| | |
| | | var definePropertyModule = require('../internals/object-define-property'); |
| | | var getPrototypeOf = require('../internals/object-get-prototype-of'); |
| | | var wellKnownSymbol = require('../internals/well-known-symbol'); |
| | | var makeBuiltIn = require('../internals/make-built-in'); |
| | | |
| | | 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) { |
| | | definePropertyModule.f(FunctionPrototype, HAS_INSTANCE, { value: makeBuiltIn(function (O) { |
| | | if (!isCallable(this) || !isObject(O)) return false; |
| | | if (!isObject(this.prototype)) return O instanceof this; |
| | | 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 (this.prototype === O) return true; |
| | | while (O = getPrototypeOf(O)) if (P === O) return true; |
| | | return false; |
| | | } }); |
| | | }, HAS_INSTANCE) }); |
| | | } |