favorite-movies.service.spec.ts

  it('should throw if the backend returns an error ', () => {
    let bubblesUpTheError = false;
    serviceUnderTest.getFavoriteMovies().subscribe(() => {}, () => (bubblesUpTheError = true));

    const req = http.expectOne(environment.favoriteUrl, 'expected to make a request');
    expect(req.request.method).toEqual('GET');
    req.flush('ERROR', { status: 500, statusText: 'Internal server error' });

    expect(bubblesUpTheError).toBeTruthy();
    http.verify();
  });