v3.15.5

fixes #5436

README.md

@@ -917,9 +917,11 @@ can pass additional arguments that control the code output:
 
 - `galio` (default: `false`) — enable workarounds for ANT Galio bugs
 
-- `indent_level` (default: `4`)
+- `indent_level` (default: `4`) — indent by specified number of spaces or the
+  exact whitespace sequence supplied, e.g. `"\t"`.
 
-- `indent_start` (default: `0`) — prefix all lines by that many spaces
+- `indent_start` (default: `0`) — prefix all lines by whitespace sequence
+  specified in the same format as `indent_level`.
 
 - `inline_script` (default: `true`) — escape HTML comments and the slash in
   occurrences of `</script>` in strings
@@ -1371,3 +1373,19 @@ To allow for better optimizations, the compiler makes various assumptions:
   // TypeError: const 'a' has already been declared
   ```
   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 {
+      class A {
+          static 42;
+          static get 42() {}
+      }
+      console.log("PASS");
+  } catch (e) {
+      console.log("FAIL");
+  }
+  // Expected: "PASS"
+  // Actual:   "FAIL"
+  ```
+  UglifyJS may modify the input which in turn may suppress those errors.

lib/ast.js

@@ -851,6 +851,9 @@ 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");
     },
@@ -2085,33 +2088,40 @@ TreeWalker.prototype = {
         }
     },
     in_boolean_context: function() {
-        var self = this.self();
-        for (var i = 0, p; p = this.parent(i); i++) {
-            if (p instanceof AST_Conditional && p.condition === self
-                || p instanceof AST_DWLoop && p.condition === self
-                || p instanceof AST_For && p.condition === self
-                || p instanceof AST_If && p.condition === self
-                || p instanceof AST_Return && p.in_bool
-                || p instanceof AST_Sequence && p.tail_node() !== self
-                || p instanceof AST_SimpleStatement
-                || p instanceof AST_UnaryPrefix && p.operator == "!" && p.expression === self) {
-                return true;
-            }
-            if (p instanceof AST_Binary && (p.operator == "&&" || p.operator == "||")
-                || p instanceof AST_Conditional
-                || p.tail_node() === self) {
-                self = p;
-            } else if (p instanceof AST_Return) {
-                for (var call, fn = p; call = this.parent(++i); fn = call) {
-                    if (call.TYPE == "Call") {
-                        if (!(fn instanceof AST_Lambda) || fn.name) return false;
-                    } else if (fn instanceof AST_Lambda) {
-                        return false;
-                    }
-                }
-            } else {
+        for (var drop = true, level = 0, parent, self = this.self(); parent = this.parent(level++); self = parent) {
+            if (parent instanceof AST_Binary) switch (parent.operator) {
+              case "&&":
+              case "||":
+                if (parent.left === self) drop = false;
+                continue;
+              default:
                 return false;
             }
+            if (parent instanceof AST_Conditional) {
+                if (parent.condition === self) return true;
+                continue;
+            }
+            if (parent instanceof AST_DWLoop) return parent.condition === self;
+            if (parent instanceof AST_For) return parent.condition === self;
+            if (parent instanceof AST_If) return parent.condition === self;
+            if (parent instanceof AST_Return) {
+                if (parent.in_bool) return true;
+                while (parent = this.parent(level++)) {
+                    if (parent instanceof AST_Lambda) {
+                        if (parent.name) return false;
+                        parent = this.parent(level++);
+                        if (parent.TYPE != "Call") return false;
+                        break;
+                    }
+                }
+            }
+            if (parent instanceof AST_Sequence) {
+                if (parent.tail_node() === self) continue;
+                return drop ? "d" : true;
+            }
+            if (parent instanceof AST_SimpleStatement) return drop ? "d" : true;
+            if (parent instanceof AST_UnaryPrefix) return parent.operator == "!";
+            return false;
         }
     }
 };

lib/minify.js

@@ -96,15 +96,14 @@ function minify(files, options) {
         }, true);
         if (options.validate) AST_Node.enable_validation();
         var timings = options.timings && { start: Date.now() };
-        if (options.rename === undefined) options.rename = options.compress && options.mangle;
         if (options.annotations !== undefined) set_shorthand("annotations", options, [ "compress", "output" ]);
         if (options.ie8) options.ie = options.ie || options.ie8;
-        if (options.ie) set_shorthand("ie", options, [ "compress", "mangle", "output" ]);
-        if (options.keep_fargs) set_shorthand("keep_fargs", options, [ "compress", "mangle" ]);
-        if (options.keep_fnames) set_shorthand("keep_fnames", options, [ "compress", "mangle" ]);
-        if (options.toplevel) set_shorthand("toplevel", options, [ "compress", "mangle" ]);
-        if (options.v8) set_shorthand("v8", options, [ "mangle", "output" ]);
-        if (options.webkit) set_shorthand("webkit", options, [ "compress", "mangle", "output" ]);
+        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.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" ]);
         var quoted_props;
         if (options.mangle) {
             options.mangle = defaults(options.mangle, {
@@ -135,6 +134,7 @@ function minify(files, options) {
             init_cache(options.mangle.cache);
             init_cache(options.mangle.properties.cache);
         }
+        if (options.rename === undefined) options.rename = options.compress && options.mangle;
         if (options.sourceMap) {
             options.sourceMap = defaults(options.sourceMap, {
                 content: null,
@@ -190,8 +190,8 @@ function minify(files, options) {
         if (options.validate) toplevel.validate_ast();
         if (timings) timings.rename = Date.now();
         if (options.rename) {
-            toplevel.figure_out_scope(options.mangle);
-            toplevel.expand_names(options.mangle);
+            toplevel.figure_out_scope(options.rename);
+            toplevel.expand_names(options.rename);
         }
         if (timings) timings.compress = Date.now();
         if (options.compress) {

lib/output.js

@@ -101,10 +101,18 @@ function OutputStream(options) {
         }
     }
 
+    function make_indent(value) {
+        if (typeof value == "number") return new Array(value + 1).join(" ");
+        if (!value) return "";
+        if (!/^\s*$/.test(value)) throw new Error("unsupported indentation: " + JSON.stringify("" + value));
+        return value;
+    }
+
     var current_col = 0;
     var current_line = 1;
-    var current_pos = 0;
-    var indentation = options.indent_start;
+    var current_indent = make_indent(options.indent_start);
+    var full_indent = make_indent(options.indent_level);
+    var half_indent = full_indent.length + 1 >> 1;
     var last;
     var line_end = 0;
     var line_fixed = true;
@@ -115,17 +123,17 @@ function OutputStream(options) {
     var might_need_semicolon;
     var need_newline_indented = false;
     var need_space = false;
-    var newline_insert = -1;
+    var output;
     var stack;
-    var OUTPUT;
+    var stored = "";
 
     function reset() {
         last = "";
         might_need_space = false;
         might_need_semicolon = false;
         stack = [];
-        var str = OUTPUT;
-        OUTPUT = "";
+        var str = output;
+        output = "";
         return str;
     }
 
@@ -227,32 +235,30 @@ function OutputStream(options) {
     } : noop;
 
     function insert_newlines(count) {
-        var index = OUTPUT.lastIndexOf("\n");
-        if (line_end < index) line_end = index;
-        var left = OUTPUT.slice(0, line_end);
-        var right = OUTPUT.slice(line_end);
-        adjust_mappings(count, right.length - current_col);
+        stored += output.slice(0, line_end);
+        output = output.slice(line_end);
+        var new_col = output.length;
+        adjust_mappings(count, new_col - current_col);
         current_line += count;
-        current_pos += count;
-        current_col = right.length;
-        OUTPUT = left;
-        while (count--) OUTPUT += "\n";
-        OUTPUT += right;
+        current_col = new_col;
+        while (count--) stored += "\n";
     }
 
-    var fix_line = options.max_line_len ? function() {
+    var fix_line = options.max_line_len ? function(flush) {
         if (line_fixed) {
             if (current_col > options.max_line_len) {
                 AST_Node.warn("Output exceeds {max_line_len} characters", options);
             }
             return;
         }
-        if (current_col > options.max_line_len) insert_newlines(1);
-        line_fixed = true;
-        flush_mappings();
+        if (current_col > options.max_line_len) {
+            insert_newlines(1);
+            line_fixed = true;
+        }
+        if (line_fixed || flush) flush_mappings();
     } : noop;
 
-    var requireSemicolonChars = makePredicate("( [ + * / - , .");
+    var require_semicolon = makePredicate("( [ + * / - , .");
 
     var print = options.beautify
         || options.comments
@@ -276,32 +282,32 @@ function OutputStream(options) {
                 space();
             }
         }
-        newline_insert = -1;
         var prev = last.slice(-1);
         if (might_need_semicolon) {
             might_need_semicolon = false;
-
-            if (prev == ":" && ch == "}" || (!ch || ";}".indexOf(ch) < 0) && prev != ";") {
-                if (options.semicolons || requireSemicolonChars[ch]) {
-                    OUTPUT += ";";
+            if (prev == ":" && ch == "}" || prev != ";" && (!ch || ";}".indexOf(ch) < 0)) {
+                var need_semicolon = require_semicolon[ch];
+                if (need_semicolon || options.semicolons) {
+                    output += ";";
                     current_col++;
-                    current_pos++;
+                    if (!line_fixed) {
+                        fix_line();
+                        if (line_fixed && !need_semicolon && output == ";") {
+                            output = "";
+                            current_col = 0;
+                        }
+                    }
+                    if (line_end == output.length - 1) line_end++;
                 } else {
                     fix_line();
-                    OUTPUT += "\n";
-                    current_pos++;
+                    output += "\n";
                     current_line++;
                     current_col = 0;
-
-                    if (/^\s+$/.test(str)) {
-                        // reset the semicolon flag, since we didn't print one
-                        // now and might still have to later
-                        might_need_semicolon = true;
-                    }
+                    // reset the semicolon flag, since we didn't print one
+                    // now and might still have to later
+                    if (/^\s+$/.test(str)) might_need_semicolon = true;
                 }
-
-                if (!options.beautify)
-                    might_need_space = false;
+                if (!options.beautify) might_need_space = false;
             }
         }
 
@@ -312,9 +318,8 @@ function OutputStream(options) {
                 || str == "--" && last == "!"
                 || str == "in" && prev == "/"
                 || last == "--" && ch == ">") {
-                OUTPUT += " ";
+                output += " ";
                 current_col++;
-                current_pos++;
             }
             if (prev != "<" || str != "!") might_need_space = false;
         }
@@ -324,14 +329,13 @@ function OutputStream(options) {
                 token: mapping_token,
                 name: mapping_name,
                 line: current_line,
-                col: current_col
+                col: current_col,
             });
             mapping_token = false;
             if (line_fixed) flush_mappings();
         }
 
-        OUTPUT += str;
-        current_pos += str.length;
+        output += str;
         var a = str.split(/\r?\n/), n = a.length - 1;
         current_line += n;
         current_col += a[0].length;
@@ -346,7 +350,7 @@ function OutputStream(options) {
         if (might_need_semicolon) {
             might_need_semicolon = false;
             if (prev == ":" && ch == "}" || (!ch || ";}".indexOf(ch) < 0) && prev != ";") {
-                OUTPUT += ";";
+                output += ";";
                 might_need_space = false;
             }
         }
@@ -357,11 +361,11 @@ function OutputStream(options) {
                 || str == "--" && last == "!"
                 || str == "in" && prev == "/"
                 || last == "--" && ch == ">") {
-                OUTPUT += " ";
+                output += " ";
             }
             if (prev != "<" || str != "!") might_need_space = false;
         }
-        OUTPUT += str;
+        output += str;
         last = str;
     };
 
@@ -373,30 +377,25 @@ function OutputStream(options) {
 
     var indent = options.beautify ? function(half) {
         if (need_newline_indented) print("\n");
-        print(repeat_string(" ", half ? indentation - (options.indent_level >> 1) : indentation));
+        print(half ? current_indent.slice(0, -half_indent) : current_indent);
     } : noop;
 
     var with_indent = options.beautify ? function(cont) {
-        var save_indentation = indentation;
-        indentation += options.indent_level;
+        var save_indentation = current_indent;
+        current_indent += full_indent;
         cont();
-        indentation = save_indentation;
+        current_indent = save_indentation;
     } : function(cont) { cont() };
 
     var may_add_newline = options.max_line_len || options.preserve_line ? function() {
         fix_line();
-        line_end = OUTPUT.length;
+        line_end = output.length;
         line_fixed = false;
     } : noop;
 
     var newline = options.beautify ? function() {
-        if (newline_insert < 0) return print("\n");
-        if (OUTPUT[newline_insert] != "\n") {
-            OUTPUT = OUTPUT.slice(0, newline_insert) + "\n" + OUTPUT.slice(newline_insert);
-            current_pos++;
-            current_line++;
-        }
-        newline_insert++;
+        print("\n");
+        line_end = output.length;
     } : may_add_newline;
 
     var semicolon = options.beautify ? function() {
@@ -452,13 +451,12 @@ function OutputStream(options) {
     } : noop;
 
     function get() {
-        if (!line_fixed) fix_line();
-        return OUTPUT;
+        if (!line_fixed) fix_line(true);
+        return stored + output;
     }
 
     function has_nlb() {
-        var index = OUTPUT.lastIndexOf("\n");
-        return /^ *$/.test(OUTPUT.slice(index + 1));
+        return /(^|\n) *$/.test(output);
     }
 
     function pad_comment(token, force) {
@@ -515,7 +513,7 @@ function OutputStream(options) {
             scan.walk(tw);
         }
 
-        if (current_pos == 0) {
+        if (current_line == 1 && current_col == 0) {
             if (comments.length > 0 && options.shebang && comments[0].type == "comment5") {
                 print("#!" + comments.shift().value + "\n");
                 indent();
@@ -559,20 +557,18 @@ function OutputStream(options) {
             return !/comment[134]/.test(c.type);
         }))) return;
         comments._dumped = self;
-        var insert = OUTPUT.length;
         comments.filter(comment_filter, node).forEach(function(comment, index) {
             pad_comment(comment, index || !tail);
             print_comment(comment);
         });
-        if (OUTPUT.length > insert) newline_insert = insert;
     }
 
     return {
         get             : get,
         reset           : reset,
         indent          : indent,
-        should_break    : options.width ? function() {
-            return current_col - indentation >= options.width;
+        should_break    : options.beautify && options.width ? function() {
+            return current_col >= options.width;
         } : return_false,
         has_parens      : function() { return last.slice(-1) == "(" },
         newline         : newline,

lib/parse.js

@@ -1194,10 +1194,10 @@ function parse($TEXT, options) {
     }
 
     function for_() {
-        var await = is("name", "await") && next();
+        var await_token = is("name", "await") && next();
         expect("(");
         var init = null;
-        if (await || !is("punc", ";")) {
+        if (await_token || !is("punc", ";")) {
             init = is("keyword", "const")
                 ? (next(), const_(true))
                 : is("name", "let") && is_vardefs()
@@ -1206,7 +1206,7 @@ function parse($TEXT, options) {
                 ? (next(), var_(true))
                 : expression(true);
             var ctor;
-            if (await) {
+            if (await_token) {
                 expect_token("name", "of");
                 ctor = AST_ForAwaitOf;
             } else if (is("operator", "in")) {

lib/scope.js

@@ -226,7 +226,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             defun.def_variable(node);
         } else if (node instanceof AST_SymbolLambda) {
             var def = defun.def_function(node, node.name == "arguments" ? undefined : defun);
-            if (options.ie) def.defun = defun.parent_scope.resolve();
+            if (options.ie && node.name != "arguments") def.defun = defun.parent_scope.resolve();
         } else if (node instanceof AST_SymbolLet) {
             var def = scope.def_variable(node);
             if (exported) def.exported = true;
@@ -469,6 +469,7 @@ AST_Lambda.DEFMETHOD("init_vars", function(parent_scope) {
     this.uses_arguments = false;
     this.def_variable(new AST_SymbolFunarg({
         name: "arguments",
+        scope: this,
         start: this.start,
         end: this.end,
     }));
@@ -616,7 +617,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             mangled_names.set(mangled_name, true);
         });
     }
-    var cutoff = 10;
+    var cutoff = 36;
     var lname = -1;
     var redefined = [];
     var tw = new TreeWalker(function(node, descend) {

lib/utils.js

@@ -55,14 +55,6 @@ function find_if(func, array) {
     for (var i = array.length; --i >= 0;) if (func(array[i])) return array[i];
 }
 
-function repeat_string(str, i) {
-    if (i <= 0) return "";
-    if (i == 1) return str;
-    var d = repeat_string(str, i >> 1);
-    d += d;
-    return i & 1 ? d + str : d;
-}
-
 function configure_error_stack(fn) {
     Object.defineProperty(fn.prototype, "stack", {
         get: function() {

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": "3.15.0",
+  "version": "3.15.5",
   "engines": {
     "node": ">=0.8.0"
   },

test/benchmark.js

@@ -17,6 +17,7 @@ var urls = [
     "https://unpkg.com/mathjs@6.2.3/dist/math.js",
     "https://unpkg.com/react@15.3.2/dist/react.js",
     "https://cdnjs.cloudflare.com/ajax/libs/d3/6.7.0/d3.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/antd/4.18.7/antd.js",
     "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.js",
     "https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js",
     "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.12.2/ember.prod.js",

test/compress.js

@@ -183,13 +183,11 @@ function parse_test(file) {
 function reminify(orig_options, input_code, input_formatted, stdout) {
     for (var i = 0; i < minify_options.length; i++) {
         var options = JSON.parse(minify_options[i]);
-        if (options.compress) [
+        [
             "keep_fargs",
             "keep_fnames",
         ].forEach(function(name) {
-            if (name in orig_options) {
-                options.compress[name] = orig_options[name];
-            }
+            if (name in orig_options) options[name] = orig_options[name];
         });
         var options_formatted = JSON.stringify(options, null, 4);
         options.validate = true;

test/compress/arrows.js

@@ -927,3 +927,182 @@ issue_5251: {
     expect_stdout: true
     node_version: ">=4"
 }
+
+issue_5342_1: {
+    options = {
+        dead_code: true,
+        inline: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        for (var a in 0) {
+            (() => {
+                while (1);
+            })(new function(NaN) {
+                a.p;
+            }());
+        }
+        console.log(function() {
+            return b;
+            try {
+                b;
+            } catch (e) {
+                var b;
+            }
+        }());
+    }
+    expect: {
+        for (var a in 0) {
+            (function(NaN) {
+                a.p;
+            })();
+            while (1);
+        }
+        console.log(b);
+        var b;
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_5342_2: {
+    rename = true
+    options = {
+        dead_code: true,
+        inline: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        for (var a in 0) {
+            (() => {
+                while (1);
+            })(new function(NaN) {
+                a.p;
+            }());
+        }
+        console.log(function() {
+            return b;
+            try {
+                b;
+            } catch (e) {
+                var b;
+            }
+        }());
+    }
+    expect: {
+        for (var a in 0) {
+            a.p;
+            while (1);
+        }
+        console.log(c);
+        var c;
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}
+
+issue_5356: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log((a => a++)(console));
+    }
+    expect: {
+        console.log((a => +a)(console));
+    }
+    expect_stdout: "NaN"
+    node_version: ">=4"
+}
+
+issue_5414_1: {
+    options = {
+        arrows: true,
+        if_return: true,
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        (() => {
+            (() => {
+                if (!console)
+                    var arguments = 42;
+                while (console.log(arguments));
+            })();
+        })();
+    }
+    expect: {
+        (() => {
+            if (!console)
+                var arguments = 42;
+            while (console.log(arguments));
+        })();
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+issue_5414_2: {
+    options = {
+        arrows: true,
+        inline: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        (() => {
+            (() => {
+                if (!console)
+                    var arguments = 42;
+                while (console.log(arguments));
+            })();
+        })();
+    }
+    expect: {
+        (() => {
+            if (!console)
+                var arguments = 42;
+            while (console.log(arguments));
+        })();
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+issue_5416: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        inline: true,
+        loops: true,
+        unused: true,
+    }
+    input: {
+        var f = () => {
+            while ((() => {
+                console;
+                var a = function g(arguments) {
+                    console.log(arguments);
+                }();
+            })());
+        };
+        f();
+    }
+    expect: {
+        var f = () => {
+            {
+                arguments = void 0;
+                console;
+                console.log(arguments);
+                var arguments;
+            }
+        };
+        f();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=4"
+}

test/compress/assignments.js

@@ -673,8 +673,7 @@ issue_4827_1: {
         c &&= b = a, console.log(b);
     }
     expect: {
-        A = "FAIL";
-        var a = A, b = "PASS", c;
+        var a = A = "FAIL", b = "PASS", c;
         c &&= b = a, console.log(b);
     }
     expect_stdout: "PASS"

test/compress/booleans.js

@@ -427,6 +427,44 @@ negated_if: {
     expect_stdout: "PASS"
 }
 
+concat_truthy: {
+    options = {
+        booleans: true,
+        evaluate: true,
+    }
+    input: {
+        console.log("foo") + (console.log("bar"), "baz") || console.log("moo");
+    }
+    expect: {
+        console.log("foo") + (console.log("bar"), "baz");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    expect_warnings: [
+        "WARN: + in boolean context always true [test/compress/booleans.js:1,8]",
+        "WARN: Condition left of || always true [test/compress/booleans.js:1,8]",
+    ]
+}
+
+process_returns: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        (function() {
+            return 42;
+        })() && console.log("PASS");
+    }
+    expect: {
+        (function() {
+            return 42;
+        })() && console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
 issue_3465_1: {
     options = {
         booleans: true,

test/compress/classes.js

@@ -939,6 +939,8 @@ keep_fnames: {
         class Foo {}
         console.log(Foo.name, class Bar {}.name);
     }
+    expect_stdout: "Foo Bar"
+    node_version: ">=4"
 }
 
 issue_805_1: {
@@ -2449,3 +2451,153 @@ issue_5294_4: {
     expect_stdout: "PASS"
     node_version: ">=12"
 }
+
+issue_5322: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 41;
+        class A {
+            static p() {
+                console.log(++a);
+            }
+            static q = this.p();
+        }
+    }
+    expect: {
+        var a = 41;
+        (class {
+            static p() {
+                console.log(++a);
+            }
+            static q = this.p();
+        });
+    }
+    expect_stdout: "42"
+    node_version: ">=12"
+}
+
+issue_5352: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a) {
+            var b;
+            new class {
+                [b = console.log(a)] = b;
+            }(a.p);
+        }
+        f("PASS");
+    }
+    expect: {
+        function f(a) {
+            var b;
+            new class {
+                [b = console.log(a)] = b;
+            }(a.p);
+        }
+        f("PASS");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=12"
+}
+
+issue_5387: {
+    options = {
+        properties: true,
+    }
+    input: {
+        "use strict";
+        (function(a) {
+            try {
+                class A extends a {}
+            } catch (e) {
+                console.log("PASS");
+            }
+        })({
+            f() {
+                return this;
+            }
+        }.f);
+    }
+    expect: {
+        "use strict";
+        (function(a) {
+            try {
+                class A extends a {}
+            } catch (e) {
+                console.log("PASS");
+            }
+        })({
+            f() {
+                return this;
+            }
+        }.f);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_5389: {
+    options = {
+        collapse_vars: true,
+        toplevel: true,
+    }
+    input: {
+        function log(m, n) {
+            console.log(m, n);
+        }
+        var a = log;
+        class A {
+            [a = "FAIL"] = a = "PASS";
+        }
+        var b = new A();
+        log(a, b.FAIL);
+    }
+    expect: {
+        function log(m, n) {
+            console.log(m, n);
+        }
+        var a = log;
+        class A {
+            [a = "FAIL"] = a = "PASS";
+        }
+        var b = new A();
+        log(a, b.FAIL);
+    }
+    expect_stdout: "PASS PASS"
+    node_version: ">=12"
+}
+
+issue_5436: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a) {
+            class A {
+                p = a;
+            }
+            var b = "FAIL";
+            A == b && b();
+            return new A();
+        }
+        console.log(f("PASS").p);
+    }
+    expect: {
+        function f(a) {
+            class A {
+                p = a;
+            }
+            var b = "FAIL";
+            A == b && b();
+            return new A();
+        }
+        console.log(f("PASS").p);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=12"
+}

test/compress/collapse_vars.js

@@ -2579,7 +2579,7 @@ side_effects_property: {
     expect_stdout: true
 }
 
-undeclared: {
+undeclared_1: {
     options = {
         collapse_vars: true,
         unused: true,
@@ -2594,8 +2594,68 @@ undeclared: {
     }
     expect: {
         function f(x, y) {
+            return (b = y) + x;
+        }
+    }
+}
+
+undeclared_2: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(x, y) {
+            var a;
+            a = x;
             b = y;
-            return b + x;
+            return a + b;
+        }
+    }
+    expect: {
+        function f(x, y) {
+            return x + (b = y);
+        }
+    }
+}
+
+undeclared_3: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(x, y) {
+            var a;
+            a = x;
+            b = y;
+            return b + a();
+        }
+    }
+    expect: {
+        function f(x, y) {
+            return (b = y) + x();
+        }
+    }
+}
+
+undeclared_4: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(x, y) {
+            var a;
+            a = x;
+            b = y;
+            return a() + b;
+        }
+    }
+    expect: {
+        function f(x, y) {
+            b = y;
+            return x() + b;
         }
     }
 }
@@ -2987,9 +3047,8 @@ compound_assignment_4: {
         console.log(a);
     }
     expect: {
-        A = "PASS";
         var a = "";
-        (a += (a = "FAIL", A)).p;
+        (a += (a = "FAIL", A = "PASS")).p;
         console.log(a);
     }
     expect_stdout: "PASS"
@@ -8955,6 +9014,27 @@ collapse_and_assign: {
     expect_stdout: "PASS"
 }
 
+collapse_and_assign_property: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function f() {
+            f && (f.p = "PASS");
+            return f.p;
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            return f.p = f ? "PASS" : f.p;
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
 collapse_or_assign: {
     options = {
         collapse_vars: true,
@@ -8972,7 +9052,7 @@ collapse_or_assign: {
         var a = {
             p: "PASS",
         };
-        log(a = !a.q ? a.p : a);
+        log(a = a.q ? a: a.p);
     }
     expect_stdout: "PASS"
 }
@@ -9845,3 +9925,57 @@ issue_5309_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_5394: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+    }
+    input: {
+        try {
+            throw A.p = (console.log("FAIL"), []), !1;
+        } catch (e) {
+            console.log(typeof e);
+        }
+    }
+    expect: {
+        try {
+            throw !(A.p = (console.log("FAIL"), []));
+        } catch (e) {
+            console.log(typeof e);
+        }
+    }
+    expect_stdout: "object"
+}
+
+issue_5396: {
+    options = {
+        collapse_vars: true,
+        merge_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var a, b;
+        function f() {}
+        b = 0;
+        new function g(c) {
+            var d = a && g(e), e = ++d, i = [ 42 ];
+            for (var j in i)
+                console.log("PASS"),
+                i;
+        }();
+    }
+    expect: {
+        var a, b;
+        function f() {}
+        b = 0;
+        (function g(c) {
+            a && g();
+            for (var j in [ 42 ])
+                console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/comparisons.js

@@ -489,7 +489,36 @@ issue_3413: {
     }
     expect: {
         var b;
-        void 0 !== ("" < b || void 0) || console.log("PASS");
+        void 0 === ("" < b || void 0) && console.log("PASS");
     }
     expect_stdout: "PASS"
 }
+
+nullish_assign: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        var a;
+        void 0 !== (a = "PASS".split("")) && null !== a && console.log(a.join("-"));
+    }
+    expect: {
+        var a;
+        null != (a = "PASS".split("")) && console.log(a.join("-"));
+    }
+    expect_stdout: "P-A-S-S"
+}
+
+nullish_chain: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        var a;
+        A || B || void 0 === a || null === a || C;
+    }
+    expect: {
+        var a;
+        A || B || null == a || C;
+    }
+}

test/compress/conditionals.js

@@ -82,14 +82,14 @@ ifs_3_should_warn: {
         "WARN: Boolean && always false [test/compress/conditionals.js:3,12]",
         "WARN: Condition left of && always false [test/compress/conditionals.js:3,12]",
         "WARN: Condition always false [test/compress/conditionals.js:3,12]",
+        "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:3,12]",
         "WARN: Dropping unreachable code [test/compress/conditionals.js:3,34]",
         "WARN: + in boolean context always true [test/compress/conditionals.js:10,19]",
         "WARN: Boolean || always true [test/compress/conditionals.js:10,12]",
         "WARN: Condition left of || always true [test/compress/conditionals.js:10,12]",
         "WARN: Condition always true [test/compress/conditionals.js:10,12]",
-        "WARN: Dropping unreachable code [test/compress/conditionals.js:12,15]",
-        "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:3,12]",
         "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:10,12]",
+        "WARN: Dropping unreachable code [test/compress/conditionals.js:12,15]",
     ]
 }
 
@@ -2007,3 +2007,58 @@ issue_5232_3: {
         "undefined",
     ]
 }
+
+issue_5334_1: {
+    options = {
+        conditionals: true,
+        hoist_props: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            if (console.log("PASS"))
+                var o = true, o = {
+                    p: o += console.log("FAIL"),
+                };
+        }
+        f();
+    }
+    expect: {
+        (function() {
+            var o;
+            console.log("PASS") && (o = true, o = {
+                p: o += console.log("FAIL"),
+            });
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5334_2: {
+    options = {
+        conditionals: true,
+        hoist_props: true,
+        inline: true,
+        passes: 3,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            if (console.log("PASS"))
+                var o = true, o = {
+                    p: o += console.log("FAIL"),
+                };
+        }
+        f();
+    }
+    expect: {
+        console.log("PASS") && console.log("FAIL");
+    }
+    expect_stdout: "PASS"
+}

test/compress/const.js

@@ -597,8 +597,7 @@ do_if_continue_1: {
     }
     expect: {
         do {
-            if (!console);
-            else {
+            if (console) {
                 console.log("PASS");
                 {
                     const a = 0;
@@ -628,8 +627,7 @@ do_if_continue_2: {
     }
     expect: {
         do {
-            if (!console);
-            else {
+            if (console) {
                 console.log("PASS");
                 {
                     const a = 0;
@@ -1518,6 +1516,7 @@ issue_4689: {
 
 issue_4691: {
     options = {
+        conditionals: true,
         if_return: true,
         toplevel: true,
     }
@@ -1813,3 +1812,46 @@ issue_5260: {
     ]
     node_version: ">=4"
 }
+
+issue_5319: {
+    options = {
+        collapse_vars: true,
+        merge_vars: true,
+    }
+    input: {
+        (function(a, c) {
+            var b = a, c = b;
+            {
+                const a = c;
+                console.log(c());
+            }
+        })(function() {
+            return "PASS";
+        });
+    }
+    expect: {
+        (function(a, c) {
+            var b = a, c;
+            {
+                const a = c = b;
+                console.log(c());
+            }
+        })(function() {
+            return "PASS";
+        });
+    }
+    expect_stdout: true
+}
+
+issue_5338: {
+    options = {
+        unused: true,
+    }
+    input: {
+        const a = a;
+    }
+    expect: {
+        const a = a;
+    }
+    expect_stdout: true
+}

test/compress/default-values.js

@@ -2007,6 +2007,7 @@ issue_5192: {
 
 issue_5246_1: {
     options = {
+        keep_fargs: false,
         pure_getters: true,
         unused: true,
     }
@@ -2016,20 +2017,20 @@ issue_5246_1: {
         }("foo"));
     }
     expect: {
-        console.log(function({} = 0) {
+        console.log(function() {
             return "PASS";
-        }("foo"));
+        }());
     }
     expect_stdout: "PASS"
     expect_warnings: [
-        "INFO: Dropping unused default argument value {}=42 [test/compress/default-values.js:1,29]",
-        "INFO: Dropping unused default argument value {}=0 [test/compress/default-values.js:1,29]",
+        "INFO: Dropping unused default argument {}=42 [test/compress/default-values.js:1,29]",
     ]
     node_version: ">=6"
 }
 
 issue_5246_2: {
     options = {
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -2038,9 +2039,9 @@ issue_5246_2: {
         })("PASS", []);
     }
     expect: {
-        (function(a = "FAIL", []) {
+        (function(a = "FAIL") {
             console.log(a);
-        })("PASS", []);
+        })("PASS");
     }
     expect_stdout: "PASS"
     node_version: ">=6"
@@ -2049,6 +2050,7 @@ issue_5246_2: {
 issue_5246_3: {
     options = {
         default_values: true,
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -2081,3 +2083,159 @@ issue_5256: {
     expect_stdout: "undefined"
     node_version: ">=8"
 }
+
+issue_5314_1: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        A = this;
+        new function() {
+            (function(a = console.log(this === A ? "PASS" : "FAIL")) {})();
+        }();
+    }
+    expect: {
+        A = this;
+        (function() {
+            (function(a = console.log(this === A ? "PASS" : "FAIL")) {})();
+        })();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5314_2: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        A = this;
+        new function() {
+            ((a = console.log(this === A ? "FAIL" : "PASS")) => {})();
+        }();
+    }
+    expect: {
+        A = this;
+        new function() {
+            console.log(this === A ? "FAIL" : "PASS");
+        }();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5336: {
+    options = {
+        default_values: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        do {
+            (function f(b = console.log("PASS")) {
+                a = f;
+            })(42);
+        } while (a());
+    }
+    expect: {
+        var a;
+        do {
+            (function f(b = console.log("PASS")) {
+                a = f;
+            })(42);
+        } while (a());
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5340_1: {
+    options = {
+        keep_fargs: true,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        var a;
+        (function(b = 42) {})(({ p: a } = true).q);
+        console.log(a);
+    }
+    expect: {
+        var a;
+        (function(b = 0) {})(({ p: a } = true).q);
+        console.log(a);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=6"
+}
+
+issue_5340_2: {
+    options = {
+        keep_fargs: true,
+        pure_getters: "strict",
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        (function(b = 42) {})(({ p: a } = true).q);
+        console.log(a);
+    }
+    expect: {
+        var a;
+        [ [].e = 0 ] = [ ({ p: a } = true).q ];
+        console.log(a);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=6"
+}
+
+issue_5340_3: {
+    options = {
+        keep_fargs: false,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        var a;
+        (function(b = 42) {})(({ p: a } = true).q);
+        console.log(a);
+    }
+    expect: {
+        var a;
+        (function() {})(a = true["p"]);
+        console.log(a);
+    }
+    expect_stdout: "undefined"
+    node_version: ">=6"
+}
+
+issue_5407: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        (function(a) {
+            for (var i = 0; i < 2; i++)
+                (function(b = 4) {
+                    console.log(b);
+                    a = 2;
+                })(a);
+        })();
+    }
+    expect: {
+        (function(a) {
+            for (var i = 0; i < 2; i++)
+                (function(b = 4) {
+                    console.log(b);
+                    a = 2;
+                })(a);
+        })();
+    }
+    expect_stdout: [
+        "4",
+        "2",
+    ]
+    node_version: ">=6"
+}

test/compress/destructured.js

@@ -692,7 +692,7 @@ funarg_inline: {
     node_version: ">=6"
 }
 
-process_boolean_returns: {
+process_returns: {
     options = {
         booleans: true,
     }
@@ -706,9 +706,7 @@ process_boolean_returns: {
     expect: {
         console.log(function({ length }) {
             return length ? "FAIL" : "PASS";
-        }(function() {
-            return 42;
-        }));
+        }(function() {}));
     }
     expect_stdout: "PASS"
     node_version: ">=6"
@@ -1130,7 +1128,7 @@ drop_unused_2: {
         }
         f();
     }
-    expect:{
+    expect: {
         (function(a) {
             console.log("PASS");
         })();
@@ -3406,6 +3404,7 @@ issue_5288: {
     options = {
         conditionals: true,
         inline: true,
+        keep_fargs: false,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -3421,8 +3420,149 @@ issue_5288: {
         }() ]));
     }
     expect: {
-        while ([ [ console ? console.log("PASS") : 0 ] ], void 0);
+        while (console ? console.log("PASS") : 0, void 0);
     }
     expect_stdout: "PASS"
     node_version: ">=6"
 }
+
+issue_5314_1: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        A = this;
+        new function() {
+            (function({
+                [console.log(this === A ? "PASS" : "FAIL")]: a,
+            }) {})(42);
+        }();
+    }
+    expect: {
+        A = this;
+        (function() {
+            (function({
+                [console.log(this === A ? "PASS" : "FAIL")]: a,
+            }) {})(42);
+        })();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5314_2: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        A = this;
+        new function() {
+            (({
+                [console.log(this === A ? "FAIL" : "PASS")]: a,
+            }) => {})(42);
+        }();
+    }
+    expect: {
+        A = this;
+        new function() {
+            [ {
+                [console.log(this === A ? "FAIL" : "PASS")]: [].e,
+            } ] = [ 42 ];
+        }();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5370: {
+    options = {
+        dead_code: true,
+        ie: true,
+        unused: true,
+    }
+    input: {
+        console.log(function arguments({}) {
+            return arguments;
+            try {} catch (e) {
+                var arguments;
+            }
+        }(42));
+    }
+    expect: {
+        console.log(function arguments({}) {
+            return arguments;
+            var arguments;
+        }(42));
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_5405_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var [ a ] = [ {} ];
+        console.log(a === a ? "PASS" : "FAIL");
+    }
+    expect: {
+        var [ a ] = [ {} ];
+        console.log(true ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5405_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+    }
+    input: {
+        var { p: a } = { p: [] };
+        console.log(a === a ? "PASS" : "FAIL");
+    }
+    expect: {
+        var { p: a } = { p: [] };
+        console.log(true ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
+
+issue_5423: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a, b;
+        function f({
+            [function() {
+                if (++a)
+                    return 42;
+            }()]: c
+        }) {}
+        f(b = f);
+        console.log(typeof b);
+    }
+    expect: {
+        var a, b;
+        function f({
+            [function() {
+                if (++a)
+                    return 42;
+            }()]: c
+        }) {}
+        f(b = f);
+        console.log(typeof b);
+    }
+    expect_stdout: "function"
+    node_version: ">=6"
+}

test/compress/directives.js

@@ -129,3 +129,32 @@ valid_after_invalid_2: {
     }
     expect_stdout: "undefined"
 }
+
+issue_5368_1: {
+    options = {
+        directives: true,
+        expression: true,
+    }
+    input: {
+        "foo";
+    }
+    expect: {
+        "foo";
+    }
+}
+
+issue_5368_2: {
+    options = {
+        directives: true,
+        expression: true,
+    }
+    input: {
+        "foo";
+        (function() {
+            "bar";
+        })();
+    }
+    expect: {
+        (function() {})();
+    }
+}

test/compress/drop-unused.js

@@ -2656,7 +2656,7 @@ issue_3956: {
         collapse_vars: true,
         evaluate: true,
         inline: true,
-        passes: 2,
+        passes: 3,
         reduce_vars: true,
         sequences: true,
         side_effects: true,
@@ -2787,7 +2787,7 @@ issue_3986: {
     expect_stdout: "0"
 }
 
-issue_4017: {
+issue_4017_1: {
     options = {
         pure_getters: "strict",
         reduce_vars: true,
@@ -2805,7 +2805,31 @@ issue_4017: {
         var a = 0;
         console.log(function() {
             c &= 0;
-            var c;
+            var c = a++ + (A = a);
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4017_2: {
+    options = {
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = 0;
+        console.log(function f() {
+            var b = c &= 0;
+            var c = a++ + (A = a);
+            var d = c && c[f];
+        }());
+    }
+    expect: {
+        var a = 0;
+        console.log(function() {
+            0;
             a++,
             A = a;
         }());
@@ -3248,7 +3272,7 @@ issue_4558_1: {
     expect: {
         var a = 0;
         var b = c >>>= a;
-        var c;
+        var c = 0;
         b && a++,
         console.log(a);
     }
@@ -3334,6 +3358,7 @@ issue_4806_1: {
 issue_4806_2: {
     options = {
         sequences: true,
+        side_effects: true,
         toplevel: true,
         unused: true,
     }

test/compress/evaluate.js

@@ -745,7 +745,7 @@ call_args: {
     expect: {
         var a = 1;
         console.log(1);
-        +(1, 1);
+        1, 1;
     }
     expect_stdout: true
 }
@@ -769,7 +769,7 @@ call_args_drop_param: {
     }
     expect: {
         console.log(1);
-        +(b, 1);
+        b, 1;
     }
     expect_stdout: true
 }
@@ -888,6 +888,25 @@ unsafe_charAt_noop: {
     expect_stdout: "f  n"
 }
 
+chained_side_effects: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log("foo") || (console.log("bar"), "baz") || console.log("moo");
+    }
+    expect: {
+        console.log("foo") || (console.log("bar"), "baz");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    expect_warnings: [
+        "WARN: Condition left of || always true [test/compress/evaluate.js:1,8]",
+    ]
+}
+
 issue_1649: {
     options = {
         evaluate: true,
@@ -3241,3 +3260,119 @@ issue_4886_2: {
     }
     expect_stdout: "true"
 }
+
+issue_5354: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        function f(a) {
+            return +a.toExponential(1);
+        }
+        function g(b) {
+            return 0 + b.toFixed(2);
+        }
+        function h(c) {
+            return 1 * c.toPrecision(3);
+        }
+        console.log(typeof f(45), typeof g(67), typeof h(89));
+    }
+    expect: {
+        function f(a) {
+            return +a.toExponential(1);
+        }
+        function g(b) {
+            return 0 + b.toFixed(2);
+        }
+        function h(c) {
+            return +c.toPrecision(3);
+        }
+        console.log(typeof f(45), typeof g(67), typeof h(89));
+    }
+    expect_stdout: "number string number"
+}
+
+issue_5356: {
+    options = {
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            return a++;
+            var a = a;
+        }());
+    }
+    expect: {
+        console.log(+a);
+        var a;
+    }
+    expect_stdout: "NaN"
+}
+
+issue_5362_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = -console;
+        console.log(delete +a);
+    }
+    expect: {
+        var a = -console;
+        console.log((+a, true));
+    }
+    expect_stdout: "true"
+}
+
+issue_5362_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = -console;
+        console.log(delete +a);
+    }
+    expect: {
+        console.log(true);
+    }
+    expect_stdout: "true"
+}
+
+issue_5380: {
+    options = {
+        evaluate: true,
+        keep_fnames: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function f(b) {
+            return function g() {
+                for (b in { PASS: 42 });
+            }(), b;
+        }("FAIL");
+        console.log(a);
+    }
+    expect: {
+        var a = function f(b) {
+            return function g() {
+                for (b in { PASS: 42 });
+            }(), b;
+        }("FAIL");
+        console.log(a);
+    }
+    expect_stdout: "PASS"
+}

test/compress/functions.js

@@ -1508,6 +1508,48 @@ unsafe_call_3: {
     expect_stdout: "3"
 }
 
+inline_eval_inner: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (function() {
+            console.log(typeof eval("arguments"));
+        })();
+    }
+    expect: {
+        (function() {
+            console.log(typeof eval("arguments"));
+        })();
+    }
+    expect_stdout: "object"
+}
+
+inline_eval_outer: {
+    options = {
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        A = 42;
+        (function(a) {
+            console.log(a);
+        })(A);
+        console.log(eval("typeof a"));
+    }
+    expect: {
+        A = 42;
+        (function(a) {
+            console.log(a);
+        })(A);
+        console.log(eval("typeof a"));
+    }
+    expect_stdout: [
+        "42",
+        "undefined",
+    ]
+}
+
 issue_2616: {
     options = {
         evaluate: true,
@@ -1713,16 +1755,14 @@ issue_2620_5: {
     }
     expect: {
         var c = "FAIL";
-        (function() {
-            var a = 0/0;
-            var NaN = void 0;
+        !function(a, NaN) {
             switch (a) {
               case a:
                 break;
               case c = "PASS", NaN:
                 break;
             }
-        })();
+        }(NaN);
         console.log(c);
     }
     expect_stdout: "PASS"
@@ -3517,6 +3557,27 @@ functions_inner_var: {
     expect_stdout: "undefined undefined"
 }
 
+functions_keep_fnames: {
+    options = {
+        functions: true,
+        keep_fnames: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var FAIL = function PASS() {};
+        FAIL.p = 42;
+        console.log(FAIL.name, FAIL.p);
+    }
+    expect: {
+        var FAIL = function PASS() {};
+        FAIL.p = 42;
+        console.log(FAIL.name, FAIL.p);
+    }
+    expect_stdout: "PASS 42"
+}
+
 issue_2437: {
     options = {
         collapse_vars: true,
@@ -6137,6 +6198,7 @@ issue_4265: {
         dead_code: true,
         inline: true,
         sequences: true,
+        side_effects: true,
     }
     input: {
         function f() {
@@ -6342,7 +6404,7 @@ issue_4612_4: {
     expect: {
         console.log(function() {
             function f() {
-                return h();
+                h();
             }
             function g() {
                 return h();
@@ -7635,9 +7697,10 @@ issue_5237: {
     }
     expect: {
         function f() {
-            while (console.log(0/0));
-            var NaN = console && console.log(NaN);
-            return;
+            while (console.log(NaN));
+            (function() {
+                var NaN = console && console.log(NaN);
+            })();
         }
         f();
     }
@@ -7981,6 +8044,7 @@ issue_5264_2: {
 
 issue_5283: {
     options = {
+        conditionals: true,
         if_return: true,
         inline: true,
         pure_getters: "strict",
@@ -8005,11 +8069,10 @@ issue_5283: {
         var a = "FAIL 1";
         (function() {
             a = "PASS";
-            if (!console)
-                (function(a) {
-                    console.log("FAIL 2");
-                    a.p;
-                })();
+            console || function(a) {
+                console.log("FAIL 2");
+                a.p;
+            }();
         })();
         console.log(a);
     }
@@ -8084,3 +8147,254 @@ issue_5296: {
     }
     expect_stdout: "PASS"
 }
+
+issue_5316_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        do {
+            console.log("PASS");
+        } while (function() {
+            var a, b = 42 && (console[a = b] = a++);
+        }());
+    }
+    expect: {
+        do {
+            console.log("PASS");
+        } while (b = a = void 0, b = (42, console[a = a] = a++), void 0);
+        var a, b;
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5316_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        do {
+            (function() {
+                var a, b = 42 && (console[a = b] = a++);
+                while (console.log("PASS"));
+            })();
+        } while (!console);
+    }
+    expect: {
+        do {
+            a = void 0;
+            var a, b = (42, console[a = b = void 0] = a++);
+            while (console.log("PASS"));
+        } while (!console);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5328: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (function(arguments) {
+            console.log(Object.keys(arguments).join());
+        })(this);
+    }
+    expect: {
+        (function(arguments) {
+            console.log(Object.keys(arguments).join());
+        })(this);
+    }
+    expect_stdout: ""
+}
+
+issue_5332_1: {
+    options = {
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        do {
+            var a = {};
+            for (A in a)
+                a;
+        } while (function() {
+            console.log(b);
+            var b = b;
+        }());
+    }
+    expect: {
+        do {
+            var a = {};
+            for (A in a);
+        } while (a = void 0, void console.log(a));
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5332_2: {
+    options = {
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        do {
+            var a = 42 in [];
+            for (A in a)
+                a;
+        } while (function() {
+            console.log(++b);
+            var b = b;
+        }());
+    }
+    expect: {
+        do {
+            var a = 42 in [];
+            for (A in a);
+        } while (a = void 0, void console.log(++a));
+    }
+    expect_stdout: "NaN"
+}
+
+issue_5366: {
+    options = {
+        inline: true,
+    }
+    input: {
+        for (console.log("foo") || function() {
+            while (console.log("bar"));
+        }(); console.log("baz") ;);
+    }
+    expect: {
+        if (!console.log("foo"))
+            while (console.log("bar"));
+        for (;console.log("baz"););
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
+issue_5376_1: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        loops: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        var a;
+        for (;42;)
+            var b = function() {
+                var c;
+                throw new Error(c++);
+            }();
+    }
+    expect: {
+        "use strict";
+        for (;;) {
+            42;
+            throw new Error(NaN);
+        }
+    }
+    expect_stdout: Error("NaN")
+}
+
+issue_5376_2: {
+    options = {
+        evaluate: true,
+        inline: true,
+        join_vars: true,
+        loops: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        var a;
+        for (;42;)
+            var b = function() {
+                var c;
+                c++;
+                throw new Error("PASS");
+            }();
+    }
+    expect: {
+        "use strict";
+        for (;;) {
+            0;
+            throw new Error("PASS");
+        }
+    }
+    expect_stdout: Error("PASS")
+}
+
+issue_5401: {
+    options = {
+        inline: true,
+    }
+    input: {
+        L: for (var a in function() {
+            while (console.log("PASS"));
+        }(), a) do {
+            continue L;
+        } while (console.log("FAIL"));
+    }
+    expect: {
+        while (console.log("PASS"));
+        L: for (var a in a) do {
+            continue L;
+        } while (console.log("FAIL"));
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5409: {
+    options = {
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            (a = console) || FAIL(a);
+            (function(b) {
+                console.log(b && b);
+                while (!console);
+            })();
+        })();
+    }
+    expect: {
+        (function(a) {
+            (a = console) || FAIL(a);
+            a = void 0;
+            console.log(a && a);
+            while (!console);
+            return;
+        })();
+    }
+    expect_stdout: "undefined"
+}

test/compress/hoist_vars.js

@@ -224,8 +224,7 @@ issue_4489: {
         console.log(k);
     }
     expect: {
-        !(A = 0);
-        for (var k in true);
+        for (var k in !(A = 0));
         console.log(k);
     }
     expect_stdout: "undefined"
@@ -250,8 +249,7 @@ issue_4517: {
     expect: {
         console.log(function() {
             var a = 2;
-            A = a;
-            return A + typeof !1;
+            return (A = a) + typeof !1;
         }());
     }
     expect_stdout: "2boolean"
@@ -408,9 +406,9 @@ issue_4893_2: {
     expect: {
         try{
             (function() {
-                var b;
-                b = null;
-                b.p += 42;
+                var a;
+                a = null;
+                a.p += 42;
             })();
         } catch (e) {
             console.log("PASS");
@@ -500,3 +498,108 @@ issue_5195: {
     }
     expect_stdout: "[object Object]"
 }
+
+issue_5378: {
+    options = {
+        hoist_vars: true,
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 2;
+        while (a--)
+            (function() {
+                var b;
+                var c;
+                while (console.log(b));
+                --b;
+            })();
+    }
+    expect: {
+        var a = 2;
+        while (a--) {
+            b = void 0;
+            var b, c;
+            while (console.log(b));
+            --b;
+        }
+    }
+    expect_stdout: [
+        "undefined",
+        "undefined",
+    ]
+}
+
+issue_5411_1: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        b++;
+        b = a;
+        var b = b, c = c && c[b];
+        console.log(b);
+    }
+    expect: {
+        var b, c, a = "PASS";
+        b++;
+        b = a;
+        c = c && c[b];
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5411_2: {
+    options = {
+        collapse_vars: true,
+        dead_code: true,
+        evaluate: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        b++;
+        b = a;
+        var b = b, c = c && c[b];
+        console.log(b);
+    }
+    expect: {
+        var b, c;
+        b++;
+        b = "PASS",
+        c = c && c[b];
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5411_3: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = console;
+        a++;
+        var a = A = a;
+        console.log(A);
+    }
+    expect: {
+        var a = console;
+        a = A = ++a;
+        console.log(A);
+    }
+    expect_stdout: "NaN"
+}

test/compress/ie.js

@@ -2631,13 +2631,14 @@ issue_3999: {
     ]
 }
 
-issue_4001: {
+issue_4001_1: {
     options = {
         collapse_vars: true,
         ie: true,
         inline: true,
         reduce_vars: true,
         sequences: true,
+        side_effects: false,
         toplevel: true,
         unused: true,
     }
@@ -2660,7 +2661,42 @@ issue_4001: {
             return a;
         }
         var a;
-        console.log((a = 42, void f()[42], void function a() {}));
+        console.log((a = 42, f()[42], void f, void function a() {}));
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4001_2: {
+    options = {
+        collapse_vars: true,
+        ie: true,
+        inline: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            function f() {
+                return a;
+                var b;
+            }
+            var c = f();
+            (function g() {
+                c[42];
+                f;
+            })();
+            (function a() {});
+        }(42));
+    }
+    expect: {
+        function f() {
+            return a;
+        }
+        var a;
+        console.log((a = 42, void f()[42]));
     }
     expect_stdout: "undefined"
 }
@@ -3408,3 +3444,33 @@ issue_5269_3_ie: {
         "bar",
     ]
 }
+
+issue_5350: {
+    options = {
+        ie: false,
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(typeof f, [ 42, function f() {} ][0]);
+    }
+    expect: {
+        console.log(typeof f, 42);
+    }
+    expect_stdout: "undefined 42"
+}
+
+issue_5350_ie: {
+    options = {
+        ie: true,
+        properties: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(typeof f, [ 42, function f() {} ][0]);
+    }
+    expect: {
+        console.log(typeof f, (function f() {}, 42));
+    }
+    expect_stdout: "undefined 42"
+}

test/compress/if_return.js

@@ -327,7 +327,7 @@ issue_512: {
     }
 }
 
-if_var_return: {
+if_var_return_1: {
     options = {
         conditionals: true,
         if_return: true,
@@ -373,6 +373,76 @@ if_var_return: {
     }
 }
 
+if_var_return_2: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+    }
+    input: {
+        (function() {
+            var a = w();
+            if (x())
+                return y();
+            z();
+        })();
+    }
+    expect: {
+        (function() {
+            var a = w();
+            return x() ? y() : (z(), void 0);
+        })();
+    }
+}
+
+if_var_retrn_3: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+    }
+    input: {
+        f(function() {
+            var a = w();
+            if (x())
+                return y(a);
+            z();
+        });
+    }
+    expect: {
+        f(function() {
+            var a = w();
+            if (x())
+                return y(a);
+            z();
+        });
+    }
+}
+
+if_var_return_4: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+    }
+    input: {
+        function f() {
+            if (u())
+                return v();
+            var a = w();
+            if (x())
+                return y();
+            z();
+        }
+    }
+    expect: {
+        function f() {
+            return u() ? v() : (a = w(), x() ? y() : (z(), void 0));
+            var a;
+        }
+    }
+}
+
 if_if_return_return: {
     options = {
         conditionals: true,
@@ -628,7 +698,9 @@ iife_if_return_simple: {
 
 nested_if_break: {
     options = {
+        conditionals: true,
         if_return: true,
+        side_effects: true,
     }
     input: {
         for (var i = 0; i < 3; i++)
@@ -639,8 +711,7 @@ nested_if_break: {
     }
     expect: {
         for (var i = 0; i < 3; i++)
-            L1: if ("number" == typeof i)
-                if (0 !== i) console.log(i);
+            L1: "number" == typeof i && 0 !== i && console.log(i);
     }
     expect_stdout: [
         "1",
@@ -679,11 +750,11 @@ nested_if_continue: {
         function f(n) {
             for (var i = 0;
                 "number" == typeof n
-                    && (0 !== n
-                        ? 1 !== n
-                            ? i++
-                            : console.log("odd", i)
-                        : console.log("even", i)),
+                    && (0 === n
+                        ? console.log("even", i)
+                        : 1 === n
+                        ? console.log("odd", i)
+                        : i++),
                 0 <= (n -= 2););
         }
         f(37);

test/compress/indentation.js

@@ -0,0 +1,100 @@
+numeric: {
+    beautify = {
+        beautify: true,
+        indent_start: 1,
+        indent_level: 3,
+    }
+    input: {
+        switch (42) {
+          case null:
+            console.log("FAIL");
+        }
+        console.log("PASS");
+    }
+    expect_exact: [
+        " switch (42) {",
+        "  case null:",
+        '    console.log("FAIL");',
+        " }",
+        "",
+        ' console.log("PASS");',
+    ]
+    expect_stdout: "PASS"
+}
+
+spaces: {
+    beautify = {
+        beautify: true,
+        indent_start: " ",
+        indent_level: "   ",
+    }
+    input: {
+        switch (42) {
+          case null:
+            console.log("FAIL");
+        }
+        console.log("PASS");
+    }
+    expect_exact: [
+        " switch (42) {",
+        "  case null:",
+        '    console.log("FAIL");',
+        " }",
+        "",
+        ' console.log("PASS");',
+    ]
+    expect_stdout: "PASS"
+}
+
+tabs: {
+    beautify = {
+        beautify: true,
+        indent_start: "\t",
+        indent_level: "\t",
+    }
+    input: {
+        switch (42) {
+          case null:
+            console.log("FAIL");
+        }
+        console.log("PASS");
+    }
+    expect_exact: [
+        "\tswitch (42) {",
+        "\tcase null:",
+        '\t\tconsole.log("FAIL");',
+        "\t}",
+        "",
+        '\tconsole.log("PASS");',
+    ]
+    expect_stdout: "PASS"
+}
+
+mixed: {
+    beautify = {
+        beautify: true,
+        indent_start: "\n",
+        indent_level: "       \t",
+    }
+    input: {
+        switch (42) {
+          case null:
+            console.log("FAIL");
+        }
+        console.log("PASS");
+    }
+    expect_exact: [
+        "",
+        "switch (42) {",
+        "",
+        "    case null:",
+        "",
+        '       \tconsole.log("FAIL");',
+        "",
+        "}",
+        "",
+        "",
+        'console.log("PASS");',
+    ]
+    expect_stdout: "PASS"
+}

test/compress/issue-1052.js

@@ -4,22 +4,21 @@ multiple_functions: {
         if_return: true,
     }
     input: {
-        ( function() {
-            if ( !window ) {
+        (function() {
+            if (!window)
                 return;
-            }
             function f() {}
             function g() {}
-        } )();
+        })();
     }
     expect: {
-        ( function() {
+        (function() {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
-            if ( !window );
+            if (!window);
             function f() {}
             function g() {}
-        } )();
+        })();
     }
 }
 
@@ -29,18 +28,17 @@ single_function: {
         if_return: true,
     }
     input: {
-        ( function() {
-            if ( !window ) {
+        (function() {
+            if (!window)
                 return;
-            }
             function f() {}
-        } )();
+        })();
     }
     expect: {
-        ( function() {
-            if ( !window );
+        (function() {
+            if (!window);
             function f() {}
-        } )();
+        })();
     }
 }
 
@@ -50,28 +48,26 @@ deeply_nested: {
         if_return: true,
     }
     input: {
-        ( function() {
-            if ( !window ) {
+        (function() {
+            if (!window)
                 return;
-            }
             function f() {}
             function g() {}
-            if ( !document ) {
+            if (!document)
                 return;
-            }
             function h() {}
-        } )();
+        })();
     }
     expect: {
-        ( function() {
+        (function() {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
-            if ( window )
-                if ( !document );
+            if (!window);
+            else if (!document);
             function f() {}
             function g() {}
             function h() {}
-        } )();
+        })();
     }
 }
 
@@ -81,18 +77,18 @@ not_hoisted_when_already_nested: {
         if_return: true,
     }
     input: {
-        ( function() {
-            if ( !window ) {
+        (function() {
+            if (!window)
                 return;
-            }
-            if ( foo ) function f() {}
-        } )();
+            if (foo) function f() {}
+        })();
     }
     expect: {
-        ( function() {
-            if ( window )
-                if ( foo ) function f() {}
-        } )();
+        (function() {
+            if (!window);
+            else if (foo)
+                function f() {}
+        })();
     }
 }
 
@@ -104,15 +100,19 @@ defun_if_return: {
     input: {
         function e() {
             function f() {}
-            if (!window) return;
-            else function g() {}
+            if (!window)
+                return;
+            else
+                function g() {}
             function h() {}
         }
     }
     expect: {
         function e() {
             function f() {}
-            if (window) function g() {}
+            if (!window);
+            else
+                function g() {}
             function h() {}
         }
     }
@@ -126,8 +126,10 @@ defun_hoist_funs: {
     input: {
         function e() {
             function f() {}
-            if (!window) return;
-            else function g() {}
+            if (!window)
+                return;
+            else
+                function g() {}
             function h() {}
         }
     }
@@ -136,7 +138,7 @@ defun_hoist_funs: {
             function f() {}
             function g() {}
             function h() {}
-            if (window);
+            if (!window);
         }
     }
 }
@@ -149,15 +151,18 @@ defun_else_if_return: {
     input: {
         function e() {
             function f() {}
-            if (window) function g() {}
-            else return;
+            if (window)
+                function g() {}
+            else
+                return;
             function h() {}
         }
     }
     expect: {
         function e() {
             function f() {}
-            if (window) function g() {}
+            if (window)
+                function g() {}
             function h() {}
         }
     }

test/compress/issue-1447.js

@@ -40,6 +40,9 @@ conditional_false_stray_else_in_loop: {
             console.log(i);
         }
     }
-    expect_exact: "for(var i=1;i<=4;++i)if(!(i<=2))console.log(i);"
-    expect_stdout: true
+    expect_exact: "for(var i=1;i<=4;++i)if(i<=2);else console.log(i);"
+    expect_stdout: [
+        "3",
+        "4",
+    ]
 }

test/compress/issue-640.js

@@ -317,7 +317,35 @@ iife: {
         typeof function g() {}();
     }
     expect: {
-        x = 42, function a() {}(), function b() {}(), function c() {}(),
-        function d() {}(), function e() {}(), function f() {}(), typeof function g() {}();
+        x = 42,
+        function a() {}(),
+        !function b() {}(),
+        ~function c() {}(),
+        +function d() {}(),
+        -function e() {}(),
+        void function f() {}(),
+        typeof function g() {}();
+    }
+}
+
+iife_drop_side_effect_free: {
+    options = {
+        expression: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        x = 42;
+        (function a() {})();
+        !function b() {}();
+        ~function c() {}();
+        +function d() {}();
+        -function e() {}();
+        void function f() {}();
+        typeof function g() {}();
+    }
+    expect: {
+        x = 42,
+        typeof void 0;
     }
 }

test/compress/issue-979.js

@@ -1,4 +1,4 @@
-issue979_reported: {
+reported: {
     options = {
         booleans: true,
         comparisons: true,
@@ -17,29 +17,26 @@ issue979_reported: {
     }
     input: {
         function f1() {
-            if (a == 1 || b == 2) {
+            if (a == 1 || b == 2)
                 foo();
-            }
         }
         function f2() {
-            if (!(a == 1 || b == 2)) {
-            }
-            else {
+            if (!(a == 1 || b == 2));
+            else
                 foo();
-            }
         }
     }
     expect: {
         function f1() {
-            1!=a&&2!=b||foo();
+            1 != a && 2 != b || foo();
         }
         function f2() {
-            1!=a&&2!=b||foo();
+            1 != a && 2 != b || foo();
         }
     }
 }
 
-issue979_test_negated_is_best: {
+test_negated_is_best: {
     options = {
         booleans: true,
         comparisons: true,
@@ -58,53 +55,47 @@ issue979_test_negated_is_best: {
     }
     input: {
         function f3() {
-            if (a == 1 | b == 2) {
+            if (a == 1 | b == 2)
                 foo();
-            }
         }
         function f4() {
-            if (!(a == 1 | b == 2)) {
-            }
-            else {
+            if (!(a == 1 | b == 2));
+            else
                 foo();
-            }
         }
         function f5() {
-            if (a == 1 && b == 2) {
+            if (a == 1 && b == 2)
                 foo();
-            }
         }
         function f6() {
-            if (!(a == 1 && b == 2)) {
-            }
-            else {
+            if (!(a == 1 && b == 2));
+            else
                 foo();
-            }
         }
         function f7() {
-            if (a == 1 || b == 2) {
+            if (a == 1 || b == 2)
                 foo();
-            }
-            else {
+            else
                 return bar();
-            }
         }
     }
     expect: {
         function f3() {
-            1==a|2==b&&foo();
+            1 == a | 2 == b && foo();
         }
         function f4() {
-            1==a|2==b&&foo();
+            1 == a | 2 == b && foo();
         }
         function f5() {
-            1==a&&2==b&&foo();
+            1 == a && 2 == b && foo();
         }
         function f6() {
-            1!=a||2!=b||foo();
+            1 == a && 2 == b && foo();
         }
         function f7() {
-            if(1!=a&&2!=b)return bar();foo()
+            if (1 != a && 2 != b)
+                return bar();
+            foo();
         }
     }
 }

test/compress/join_vars.js

@@ -1144,7 +1144,7 @@ conditional_assignments_3: {
     expect_stdout: "PASS"
 }
 
-issue_3856: {
+issue_3856_1: {
     options = {
         booleans: true,
         conditionals: true,
@@ -1169,9 +1169,46 @@ issue_3856: {
         console.log(function() {
             (function() {
                 var a, b;
-                if (a) return a, 1;
-                for (a = 0; !console;);
-                return 0;
+                if (a) a;
+                else {
+                    a = 0;
+                    for (; !console;);
+                }
+            })();
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_3856_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        if_return: true,
+        join_vars: true,
+        passes: 2,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(function() {
+            (function() {
+                var a;
+                if (!a) {
+                    a = 0;
+                    for (var b; !console;);
+                    return 0;
+                }
+                if (a) return 1;
+            })();
+        }());
+    }
+    expect: {
+        console.log(function() {
+            (function() {
+                var a, b;
+                if (!a)
+                    for (a = 0; !console;);
             })();
         }());
     }

test/compress/keep_fargs.js

@@ -1258,8 +1258,7 @@ issues_3267_1: {
     }
     expect: {
         !function() {
-            var i = Object();
-            if (i)
+            if (Object())
                 return console.log("PASS");
             throw "FAIL";
         }();

test/compress/let.js

@@ -912,8 +912,7 @@ do_if_continue_1: {
     expect: {
         "use strict";
         do {
-            if (!console);
-            else {
+            if (console) {
                 console.log("PASS");
                 {
                     let a = 0;
@@ -946,8 +945,7 @@ do_if_continue_2: {
     expect: {
         "use strict";
         do {
-            if (!console);
-            else {
+            if (console) {
                 console.log("FAIL");
                 {
                     let a = 0;
@@ -1667,9 +1665,7 @@ issue_4438: {
     expect: {
         "use strict";
         function f() {
-            if (!console)
-                ;
-            else {
+            if (console) {
                 let a = console.log;
                 void a("PASS");
             }
@@ -1757,6 +1753,7 @@ issue_4689: {
 
 issue_4691: {
     options = {
+        conditionals: true,
         if_return: true,
         toplevel: true,
     }
@@ -1973,3 +1970,53 @@ issue_5260: {
     ]
     node_version: ">=4"
 }
+
+issue_5319: {
+    options = {
+        collapse_vars: true,
+        merge_vars: true,
+    }
+    input: {
+        "use strict";
+        (function(a, c) {
+            var b = a, c = b;
+            {
+                let a = c;
+                console.log(c());
+            }
+        })(function() {
+            return "PASS";
+        });
+    }
+    expect: {
+        "use strict";
+        (function(a, c) {
+            var b = a, c;
+            {
+                let a = c = b;
+                console.log(c());
+            }
+        })(function() {
+            return "PASS";
+        });
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_5338: {
+    options = {
+        unused: true,
+    }
+    input: {
+        "use strict";
+        let a = a;
+    }
+    expect: {
+        "use strict";
+        a;
+        let a;
+    }
+    expect_stdout: ReferenceError("a is not defined")
+    node_version: ">=4"
+}

test/compress/max_line_len.js

@@ -37,6 +37,51 @@ just_enough: {
     expect_warnings: []
 }
 
+drop_semicolon: {
+    beautify = {
+        max_line_len: 5,
+        semicolons: true,
+    }
+    input: {
+        var a;
+        console.log(a || 42);
+    }
+    expect_exact: [
+        "var a",
+        "console.log(",
+        "a||42",
+        ");",
+    ]
+    expect_stdout: "42"
+    expect_warnings: [
+        "WARN: Output exceeds 5 characters",
+    ]
+}
+
+template_newline: {
+    beautify = {
+        max_line_len: 2,
+    }
+    input: {
+        console.log(`foo
+bar`);
+    }
+    expect_exact: [
+        "console.log(",
+        "`foo",
+        "bar`",
+        ");",
+    ]
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+    expect_warnings: [
+        "WARN: Output exceeds 2 characters",
+    ]
+    node_version: ">=4"
+}
+
 issue_304: {
     beautify = {
         max_line_len: 10,

test/compress/merge_vars.js

@@ -169,6 +169,158 @@ conditional_branch: {
     expect_stdout: "PASS"
 }
 
+conditional_chain_1: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a, b) {
+            var c, d;
+            if (a && (c = a))
+                console.log(c);
+            else
+                b || (d = b) ? console.log("foo") : console.log(d);
+        }
+        f("", null);
+        f("", true);
+        f(42, null);
+        f(42, true);
+    }
+    expect: {
+        function f(a, b) {
+            var a, a;
+            if (a && (a = a))
+                console.log(a);
+            else
+                b || (a = b) ? console.log("foo") : console.log(a);
+        }
+        f("", null);
+        f("", true);
+        f(42, null);
+        f(42, true);
+    }
+    expect_stdout: [
+        "null",
+        "foo",
+        "42",
+        "42",
+    ]
+}
+
+conditional_chain_2: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a, b) {
+            var c, d;
+            if (a && (c = a))
+                console.log(c);
+            else
+                b || (d = b) ? console.log(c) : console.log(d);
+        }
+        f("", null);
+        f("", true);
+        f(42, null);
+        f(42, true);
+    }
+    expect: {
+        function f(a, b) {
+            var c, a;
+            if (a && (c = a))
+                console.log(c);
+            else
+                b || (a = b) ? console.log(c) : console.log(a);
+        }
+        f("", null);
+        f("", true);
+        f(42, null);
+        f(42, true);
+    }
+    expect_stdout: [
+        "null",
+        "undefined",
+        "42",
+        "42",
+    ]
+}
+
+conditional_chain_3: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a, b) {
+            var c, d;
+            if (a && (c = a) || b || (d = b))
+                console.log(c);
+            else
+                console.log(d);
+        }
+        f("", null);
+        f("", true);
+        f(42, null);
+        f(42, true);
+    }
+    expect: {
+        function f(a, b) {
+            var c, a;
+            if (a && (c = a) || b || (a = b))
+                console.log(c);
+            else
+                console.log(a);
+        }
+        f("", null);
+        f("", true);
+        f(42, null);
+        f(42, true);
+    }
+    expect_stdout: [
+        "null",
+        "undefined",
+        "42",
+        "42",
+    ]
+}
+
+conditional_chain_4: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        function f(a, b) {
+            var c, d;
+            if (a && b ? c = a : d = b)
+                console.log(c);
+            else
+                console.log(d);
+        }
+        f("", null);
+        f("", true);
+        f(42, null);
+        f(42, true);
+    }
+    expect: {
+        function f(a, b) {
+            var c, d;
+            if (a && b ? c = a : d = b)
+                console.log(c);
+            else
+                console.log(d);
+        }
+        f("", null);
+        f("", true);
+        f(42, null);
+        f(42, true);
+    }
+    expect_stdout: [
+        "null",
+        "undefined",
+        "null",
+        "42",
+    ]
+}
+
 if_branch: {
     options = {
         merge_vars: true,
@@ -253,6 +405,7 @@ read_before_assign_1: {
         inline: true,
         merge_vars: true,
         sequences: true,
+        side_effects: true,
         toplevel: true,
     }
     input: {
@@ -3549,3 +3702,33 @@ issue_5182: {
     ]
     node_version: ">=4"
 }
+
+issue_5420: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        do {
+            var a = "FAIL 1";
+            a && a.p;
+            a = "FAIL 2";
+            try {
+                continue;
+            } catch (e) {}
+            var b = "FAIL 3";
+        } while (console.log(b || "PASS"));
+    }
+    expect: {
+        do {
+            var a = "FAIL 1";
+            a && a.p;
+            a = "FAIL 2";
+            try {
+                continue;
+            } catch (e) {}
+            var b = "FAIL 3";
+        } while (console.log(b || "PASS"));
+    }
+    expect_stdout: "PASS"
+}

test/compress/negate-iife.js

@@ -122,13 +122,41 @@ negate_iife_4: {
         sequences: true,
     }
     input: {
-        (function(){ return t })() ? console.log(true) : console.log(false);
-        (function(){
+        (function() {
+            return t;
+        })() ? console.log(true) : console.log(false);
+        (function() {
             console.log("something");
         })();
     }
     expect: {
-        !function(){ return t }() ? console.log(false) : console.log(true), function(){
+        !function() {
+            return t;
+        }() ? console.log(false) : console.log(true), !function() {
+            console.log("something");
+        }();
+    }
+}
+
+negate_iife_4_drop_side_effect_free: {
+    options = {
+        conditionals: true,
+        negate_iife: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        (function() {
+            return t;
+        })() ? console.log(true) : console.log(false);
+        (function() {
+            console.log("something");
+        })();
+    }
+    expect: {
+        !function() {
+            return t;
+        }() ? console.log(false) : console.log(true), function() {
             console.log("something");
         }();
     }
@@ -176,17 +204,49 @@ negate_iife_5: {
         sequences: true,
     }
     input: {
-        if ((function(){ return t })()) {
+        if (function() {
+            return t;
+        }()) {
             foo(true);
         } else {
             bar(false);
         }
-        (function(){
+        (function() {
             console.log("something");
         })();
     }
     expect: {
-        !function(){ return t }() ? bar(false) : foo(true), function(){
+        !function() {
+            return t;
+        }() ? bar(false) : foo(true), !function() {
+            console.log("something");
+        }();
+    }
+}
+
+negate_iife_5_drop_side_effect_free: {
+    options = {
+        conditionals: true,
+        negate_iife: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        if (function() {
+            return t;
+        }()) {
+            foo(true);
+        } else {
+            bar(false);
+        }
+        (function() {
+            console.log("something");
+        })();
+    }
+    expect: {
+        !function() {
+            return t;
+        }() ? bar(false) : foo(true), function() {
             console.log("something");
         }();
     }

test/compress/numbers.js

@@ -842,9 +842,9 @@ unary_binary_parentheses: {
         v.forEach(function(x) {
             v.forEach(function(y) {
                 console.log(
-                    +x*y,
-                    +x/y,
-                    +x%y,
+                    x*y,
+                    x/y,
+                    x%y,
                     -x*y,
                     -x/y,
                     -x%y
@@ -1397,7 +1397,7 @@ issue_3695: {
     }
     expect: {
         var a = [];
-        console.log(+(a * (a[0] = false)));
+        console.log(a * (a[0] = false));
     }
     expect_stdout: "NaN"
 }

test/compress/preserve_line.js

@@ -97,10 +97,10 @@ return_5: {
     }
     expect_exact: [
         "_is_selected=function(tags,slug){",
-        "var ref",
+        "var ref;",
         "",
         "",
-        ";return null!=(ref=_.find(tags,{slug:slug}))?ref.selected:void 0};",
+        "return null!=(ref=_.find(tags,{slug:slug}))?ref.selected:void 0};",
     ]
 }
 
@@ -146,10 +146,10 @@ return_7: {
     }
     expect_exact: [
         "_is_selected=function(e,l){",
-        "var n",
+        "var n;",
         "",
         "",
-        ";return null!=(n=_.find(e,{slug:l}))?n.selected:void 0};",
+        "return null!=(n=_.find(e,{slug:l}))?n.selected:void 0};",
     ]
 }
 

test/compress/pure_getters.js

@@ -1289,6 +1289,7 @@ issue_2878: {
         collapse_vars: true,
         pure_getters: true,
         sequences: true,
+        side_effects: true,
     }
     input: {
         var c = 0;

test/compress/reduce_vars.js

@@ -6,6 +6,7 @@ reduce_vars: {
             C: 0,
         },
         inline: true,
+        passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
         toplevel: true,
@@ -6688,8 +6689,7 @@ issues_3267_1: {
     }
     expect: {
         !function(x) {
-            var i = Object();
-            if (i)
+            if (Object())
                 return console.log("PASS");
             throw "FAIL";
         }();
@@ -7832,3 +7832,67 @@ issue_5055_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_5324: {
+    options = {
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        A = 0;
+        do {
+            var a, b = A;
+            for (a in b)
+                var c = b;
+        } while (function() {
+            var d;
+            console.log(d *= A);
+        }());
+    }
+    expect: {
+        A = 0;
+        do {
+            var a, b = A;
+            for (a in b);
+        } while (b = void 0, void console.log(b *= A));
+    }
+    expect_stdout: "NaN"
+}
+
+issue_5434: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            for (var i = 0; i < 2; i++) {
+                var b = "FAIL";
+                f && f();
+                a = b;
+                var f = function() {
+                    b = "PASS";
+                };
+            }
+            return a;
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            for (var i = 0; i < 2; i++) {
+                var b = "FAIL";
+                f && f();
+                a = b;
+                var f = function() {
+                    b = "PASS";
+                };
+            }
+            return a;
+        }());
+    }
+    expect_stdout: "PASS"
+}

test/compress/rests.js

@@ -349,6 +349,7 @@ retain_funarg_destructured_object_1: {
 
 retain_funarg_destructured_object_2: {
     options = {
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1048,7 +1049,9 @@ issue_5100_1: {
             p: {},
             ...a
         } = [ {
-            p: [ a = 42["q"] ],
+            p: {
+                q: a,
+            } = 42,
             r: "PASS",
         } ][0]);
         console.log(a.r);
@@ -1081,7 +1084,9 @@ issue_5100_2: {
             p: {},
             ...a
         } = [ {
-            p: [ console.log("PASS"), a = 42["q"] ],
+            p: (console.log("PASS"), {
+                q: a,
+            } = 42),
         } ][0]);
     }
     expect_stdout: "PASS"
@@ -1091,6 +1096,7 @@ issue_5100_2: {
 issue_5108: {
     options = {
         evaluate: true,
+        keep_fargs: false,
         reduce_vars: true,
         rests: true,
         unsafe: true,
@@ -1102,9 +1108,7 @@ issue_5108: {
         }([ "PASS", "FAIL" ]));
     }
     expect: {
-        console.log(function([]) {
-            return "PASS";
-        }([]));
+        console.log("PASS");
     }
     expect_stdout: "PASS"
     node_version: ">=6"
@@ -1208,6 +1212,7 @@ issue_5165_2: {
 
 issue_5246_1: {
     options = {
+        keep_fargs: false,
         reduce_vars: true,
         rests: true,
         unused: true,
@@ -1218,9 +1223,9 @@ issue_5246_1: {
         }([ , function(){} ])[0]);
     }
     expect: {
-        console.log(typeof function([]) {
+        console.log(typeof function() {
             return this && [ function(){} ];
-        }([])[0]);
+        }()[0]);
     }
     expect_stdout: "function"
     node_version: ">=6"
@@ -1228,6 +1233,7 @@ issue_5246_1: {
 
 issue_5246_2: {
     options = {
+        keep_fargs: false,
         reduce_vars: true,
         rests: true,
         toplevel: true,
@@ -1249,6 +1255,7 @@ issue_5246_2: {
 
 issue_5246_3: {
     options = {
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1264,3 +1271,95 @@ issue_5246_3: {
     expect_stdout: "PASS"
     node_version: ">=6"
 }
+
+issue_5360: {
+    options = {
+        keep_fargs: false,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        var a;
+        console.log(function({ p: {}, ...b }) {
+            return b.q;
+        }({
+            p: ~a && ([ a ] = []),
+            q: "PASS",
+        }));
+    }
+    expect: {
+        var a;
+        console.log(function({ p: {}, ...b }) {
+            return b.q;
+        }({
+            p: ~a && ([ a ] = []),
+            q: "PASS",
+        }));
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8.3.0"
+}
+
+issue_5370: {
+    options = {
+        dead_code: true,
+        ie: true,
+        unused: true,
+    }
+    input: {
+        console.log(function arguments(...a) {
+            return arguments;
+            try {} catch (e) {
+                var arguments;
+            }
+        }());
+    }
+    expect: {
+        console.log(function arguments(...a) {
+            return arguments;
+            var arguments;
+        }());
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+issue_5391: {
+    options = {
+        evaluate: true,
+        keep_fargs: false,
+        objects: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a, b = function f({
+            p: {},
+            ...c
+        }) {
+            while (c.q);
+        }({
+            p: {
+                r: a++,
+                r: 0,
+            }
+        });
+        console.log(a);
+    }
+    expect: {
+        (function({
+            p: {},
+            ...c
+        }) {
+            while (c.q);
+        })({
+            p: 0,
+        });
+        console.log(NaN);
+    }
+    expect_stdout: "NaN"
+    node_version: ">=8.3.0"
+}

test/compress/sequences.js

@@ -289,8 +289,34 @@ iife: {
         typeof function g() {}();
     }
     expect: {
-        x = 42, function a() {}(), function b() {}(), function c() {}(),
-        function d() {}(), function e() {}(), function f() {}(), function g() {}();
+        x = 42,
+        function a() {}(),
+        !function b() {}(),
+        ~function c() {}(),
+        +function d() {}(),
+        -function e() {}(),
+        void function f() {}(),
+        typeof function g() {}();
+    }
+}
+
+iife_drop_side_effect_free: {
+    options = {
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        x = 42;
+        (function a() {})();
+        !function b() {}();
+        ~function c() {}();
+        +function d() {}();
+        -function e() {}();
+        void function f() {}();
+        typeof function g() {}();
+    }
+    expect: {
+        x = 42;
     }
 }
 
@@ -1045,11 +1071,102 @@ call: {
         b.c = function() {
             console.log(this === b ? "bar" : "baz");
         },
+        a,
         b(),
+        a,
         b.c(),
         (a, b.c)(),
+        a,
         b["c"](),
         (a, b["c"])(),
+        a,
+        function() {
+            console.log(this === a);
+        }(),
+        a,
+        new b(),
+        a,
+        new b.c(),
+        a,
+        new b.c(),
+        a,
+        new b["c"](),
+        a,
+        new b["c"](),
+        a,
+        new function() {
+            console.log(this === a);
+        }(),
+        console.log((a, typeof b.c)),
+        console.log((a, typeof b["c"]));
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+        "bar",
+        "baz",
+        "true",
+        "foo",
+        "baz",
+        "baz",
+        "baz",
+        "baz",
+        "false",
+        "function",
+        "function",
+    ]
+}
+
+call_drop_side_effect_free: {
+    options = {
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = function() {
+            return this;
+        }();
+        function b() {
+            console.log("foo");
+        }
+        b.c = function() {
+            console.log(this === b ? "bar" : "baz");
+        };
+        (a, b)();
+        (a, b).c();
+        (a, b.c)();
+        (a, b)["c"]();
+        (a, b["c"])();
+        (a, function() {
+            console.log(this === a);
+        })();
+        new (a, b)();
+        new (a, b).c();
+        new (a, b.c)();
+        new (a, b)["c"]();
+        new (a, b["c"])();
+        new (a, function() {
+            console.log(this === a);
+        })();
+        console.log(typeof (a, b).c);
+        console.log(typeof (a, b)["c"]);
+    }
+    expect: {
+        var a = function() {
+            return this;
+        }();
+        function b() {
+            console.log("foo");
+        }
+        b.c = function() {
+            console.log(this === b ? "bar" : "baz");
+        },
+        b(),
+        b.c(),
+        (0, b.c)(),
+        b["c"](),
+        (0, b["c"])(),
         function() {
             console.log(this === a);
         }(),
@@ -1061,8 +1178,8 @@ call: {
         new function() {
             console.log(this === a);
         }(),
-        console.log((a, typeof b.c)),
-        console.log((a, typeof b["c"]));
+        console.log(typeof b.c),
+        console.log(typeof b["c"]);
     }
     expect_stdout: [
         "foo",
@@ -1097,6 +1214,26 @@ missing_link: {
     expect: {
         var a = 100;
         a,
+        a++ + (0, 1),
+        console.log(a);
+    }
+}
+
+missing_link_drop_side_effect_free: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100;
+        a;
+        a++ + (0 ? 2 : 1);
+        console.log(a);
+    }
+    expect: {
+        var a = 100;
         a++,
         console.log(a);
     }
@@ -1192,7 +1329,7 @@ issue_3490_2: {
     expect: {
         var b = 42, c = "FAIL";
         var a;
-        for (c = "PASS", b; "" == typeof d;);
+        for (c = "PASS"; "" == typeof d;);
         console.log(c, b);
     }
     expect_stdout: "PASS 42"

test/compress/side_effects.js

@@ -617,7 +617,7 @@ issue_4730_2: {
     }
     expect: {
         var a;
-        !console.log("PASS") || a && a[a.p];
+        console.log("PASS") && a && a[a.p];
     }
     expect_stdout: "PASS"
 }

test/compress/spreads.js

@@ -1166,3 +1166,31 @@ issue_5006: {
     expect_stdout: "PASS"
     node_version: ">=6"
 }
+
+issue_5382: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        ({
+            f() {
+                ({ ...this });
+            },
+            get p() {
+                console.log("PASS");
+            },
+        }).f();
+    }
+    expect: {
+        ({
+            f() {
+                ({ ...this });
+            },
+            get p() {
+                console.log("PASS");
+            },
+        }).f();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=8.3.0"
+}

test/compress/typeof.js

@@ -307,7 +307,7 @@ typeof_defined_1: {
     }
     expect: {
         "undefined" == typeof A && A;
-        "undefined" != typeof A || A;
+        "undefined" == typeof A && A;
     }
 }
 
@@ -324,7 +324,7 @@ typeof_defined_2: {
     }
     expect: {
         "function" != typeof A && A;
-        "function" == typeof A || A;
+        "function" != typeof A && A;
     }
 }
 
@@ -355,16 +355,19 @@ typeof_defined_3: {
         "undefined" == typeof A && "undefined" == typeof B && (A, B);
         "undefined" == typeof A && "undefined" != typeof B && A;
         "undefined" != typeof A && "undefined" == typeof B && B;
+        // dropped
         "undefined" == typeof A && "undefined" == typeof B || (A, B);
         "undefined" == typeof A && "undefined" != typeof B || (A, B);
         "undefined" != typeof A && "undefined" == typeof B || (A, B);
         "undefined" != typeof A && "undefined" != typeof B || (A, B);
-        "undefined" == typeof A || "undefined" == typeof B && B;
-        "undefined" != typeof A || "undefined" == typeof B && (A, B);
-        "undefined" != typeof A || "undefined" != typeof B && A;
-        "undefined" == typeof A || "undefined" != typeof B || B;
-        "undefined" != typeof A || "undefined" == typeof B || A;
-        "undefined" != typeof A || "undefined" != typeof B || (A, B);
+        "undefined" != typeof A && "undefined" == typeof B && B;
+        // dropped
+        "undefined" == typeof A && "undefined" == typeof B && (A, B);
+        "undefined" == typeof A && "undefined" != typeof B && A;
+        // dropped
+        "undefined" != typeof A && "undefined" == typeof B && B;
+        "undefined" == typeof A && "undefined" != typeof B && A;
+        "undefined" == typeof A && "undefined" == typeof B && (A, B);
     }
 }
 
@@ -392,6 +395,7 @@ typeof_defined_4: {
         "object" != typeof A || "object" != typeof B || (A, B);
     }
     expect: {
+        // dropped
         "object" == typeof A && "object" != typeof B && B;
         "object" != typeof A && "object" == typeof B && A;
         "object" != typeof A && "object" != typeof B && (A, B);
@@ -399,12 +403,14 @@ typeof_defined_4: {
         "object" == typeof A && "object" != typeof B || (A, B);
         "object" != typeof A && "object" == typeof B || (A, B);
         "object" != typeof A && "object" != typeof B || (A, B);
-        "object" == typeof A || "object" == typeof B && A;
-        "object" == typeof A || "object" != typeof B && (A, B);
-        "object" != typeof A || "object" != typeof B && B;
-        "object" == typeof A || "object" == typeof B || (A, B);
-        "object" == typeof A || "object" != typeof B || A;
-        "object" != typeof A || "object" == typeof B || B;
+        "object" != typeof A && "object" == typeof B && A;
+        "object" != typeof A && "object" != typeof B && (A, B);
+        // dropped
+        "object" == typeof A && "object" != typeof B && B;
+        "object" != typeof A && "object" != typeof B && (A, B);
+        "object" != typeof A && "object" == typeof B && A;
+        "object" == typeof A && "object" != typeof B && B;
+        // dropped
     }
 }
 

test/compress/yields.js

@@ -1375,6 +1375,7 @@ issue_5076_1: {
     options = {
         evaluate: true,
         hoist_vars: true,
+        keep_fargs: false,
         pure_getters: "strict",
         sequences: true,
         side_effects: true,
@@ -1404,6 +1405,7 @@ issue_5076_2: {
     options = {
         evaluate: true,
         hoist_vars: true,
+        keep_fargs: false,
         passes: 2,
         pure_getters: "strict",
         sequences: true,
@@ -1449,3 +1451,99 @@ issue_5177: {
     expect_stdout: "function"
     node_version: ">=4"
 }
+
+issue_5385_1: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (async function*() {
+            (function() {
+                try {
+                    return console.log("foo");
+                } finally {
+                    return console.log("bar");
+                }
+                console.log("baz");
+            })();
+        })().next();
+        console.log("moo");
+    }
+    expect: {
+        (async function*() {
+            (function() {
+                try {
+                    return console.log("foo");
+                } finally {
+                    return console.log("bar");
+                }
+                console.log("baz");
+            })();
+        })().next();
+        console.log("moo");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "moo",
+    ]
+    node_version: ">=10"
+}
+
+issue_5385_2: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (async function*() {
+            return function() {
+                try {
+                    return console.log("foo");
+                } finally {
+                    return console.log("bar");
+                }
+            }();
+        })().next();
+        console.log("moo");
+    }
+    expect: {
+        (async function*() {
+            return function() {
+                try {
+                    return console.log("foo");
+                } finally {
+                    return console.log("bar");
+                }
+            }();
+        })().next();
+        console.log("moo");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "moo",
+    ]
+    node_version: ">=10"
+}
+
+issue_5425: {
+    options = {
+        assignments: true,
+        ie: true,
+        toplevel: true,
+        unused: true,
+        yields: true,
+    }
+    input: {
+        var a = "FAIL";
+        var b = function* f() {}(a ? a = "PASS" : 42);
+        console.log(a, typeof f);
+    }
+    expect: {
+        var a = "FAIL";
+        (function* f() {})(a && (a = "PASS"));
+        console.log(a, typeof f);
+    }
+    expect_stdout: "PASS undefined"
+    node_version: ">=4"
+}

test/input/issue-505/output.js

@@ -1,5 +1,5 @@
 function test(a){
-"aaaaaaaaaaaaaaaa"
-;a(err,data),a(err,
+"aaaaaaaaaaaaaaaa";
+a(err,data),a(err,
 data)}
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsidGVzdCIsImNhbGxiYWNrIiwiZXJyIiwiZGF0YSJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0EsS0FBS0M7O0NBRVZBLEVBQVNDLElBQUtDLE1BQ2RGLEVBQVNDO0FBQUtDIn0=
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsidGVzdCIsImNhbGxiYWNrIiwiZXJyIiwiZGF0YSJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0E7SEFBS0M7QUFFVkE7aEJBQVNDLElBQUtDLE1BQ2RGLEVBQVNDLElBQUtDIn0=

test/input/reduce/export_default.js

@@ -0,0 +1,17 @@
+var unused;
+export default class {
+    ____11111() {
+        a, b, c, d, e;
+        f, g, h, i, j;
+        k, l, m, n, o;
+        p, q, r, s, t;
+        u, v, w, x, y, z;
+        A, B, C, D, E;
+        F, G, H, I, J;
+        K, L, M, N, O;
+        P, Q, R, S, T;
+        U, V, W, X, Y, Z;
+        $, _;
+        unused;
+    }
+}

test/mocha/awaits.js

@@ -7,7 +7,7 @@ describe("async", function() {
             "function await() {}",
             "function(await) {}",
             "function() { await; }",
-            "function() { await:{} }",
+            "function() { await: {} }",
             "function() { var await; }",
             "function() { function await() {} }",
             "function() { try {} catch (await) {} }",

test/mocha/reduce.js

@@ -434,4 +434,55 @@ describe("test/reduce.js", function() {
             "// }",
         ].join("\n"));
     });
+    it("Should transform `export default class` correctly", function() {
+        var result = reduce_test(read("test/input/reduce/export_default.js"), {
+            compress: false,
+            toplevel: true,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "// Can't reproduce test failure",
+            "// minify options: {",
+            '//   "compress": false,',
+            '//   "toplevel": true',
+            "// }",
+        ].join("\n"));
+    });
+    it("Should transform `export default function` correctly", function() {
+        var code = [
+            "for (var k in this)",
+            "    console.log(k);",
+            "export default (function f() {});",
+            "console.log(k);",
+        ].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 (42)` correctly", function() {
+        var code = [
+            "export default (42);",
+            "for (var k in this)",
+            "    console.log(k);",
+        ].join("\n");
+        var result = reduce_test(code, {
+            compress: false,
+            mangle: false,
+        });
+        if (result.error) throw result.error;
+        assert.strictEqual(result.code, [
+            "// Can't reproduce test failure",
+            "// minify options: {",
+            '//   "compress": false,',
+            '//   "mangle": false',
+            "// }",
+        ].join("\n"));
+    });
 });

test/mocha/yields.js

@@ -6,7 +6,7 @@ describe("generator", function() {
         [
             "function yield() {}",
             "function(yield) {}",
-            "function() { yield:{} }",
+            "function() { yield: {} }",
             "function() { var yield; }",
             "function() { function yield() {} }",
             "function() { try {} catch (yield) {} }",

test/sandbox.js

@@ -52,11 +52,19 @@ exports.same_stdout = semver.satisfies(process.version, "0.12") ? function(expec
     return typeof expected == typeof actual && strip_func_ids(expected) == strip_func_ids(actual);
 };
 exports.patch_module_statements = function(code) {
-    var count = 0, imports = [];
-    code = code.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) {
+    var count = 0, has_default = "", imports = [], strict_mode = "";
+    code = code.replace(/^\s*("|')use strict\1\s*;?/, function(match) {
+        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 (!header) return "";
         if (header.length == 1) return "0, " + header;
-        return header.slice(0, -1) + " _" + ++count + header.slice(-1);
+        var name = "_uglify_export_default_";
+        if (/^class\b/.test(header)) do {
+            name = "_uglify_export_default_" + ++count;
+        } while (code.indexOf(name) >= 0);
+        return header.slice(0, -1) + " " + name + header.slice(-1);
     }).replace(/\bimport\.meta\b/g, function() {
         return '({ url: "https://example.com/path/index.html" })';
     }).replace(/\bimport\b(?:\s*([^\s('"][^('"]*)\bfrom\b)?\s*(['"]).*?\2(?:$|\n|;)/g, function(match, symbols) {
@@ -73,7 +81,7 @@ exports.patch_module_statements = function(code) {
         return "";
     });
     imports.push("");
-    return imports.join("\n") + code;
+    return strict_mode + has_default + imports.join("\n") + code;
 };
 
 function is_error(result) {

test/ufuzz/index.js

@@ -128,7 +128,7 @@ for (var i = 2; i < process.argv.length; ++i) {
 
 var SUPPORT = function(matrix) {
     for (var name in matrix) {
-        matrix[name] = typeof sandbox.run_code(matrix[name]) == "string";
+        matrix[name] = !sandbox.is_error(sandbox.run_code(matrix[name]));
     }
     return matrix;
 }({
@@ -1824,7 +1824,13 @@ function createClassLiteral(recurmax, stmtDepth, canThrow, name) {
             declared.push(internal);
         }
         if (SUPPORT.class_field && rng(2)) {
-            s += internal || createObjectKey(recurmax, stmtDepth, canThrow);
+            if (internal) {
+                s += internal;
+            } else if (fixed && bug_static_class_field) {
+                s += getDotKey();
+            } else {
+                s += createObjectKey(recurmax, stmtDepth, canThrow);
+            }
             if (rng(5)) {
                 async = bug_async_class_await && fixed && 0;
                 generator = false;
@@ -2110,7 +2116,7 @@ function try_beautify(code, toplevel, result, printfn, options) {
     } else if (options) {
         var uglified = UglifyJS.minify(beautified.code, JSON.parse(options));
         var expected, actual;
-        if (typeof uglify_code != "string" || uglified.error) {
+        if (sandbox.is_error(uglify_code) || uglified.error) {
             expected = uglify_code;
             actual = uglified.error;
         } else {
@@ -2139,7 +2145,7 @@ function log_suspects(minify_options, component) {
     var defs = default_options[component];
     var toplevel = sandbox.has_toplevel(minify_options);
     var suspects = Object.keys(defs).filter(function(name) {
-        var flip = name == "keep_fargs";
+        var flip = component == "compress" && name == "keep_fargs";
         if (flip !== (name in options ? options : defs)[name]) {
             var m = JSON.parse(JSON.stringify(minify_options));
             var o = JSON.parse(JSON.stringify(options));
@@ -2147,7 +2153,7 @@ function log_suspects(minify_options, component) {
             m[component] = o;
             m.validate = true;
             var result = UglifyJS.minify(original_code, m);
-            if (typeof uglify_code != "string") {
+            if (sandbox.is_error(uglify_code)) {
                 return !sandbox.same_stdout(uglify_code, result.error);
             } else if (result.error) {
                 errorln("Error testing options." + component + "." + name);
@@ -2175,7 +2181,7 @@ function log_suspects_global(options, toplevel) {
         m[component] = false;
         m.validate = true;
         var result = UglifyJS.minify(original_code, m);
-        if (typeof uglify_code != "string") {
+        if (sandbox.is_error(uglify_code)) {
             return !sandbox.same_stdout(uglify_code, result.error);
         } else if (result.error) {
             errorln("Error testing options." + component);
@@ -2204,7 +2210,16 @@ function log(options) {
     errorln();
     errorln();
     errorln("//-------------------------------------------------------------");
-    if (typeof uglify_code == "string") {
+    if (sandbox.is_error(uglify_code)) {
+        errorln("// !!! uglify failed !!!");
+        errorln(uglify_code);
+        if (original_erred) {
+            errorln();
+            errorln();
+            errorln("original stacktrace:");
+            errorln(original_result);
+        }
+    } else {
         errorln("// uglified code");
         try_beautify(uglify_code, toplevel, uglify_result, errorln);
         errorln();
@@ -2213,15 +2228,6 @@ function log(options) {
         errorln(original_result);
         errorln("uglified result:");
         errorln(uglify_result);
-    } else {
-        errorln("// !!! uglify failed !!!");
-        errorln(uglify_code);
-        if (errored) {
-            errorln();
-            errorln();
-            errorln("original stacktrace:");
-            errorln(original_result);
-        }
     }
     errorln("//-------------------------------------------------------------");
     if (!ok) {
@@ -2426,22 +2432,23 @@ var beautify_options = {
     },
 };
 var minify_options = require("./options.json");
-if (typeof sandbox.run_code("A:if (0) B:; else B:;") != "string") {
+if (sandbox.is_error(sandbox.run_code("A:if (0) B:; else B:;"))) {
     minify_options.forEach(function(o) {
         if (!("mangle" in o)) o.mangle = {};
         if (o.mangle) o.mangle.v8 = true;
     });
 }
 var bug_async_arrow_rest = function() {};
-if (SUPPORT.arrow && SUPPORT.async && SUPPORT.rest && typeof sandbox.run_code("async (a = f(...[], b)) => 0;") != "string") {
+if (SUPPORT.arrow && SUPPORT.async && SUPPORT.rest && sandbox.is_error(sandbox.run_code("async (a = f(...[], b)) => 0;"))) {
     bug_async_arrow_rest = function(ex) {
         return ex.name == "SyntaxError" && ex.message == "Rest parameter must be last formal parameter";
     };
 }
-var bug_async_class_await = SUPPORT.async && SUPPORT.class_field && typeof sandbox.run_code("var await; async function f() { class A { static p = await; } }") != "string";
-var bug_for_of_async = SUPPORT.for_await_of && typeof sandbox.run_code("var async; for (async of []);") != "string";
-var bug_for_of_var = SUPPORT.for_of && SUPPORT.let && typeof sandbox.run_code("try {} catch (e) { for (var e of []); }") != "string";
-if (SUPPORT.destructuring && typeof sandbox.run_code("console.log([ 1 ], {} = 2);") != "string") {
+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_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() {} }"));
+if (SUPPORT.destructuring && sandbox.is_error(sandbox.run_code("console.log([ 1 ], {} = 2);"))) {
     beautify_options.output.v8 = true;
     minify_options.forEach(function(o) {
         if (!("output" in o)) o.output = {};
@@ -2450,7 +2457,7 @@ if (SUPPORT.destructuring && typeof sandbox.run_code("console.log([ 1 ], {} = 2)
 }
 beautify_options = JSON.stringify(beautify_options);
 minify_options = minify_options.map(JSON.stringify);
-var original_code, original_result, errored;
+var original_code, original_result, original_erred;
 var uglify_code, uglify_result, ok;
 for (var round = 1; round <= num_iterations; round++) {
     process.stdout.write(round + " of " + num_iterations + "\r");
@@ -2458,7 +2465,7 @@ for (var round = 1; round <= num_iterations; round++) {
     original_code = createTopLevelCode();
     var orig_result = [ run_code(original_code), run_code(original_code, true) ];
     if (orig_result.some(function(result, toplevel) {
-        if (typeof result == "string") return;
+        if (!sandbox.is_error(result)) return;
         println();
         println();
         println("//=============================================================");
@@ -2480,35 +2487,44 @@ for (var round = 1; round <= num_iterations; round++) {
         o.validate = true;
         uglify_code = UglifyJS.minify(original_code, o);
         original_result = orig_result[toplevel ? 1 : 0];
-        errored = typeof original_result != "string";
+        original_erred = sandbox.is_error(original_result);
         if (!uglify_code.error) {
             uglify_code = uglify_code.code;
             uglify_result = run_code(uglify_code, toplevel);
             ok = sandbox.same_stdout(original_result, uglify_result);
+            var uglify_erred = sandbox.is_error(uglify_result);
             // ignore v8 parser bug
-            if (!ok && bug_async_arrow_rest(uglify_result)) ok = true;
+            if (!ok && uglify_erred && bug_async_arrow_rest(uglify_result)) ok = true;
             // ignore runtime platform bugs
-            if (!ok && uglify_result.message == "Script execution aborted.") ok = true;
+            if (!ok && uglify_erred && uglify_result.message == "Script execution aborted.") ok = true;
             // handle difference caused by time-outs
-            if (!ok && errored && is_error_timeout(original_result)) {
-                if (is_error_timeout(uglify_result)) {
-                    // ignore difference in error message
-                    ok = true;
-                } else {
+            if (!ok) {
+                if (original_erred && is_error_timeout(original_result)) {
+                    if (uglify_erred && is_error_timeout(uglify_result)) {
+                        // ignore difference in error message
+                        ok = true;
+                    } else {
+                        // ignore spurious time-outs
+                        if (!orig_result[toplevel ? 3 : 2]) orig_result[toplevel ? 3 : 2] = run_code(original_code, toplevel, 10000);
+                        ok = sandbox.same_stdout(orig_result[toplevel ? 3 : 2], uglify_result);
+                    }
+                } else if (uglify_erred && is_error_timeout(uglify_result)) {
                     // ignore spurious time-outs
-                    if (!orig_result[toplevel ? 3 : 2]) orig_result[toplevel ? 3 : 2] = run_code(original_code, toplevel, 10000);
-                    ok = sandbox.same_stdout(orig_result[toplevel ? 3 : 2], uglify_result);
+                    var waited_result = run_code(uglify_code, toplevel, 10000);
+                    ok = sandbox.same_stdout(original_result, waited_result);
                 }
             }
             // ignore declaration order of global variables
-            if (!ok && !toplevel && uglify_result.name != "SyntaxError" && original_result.name != "SyntaxError") {
-                ok = sandbox.same_stdout(run_code(sort_globals(original_code)), run_code(sort_globals(uglify_code)));
+            if (!ok && !toplevel) {
+                if (!(original_erred && original_result.name == "SyntaxError") && !(uglify_erred && uglify_result.name == "SyntaxError")) {
+                    ok = sandbox.same_stdout(run_code(sort_globals(original_code)), run_code(sort_globals(uglify_code)));
+                }
             }
             // ignore numerical imprecision caused by `unsafe_math`
-            if (!ok && o.compress && o.compress.unsafe_math && typeof original_result == typeof uglify_result) {
-                if (typeof original_result == "string") {
+            if (!ok && o.compress && o.compress.unsafe_math) {
+                if (typeof original_result == "string" && typeof uglify_result == "string") {
                     ok = fuzzy_match(original_result, uglify_result);
-                } else if (sandbox.is_error(original_result)) {
+                } else if (original_erred && uglify_erred) {
                     ok = original_result.name == uglify_result.name && fuzzy_match(original_result.message, uglify_result.message);
                 }
                 if (!ok) {
@@ -2517,19 +2533,19 @@ for (var round = 1; round <= num_iterations; round++) {
                 }
             }
             // ignore difference in error message caused by Temporal Dead Zone
-            if (!ok && errored && uglify_result.name == "ReferenceError" && original_result.name == "ReferenceError") ok = true;
+            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 (/^(Syntax|Type)Error$/.test(uglify_result.name)) {
-                    ok = typeof original_strict != "string";
+                if (uglify_erred && /^(Syntax|Type)Error$/.test(uglify_result.name)) {
+                    ok = sandbox.is_error(original_strict);
                 } else {
                     ok = sandbox.same_stdout(original_strict, uglify_result);
                 }
             }
             // ignore difference in error message caused by `import` symbol redeclaration
-            if (!ok && errored && /\bimport\b/.test(original_code)) {
-                if (is_error_redeclaration(uglify_result) && is_error_redeclaration(original_result)) ok = true;
+            if (!ok && original_erred && uglify_erred && /\bimport\b/.test(original_code)) {
+                if (is_error_redeclaration(original_result) && is_error_redeclaration(uglify_result)) ok = true;
             }
             // ignore difference due to `__proto__` assignment
             if (!ok && /\b__proto__\b/.test(original_code)) {
@@ -2538,24 +2554,32 @@ for (var round = 1; round <= num_iterations; round++) {
                 ok = sandbox.same_stdout(original_proto, uglify_proto);
             }
             // ignore difference in error message caused by `in`
-            if (!ok && errored && is_error_in(uglify_result) && is_error_in(original_result)) ok = true;
+            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 && errored && is_error_spread(uglify_result) && is_error_spread(original_result)) ok = true;
+            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 && errored && is_error_recursion(original_result)) {
-                if (is_error_recursion(uglify_result) || typeof uglify_result == "string") ok = true;
+            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 && errored && is_error_destructuring(uglify_result) && is_error_destructuring(original_result)) {
-                ok = true;
+            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 && errored && is_error_class_constructor(uglify_result) && is_error_class_constructor(original_result)) {
-                ok = true;
+            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 && errored && is_error_getter_only_property(uglify_result) && is_error_getter_only_property(original_result)) {
-                ok = true;
+            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) {
@@ -2567,7 +2591,7 @@ for (var round = 1; round <= num_iterations; round++) {
             }
         } else {
             uglify_code = uglify_code.error;
-            ok = errored && uglify_code.name == original_result.name;
+            ok = original_erred && uglify_code.name == original_result.name;
         }
         if (verbose || (verbose_interval && !(round % INTERVAL_COUNT)) || !ok) log(options);
         if (!ok && isFinite(num_iterations)) {