Test Broadcast Service

问题

Hi I am trying to write angular code for a component with an observable but I can't test the broadcast service. I get an error saying the service is not being called. How Should I access the service? Any help would be appreciated. Thank you.

This is my component with the observable:

  ngOnInit(): void {

    this.subscription.add(
      this.broadcastService.subscribe('msal:acquireTokenSuccess', (payload) => {
        // do something here
        this.roleService.checkServerEventReviewers().subscribe(res => {
          this.userService.userDetails.role = res ? 'Data Steward' : 'Mosaic Consumer';
          if (this.isLoggedIn !== true) {
            const redirectUri = sessionStorage.getItem('redirectUri');
            if (redirectUri !== undefined || redirectUri !== null) {
              this.router.navigateByUrl(redirectUri);
            }
          }
          this.isLoggedIn = true;
};

This is my spec file that I am trying:

    describe('AppComponent', () => {
      beforeEach(() => {
       TestBed.configureTestingModule({
         imports: [RouterTestingModule],
         declarations: [AppComponent],
         providers: [WindowService, HttpClient, RoleService, UserService, HttpHandler, BroadcastService, MsalService,
        {
          provide: MSAL_CONFIG,  // MsalService needs config, this provides it.
          useFactory: () => ({   // Note this is an arrow fn that returns the config object
            redirectUri: window.location.origin + '/',
            clientID: mockData.clientID,
          }),
        }],
      schemas: [CUSTOM_ELEMENTS_SCHEMA]
    }).compileComponents();
  });

  describe(':', () => {
    function setup() {
      const fixture = TestBed.createComponent(AppComponent);
      const app = fixture.debugElement.componentInstance;
      const compiled = fixture.debugElement.nativeElement;
      return {fixture, app, compiled};
    }

    it("Role should be Data Steward", fakeAsync (() => {
    const fn = 'msal:acquireTokenSuccess';
    const subscription = new Subscription();
    const fixture = TestBed.createComponent(AppComponent);
    const app = fixture.debugElement.componentInstance;
    const spyOnBS = spyOn(app.broadcastService,'subscribe');
    const roleServiceCall = 
    spyOn(app.roleService,'checkServerEventReviewers');
    app.ngOnInit();
    tick();
    fixture.whenStable().then(() => {
      expect(spyOnBS).toHaveBeenCalled();
      expect(roleServiceCall).toHaveBeenCalled();
});
}));

回答1:

Sorry, I read wrong the issue. (Response Updated). I think that the problem is that you are testing an observable service. I think that you should use fakeAsync and tick to test it.

    describe('AppComponent', () => {
      beforeEach(() => {
       TestBed.configureTestingModule({
         imports: [RouterTestingModule],
         declarations: [AppComponent],
         providers: [WindowService, HttpClient, RoleService, UserService, HttpHandler, BroadcastService, MsalService,
        {
          provide: MSAL_CONFIG,  // MsalService needs config, this provides it.
          useFactory: () => ({   // Note this is an arrow fn that returns the config object
            redirectUri: window.location.origin + '/',
            clientID: mockData.clientID,
          }),
        }],
      schemas: [CUSTOM_ELEMENTS_SCHEMA]
    }).compileComponents();
  });

  describe(':', () => {
    function setup() {
      const fixture = TestBed.createComponent(AppComponent);
      const app = fixture.debugElement.componentInstance;
      const compiled = fixture.debugElement.nativeElement;
      return {fixture, app, compiled};
    }

    it('Init with QA environment', fakeAsync(() => {
      const {app} = setup();
      spyOnBS = spyOn(app.broadcastService,'subscribe');
      spyOn(app.authService, 'getUser').and.returnValue(mockData.userDetails);
      spyOn(app.authService, 'acquireTokenSilent').and.returnValue('msal:acquireTokenSuccess');
      app.ngOnInit();
      tick();
      fixture.detectChanges();
      fixture.whenStable().then(() => {
          expect(spyOnBS).toHaveBeenCalled();
      });
    ));

Try if that works.

来源：https://stackoverflow.com/questions/58860227/test-broadcast-service