I'm writing unit test cases in angular 7 for a Component with async service and getting this error:

Error: Expected spy create to have been called once. It was called 0
times.

Here is my Component:

export class RegistrationComponent implements OnInit {

    

   submitRegistrationForm() {

        if (this.profileForm.invalid) {

          this.validateAllFields(this.profileForm);

        } else {

          // send a http request to save this data

          this.guestUserService.create(this.profileForm.value).subscribe(

            result => {

              if (result) {

                console.log('result', result);

                this.router.navigate(['/login']);

              }

            },

            error => {

              console.log('error', error);

            });

        }

  }

Unit test case:

  describe('RegistrationComponent', () => {

      let component: RegistrationComponent;

      let fixture: ComponentFixture<RegistrationComponent>;

      let myService;

      let mySpy;

    

      beforeEach(async(() => {

    

        TestBed.configureTestingModule({

          declarations: [RegistrationComponent],

          imports: [ ],

          providers: [

            { provide: GuestUserService, useValue: new MyServiceStub() }]

        })

          .compileComponents();

      }));

    

      beforeEach(() => {

        fixture = TestBed.createComponent(RegistrationComponent);

        component = fixture.componentInstance;

        fixture.detectChanges();

      });



 it('should submit Registration Form', async(inject([Router], (router) => {

    myService = TestBed.get(GuestUserService);

    mySpy = spyOn(myService, 'create');

    spyOn(router, 'navigate');

    spyOn(component, 'submitRegistrationForm');





component.profileForm.controls['firstName'].setValue('Arjun');

    component.profileForm.controls['lastName'].setValue('Singh');

    component.profileForm.controls['password'].setValue('12345678');

    component.profileForm.controls['confirmPassword'].setValue('12345678');

    component.submitRegistrationForm();



    expect(component.profileForm.invalid).toBe(false);



    expect(component.submitRegistrationForm).toHaveBeenCalled();



    expect(myService).toBeDefined();

    expect(mySpy).toBeDefined();

    expect(mySpy).toHaveBeenCalledTimes(1); // Getting error is this

    expect(router.navigate).toHaveBeenCalled();

  })

  ));

I tried to move the spy deceleration in beforeEach but still its giving the same error.

how to fix this error?

Thanks!