21 lines
926 B
JavaScript
21 lines
926 B
JavaScript
|
'use strict';
|
||
|
|
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 (typeof this != 'function' || !isObject(O)) return false;
|
||
|
|
if (!isObject(this.prototype)) return O instanceof this;
|
||
|
|
// for environment w/o native `@@hasInstance` logic enough `instanceof`, but add this:
|
||
|
|
while (O = getPrototypeOf(O)) if (this.prototype === O) return true;
|
||
|
|
return false;
|
||
|
|
} });
|
||
|
|
}
|