test3.ts

beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        AppService,
        MockBackend,
        BaseRequestOptions,
        {
          provide: Http,
          useFactory: (backend: MockBackend, defaultOptions: BaseRequestOptions) => {
            return new Http(backend, defaultOptions);
          },
          deps: [MockBackend, BaseRequestOptions],
        }
      ]
      });

    service = TestBed.get(AppService)
  });