Angular test how to mock ActivatedRoute data

I have a real big problem with mocking ActivatedRoute data property. No matter what I am doing all it ends up with error message : Error: <spyOnProperty> : Property data does not have access type get. Moving stub const to separate mock class also not solving the issue. I have found that this should be straight forward but I am struggling with this for a few days now.

Component

@Component({
  selector: 'app-notifications',
  templateUrl: './notifications.component.html',
  styleUrls: ['./notifications.component.css']
})
export class NotificationsComponent implements OnInit {
  notifications: NotificationEntry[];

  constructor(
    private route: ActivatedRoute,
    private modalService: ModalService,
    private messageBoxService: MessageBoxService,
    private notificationsService: NotificationsService
  ) {}

  ngOnInit() {
    this.route.data.subscribe(
      (data: { notifications: NotificationEntry[] }) => {
        this.notifications = data.notifications;
      }
    );
  }
}

Component.spec

describe('NotificationsComponent', () => {
  let component: NotificationsComponent;
  let fixture: ComponentFixture<NotificationsComponent>;

  const registryVersionBasicData = new RegistryVersionBasicData(
    false,
    'versionId',
    new JsonDate('Unspecified', 631894104000000000),
    'user',
    'comment'
  )

  const notifications = new NotificationEntry(
    new JsonDate('Unspecified', 631894104000000000),
    'summary',
    'message',
    NotificationEntityType.StressScenario,
    'instance name',
    'instance key',
    registryVersionBasicData,
    'additional information')

  const notificationsArray = [notifications]

  beforeEach(() => {
    const activatedRouteStub = { data: of({ notifications: notificationsArray }) };
    const modalServiceStub = {};
    const messageBoxServiceStub = {};
    const notificationsServiceStub = {};

    TestBed.configureTestingModule({
      schemas: [NO_ERRORS_SCHEMA],
      declarations: [NotificationsComponent, OrderPipe, RenderDatePipe, VersionInfoPipe],
      providers: [
        { provide: ActivatedRoute, useValue: activatedRouteStub },
        { provide: ModalService, useValue: modalServiceStub },
        { provide: MessageBoxService, useValue: messageBoxServiceStub },
        { provide: NotificationsService, useValue: notificationsServiceStub },
      ]
    }).compileComponents();

    fixture = TestBed.createComponent(NotificationsComponent);
    component = fixture.componentInstance;
  });

  it('can load instance', () => {
    expect(component).toBeTruthy();
  });

  describe('ngOnInit', () => {
    it('should get notifications entry', () => {
      const activatedRouteStub = TestBed.get(ActivatedRoute);
      spyOnProperty(activatedRouteStub, 'data')

      component.ngOnInit();

      expect(component.notifications).toEqual(notificationsArray)
    });
  });
});

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Source Url Angular test how to mock ActivatedRoute data