debian-mirror-gitlab/core-js/internals/fix-regexp-well-known-symbol-logic.js
2019-10-31 01:37:42 +05:30

100 lines
3.7 KiB
JavaScript

'use strict';
var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
var redefine = require('../internals/redefine');
var fails = require('../internals/fails');
var wellKnownSymbol = require('../internals/well-known-symbol');
var regexpExec = require('../internals/regexp-exec');
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';
});
// 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 () {
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) ||
(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 };
});
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);
}
};