객체 비교

test(‘matcher’, () => {
  const received = {
     a: 1,
     b: 2
  };
  const expected = {
    a: 1,
  };
  expect(received).toMatchObject(expected) // 서브셋 관계냐 -> true
  expect(received).toStrictEqual(expected) // 완전히 동일하냐 -> false
});