Jest – How To Test a Fetch() Call That Returns A Rejected Promise?

I have the following function that uses fetch() to make an API call:

export async function fetchCars(dealershipId) {
  return request('path/to/endpoint/' + dealershipId)
    .then((response) => {
      if (response.ok === false) {
        return Promise.reject();
      }
      return response.json();
    })
    .then((cars) => {
      return parseMyCars(cars);
    });
}

I want to test when the call fails (specifically when return Promise.reject() is returned). I have the following Jest test right now:

(fetch as jest.Mock).mockImplementation(() =>
    Promise.resolve({ ok: false })
);
const result = await fetchCars(1);
expect(request).toHaveBeenCalledWith('/path/to/endpoint/1');
expect(result).toEqual(Promise.reject());

but I get a Failed: undefined message when running the test. I’ve tried using:

(fetch as jest.Mock).mockRejectedValue(() =>
  Promise.resolve({ ok: false })
);

but get a similar Failed: [Function anonymous] message.

What’s the proper way to test for the rejected promise here?