require("../tools/node").FILES.map(function(file) {
    if (/exports\.js$/.test(file)) file = require.resolve("./exports");
    return fs.readFileSync(file, "utf8");
-}).join("\n\n"))(exports);
+}).join("\n\n"))(require("../tools/domprops.json"), exports);
--- a/test/reduce.js
+++ b/test/reduce.js
@@ -160,6 +160,11 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                return expr instanceof U.AST_Spread ? expr.expression : expr;
            }
        }
+        else if (node instanceof U.AST_Await) {
+            node.start._permute++;
+            CHANGED = true;
+            return node.expression;
+        }
        else if (node instanceof U.AST_Binary) {
            var permute = ((node.start._permute += step) * steps | 0) % 4;
            var expr = [
@@ -210,10 +215,10 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
            }
            if (node.expression instanceof U.AST_Function) {
                // hoist and return expressions from the IIFE function expression
-                var seq = [];
+                var scope = tt.find_parent(U.AST_Scope), seq = [];
                node.expression.body.forEach(function(node) {
                    var expr = node instanceof U.AST_Exit ? node.value : node.body;
-                    if (expr instanceof U.AST_Node && !U.is_statement(expr) && can_hoist(expr)) {
+                    if (expr instanceof U.AST_Node && !U.is_statement(expr) && can_hoist(expr, scope)) {
                        // collect expressions from each statement's body
                        seq.push(expr);
                    }
@@ -241,6 +246,23 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
            CHANGED = true;
            return node.name;
        }
+        else if (node instanceof U.AST_Defun) {
+            switch (((node.start._permute += step) * steps | 0) % 2) {
+              case 0:
+                CHANGED = true;
+                return List.skip;
+              default:
+                if (can_hoist(node, tt.find_parent(U.AST_Scope))) {
+                    // hoist function declaration body
+                    var body = node.body;
+                    node.body = [];
+                    // retain function with empty body to be dropped later
+                    body.push(node);
+                    CHANGED = true;
+                    return List.splice(body);
+                }
+            }
+        }
        else if (node instanceof U.AST_DestructuredArray) {
            var expr = node.elements[0];
            if (expr && !(expr instanceof U.AST_Hole)) {
@@ -258,22 +280,6 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                return expr.value;
            }
        }
-        else if (node instanceof U.AST_Defun) {
-            switch (((node.start._permute += step) * steps | 0) % 2) {
-              case 0:
-                CHANGED = true;
-                return List.skip;
-              default:
-                if (!has_exit(node) && can_hoist(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,
@@ -295,6 +301,16 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                return to_statement(expr);
            }
        }
+        else if (node instanceof U.AST_ExportDeclaration) {
+            node.start._permute++;
+            CHANGED = true;
+            return node.body;
+        }
+        else if (node instanceof U.AST_ExportDefault) {
+            node.start._permute++;
+            CHANGED = true;
+            return to_statement(node.body);
+        }
        else if (node instanceof U.AST_Finally) {
            // drop finally block
            node.start._permute++;
@@ -350,6 +366,15 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                return to_statement(expr);
            }
        }
+        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;
+            }
+        }
        else if (node instanceof U.AST_Object) {
            // first property's value
            var expr = node.properties[0];
@@ -382,7 +407,7 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
            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) && can_hoist(node.body.expression)) {
+                if (can_hoist(node.body.expression, tt.find_parent(U.AST_Scope))) {
                    CHANGED = true;
                    return List.splice(node.body.expression.body);
                }
@@ -440,13 +465,14 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                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;
+        else if (node instanceof U.AST_VarDef) {
+            if (node.value && !(node.name instanceof U.AST_Destructured || parent instanceof U.AST_Const)) {
+                node.start._permute++;
                CHANGED = true;
-                return node.body;
+                return new U.AST_VarDef({
+                    name: node.name,
+                    start: {},
+                });
            }
        }

@@ -647,21 +673,6 @@ function trim_trailing_whitespace(value) {
    return ("" + value).replace(/\s+$/, "");
 }

-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) {
@@ -676,17 +687,31 @@ function has_loopcontrol(body, loop, label) {
    return found;
 }

-function can_hoist(body) {
+function can_hoist(body, scope) {
    var found = false;
-    body.walk(new U.TreeWalker(function(node) {
+    var tw = new U.TreeWalker(function(node) {
        if (found) return true;
+        if (node instanceof U.AST_Exit) return found = true;
        if (node instanceof U.AST_NewTarget) return found = true;
        if (node instanceof U.AST_Scope) {
            if (node === body) return;
+            if (node instanceof U.AST_Arrow || node instanceof U.AST_AsyncArrow) node.argnames.forEach(function(sym) {
+                sym.walk(tw);
+            });
+            // don't descend into nested functions
            return true;
        }
        if (node instanceof U.AST_Super) return found = true;
-    }));
+        if (node instanceof U.AST_SymbolDeclaration || node instanceof U.AST_SymbolRef) switch (node.name) {
+          case "await":
+            if (/^Async/.test(scope.TYPE)) return found = true;
+            return;
+          case "yield":
+            if (/Generator/.test(scope.TYPE)) return found = true;
+            return;
+        }
+    });
+    body.walk(tw);
    return !found;
 }

@@ -760,9 +785,9 @@ function compare_run_code(code, minify_options, result_cache, max_timeout) {
    if (minified.error) return minified;

    var toplevel = sandbox.has_toplevel(minify_options);
-    var unminified = run_code(code, toplevel, result_cache, max_timeout);
+    var unminified = run(code, max_timeout);
    var timeout = Math.min(100 * unminified.elapsed, max_timeout);
-    var minified_result = run_code(minified.code, toplevel, result_cache, timeout).result;
+    var minified_result = run(minified.code, timeout).result;

    if (sandbox.same_stdout(unminified.result, minified_result)) {
        return is_timed_out(unminified.result) && is_timed_out(minified_result) && {
@@ -774,6 +799,16 @@ function compare_run_code(code, minify_options, result_cache, max_timeout) {
        minified_result: minified_result,
        elapsed: unminified.elapsed,
    };
+
+    function run(code, timeout) {
+        if (minify_options.module) code = [
+            '"use strict";',
+            "(async()=>{",
+            code,
+            '})().catch(e=>process.on("exit",()=>{throw e}));',
+        ].join("\n");
+        return run_code(code, toplevel, result_cache, timeout);
+    }
 }

 function test_minify(code, minify_options) {
--- a/test/release/install.sh
+++ b/test/release/install.sh
@@ -36,7 +36,7 @@ EOF
 }
 if [ $NATIVE ]; then unset -f timeout; fi

-while !(git clone --branch v1.6.0 --depth 1 https://github.com/jasongin/nvs.git ~/.nvs); do
+while !(git clone --branch v1.6.2 --depth 1 https://github.com/jasongin/nvs.git ~/.nvs); do
    rm -rf ~/.nvs
 done
 while ! timeout 60 bash -c ". ~/.nvs/nvs.sh add $NODE && nvs use $NODE"; do
@@ -48,6 +48,8 @@ done
 nvs use $NODE
 node --version
 npm config set audit false
+npm config set fund false
+npm config set loglevel error
 npm config set optional false
 npm config set save false
 npm config set strict-ssl false
--- a/test/release/web-tooling-benchmark.sh
+++ b/test/release/web-tooling-benchmark.sh
@@ -54,7 +54,7 @@ ERR=$?; if [ "$ERR" != "0" ]; then echo "Error: $ERR"; exit $ERR; fi
 minify_in_situ "src" \
 && minify_in_situ "third_party" \
 && rm -rf node_modules \
-&& npm_install \
+&& npm_install --package-lock \
 && rm -rf build/* \
 && npm run build:terser-bundled \
 && npm run build:uglify-js-bundled \
--- a/test/sandbox.js
+++ b/test/sandbox.js
@@ -25,7 +25,7 @@ exports.run_code = semver.satisfies(process.version, "0.8") ? function(code, top
    } while (prev !== stdout);
    return stdout;
 } : semver.satisfies(process.version, "<0.12") ? run_code_vm : function(code, toplevel, timeout) {
-    if ([
+    var stdout = ([
        /\b(async[ \t]+function|Promise|setImmediate|setInterval|setTimeout)\b/,
        /\basync([ \t]+|[ \t]*#)[^\s()[\]{}#:;,.&|!~=*%/+-]+(\s*\(|[ \t]*=>)/,
        /\basync[ \t]*\*[ \t]*[^\s()[\]{}#:;,.&|!~=*%/+-]+\s*\(/,
@@ -33,11 +33,8 @@ exports.run_code = semver.satisfies(process.version, "0.8") ? function(code, top
        /\basync[ \t]*\([\s\S]*?\)[ \t]*=>/,
    ].some(function(pattern) {
        return pattern.test(code);
-    })) {
-        return run_code_exec(code, toplevel, timeout);
-    } else {
-        return run_code_vm(code, toplevel, timeout);
-    }
+    }) ? run_code_exec : run_code_vm)(code, toplevel, timeout);
+    return stdout.length > 1000 ? stdout.slice(0, 1000) + "…《" + stdout.length + "》" : stdout;
 };
 exports.same_stdout = semver.satisfies(process.version, "0.12") ? function(expected, actual) {
    if (typeof expected != typeof actual) return false;
@@ -57,7 +54,7 @@ exports.patch_module_statements = function(code) {
        strict_mode = match;
        return "";
    }).replace(/\bexport(?:\s*\{[^{}]*}\s*?(?:$|\n|;)|\s+default\b(?:\s*(\(|\{|class\s*\{|class\s+(?=extends\b)|(?:async\s+)?function\s*(?:\*\s*)?\())?|\b)/g, function(match, header) {
-        if (/^export\s+default/.test(match)) has_default = "var _uglify_export_default_;";
+        if (/^export\s+default/.test(match)) has_default = "function _uglify_export_default_() {}";
        if (!header) return "";
        if (header.length == 1) return "0, " + header;
        var name = "_uglify_export_default_";
@@ -286,6 +283,7 @@ function run_code_exec(code, toplevel, timeout) {
    var result = spawnSync(process.argv[0], [ '--max-old-space-size=2048' ], {
        encoding: "utf8",
        input: code,
+        maxBuffer: 1073741824,
        stdio: "pipe",
        timeout: timeout || 5000,
    });
--- a/test/ufuzz/actions.js
+++ b/test/ufuzz/actions.js
@@ -2,15 +2,18 @@ var get = require("https").get;
 var parse = require("url").parse;

 var base, token, run_number;
+var expires = Date.now() + (6 * 60 - 10) * 60 * 1000;
 exports.init = function(url, auth, num) {
    base = url;
    token = auth;
    run_number = num;
 };
 exports.should_stop = function(callback) {
+    if (Date.now() > expires) return callback();
    read(base + "/actions/runs?per_page=100", function(reply) {
-        if (!reply || !Array.isArray(reply.workflow_runs)) return;
-        var runs = reply.workflow_runs.sort(function(a, b) {
+        var runs = verify(reply, "workflow_runs").filter(function(workflow) {
+            return workflow.status != "completed";
+        }).sort(function(a, b) {
            return b.run_number - a.run_number;
        });
        var found = false, remaining = 20;
@@ -19,15 +22,13 @@ exports.should_stop = function(callback) {
            do {
                workflow = runs.pop();
                if (!workflow) return;
-                if (is_cron(workflow) && workflow.run_number == run_number) found = true;
-            } while (!found && workflow.status == "completed");
+                if (!is_cron(workflow)) break;
+                if (workflow.run_number == run_number) found = true;
+            } while (!found);
            read(workflow.jobs_url, function(reply) {
-                if (!reply || !Array.isArray(reply.jobs)) return;
-                if (!reply.jobs.every(function(job) {
-                    if (job.status == "completed") return true;
-                    remaining--;
-                    return found || !is_cron(workflow);
-                })) return;
+                verify(reply, "jobs").forEach(function(job) {
+                    if (job.status != "completed") remaining--;
+                });
                if (remaining >= 0) {
                    next();
                } else {
@@ -70,3 +71,12 @@ function read(url, callback) {
        done();
    });
 }
+
+function verify(reply, field) {
+    if (!reply) return [];
+    var values = reply[field];
+    if (!Array.isArray(values)) return [];
+    return values.filter(function(value) {
+        return value;
+    });
+}
--- a/test/ufuzz/index.js
+++ b/test/ufuzz/index.js
@@ -140,6 +140,7 @@ var SUPPORT = function(matrix) {
    class: "class C { f() {} }",
    class_field: "class C { p = 0; }",
    class_private: "class C { #f() {} }",
+    class_static_init: "class C { static {} }",
    computed_key: "({[0]: 0});",
    const_block: "var a; { const a = 0; }",
    default_value: "[ a = 0 ] = [];",
@@ -252,7 +253,7 @@ BINARY_OPS = BINARY_OPS.concat(BINARY_OPS);
 if (SUPPORT.exponentiation) BINARY_OPS.push("**");
 BINARY_OPS = BINARY_OPS.concat(BINARY_OPS);
 BINARY_OPS = BINARY_OPS.concat(BINARY_OPS);
-BINARY_OPS.push(" in ");
+BINARY_OPS.push(" in ", " instanceof ");

 var ASSIGNMENTS = [ "=" ];
 ASSIGNMENTS = ASSIGNMENTS.concat(ASSIGNMENTS);
@@ -370,9 +371,16 @@ var in_class = 0;
 var called = Object.create(null);
 var labels = 10000;

-function rng(max) {
+function rng(limit) {
    var r = randomBytes(2).readUInt16LE(0) / 65536;
-    return Math.floor(max * r);
+    return Math.floor(limit * r);
+}
+
+function get_num(max) {
+    if (rng(max + 1) == 0) return 0;
+    var i = 1;
+    while (i < max && rng(2)) i++;
+    return i;
 }

 function strictMode() {
@@ -405,7 +413,7 @@ function createTopLevelCode() {
    unique_vars.length = 0;
    classes.length = 0;
    allow_this = true;
-    async = false;
+    async = SUPPORT.async && rng(200) == 0;
    has_await = false;
    export_default = false;
    generator = false;
@@ -413,7 +421,7 @@ function createTopLevelCode() {
    funcs = 0;
    clazz = 0;
    imports = 0;
-    in_class = 0;
+    in_class = async;
    called = Object.create(null);
    var s = [
        strictMode(),
@@ -424,7 +432,7 @@ function createTopLevelCode() {
        if (rng(2)) {
            s.push(createStatements(3, MAX_GENERATION_RECURSION_DEPTH, CANNOT_THROW, CANNOT_BREAK, CANNOT_CONTINUE, CANNOT_RETURN, 0));
        } else {
-            s.push(createFunctions(rng(MAX_GENERATED_TOPLEVELS_PER_RUN) + 1, MAX_GENERATION_RECURSION_DEPTH, DEFUN_OK, CANNOT_THROW, 0));
+            s.push(createFunctions(MAX_GENERATED_TOPLEVELS_PER_RUN, MAX_GENERATION_RECURSION_DEPTH, DEFUN_OK, CANNOT_THROW, 0));
        }
    });
    // preceding `null` makes for a cleaner output (empty string still shows up etc)
@@ -437,7 +445,7 @@ function createTopLevelCode() {
 function createFunctions(n, recurmax, allowDefun, canThrow, stmtDepth) {
    if (--recurmax < 0) { return ";"; }
    var s = "";
-    while (n-- > 0) {
+    for (var i = get_num(n - 1) + 1; --i >= 0;) {
        s += createFunction(recurmax, allowDefun, canThrow, stmtDepth) + "\n";
    }
    return s;
@@ -454,7 +462,7 @@ function createParams(was_async, was_generator, noDuplicate) {
    if (!generator) generator = was_generator;
    var len = unique_vars.length;
    var params = [];
-    for (var n = rng(4); --n >= 0;) {
+    for (var i = get_num(3); --i >= 0;) {
        var name = createVarName(MANDATORY);
        if (noDuplicate || in_class) unique_vars.push(name);
        params.push(name);
@@ -469,7 +477,7 @@ function createArgs(recurmax, stmtDepth, canThrow, noTemplate) {
    recurmax--;
    if (SUPPORT.template && !noTemplate && rng(20) == 0) return createTemplateLiteral(recurmax, stmtDepth, canThrow);
    var args = [];
-    for (var n = rng(4); --n >= 0;) switch (SUPPORT.spread ? rng(50) : 3) {
+    for (var i = get_num(3); --i >= 0;) switch (SUPPORT.spread ? rng(50) : 3) {
      case 0:
      case 1:
        var name = getVarName();
@@ -849,7 +857,7 @@ function createFunction(recurmax, allowDefun, canThrow, stmtDepth) {
        s.push(defns());
        if (rng(5) === 0) {
            // functions with functions. lower the recursion to prevent a mess.
-            s.push(createFunctions(rng(5) + 1, Math.ceil(recurmax * 0.7), DEFUN_OK, canThrow, stmtDepth));
+            s.push(createFunctions(5, Math.ceil(recurmax * 0.7), DEFUN_OK, canThrow, stmtDepth));
        } else {
            // functions with statements
            s.push(_createStatements(3, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth));
@@ -879,9 +887,9 @@ function createFunction(recurmax, allowDefun, canThrow, stmtDepth) {
 }

 function _createStatements(n, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) {
-    if (--recurmax < 0) { return ";"; }
+    if (--recurmax < 0) return ";";
    var s = "";
-    while (--n > 0) {
+    for (var i = get_num(n); --i >= 0;) {
        s += createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) + "\n";
    }
    return s;
@@ -962,7 +970,7 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
    switch (target) {
      case STMT_BLOCK:
        var label = createLabel(canBreak);
-        return label.target + "{" + createStatements(rng(5) + 1, recurmax, canThrow, label.break, canContinue, cannotReturn, stmtDepth) + "}";
+        return label.target + "{" + createStatements(5, recurmax, canThrow, label.break, canContinue, cannotReturn, stmtDepth) + "}";
      case STMT_IF_ELSE:
        return "if (" + createExpression(recurmax, COMMA_OK, stmtDepth, canThrow) + ")" + createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) + (rng(2) ? " else " + createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) : "");
      case STMT_DO_WHILE:
@@ -1075,7 +1083,7 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
                    s += " * as " + createImportAlias();
                } else {
                    var names = [];
-                    for (var i = rng(4); --i >= 0;) {
+                    for (var i = get_num(3); --i >= 0;) {
                        var name = createImportAlias();
                        names.push(rng(2) ? getDotKey() + " as " + name : name);
                    }
@@ -1134,7 +1142,7 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
        }
      case STMT_FUNC_EXPR:
        // "In non-strict mode code, functions can only be declared at top level, inside a block, or ..."
-        // (dont both with func decls in `if`; it's only a parser thing because you cant call them without a block)
+        // (don't make func decls in `if`; it's only a parser thing because you can't call them without a block)
        return "{" + createFunction(recurmax, NO_DEFUN, canThrow, stmtDepth) + "}";
      case STMT_TRY:
        // catch var could cause some problems
@@ -1181,7 +1189,11 @@ function createStatement(recurmax, canThrow, canBreak, canContinue, cannotReturn
                unique_vars.length = unique_len;
            });
        }
-        if (n !== 0) s += " finally { " + createStatements(3, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth) + " }";
+        if (n !== 0) s += [
+            " finally { ",
+            createStatements(5, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
+            " }",
+        ].join("");
        return s;
      case STMT_C:
        return "c = c + 1;";
@@ -1199,7 +1211,7 @@ function createSwitchParts(recurmax, n, canThrow, canBreak, canContinue, cannotR
        if (hadDefault || rng(5) > 0) {
            s.push(
                "case " + createExpression(recurmax, NO_COMMA, stmtDepth, canThrow) + ":",
-                _createStatements(rng(3) + 1, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
+                _createStatements(3, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
                rng(10) > 0 ? " break;" : "/* fall-through */",
                ""
            );
@@ -1207,7 +1219,7 @@ function createSwitchParts(recurmax, n, canThrow, canBreak, canContinue, cannotR
            hadDefault = true;
            s.push(
                "default:",
-                _createStatements(rng(3) + 1, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
+                _createStatements(3, recurmax, canThrow, canBreak, canContinue, cannotReturn, stmtDepth),
                ""
            );
        }
@@ -1338,7 +1350,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
                            "(" + params + "{",
                            strictMode(),
                            defns(),
-                            _createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth)
+                            _createStatements(5, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth)
                        );
                        suffix = "})";
                    } else {
@@ -1370,7 +1382,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
                s.push(
                    "(" + makeFunction(name) + "(){",
                    strictMode(),
-                    createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+                    createStatements(5, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
                    rng(2) ? "})" : "})()" + invokeGenerator(save_generator)
                );
            }
@@ -1379,7 +1391,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
            s.push(
                "+" + makeFunction(name) + "(){",
                strictMode(),
-                createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+                createStatements(5, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
                "}()" + invokeGenerator(save_generator)
            );
            break;
@@ -1387,7 +1399,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
            s.push(
                "!" + makeFunction(name) + "(){",
                strictMode(),
-                createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+                createStatements(5, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
                "}()" + invokeGenerator(save_generator)
            );
            break;
@@ -1395,7 +1407,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
            s.push(
                "void " + makeFunction(name) + "(){",
                strictMode(),
-                createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
+                createStatements(5, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth),
                "}()" + invokeGenerator(save_generator)
            );
            break;
@@ -1411,10 +1423,10 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
                var add_new_target = SUPPORT.new_target && VALUES.indexOf("new.target") < 0;
                if (add_new_target) VALUES.push("new.target");
                s.push(defns());
-                if (instantiate) for (var i = rng(4); --i >= 0;) {
+                if (instantiate) for (var i = get_num(3); --i >= 0;) {
                    s.push((in_class ? "if (this) " : "") + createThisAssignment(recurmax, stmtDepth, canThrow));
                }
-                s.push(_createStatements(rng(5) + 1, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth));
+                s.push(_createStatements(5, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth));
                if (add_new_target) VALUES.splice(VALUES.indexOf("new.target"), 1);
            });
            generator = save_generator;
@@ -1560,7 +1572,7 @@ function _createExpression(recurmax, noComma, stmtDepth, canThrow) {
 function createArrayLiteral(recurmax, stmtDepth, canThrow) {
    recurmax--;
    var arr = [];
-    for (var i = rng(6); --i >= 0;) switch (SUPPORT.spread ? rng(50) : 3 + rng(47)) {
+    for (var i = get_num(5); --i >= 0;) switch (SUPPORT.spread ? rng(50) : 3 + rng(47)) {
      case 0:
      case 1:
        var name = getVarName();
@@ -1589,7 +1601,7 @@ function createTemplateLiteral(recurmax, stmtDepth, canThrow) {
    recurmax--;
    var s = [];
    addText();
-    for (var i = rng(6); --i >= 0;) {
+    for (var i = get_num(5); --i >= 0;) {
        s.push("${", createExpression(recurmax, COMMA_OK, stmtDepth, canThrow), "}");
        addText();
    }
@@ -1744,7 +1756,7 @@ function createObjectFunction(recurmax, stmtDepth, canThrow, internal, isClazz)
            s.push(_createStatements(2, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CANNOT_RETURN, stmtDepth));
            if (internal == "super") s.push("super" + createArgs(recurmax, stmtDepth, canThrow, NO_TEMPLATE) + ";");
            allow_this = save_allow;
-            if (/^(constructor|super)$/.test(internal) || rng(10) == 0) for (var i = rng(4); --i >= 0;) {
+            if (/^(constructor|super)$/.test(internal) || rng(10) == 0) for (var i = get_num(3); --i >= 0;) {
                s.push(rng(2) ? createSuperAssignment(recurmax, stmtDepth, canThrow) : createThisAssignment(recurmax, stmtDepth, canThrow));
            }
            s.push(_createStatements(2, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CAN_RETURN, stmtDepth), "}");
@@ -1763,7 +1775,7 @@ function createObjectLiteral(recurmax, stmtDepth, canThrow) {
    var obj = [ "({" ];
    var offset = SUPPORT.spread_object ? 0 : SUPPORT.computed_key ? 2 : 4;
    var has_proto = false;
-    for (var i = rng(6); --i >= 0;) switch (offset + rng(50 - offset)) {
+    for (var i = get_num(5); --i >= 0;) switch (offset + rng(50 - offset)) {
      case 0:
        obj.push("..." + getVarName() + ",");
        break;
@@ -1805,12 +1817,12 @@ function createClassLiteral(recurmax, stmtDepth, canThrow, name) {
        if (canThrow && rng(20) == 0) {
            s += p;
        } else {
-            s += "(" + p + " && " + p + ".constructor === Function ? " + p + " : function() {})";
+            s += "(typeof " + p + ' == "function" && typeof ' + p + '.prototype == "object" && ' + p + ".constructor === Function ? " + p + " : function() {})";
        }
    }
    s += " {\n";
    var declared = [];
-    for (var i = rng(6); --i >= 0;) {
+    for (var i = get_num(5); --i >= 0;) {
        var fixed = false;
        if (rng(5) == 0) {
            fixed = true;
@@ -1826,19 +1838,29 @@ function createClassLiteral(recurmax, stmtDepth, canThrow, name) {
        if (SUPPORT.class_field && rng(2)) {
            if (internal) {
                s += internal;
-            } else if (fixed && bug_static_class_field) {
+            } else if (fixed && bug_class_static_nontrivial) {
                s += getDotKey();
            } else {
                s += createObjectKey(recurmax, stmtDepth, canThrow);
            }
            if (rng(5)) {
-                async = bug_async_class_await && fixed && 0;
+                async = false;
                generator = false;
                s += " = " + createExpression(recurmax, NO_COMMA, stmtDepth, fixed ? canThrow : CANNOT_THROW);
                generator = save_generator;
                async = save_async;
            }
            s += ";\n";
+        } else if (SUPPORT.class_static_init && fixed && !internal && rng(10) == 0) {
+            async = false;
+            generator = false;
+            s += [
+                "{ ",
+                createStatements(5, recurmax, canThrow, CANNOT_BREAK, CANNOT_CONTINUE, CANNOT_RETURN, stmtDepth),
+                " }\n",
+            ].join("");
+            generator = save_generator;
+            async = save_async;
        } else {
            if (!fixed && !internal && constructor && rng(10) == 0) {
                internal = constructor;
@@ -1994,7 +2016,7 @@ function createBinaryOp(noComma, canThrow) {
    var op;
    do {
        op = BINARY_OPS[rng(BINARY_OPS.length)];
-    } while (noComma && op == "," || !canThrow && op == " in ");
+    } while (noComma && op == "," || !canThrow && /^ in/.test(op));
    return op;
 }

@@ -2037,7 +2059,7 @@ function isBannedKeyword(name) {
      case "let":
        return in_class;
      case "await":
-        return async !== false;
+        return async || in_class && bug_class_static_await;
      case "yield":
        return generator || in_class;
    }
@@ -2080,13 +2102,23 @@ function createVarName(maybe, dontStore) {
 }

 if (require.main !== module) {
-    exports.createTopLevelCode = createTopLevelCode;
+    exports.createTopLevelCode = function() {
+        var code = createTopLevelCode();
+        exports.module = async && has_await;
+        return code;
+    };
    exports.num_iterations = num_iterations;
    exports.verbose = verbose;
    return;
 }

 function run_code(code, toplevel, timeout) {
+    if (async && has_await) code = [
+        '"use strict";',
+        "(async()=>{",
+        code,
+        '})().catch(e=>process.on("exit",()=>{throw e}));',
+    ].join("\n");
    return sandbox.run_code(sandbox.patch_module_statements(code), toplevel, timeout);
 }

@@ -2106,7 +2138,9 @@ function errorln(msg) {
 }

 function try_beautify(code, toplevel, result, printfn, options) {
-    var beautified = UglifyJS.minify(code, JSON.parse(beautify_options));
+    var o = JSON.parse(beautify_options);
+    if (async && has_await) o.module = true;
+    var beautified = UglifyJS.minify(code, o);
    if (beautified.error) {
        printfn("// !!! beautify failed !!!");
        printfn(beautified.error);
@@ -2259,12 +2293,27 @@ function log(options) {
 }

 function sort_globals(code) {
-    var globals = run_code("throw Object.keys(this).sort(" + function(global) {
+    var injected = "throw Object.keys(this).sort(" + function(global) {
        return function(m, n) {
            return (typeof global[n] == "function") - (typeof global[m] == "function")
                || (m < n ? -1 : m > n ? 1 : 0);
        };
-    } + "(this));\n" + code);
+    } + "(this));";
+    var save_async = async;
+    if (async && has_await) {
+        async = false;
+        injected = [
+            '"use strict";',
+            injected,
+            "(async function(){",
+            code,
+            "})();"
+        ].join("\n");
+    } else {
+        injected += "\n" + code;
+    }
+    var globals = run_code(injected);
+    async = save_async;
    if (!Array.isArray(globals)) {
        errorln();
        errorln();
@@ -2324,20 +2373,28 @@ function is_error_in(ex) {
    return ex.name == "TypeError" && /'in'/.test(ex.message);
 }

+function is_error_tdz(ex) {
+    return ex.name == "ReferenceError";
+}
+
 function is_error_spread(ex) {
-    return ex.name == "TypeError" && /Found non-callable @@iterator| is not iterable| not a function/.test(ex.message);
+    return ex.name == "TypeError" && /Found non-callable @@iterator| is not iterable| not a function|Symbol\(Symbol\.iterator\)/.test(ex.message);
 }

 function is_error_recursion(ex) {
    return ex.name == "RangeError" && /Invalid string length|Maximum call stack size exceeded/.test(ex.message);
 }

+function is_error_set_property(ex) {
+    return ex.name == "TypeError" && /^Cannot set propert[\s\S]+? of (null|undefined)/.test(ex.message);
+}
+
 function is_error_redeclaration(ex) {
    return ex.name == "SyntaxError" && /already been declared|redeclaration/.test(ex.message);
 }

 function is_error_destructuring(ex) {
-    return ex.name == "TypeError" && /^Cannot destructure /.test(ex.message);
+    return ex.name == "TypeError" && /^Cannot (destructure|read propert)/.test(ex.message);
 }

 function is_error_class_constructor(ex) {
@@ -2351,6 +2408,8 @@ function is_error_getter_only_property(ex) {
 }

 function patch_try_catch(orig, toplevel) {
+    var patched = Object.create(null);
+    var patches = [];
    var stack = [ {
        code: orig,
        index: 0,
@@ -2388,7 +2447,7 @@ function patch_try_catch(orig, toplevel) {
                    "throw " + match[1] + ";",
                ].join("\n");
            }
-            var new_code = code.slice(0, index) + insert + code.slice(index) + tail_throw;
+            var new_code = code.slice(0, index) + insert + code.slice(index) + tail_throw + "var UFUZZ_ERROR;";
            var result = run_code(new_code, toplevel);
            if (!sandbox.is_error(result)) {
                if (!stack.filled && match[1]) stack.push({
@@ -2400,27 +2459,35 @@ function patch_try_catch(orig, toplevel) {
                offset += insert.length;
                code = new_code;
            } else if (is_error_in(result)) {
-                index = result.ufuzz_catch;
-                return orig.slice(0, index) + result.ufuzz_var + ' = new Error("invalid `in`");' + orig.slice(index);
+                patch(result.ufuzz_catch, result.ufuzz_var + ' = new Error("invalid `in`");');
+            } else if (is_error_tdz(result)) {
+                patch(result.ufuzz_catch, result.ufuzz_var + ' = new Error("TDZ");');
            } else if (is_error_spread(result)) {
-                index = result.ufuzz_catch;
-                return orig.slice(0, index) + result.ufuzz_var + ' = new Error("spread not iterable");' + orig.slice(index);
+                patch(result.ufuzz_catch, result.ufuzz_var + ' = new Error("spread not iterable");');
            } else if (is_error_recursion(result)) {
-                index = result.ufuzz_try;
-                return orig.slice(0, index) + 'throw new Error("skipping infinite recursion");' + orig.slice(index);
+                patch(result.ufuzz_try, 'throw new Error("skipping infinite recursion");');
+            } else if (is_error_set_property(result)) {
+                patch(result.ufuzz_catch, result.ufuzz_var + ' = new Error("cannot set property");');
            } else if (is_error_destructuring(result)) {
-                index = result.ufuzz_catch;
-                return orig.slice(0, index) + result.ufuzz_var + ' = new Error("cannot destructure");' + orig.slice(index);
+                patch(result.ufuzz_catch, result.ufuzz_var + ' = new Error("cannot destructure");');
            } else if (is_error_class_constructor(result)) {
-                index = result.ufuzz_catch;
-                return orig.slice(0, index) + result.ufuzz_var + ' = new Error("missing new for class");' + orig.slice(index);
+                patch(result.ufuzz_catch, result.ufuzz_var + ' = new Error("missing new for class");');
            } else if (is_error_getter_only_property(result)) {
-                index = result.ufuzz_catch;
-                return orig.slice(0, index) + result.ufuzz_var + ' = new Error("setting getter-only property");' + orig.slice(index);
+                patch(result.ufuzz_catch, result.ufuzz_var + ' = new Error("setting getter-only property");');
            }
        }
        stack.filled = true;
    }
+    if (patches.length) return patches.reduce(function(code, patch) {
+        var index = patch[0];
+        return code.slice(0, index) + patch[1] + code.slice(index);
+    }, orig);
+
+    function patch(index, code) {
+        if (patched[index]) return;
+        patched[index] = true;
+        patches.unshift([ index, code ]);
+    }
 }

 var beautify_options = {
@@ -2444,10 +2511,13 @@ if (SUPPORT.arrow && SUPPORT.async && SUPPORT.rest && sandbox.is_error(sandbox.r
        return ex.name == "SyntaxError" && ex.message == "Rest parameter must be last formal parameter";
    };
 }
-var bug_async_class_await = SUPPORT.async && SUPPORT.class_field && sandbox.is_error(sandbox.run_code("var await; async function f() { class A { static p = await; } }"));
+var bug_class_static_await = SUPPORT.async && SUPPORT.class_field && sandbox.is_error(sandbox.run_code("var await; class A { static p = await; }"));
+var bug_class_static_nontrivial = SUPPORT.class_field && sandbox.is_error(sandbox.run_code("class A { static 42; static get 42() {} }"));
 var bug_for_of_async = SUPPORT.for_await_of && sandbox.is_error(sandbox.run_code("var async; for (async of []);"));
 var bug_for_of_var = SUPPORT.for_of && SUPPORT.let && sandbox.is_error(sandbox.run_code("try {} catch (e) { for (var e of []); }"));
-var bug_static_class_field = SUPPORT.class_field && sandbox.is_error(sandbox.run_code("class A { static 42; static get 42() {} }"));
+var bug_proto_stream = function(ex) {
+    return ex.name == "TypeError" && ex.message == "callback is not a function";
+}
 if (SUPPORT.destructuring && sandbox.is_error(sandbox.run_code("console.log([ 1 ], {} = 2);"))) {
    beautify_options.output.v8 = true;
    minify_options.forEach(function(o) {
@@ -2478,11 +2548,17 @@ for (var round = 1; round <= num_iterations; round++) {
        println();
            // ignore v8 parser bug
        return bug_async_arrow_rest(result)
+            // ignore Node.js `__proto__` quirks
+            || bug_proto_stream(result)
            // ignore runtime platform bugs
            || result.message == "Script execution aborted.";
    })) continue;
    minify_options.forEach(function(options) {
        var o = JSON.parse(options);
+        if (async && has_await) {
+            o.module = true;
+            options = JSON.stringify(o);
+        }
        var toplevel = sandbox.has_toplevel(o);
        o.validate = true;
        uglify_code = UglifyJS.minify(original_code, o);
@@ -2495,6 +2571,8 @@ for (var round = 1; round <= num_iterations; round++) {
            var uglify_erred = sandbox.is_error(uglify_result);
            // ignore v8 parser bug
            if (!ok && uglify_erred && bug_async_arrow_rest(uglify_result)) ok = true;
+            // ignore Node.js `__proto__` quirks
+            if (!ok && uglify_erred && bug_proto_stream(uglify_result)) ok = true;
            // ignore runtime platform bugs
            if (!ok && uglify_erred && uglify_result.message == "Script execution aborted.") ok = true;
            // handle difference caused by time-outs
@@ -2532,55 +2610,34 @@ for (var round = 1; round <= num_iterations; round++) {
                    ok = sandbox.same_stdout(fuzzy_result, uglify_result);
                }
            }
+            if (!ok && original_erred && uglify_erred && (
+                // ignore difference in error message caused by `in`
+                is_error_in(original_result) && is_error_in(uglify_result)
                // ignore difference in error message caused by Temporal Dead Zone
-            if (!ok && original_erred && uglify_erred && original_result.name == "ReferenceError" && uglify_result.name == "ReferenceError") ok = true;
-            // ignore difference due to implicit strict-mode in `class`
-            if (!ok && /\bclass\b/.test(original_code)) {
-                var original_strict = run_code('"use strict";\n' + original_code, toplevel);
-                if (uglify_erred && /^(Syntax|Type)Error$/.test(uglify_result.name)) {
-                    ok = sandbox.is_error(original_strict);
-                } else {
-                    ok = sandbox.same_stdout(original_strict, uglify_result);
-                }
-            }
+                || is_error_tdz(original_result) && is_error_tdz(uglify_result)
+                // ignore difference in error message caused by spread syntax
+                || is_error_spread(original_result) && is_error_spread(uglify_result)
+                // ignore difference in error message caused by destructuring assignment
+                || is_error_set_property(original_result) && is_error_set_property(uglify_result)
                // ignore difference in error message caused by `import` symbol redeclaration
-            if (!ok && original_erred && uglify_erred && /\bimport\b/.test(original_code)) {
-                if (is_error_redeclaration(original_result) && is_error_redeclaration(uglify_result)) ok = true;
-            }
+                || /\bimport\b/.test(original_code) && is_error_redeclaration(original_result) && is_error_redeclaration(uglify_result)
+                // ignore difference in error message caused by destructuring
+                || is_error_destructuring(original_result) && is_error_destructuring(uglify_result)
+                // ignore difference in error message caused by call on class
+                || is_error_class_constructor(original_result) && is_error_class_constructor(uglify_result)
+                // ignore difference in error message caused by setting getter-only property
+                || is_error_getter_only_property(original_result) && is_error_getter_only_property(uglify_result)
+            )) ok = true;
            // ignore difference due to `__proto__` assignment
            if (!ok && /\b__proto__\b/.test(original_code)) {
                var original_proto = run_code("(" + patch_proto + ")();\n" + original_code, toplevel);
                var uglify_proto = run_code("(" + patch_proto + ")();\n" + uglify_code, toplevel);
                ok = sandbox.same_stdout(original_proto, uglify_proto);
            }
-            // ignore difference in error message caused by `in`
-            if (!ok && original_erred && uglify_erred) {
-                if (is_error_in(original_result) && is_error_in(uglify_result)) ok = true;
-            }
-            // ignore difference in error message caused by spread syntax
-            if (!ok && original_erred && uglify_erred) {
-                if (is_error_spread(original_result) && is_error_spread(uglify_result)) ok = true;
-            }
            // ignore difference in depth of termination caused by infinite recursion
            if (!ok && original_erred && is_error_recursion(original_result)) {
                if (!uglify_erred || is_error_recursion(uglify_result)) ok = true;
            }
-            // ignore difference in error message caused by destructuring
-            if (!ok && original_erred && uglify_erred) {
-                if (is_error_destructuring(original_result) && is_error_destructuring(uglify_result)) ok = true;
-            }
-            // ignore difference in error message caused by call on class
-            if (!ok && original_erred && uglify_erred) {
-                if (is_error_class_constructor(original_result) && is_error_class_constructor(uglify_result)) {
-                    ok = true;
-                }
-            }
-            // ignore difference in error message caused by setting getter-only property
-            if (!ok && original_erred && uglify_erred) {
-                if (is_error_getter_only_property(original_result) && is_error_getter_only_property(uglify_result)) {
-                    ok = true;
-                }
-            }
            // ignore errors above when caught by try-catch
            if (!ok) {
                var orig_skipped = patch_try_catch(original_code, toplevel);
--- a/tools/node.js
+++ b/tools/node.js
@@ -15,13 +15,13 @@ exports.FILES = [
    require.resolve("./exports.js"),
 ];

-new Function("exports", function() {
+new Function("domprops", "exports", function() {
    var code = exports.FILES.map(function(file) {
        return fs.readFileSync(file, "utf8");
    });
    code.push("exports.describe_ast = " + describe_ast.toString());
    return code.join("\n\n");
-}())(exports);
+}())(require("./domprops.json"), exports);

 function to_comment(value) {
    if (typeof value != "string") value = JSON.stringify(value, function(key, value) {
Author	SHA1	Message	Date
Alex Lam S.L	4a1da492dd	v3.17.3	2022-10-06 02:14:42 +08:00
Alex Lam S.L	94a954c3d1	minor clean-ups (#5701 )	2022-10-06 02:06:21 +08:00
Alex Lam S.L	be8ccc3ab5	fix corner case in `varify` (#5698 ) fixes #5697	2022-10-04 16:03:24 +08:00
Alex Lam S.L	58d997a3d6	fix corner case in `booleans` & `conditionals` (#5696 )	2022-10-04 12:58:55 +08:00
Alex Lam S.L	dabcc39b51	fix corner cases in `booleans` & `conditionals` (#5695 ) fixes #5694	2022-10-03 22:47:15 +08:00
Alex Lam S.L	140e4e0da8	fix corner case in `inline` (#5693 ) fixes #5692	2022-10-03 08:01:56 +08:00
Alex Lam S.L	80fc862547	enhance `assignments`, `booleans` & `conditionals` (#5691 )	2022-10-03 08:01:23 +08:00
Alex Lam S.L	6cdc035b2f	fix corner case in `if_return` (#5689 ) fixes #5688	2022-09-30 06:49:51 +08:00
Alex Lam S.L	e1e3516397	fix corner case in `reduce_vars` (#5687 )	2022-09-30 02:00:37 +08:00
Alex Lam S.L	bd5fc4cb1b	implement `mangle.properties.domprops` (#5686 ) - support destructuring syntax - fix corner case with comma operator	2022-09-29 12:18:04 +08:00
Alex Lam S.L	a570c00251	fix corner case in `conditionals` & `if_return` (#5685 ) fixes #5684	2022-09-28 00:04:32 +08:00
Alex Lam S.L	3fa2086681	improve usability of `mangle.properties` (#5683 ) fixes #5682	2022-09-27 13:52:58 +08:00
Alex Lam S.L	8e65413b99	fix corner cases in `conditionals` & `if_return` (#5680 ) fixes #5679	2022-09-27 01:28:03 +08:00
Alex Lam S.L	8ca40070a4	workaround GitHub Actions quirks (#5678 )	2022-09-27 00:16:40 +08:00
Alex Lam S.L	f9b811ce83	v3.17.2	2022-09-26 00:12:51 +08:00
Alex Lam S.L	9ac3879b06	fix corner case in `conditionals` (#5676 )	2022-09-23 11:09:55 +08:00
Alex Lam S.L	37d3e4feaa	fix corner case in `if_return` (#5675 )	2022-09-22 23:27:06 +08:00
Alex Lam S.L	43ec350cd2	fix corner case in `conditionals` (#5674 ) fixes #5673	2022-09-22 10:58:44 +08:00
Alex Lam S.L	63b04a687a	minor tweaks (#5672 )	2022-09-21 23:11:46 +08:00
Alex Lam S.L	9efa02afb6	fix corner case in `assignments` (#5671 ) fixes #5670	2022-09-21 07:56:16 +08:00
Alex Lam S.L	3a6e58109e	v3.17.1	2022-09-20 04:13:28 +08:00
Alex Lam S.L	5ac6ec5496	improve usability of `--mangle-props` (#5669 )	2022-09-18 09:37:06 +08:00
Alex Lam S.L	eb22f0101e	fix corner case in `unused` (#5668 ) fixes #5663	2022-09-17 13:32:41 +08:00
Alex Lam S.L	e4bff315eb	fix corner case in `conditionals` (#5667 ) fixes #5666	2022-09-17 10:42:32 +08:00
Alex Lam S.L	001f6f9719	fix corner case in `inline` (#5664 ) fixes #5662	2022-09-17 08:54:54 +08:00
Alex Lam S.L	e0b302d651	fix corner case in `merge_vars` (#5661 ) fixes #5660	2022-09-14 23:36:54 +08:00
Alex Lam S.L	fa2511f71c	tweak `ufuzz` job scheduling (#5659 )	2022-09-11 04:05:21 +08:00
Alex Lam S.L	edf1bf1106	enhance `varify` (#5658 )	2022-09-11 03:28:54 +08:00
Alex Lam S.L	88dfc49683	fix corner case in `merge_vars` (#5657 ) fixes #5656	2022-09-10 04:14:33 +08:00
Alex Lam S.L	9dec612cd5	enhance `inline` (#5655 ) - improve fix for #5653	2022-09-09 04:07:47 +08:00
Alex Lam S.L	02d966d914	fix corner case in `hoist_props` (#5654 ) fixes #5653	2022-09-08 10:55:59 +08:00
Alex Lam S.L	5b5f6e329c	fix corner case in `ie` (#5652 ) fixes #5651	2022-09-08 10:49:40 +08:00
Alex Lam S.L	4e4a2f8ed3	fix corner case in `if_return` (#5650 ) fixes #5649	2022-09-08 10:49:05 +08:00
Alex Lam S.L	32bd65a87f	support ExtendScript parser quirks (#5648 ) closes #1144	2022-09-07 02:28:34 +08:00
Alex Lam S.L	318206d41d	suppress false positives in `ufuzz` (#5647 )	2022-09-06 01:33:22 +08:00
Alex Lam S.L	535212c69e	allow glob-style input for `--in-situ` (#5646 ) closes #5645	2022-09-05 22:54:35 +08:00
Alex Lam S.L	1d42e9ad55	fix corner case in `collapse_vars` (#5644 ) fixes #5643	2022-09-04 10:10:31 +08:00
Alex Lam S.L	78f354beb8	fix corner case in `dead_code` (#5642 ) fixes #5641	2022-09-04 06:18:25 +08:00
Alex Lam S.L	e012f046bc	tweak test cases (#5640 )	2022-08-31 12:16:42 +08:00
Alex Lam S.L	f63b7b079d	fix corner case in `collapse_vars` (#5639 ) fixes #5638	2022-08-31 08:44:04 +08:00
Alex Lam S.L	d530f9332c	enhance `awaits` (#5637 )	2022-08-31 02:51:42 +08:00
Alex Lam S.L	10bc86ba10	enhance `reduce_vars` (#5636 )	2022-08-30 16:00:43 +08:00
Alex Lam S.L	15b608f74c	fix corner case in `inline` (#5635 ) fixes #5634	2022-08-30 00:45:35 +08:00
Alex Lam S.L	7c52af0dec	workaround quirks from npm (#5633 )	2022-08-26 20:08:04 +08:00
Alex Lam S.L	cd97237c59	workaround quirks from GitHub Actions (#5632 )	2022-08-26 15:16:03 +08:00
Alex Lam S.L	965e9767e5	workaround quirks from Node.js (#5631 )	2022-08-26 06:25:44 +08:00
Alex Lam S.L	41a7000745	workaround quirks from GitHub Actions (#5630 )	2022-08-26 02:35:53 +08:00
Alex Lam S.L	9cdc1ef6c2	fix corner case in `unused` (#5629 ) fixes #5628	2022-08-25 05:01:12 +08:00
Alex Lam S.L	4db81065ee	fix corner case in `hoist_vars` (#5627 ) fixes #5626	2022-08-24 00:19:47 +08:00
Alex Lam S.L	4653e8aec0	improve diagnostics on `top_retain` & `mangle.properties` (#5622 ) closes #5618	2022-08-19 02:32:21 +08:00
Alex Lam S.L	ac002b6338	fix corner case in `reduce_vars` (#5624 ) fixes #5623	2022-08-19 02:31:48 +08:00
Alex Lam S.L	9eea3a673a	provide diagnostic details on `--mangle-props` (#5621 ) closes #5618	2022-08-17 22:22:30 +08:00
Alex Lam S.L	d6d2f5ced2	enhance `reduce_vars` (#5616 ) closes #5614	2022-08-17 09:25:59 +08:00
Alex Lam S.L	887e086890	fix corner case in `if_return` (#5620 ) fixes #5619	2022-08-17 09:10:33 +08:00
Alex Lam S.L	8602d1ba17	v3.17.0	2022-08-17 03:45:32 +08:00
Alex Lam S.L	dd90135944	fix corner case in `pure_getters` (#5617 )	2022-08-14 02:54:06 +08:00
Alex Lam S.L	612701a706	tweak `ufuzz` test case generation (#5615 )	2022-08-12 03:55:54 +08:00
Alex Lam S.L	503532cf77	workaround sporadic I/O lags in GitHub Actions (#5613 )	2022-08-10 07:36:14 +08:00
Alex Lam S.L	6c0e522922	workaround sporadic I/O lags in GitHub Actions (#5612 )	2022-08-10 04:33:32 +08:00
Alex Lam S.L	9d37276986	tweak `ufuzz` test case generation (#5611 )	2022-08-10 00:20:20 +08:00
Alex Lam S.L	5a4cd09938	enhance `inline` (#5610 )	2022-08-09 22:54:29 +08:00
Alex Lam S.L	c32fe26b8d	fix corner case in `merge_vars` (#5609 )	2022-08-09 10:18:11 +08:00
Alex Lam S.L	2c3c4ec323	improve source mapping accuracy (#5608 )	2022-08-09 02:02:43 +08:00
Alex Lam S.L	f451a7ad79	implement `--expression` (#5607 )	2022-08-08 03:42:18 +08:00
Alex Lam S.L	07953b36b0	update dependencies (#5605 )	2022-08-06 13:16:47 +08:00
Alex Lam S.L	387c69b194	minor clean-ups (#5604 )	2022-08-06 10:45:44 +08:00
Alex Lam S.L	a9d9af53e9	fix corner case in `if_return` (#5603 ) fixes #5602	2022-08-06 07:56:20 +08:00
Alex Lam S.L	8a07f1202c	expand `builtins` exclusions (#5601 ) closes #5600	2022-08-05 13:37:02 +08:00
Alex Lam S.L	41b65af6e2	fix corner cases with `static` modifier (#5599 )	2022-08-05 02:48:21 +08:00
Alex Lam S.L	884842cd6c	fix corner case in `if_return` (#5598 ) fixes #5597	2022-08-04 06:50:51 +08:00
Alex Lam S.L	8076d66ae5	fix corner case in `if_return` (#5596 ) fixes #5595	2022-08-03 20:07:55 +08:00
Alex Lam S.L	64e3ceec3b	enhance `if_return` (#5594 )	2022-08-03 07:37:31 +08:00
Alex Lam S.L	672cdfa57a	enhance `conditionals` (#5593 )	2022-08-02 19:01:57 +08:00
Alex Lam S.L	e39f33e41b	fix corner cases in `if_return` (#5590 ) fixes #5589 fixes #5591 fixes #5592	2022-07-31 02:45:52 +08:00
Alex Lam S.L	6667440aaf	enhance `if_return` (#5588 ) fixes #5587	2022-07-30 20:53:46 +08:00
Alex Lam S.L	ab5c7e6863	fix corner cases in `if_return` (#5585 ) fixes #5583 fixes #5584 fixes #5586	2022-07-30 16:07:19 +08:00
Alex Lam S.L	08c386f363	enhance `if_return` (#5582 )	2022-07-30 05:25:17 +08:00
Alex Lam S.L	937a672879	fix corner case in `mangle` (#5581 ) fixes #5580	2022-07-29 03:04:10 +08:00
Alex Lam S.L	513995f57d	fix corner case in `inline` & `reduce_vars` (#5579 )	2022-07-28 23:53:11 +08:00
Alex Lam S.L	db6fd6db3e	enhance `side_effects` (#5578 )	2022-07-28 04:06:11 +08:00
Alex Lam S.L	da930affd2	fix corner case in `inline` (#5577 ) fixes #5576	2022-07-26 10:46:54 +08:00
Alex Lam S.L	996836b67e	enhance `conditionals` (#5575 )	2022-07-26 01:49:45 +08:00
Alex Lam S.L	fc7678c115	v3.16.3	2022-07-25 06:08:04 +08:00
Alex Lam S.L	b371dc2d1e	fix corner case in `collapse_vars` (#5574 ) fixes #5573	2022-07-23 07:18:26 +08:00
Alex Lam S.L	56e9454f1f	fix corner case with spread syntax (#5572 )	2022-07-23 03:07:04 +08:00
Alex Lam S.L	d67daa8314	support string namespace in `import` & `export` (#5570 )	2022-07-20 05:55:38 +08:00
Alex Lam S.L	f0120e90b6	fix corner case `collapse_vars` (#5569 ) fixes #5568	2022-07-18 09:04:51 +08:00
Alex Lam S.L	ec4558be29	fix corner cases with parameter scope (#5567 ) fixes #5566	2022-07-17 16:03:12 +08:00
Alex Lam S.L	685ab357cc	document v8 quirks (#5565 ) closes #5564	2022-07-17 00:22:16 +08:00
Alex Lam S.L	5792f30175	fix corner case in `evaluate` (#5559 ) fixes #5558	2022-07-15 20:36:52 +08:00
Alex Lam S.L	24443b6764	enhance `collapse_vars` (#5556 )	2022-07-12 23:49:43 +08:00
Alex Lam S.L	154edf0427	enhance `collapse_vars` (#5555 )	2022-07-11 23:10:40 +08:00
Alex Lam S.L	4778cf88e2	upgrade AST<->ESTree translation (#5554 )	2022-07-11 07:18:25 +08:00
Alex Lam S.L	38bd4f65d0	fix corner cases in `collapse_vars` (#5553 ) fixes #5552	2022-07-09 20:50:54 +08:00
Alex Lam S.L	0b808f6428	parse `import` expressions correctly (#5551 ) fixes #5550	2022-07-08 19:25:30 +08:00
Alex Lam S.L	b2bc2e1173	parse `export` & `import` statements correctly (#5550 ) fixes #5548	2022-07-08 04:04:56 +08:00
Alex Lam S.L	80787ff7ef	minor cleanups (#5549 )	2022-07-08 03:14:54 +08:00
Alex Lam S.L	b92a89f325	fix corner case in `conditionals` (#5548 )	2022-07-07 21:28:33 +08:00
Alex Lam S.L	902292f776	fix corner case in `conditionals` (#5547 ) fixes #5546	2022-07-07 15:49:33 +08:00
Alex Lam S.L	3dcf098468	fix corner cases in `conditionals` & `switches` (#5545 ) fixes #5543 fixes #5544	2022-07-07 14:59:06 +08:00
Alex Lam S.L	d89f0965aa	enhance `conditionals` (#5542 )	2022-07-07 12:17:23 +08:00
Alex Lam S.L	c8d98f4787	enhance `if_return` (#5541 )	2022-07-07 04:28:00 +08:00
Alex Lam S.L	0207b46d70	enhance `if_return` & `inline` (#5538 )	2022-07-06 11:40:07 +08:00
Alex Lam S.L	aa2a9fbedb	v3.16.2	2022-07-04 08:50:56 +08:00
Alex Lam S.L	3596b4feda	fix corner case in `inline` (#5537 ) fixes #5536	2022-07-02 00:10:02 +08:00
Alex Lam S.L	51deeff72e	enhance `inline` (#5535 )	2022-07-01 11:24:16 +08:00
Alex Lam S.L	4c227cc6bd	fix corner cases in `inline` & `unused` (#5534 ) fixes #5533	2022-06-30 15:34:45 +08:00
Alex Lam S.L	2426657daa	fix corner case in `inline` (#5532 ) fixes #5531	2022-06-30 04:09:53 +08:00
Alex Lam S.L	e1b03d0235	fix corner case in `inline` (#5529 ) fixes #5528	2022-06-29 07:37:58 +08:00
Alex Lam S.L	f1b3e9df1e	fix corner case in `inline` (#5527 ) fixes #5526	2022-06-26 20:48:14 +08:00
Alex Lam S.L	fcc87edb71	fix corner cases in `dead_code` & `if_return` (#5525 ) fixes #5521 fixes #5522 fixes #5523 fixes #5524	2022-06-26 18:40:56 +08:00
Alex Lam S.L	8b464331ba	enhance `dead_code` & `if_return` (#5520 )	2022-06-26 12:32:25 +08:00
Alex Lam S.L	9f57920566	enhance `if_return` (#5518 )	2022-06-24 00:52:22 +08:00
Alex Lam S.L	933ca9ddd8	fix corner case in `reduce_vars` (#5517 ) fixes #5516	2022-06-19 03:27:00 +08:00
Alex Lam S.L	74e36e4456	v3.16.1	2022-06-17 07:53:29 +08:00
Alex Lam S.L	4382bfe848	fix corner case in `collapse_vars` (#5513 ) fixes #5512	2022-06-13 07:55:15 +08:00
Alex Lam S.L	b6f250f5c9	enhance `unused` (#5511 )	2022-06-12 21:24:42 +08:00
Alex Lam S.L	5d69545299	enhance `unsafe_comps` (#5510 )	2022-06-12 12:15:43 +08:00
Alex Lam S.L	139fad0c05	fix corner cases with `instanceof` (#5509 ) - enhance `evaluate`	2022-06-12 10:01:54 +08:00
Alex Lam S.L	99946a3993	fix corner case in `dead_code` (#5507 ) fixes #5506	2022-06-12 05:26:51 +08:00
Alex Lam S.L	053cb27fe3	fix corner case in `collapse_vars` (#5505 ) fixes #5504	2022-06-10 09:12:59 +08:00
Alex Lam S.L	25017978e7	fix corner case in `collapse_vars` (#5503 ) fixes #5502	2022-06-10 02:07:07 +08:00
Alex Lam S.L	f749863cb2	document ECMAScript quirks (#5501 ) closes #5500	2022-06-09 03:01:00 +08:00
Alex Lam S.L	123f9cf987	fix corner case in `hoist_props` (#5499 ) fixes #5498	2022-06-07 23:29:42 +08:00
Alex Lam S.L	a758b40e3f	suppress false positives in `ufuzz` (#5497 )	2022-06-07 23:28:06 +08:00
Alex Lam S.L	44e5e99aae	parse directives within arrow functions correctly (#5496 ) fixes #5495	2022-06-07 10:33:17 +08:00
Alex Lam S.L	be53c4838b	fix corner case in `collapse_vars` (#5494 ) fixes #5493	2022-06-06 23:36:19 +08:00
Alex Lam S.L	0c7b016fa7	fix corner case in `inline` & `module` (#5492 ) fixes #5491	2022-06-06 22:52:22 +08:00
Alex Lam S.L	00665766da	fix corner case in `side_effects` (#5490 ) fixes #5489	2022-06-06 20:32:32 +08:00
Alex Lam S.L	88b4283200	support `class static` initialization block (#5488 )	2022-06-06 12:01:15 +08:00
Alex Lam S.L	d2bd0d1c1c	support top-level `await` (#5487 )	2022-06-06 11:52:01 +08:00
Alex Lam S.L	25441d44f6	v3.16.0	2022-06-06 11:29:26 +08:00
Alex Lam S.L	a025392a30	fix corner case in `comparisons` (#5486 ) fixes #5485	2022-06-05 00:47:38 +08:00
Alex Lam S.L	ad5f5ef2a3	fix corner case in `webkit` (#5483 ) fixes #5480	2022-06-02 02:45:02 +08:00
Chen Yangjian	40e669eacb	docs: toplevel `webkit` option sets `compress.webkit` as well (#5480 )	2022-06-02 02:44:06 +08:00
Alex Lam S.L	ad3a331ca3	fix corner case in `collapse_vars` (#5482 ) fixes #5481	2022-06-02 02:42:39 +08:00
Alex Lam S.L	3c9e1693d5	fix corner case in `side_effects` (#5479 ) fixes #5478	2022-05-31 00:27:40 +08:00
Alex Lam S.L	8bc03dc6c4	fix corner case in `keep_fargs` (#5477 ) fixes #5476	2022-05-29 12:10:19 +08:00
Alex Lam S.L	2152f00de2	enhance `inline` & `module` (#5475 )	2022-05-27 11:57:05 +08:00
Alex Lam S.L	94aae05d45	fix corner case in `merge_vars` (#5472 ) fixes #5471	2022-05-27 03:13:24 +08:00
Alex Lam S.L	0dbf2b1d3c	suppress false positives in `ufuzz` (#5473 )	2022-05-26 23:17:47 +08:00
Alex Lam S.L	59b23b8c13	fix corner case in `booleans` (#5470 ) fixes #5469	2022-05-26 05:33:50 +08:00
Alex Lam S.L	5979b195fe	suppress false positives in `ufuzz` (#5468 )	2022-05-25 23:50:47 +08:00
Alex Lam S.L	a1cff23377	suppress false positives in `ufuzz` (#5467 )	2022-05-25 06:35:59 +08:00
Alex Lam S.L	c82fc1ef71	implement `--module` (#5462 )	2022-05-24 05:45:47 +08:00
Alex Lam S.L	740f93f5a9	fix corner case in `merge_vars` (#5466 ) fixes #5465	2022-05-24 05:45:07 +08:00
Alex Lam S.L	d4caa97b88	fix corner case in `reduce_vars` (#5464 ) fixes #5463	2022-05-23 11:08:12 +08:00
Alex Lam S.L	c2ca7b7659	drop unused `extends` properly (#5461 )	2022-05-23 03:53:32 +08:00
Alex Lam S.L	59edda6ca5	suppress false positives in `ufuzz` (#5460 )	2022-05-22 01:36:45 +08:00
Alex Lam S.L	1668bc33c3	improve `ufuzz` coverage (#5459 )	2022-05-21 02:57:13 +08:00
Alex Lam S.L	01f1e3fef8	avoid v8 quirks in `ufuzz` (#5458 )	2022-05-20 00:00:24 +08:00
Alex Lam S.L	27aa85f84b	fix corner cases in `merge_vars` (#5457 ) fixes #5456	2022-05-19 06:39:20 +08:00
Alex Lam S.L	33c9c48318	fix corner case in `hoist_props` & `unused` (#5455 ) fixes #5454	2022-05-19 04:45:38 +08:00
Alex Lam S.L	63f16e4616	fix corner case in `merge_vars` (#5452 ) fixes #5451	2022-05-18 02:41:05 +08:00
Alex Lam S.L	cb6dd34b98	avoid broken versions of Node.js (#5453 )	2022-05-18 02:40:31 +08:00
Alex Lam S.L	27727e6926	fix corner cases in `unused` (#5449 ) fixes #5448	2022-05-17 17:03:06 +08:00
Alex Lam S.L	a968ddc78c	avoid webpack bug in web-tooling-benchmark (#5450 )	2022-05-17 14:08:11 +08:00
Alex Lam S.L	f70462aeb2	fix corner case in `merge_vars` (#5445 ) fixes #5444	2022-05-16 16:30:14 +08:00
Alex Lam S.L	3aa92c76cc	avoid `extends` error in `ufuzz` (#5447 )	2022-05-16 11:11:10 +08:00
Alex Lam S.L	fc6a66836a	fix corner case in `unused` (#5446 ) fixes #5444	2022-05-16 09:13:30 +08:00
Alex Lam S.L	31167da1a9	avoid `extends` error in test cases (#5443 )	2022-05-16 06:50:22 +08:00
Alex Lam S.L	7db2ada880	fix corner case in `hoist_props` (#5442 ) fixes #5441	2022-05-16 06:49:09 +08:00
Alex Lam S.L	e31bbe329a	improve compatibility with `use strict` (#5440 )	2022-05-14 12:15:54 +08:00
Alex Lam S.L	8946c87011	suppress invalid test case generation (#5439 ) - document v8 quirks closes #5438	2022-05-12 04:38:11 +08:00
				`@@ -0,0 +1 @@`
				`function n(){return this\|\|arguments[0]+arguments[1]}function o(){return this\|\|arguments[0]+arguments[1]}console.log(n(n(1,3),5)),console.log(o(o(2,4),6));`