test("__proto__ property", () => { expect(Object.getPrototypeOf({ __proto__: null })).toBeNull(); expect(Object.getPrototypeOf({ __proto__: Array.prototype })).toEqual(Array.prototype); expect(Object.getPrototypeOf({ "__proto__": Array.prototype })).toEqual(Array.prototype); // prettier-ignore expect(Object.getOwnPropertyNames({ __proto__: Array.prototype, test: 1 })).toEqual(["test"]); });