"use strict"; var _obj; const Base = {}; const obj = _obj = { set() { return babelHelpers.set(babelHelpers.getPrototypeOf(_obj), "test", 3, this, true); } }; Object.defineProperty(obj, 'test', { value: 2, writable: true, configurable: false, enumerable: true }); Object.setPrototypeOf(obj, Base); expect(obj.set()).toBe(3); expect(Base.test).toBeUndefined(); expect(obj.test).toBe(3); const desc = Object.getOwnPropertyDescriptor(obj, 'test'); expect(desc.configurable).toBe(false); expect(desc.writable).toBe(true); expect(desc.enumerable).toBe(true);