CODEWITHSUNDEEP
angular5karma-jasmine
k_hotspot
k_hotspot

Reputation: 134

how to test angular service injected in another service

i am testing a service in angular(1.6.3) My service is dependent on another service. every time i run ng test i get no provider for ServiceName or HTTpclient any help???? service:

export class TraitsService {


 constructor(private gs: GenericService) {}

  getAll(callback: Function) {
    this.gs
      .callGet(`${environment.serviceURL}${environment.serviceConfigAPI.getMyTraits}?active=true`)
      .subscribe(traits => callback(this.flatten(traits)));
  }

test:

describe('TraitsService', () => {
  let service: TraitsService;
  let gs: GenericService;

  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [TraitsService, GenericService]
    });
    service = TestBed.get(TraitsService);
    gs = TestBed.get(GenericService);
  });

  it('should be created', inject([TraitsService], (service: TraitsService) => {
    expect(service).toBeTruthy();
  }));

Upvotes: 2

Views: 3008

Answers (1)

dmcgrandle
dmcgrandle

Reputation: 6060

This is dealt with extensively in the Official Documentation, but it can be a bit intimidating to start with. :)

As the documentation points out, there are many ways you can test this. I personally tend to prefer spying on the original service to test the one under consideration in isolation. I have put together a Stackblitz for you to demonstrate how you could do this in your case.

From that Stackblitz, here is the describe() function in the .spec file:

describe('TraitsService', () => {
    const mockReturnValue = [1, 2, 3]; // change this!
    const gsSpy = jasmine.createSpyObj('GenericService', ['callGet']);
    gsSpy.callGet.and.returnValue(of(mockReturnValue));
    let service: TraitsService;
    // let gs: GenericService;

    beforeEach(() => {
        TestBed.configureTestingModule({
            providers: [
                TraitsService, 
                { provide: GenericService, useValue: gsSpy }
            ]
        });
        service = TestBed.get(TraitsService);
        // gs = TestBed.get(GenericService);
    });

    it('should be created', inject([TraitsService], (service: TraitsService) => {
        expect(service).toBeTruthy();
    }));
});

You can see in the Stackblitz that the service creates correctly. I hope this helps.

Upvotes: 3

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