I want to write a test that assert a given object does not have certain properties.

Say I have a function

function removeFooAndBar(input) {
  delete input.foo;
  delete input.bar;
  return input;
}

Now I want to write a test:

describe('removeFooAndBar', () => {
  it('removes properties `foo` and `bar`', () => {
    const data = {
      foo: 'Foo',
      bar: 'Bar',
      baz: 'Baz',
    };
    expect(removeFooAndBar(data))
      .toEqual(expect.objectContaining({
        baz: 'Baz', // what's left
        foo: expect.not.exists() // pseudo
        bar: undefined // this doesn't work, and not what I want
      }));
  });
});

What's the proper way to do assert this?