12345678910111213141516171819202122 |
- 'use strict';
- var isCallable = require('../internals/is-callable');
- var isObject = require('../internals/is-object');
- var definePropertyModule = require('../internals/object-define-property');
- var getPrototypeOf = require('../internals/object-get-prototype-of');
- var wellKnownSymbol = require('../internals/well-known-symbol');
- var HAS_INSTANCE = wellKnownSymbol('hasInstance');
- var FunctionPrototype = Function.prototype;
- // `Function.prototype[@@hasInstance]` method
- // https://tc39.es/ecma262/#sec-function.prototype-@@hasinstance
- if (!(HAS_INSTANCE in FunctionPrototype)) {
- definePropertyModule.f(FunctionPrototype, HAS_INSTANCE, { value: function (O) {
- if (!isCallable(this) || !isObject(O)) return false;
- var P = this.prototype;
- if (!isObject(P)) return O instanceof this;
- // for environment w/o native `@@hasInstance` logic enough `instanceof`, but add this:
- while (O = getPrototypeOf(O)) if (P === O) return true;
- return false;
- } });
- }
|