I have an observable that ultimately triggers a call to Angular HttpClient. I need to mock the response from the HttpClient, but I'm at a loss how to do it within the context of the TestScheduler run method. Say I have the following test:
it('observable should trigger call to HttpClient', () => {
scheduler.run(helpers => {
const { expectObservable, cold } = helpers;
const transferObservable = cold('-a-', { a: someInput });
transferService.value$ = transferObservable;
sut = new MyService(transferService, apiService);
const expectedMarble = '-a-';
const expectedValues = { a: expectedData };
expectObservable(sut.data$).toBe(expectedMarble, expectedValues);
});
});
Values emitted on transferObservable cascade to a switchMap call to a service which in turn sends a GET request via Angular HttpClient; the resulting value is emitted from sut.data$.
I've tried placing following lines at various places within and outside the scheduler.run method, but I always get the same error: Expected one matching request for criteria "Match URL: http://foo", found none.
const request = httpMock.expectOne(`http://foo`);
request.flush(expectedContract);
Roughly where and how would I mock a single call to http://foo and flush expectedData as the desired response?
EDIT Stripped-down beforeEach setup showing configuration of HttpTestingController:
beforeEach(() => {
scheduler = new TestScheduler((actual, expected) => {
expect(actual).toEqual(expected);
});
transferService = jasmine.createSpyObj<TransferService>(['value$']);
TestBed.configureTestingModule({
imports: [HttpClientTestingModule],
declarations: [],
providers: [],
schemas: [NO_ERRORS_SCHEMA]
});
httpMock = TestBed.inject(HttpTestingController);
});
EDIT 2: Screenshot of HttpClient instance from within my service when debugging.
EDIT 3: Stackblitz for issue here. The failing test contract$ should return contract is the one of interest.
