1234567891011121314151617181920212223242526272829303132 |
- 'use strict';
- var $ = require('../internals/export');
- var uncurryThis = require('../internals/function-uncurry-this-clause');
- var getOwnPropertyDescriptor = require('../internals/object-get-own-property-descriptor').f;
- var toLength = require('../internals/to-length');
- var toString = require('../internals/to-string');
- var notARegExp = require('../internals/not-a-regexp');
- var requireObjectCoercible = require('../internals/require-object-coercible');
- var correctIsRegExpLogic = require('../internals/correct-is-regexp-logic');
- var IS_PURE = require('../internals/is-pure');
-
- var stringSlice = uncurryThis(''.slice);
- var min = Math.min;
-
- var CORRECT_IS_REGEXP_LOGIC = correctIsRegExpLogic('startsWith');
- // https://github.com/zloirock/core-js/pull/702
- var MDN_POLYFILL_BUG = !IS_PURE && !CORRECT_IS_REGEXP_LOGIC && !!function () {
- var descriptor = getOwnPropertyDescriptor(String.prototype, 'startsWith');
- return descriptor && !descriptor.writable;
- }();
-
- // `String.prototype.startsWith` method
- // https://tc39.es/ecma262/#sec-string.prototype.startswith
- $({ target: 'String', proto: true, forced: !MDN_POLYFILL_BUG && !CORRECT_IS_REGEXP_LOGIC }, {
- startsWith: function startsWith(searchString /* , position = 0 */) {
- var that = toString(requireObjectCoercible(this));
- notARegExp(searchString);
- var index = toLength(min(arguments.length > 1 ? arguments[1] : undefined, that.length));
- var search = toString(searchString);
- return stringSlice(that, index, index + search.length) === search;
- }
- });
|