--- /dev/null
+'use strict';
+// TODO: Remove from `core-js@4` since it's moved to entry points
+require('../modules/es.regexp.exec');
+var redefine = require('../internals/redefine');
+var fails = require('../internals/fails');
+var wellKnownSymbol = require('../internals/well-known-symbol');
+var regexpExec = require('../internals/regexp-exec');
+var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
+
+var SPECIES = wellKnownSymbol('species');
+
+var REPLACE_SUPPORTS_NAMED_GROUPS = !fails(function () {
+ // #replace needs built-in support for named groups.
+ // #match works fine because it just return the exec results, even if it has
+ // a "grops" property.
+ var re = /./;
+ re.exec = function () {
+ var result = [];
+ result.groups = { a: '7' };
+ return result;
+ };
+ return ''.replace(re, '$<a>') !== '7';
+});
+
+// IE <= 11 replaces $0 with the whole match, as if it was $&
+// https://stackoverflow.com/questions/6024666/getting-ie-to-replace-a-regex-with-the-literal-string-0
+var REPLACE_KEEPS_$0 = (function () {
+ return 'a'.replace(/./, '$0') === '$0';
+})();
+
+var REPLACE = wellKnownSymbol('replace');
+// Safari <= 13.0.3(?) substitutes nth capture where n>m with an empty string
+var REGEXP_REPLACE_SUBSTITUTES_UNDEFINED_CAPTURE = (function () {
+ if (/./[REPLACE]) {
+ return /./[REPLACE]('a', '$0') === '';
+ }
+ return false;
+})();
+
+// Chrome 51 has a buggy "split" implementation when RegExp#exec !== nativeExec
+// Weex JS has frozen built-in prototypes, so use try / catch wrapper
+var SPLIT_WORKS_WITH_OVERWRITTEN_EXEC = !fails(function () {
+ // eslint-disable-next-line regexp/no-empty-group -- required for testing
+ var re = /(?:)/;
+ var originalExec = re.exec;
+ re.exec = function () { return originalExec.apply(this, arguments); };
+ var result = 'ab'.split(re);
+ return result.length !== 2 || result[0] !== 'a' || result[1] !== 'b';
+});
+
+module.exports = function (KEY, length, exec, sham) {
+ var SYMBOL = wellKnownSymbol(KEY);
+
+ var DELEGATES_TO_SYMBOL = !fails(function () {
+ // String methods call symbol-named RegEp methods
+ var O = {};
+ O[SYMBOL] = function () { return 7; };
+ return ''[KEY](O) != 7;
+ });
+
+ var DELEGATES_TO_EXEC = DELEGATES_TO_SYMBOL && !fails(function () {
+ // Symbol-named RegExp methods call .exec
+ var execCalled = false;
+ var re = /a/;
+
+ if (KEY === 'split') {
+ // We can't use real regex here since it causes deoptimization
+ // and serious performance degradation in V8
+ // https://github.com/zloirock/core-js/issues/306
+ re = {};
+ // RegExp[@@split] doesn't call the regex's exec method, but first creates
+ // a new one. We need to return the patched regex when creating the new one.
+ re.constructor = {};
+ re.constructor[SPECIES] = function () { return re; };
+ re.flags = '';
+ re[SYMBOL] = /./[SYMBOL];
+ }
+
+ re.exec = function () { execCalled = true; return null; };
+
+ re[SYMBOL]('');
+ return !execCalled;
+ });
+
+ if (
+ !DELEGATES_TO_SYMBOL ||
+ !DELEGATES_TO_EXEC ||
+ (KEY === 'replace' && !(
+ REPLACE_SUPPORTS_NAMED_GROUPS &&
+ REPLACE_KEEPS_$0 &&
+ !REGEXP_REPLACE_SUBSTITUTES_UNDEFINED_CAPTURE
+ )) ||
+ (KEY === 'split' && !SPLIT_WORKS_WITH_OVERWRITTEN_EXEC)
+ ) {
+ var nativeRegExpMethod = /./[SYMBOL];
+ var methods = exec(SYMBOL, ''[KEY], function (nativeMethod, regexp, str, arg2, forceStringMethod) {
+ if (regexp.exec === regexpExec) {
+ if (DELEGATES_TO_SYMBOL && !forceStringMethod) {
+ // The native String method already delegates to @@method (this
+ // polyfilled function), leasing to infinite recursion.
+ // We avoid it by directly calling the native @@method method.
+ return { done: true, value: nativeRegExpMethod.call(regexp, str, arg2) };
+ }
+ return { done: true, value: nativeMethod.call(str, regexp, arg2) };
+ }
+ return { done: false };
+ }, {
+ REPLACE_KEEPS_$0: REPLACE_KEEPS_$0,
+ REGEXP_REPLACE_SUBSTITUTES_UNDEFINED_CAPTURE: REGEXP_REPLACE_SUBSTITUTES_UNDEFINED_CAPTURE
+ });
+ var stringMethod = methods[0];
+ var regexMethod = methods[1];
+
+ redefine(String.prototype, KEY, stringMethod);
+ redefine(RegExp.prototype, SYMBOL, length == 2
+ // 21.2.5.8 RegExp.prototype[@@replace](string, replaceValue)
+ // 21.2.5.11 RegExp.prototype[@@split](string, limit)
+ ? function (string, arg) { return regexMethod.call(string, this, arg); }
+ // 21.2.5.6 RegExp.prototype[@@match](string)
+ // 21.2.5.9 RegExp.prototype[@@search](string)
+ : function (string) { return regexMethod.call(string, this); }
+ );
+ }
+
+ if (sham) createNonEnumerableProperty(RegExp.prototype[SYMBOL], 'sham', true);
+};