test("use with array", () => { let names = Object.getOwnPropertySymbols([1, 2, 3]); console.log(names); expect(names).toEqual([]); }); test("use with object", () => { let names = Object.getOwnPropertySymbols({ [Symbol.iterator]: 1, [Symbol.species]: 2 }); expect(names).toEqual([Symbol.iterator, Symbol.species]); }); test("use with object with string keys", () => { let symbol = Symbol("bar"); let names = Object.getOwnPropertySymbols({ foo: 1, [symbol]: 2, baz: 3 }); expect(names).toEqual([symbol]); });