it('can test for 404 error', () => { const emsg = 'deliberate 404 error'; httpClient.get(testUrl).subscribe( data => fail('should have failed with the 404 error'), (error: HttpErrorResponse) => { expect(error.status).toEqual(404, 'status'); expect(error.error).toEqual(emsg, 'message'); } ); const req = httpTestingController.expectOne(testUrl); // Respond with mock error req.flush(emsg, { status: 404, statusText: 'Not Found' }); });