workaround various IE quirks (#5084)

fixes #5081

Author: alexlamsl

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
       matrix:
         options:
           - '-mb braces'
-          - '--ie8 -c'
+          - '--ie -c'
           - '-mc'
           - '-p acorn --toplevel -mco spidermonkey'
           - '--toplevel -mc passes=3,pure_getters,unsafe'

README.md

@@ -111,8 +111,8 @@ a double dash to prevent input files being used as option arguments:
     -d, --define <expr>[=value] Global definitions.
     -e, --enclose [arg[:value]] Embed everything in a big function, with configurable
                                 argument(s) & value(s).
-    --ie8                       Support non-standard Internet Explorer 8.
-                                Equivalent to setting `ie8: true` in `minify()`
+    --ie                        Support non-standard Internet Explorer.
+                                Equivalent to setting `ie: true` in `minify()`
                                 for `compress`, `mangle` and `output` options.
                                 By default UglifyJS will not try to be IE-proof.
     --keep-fnames               Do not mangle/drop function names.  Useful for
@@ -502,7 +502,7 @@ if (result.error) throw result.error;
 - `compress` (default: `{}`) — pass `false` to skip compressing entirely.
   Pass an object to specify custom [compress options](#compress-options).
 
-- `ie8` (default: `false`) — set to `true` to support IE8.
+- `ie` (default: `false`) — enable workarounds for Internet Explorer bugs.
 
 - `keep_fnames` (default: `false`) — pass `true` to prevent discarding or mangling
   of function names.  Useful for code relying on `Function.prototype.name`.
@@ -566,7 +566,6 @@ if (result.error) throw result.error;
     },
     nameCache: null, // or specify a name cache object
     toplevel: false,
-    ie8: false,
     warnings: false,
 }
 ```
@@ -795,9 +794,8 @@ to be `false` and all symbol names will be omitted.
   variables (`"vars"`) in the top level scope (`false` by default, `true` to drop
   both unreferenced functions and variables)
 
-- `typeofs` (default: `true`) — Transforms `typeof foo == "undefined"` into
-  `foo === void 0`.  Note: recommend to set this value to `false` for IE10 and
-  earlier versions due to known issues.
+- `typeofs` (default: `true`) — compress `typeof` expressions, e.g.
+  `typeof foo == "undefined" → void 0 === foo`
 
 - `unsafe` (default: `false`) — apply "unsafe" transformations (discussion below)
 

bin/uglifyjs

@@ -101,7 +101,7 @@ function process_option(name, no_value) {
                 "  --config-file <file>                     Read minify() options from JSON file.",
                 "  -d, --define <expr>[=value]              Global definitions.",
                 "  -e, --enclose [arg[,...][:value[,...]]]  Embed everything in a big function, with configurable argument(s) & value(s).",
-                "  --ie8                                    Support non-standard Internet Explorer 8.",
+                "  --ie                                     Support non-standard Internet Explorer.",
                 "  --keep-fnames                            Do not mangle/drop function names. Useful for code relying on Function.prototype.name.",
                 "  --name-cache <file>                      File to hold mangled name mappings.",
                 "  --rename                                 Force symbol expansion.",
@@ -110,6 +110,7 @@ function process_option(name, no_value) {
                 "  --source-map [options]                   Enable source map/specify source map options.",
                 "  --timings                                Display operations run time on STDERR.",
                 "  --toplevel                               Compress and/or mangle variables in toplevel scope.",
+                "  --v8                                     Support non-standard Chrome & Node.js.",
                 "  --validate                               Perform validation during AST manipulations.",
                 "  --verbose                                Print diagnostic messages.",
                 "  --warn                                   Print warning messages.",
@@ -145,9 +146,11 @@ function process_option(name, no_value) {
         options[name] = read_value();
         break;
       case "annotations":
+      case "ie":
       case "ie8":
       case "timings":
       case "toplevel":
+      case "v8":
       case "validate":
       case "webkit":
         options[name] = true;

lib/compress.js

@@ -70,7 +70,7 @@ function Compressor(options, false_by_default) {
         hoist_funs      : false,
         hoist_props     : !false_by_default,
         hoist_vars      : false,
-        ie8             : false,
+        ie              : false,
         if_return       : !false_by_default,
         imports         : !false_by_default,
         inline          : !false_by_default,
@@ -206,7 +206,7 @@ merge(Compressor.prototype, {
         var passes = +this.options.passes || 1;
         var min_count = 1 / 0;
         var stopping = false;
-        var mangle = { ie8: this.option("ie8") };
+        var mangle = { ie: this.option("ie") };
         for (var pass = 0; pass < passes; pass++) {
             node.figure_out_scope(mangle);
             if (pass > 0 || this.option("reduce_vars"))
@@ -513,7 +513,7 @@ merge(Compressor.prototype, {
             if (scope.uses_arguments) scope.each_argname(function(node) {
                 node.definition().last_ref = false;
             });
-            if (compressor.option("ie8")) scope.variables.each(function(def) {
+            if (compressor.option("ie")) scope.variables.each(function(def) {
                 var d = def.orig[0].definition();
                 if (d !== def) d.fixed = false;
             });
@@ -2249,7 +2249,7 @@ merge(Compressor.prototype, {
                     return side_effects || lhs instanceof AST_PropAccess || may_modify(lhs);
                 }
                 if (node instanceof AST_Function) {
-                    return compressor.option("ie8") && node.name && lvalues.has(node.name.name);
+                    return compressor.option("ie") && node.name && lvalues.has(node.name.name);
                 }
                 if (node instanceof AST_ObjectIdentity) return symbol_in_lvalues(node, parent);
                 if (node instanceof AST_PropAccess) {
@@ -4208,7 +4208,7 @@ merge(Compressor.prototype, {
 
         AST_Toplevel.DEFMETHOD("resolve_defines", function(compressor) {
             if (!compressor.option("global_defs")) return this;
-            this.figure_out_scope({ ie8: compressor.option("ie8") });
+            this.figure_out_scope({ ie: compressor.option("ie") });
             return this.transform(new TreeTransformer(function(node) {
                 var def = node._find_defs(compressor, "");
                 if (!def) return;
@@ -5672,7 +5672,7 @@ merge(Compressor.prototype, {
             if (node instanceof AST_Call) {
                 var exp = node.expression;
                 var tail = exp.tail_node();
-                if (!(tail instanceof AST_LambdaExpression)) return;
+                if (!(tail instanceof AST_LambdaExpression)) return walk_node_with_expr(node);
                 if (exp !== tail) exp.expressions.slice(0, -1).forEach(function(node) {
                     node.walk(tw);
                 });
@@ -5788,6 +5788,7 @@ merge(Compressor.prototype, {
                 pop();
                 return true;
             }
+            if (node instanceof AST_Sub) return walk_node_with_expr(node);
             if (node instanceof AST_Switch) {
                 node.expression.walk(tw);
                 var save = segment;
@@ -5886,6 +5887,15 @@ merge(Compressor.prototype, {
                 pop();
                 return true;
             }
+
+            function walk_node_with_expr(node) {
+                descend();
+                if (compressor.option("ie")) {
+                    var sym = root_expr(node.expression);
+                    if (sym instanceof AST_SymbolRef) sym.walk(tw);
+                }
+                return true;
+            }
         });
         tw.directives = Object.create(compressor.directives);
         self.walk(tw);
@@ -6235,7 +6245,7 @@ merge(Compressor.prototype, {
         });
         tw.directives = Object.create(compressor.directives);
         self.walk(tw);
-        var drop_fn_name = compressor.option("keep_fnames") ? return_false : compressor.option("ie8") ? function(def) {
+        var drop_fn_name = compressor.option("keep_fnames") ? return_false : compressor.option("ie") ? function(def) {
             return !compressor.exposed(def) && def.references.length == def.replaced;
         } : function(def) {
             if (!(def.id in in_use_ids)) return true;
@@ -6247,7 +6257,7 @@ merge(Compressor.prototype, {
                 return !ref.in_arg;
             });
         };
-        if (compressor.option("ie8")) initializations.each(function(init, id) {
+        if (compressor.option("ie")) initializations.each(function(init, id) {
             if (id in in_use_ids) return;
             init.forEach(function(init) {
                 init.walk(new TreeWalker(function(node) {
@@ -6535,7 +6545,7 @@ merge(Compressor.prototype, {
                                 head.push(def);
                             }
                         } else if (compressor.option("functions")
-                            && !compressor.option("ie8")
+                            && !compressor.option("ie")
                             && drop_sym
                             && var_defs[sym.id] == 1
                             && sym.assignments == 0
@@ -7652,7 +7662,7 @@ merge(Compressor.prototype, {
     });
 
     function fn_name_unused(fn, compressor) {
-        if (!fn.name || !compressor.option("ie8")) return true;
+        if (!fn.name || !compressor.option("ie")) return true;
         var def = fn.name.definition();
         if (compressor.exposed(def)) return false;
         return all(def.references, function(sym) {
@@ -7969,7 +7979,7 @@ merge(Compressor.prototype, {
             var alternative = this.alternative.drop_side_effect_free(compressor);
             if (consequent === this.consequent && alternative === this.alternative) return this;
             var exprs;
-            if (compressor.option("ie8")) {
+            if (compressor.option("ie")) {
                 exprs = [];
                 if (consequent instanceof AST_Function) {
                     exprs.push(consequent);
@@ -7998,7 +8008,7 @@ merge(Compressor.prototype, {
                 node.consequent = consequent;
                 node.alternative = alternative;
             }
-            if (!compressor.option("ie8")) return node;
+            if (!compressor.option("ie")) return node;
             if (node) exprs.push(node);
             return exprs.length == 0 ? null : make_sequence(this, exprs);
         });
@@ -9411,7 +9421,7 @@ merge(Compressor.prototype, {
                         return arg.value;
                     }).join() + "){" + self.args[self.args.length - 1].value + "})";
                     var ast = parse(code);
-                    var mangle = { ie8: compressor.option("ie8") };
+                    var mangle = { ie: compressor.option("ie") };
                     ast.figure_out_scope(mangle);
                     var comp = new Compressor(compressor.options);
                     ast = ast.transform(comp);
@@ -10465,7 +10475,7 @@ merge(Compressor.prototype, {
                 && self.right.operator == "typeof") {
                 var expr = self.right.expression;
                 if (expr instanceof AST_SymbolRef ? expr.is_declared(compressor)
-                    : !(expr instanceof AST_PropAccess && compressor.option("ie8"))) {
+                    : !(expr instanceof AST_PropAccess && compressor.option("ie"))) {
                     self.right = expr;
                     self.left = make_node(AST_Undefined, self.left).optimize(compressor);
                     if (self.operator.length == 2) self.operator += "=";
@@ -11079,7 +11089,7 @@ merge(Compressor.prototype, {
     }
 
     OPT(AST_SymbolRef, function(self, compressor) {
-        if (!compressor.option("ie8")
+        if (!compressor.option("ie")
             && is_undeclared_ref(self)
             // testing against `self.scope.uses_with` is an optimization
             && !(self.scope.resolve().uses_with && compressor.find_parent(AST_With))) {
@@ -11121,7 +11131,7 @@ merge(Compressor.prototype, {
                         single_use = false;
                     } else if (fixed.has_side_effects(compressor)) {
                         single_use = false;
-                    } else if (compressor.option("ie8") && fixed instanceof AST_Class) {
+                    } else if (compressor.option("ie") && fixed instanceof AST_Class) {
                         single_use = false;
                     }
                     if (single_use) fixed.parent_scope = self.scope;

lib/minify.js

@@ -76,6 +76,7 @@ function minify(files, options) {
             annotations: undefined,
             compress: {},
             enclose: false,
+            ie: false,
             ie8: false,
             keep_fnames: false,
             mangle: {},
@@ -96,7 +97,7 @@ function minify(files, options) {
         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) set_shorthand("ie8", options, [ "compress", "mangle", "output" ]);
+        if (options.ie || options.ie8) set_shorthand("ie", options, [ "compress", "mangle", "output" ]);
         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" ]);
@@ -106,7 +107,7 @@ function minify(files, options) {
             options.mangle = defaults(options.mangle, {
                 cache: options.nameCache && (options.nameCache.vars || {}),
                 eval: false,
-                ie8: false,
+                ie: false,
                 keep_fnames: false,
                 properties: false,
                 reserved: [],

lib/output.js

@@ -56,7 +56,7 @@ function OutputStream(options) {
         braces           : false,
         comments         : false,
         galio            : false,
-        ie8              : false,
+        ie               : false,
         indent_level     : 4,
         indent_start     : 0,
         inline_script    : true,
@@ -193,7 +193,7 @@ function OutputStream(options) {
               case "\t": return "\\t";
               case "\b": return "\\b";
               case "\f": return "\\f";
-              case "\x0B": return options.ie8 ? "\\x0B" : "\\v";
+              case "\x0B": return options.ie ? "\\x0B" : "\\v";
               case "\u2028": return "\\u2028";
               case "\u2029": return "\\u2029";
               case "\ufeff": return "\\ufeff";
@@ -1290,7 +1290,7 @@ function OutputStream(options) {
     function make_then(self, output) {
         var b = self.body;
         if (output.option("braces") && !(b instanceof AST_Const || b instanceof AST_Let)
-            || output.option("ie8") && b instanceof AST_Do)
+            || output.option("ie") && b instanceof AST_Do)
             return make_block(b, output);
         // The squeezer replaces "block"-s that contain only a single
         // statement with the statement itself; technically, the AST
@@ -1515,7 +1515,7 @@ function OutputStream(options) {
         var expr = self.expression;
         expr.print(output);
         var prop = self.property;
-        if (output.option("ie8") && RESERVED_WORDS[prop]) {
+        if (output.option("ie") && RESERVED_WORDS[prop]) {
             output.print(self.optional ? "?.[" : "[");
             output.add_mapping(self.end);
             output.print_string(prop);
@@ -1702,7 +1702,7 @@ function OutputStream(options) {
             var quote = self.start && self.start.quote;
             if (self.private) {
                 output.print_name(key);
-            } else if (RESERVED_WORDS[key] ? !output.option("ie8") : is_identifier_string(key)) {
+            } else if (RESERVED_WORDS[key] ? !output.option("ie") : is_identifier_string(key)) {
                 if (quote && output.option("keep_quoted_props")) {
                     output.print_string(key, quote);
                 } else {

lib/scope.js

@@ -118,7 +118,7 @@ function is_lhs(node, parent) {
 AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     options = defaults(options, {
         cache: null,
-        ie8: false,
+        ie: false,
     });
 
     // pass 1: setup scope chaining and handle definitions
@@ -211,7 +211,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             entangle(defun, scope);
         } else if (node instanceof AST_SymbolLambda) {
             var def = defun.def_function(node, node.name == "arguments" ? undefined : defun);
-            if (options.ie8) def.defun = defun.parent_scope.resolve();
+            if (options.ie) def.defun = defun.parent_scope.resolve();
         } else if (node instanceof AST_SymbolLet) {
             var def = scope.def_variable(node);
             if (exported) def.exported = true;
@@ -351,7 +351,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     self.walk(tw);
 
     // pass 3: fix up any scoping issue with IE8
-    if (options.ie8) self.walk(new TreeWalker(function(node) {
+    if (options.ie) self.walk(new TreeWalker(function(node) {
         if (node instanceof AST_SymbolCatch) {
             var scope = node.thedef.defun;
             if (scope.name instanceof AST_SymbolLambda && scope.name.name == node.name) {
@@ -572,7 +572,7 @@ AST_Symbol.DEFMETHOD("definition", function() {
 function _default_mangler_options(options) {
     options = defaults(options, {
         eval        : false,
-        ie8         : false,
+        ie          : false,
         keep_fnames : false,
         reserved    : [],
         toplevel    : false,

test/compress/classes.js

@@ -1157,7 +1157,7 @@ issue_4705: {
 
 issue_4720: {
     options = {
-        ie8: true,
+        ie: true,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -1629,7 +1629,7 @@ issue_4951_2: {
 
 issue_4962_1: {
     options = {
-        ie8: true,
+        ie: true,
         inline: true,
         reduce_vars: true,
         unused: true,
@@ -1656,7 +1656,7 @@ issue_4962_1: {
 
 issue_4962_2: {
     options = {
-        ie8: true,
+        ie: true,
         inline: true,
         reduce_vars: true,
         unused: true,