Angular spy On not working for stubbing mock

Question

I have angular 4 application and i am writing test cases using jasmin + Karma

My first test case working properly as it creates component and service instance,

But second test cases is failing as it is not able to fetch mock data for 'getorders' method, when i log its value is undefined.

    beforeEach(async(() => {
        TestBed.configureTestingModule({
          declarations: [ OrderListComponent ],
          providers: [
            OrderFormFetchService,
          ],
          imports: [
            BrowserModule,
            BrowserAnimationsModule,
            FormsModule,
            ReactiveFormsModule,
            HttpClientModule,
            RouterModule.forRoot([]),
            NglModule.forRoot({svgPath: 'assets/icons'}),
          LayoutModule,
          NgbModule.forRoot()
        ],
        })
        .compileComponents();
      }));


 beforeEach(() => {
        orderFormFetchService = TestBed.get(OrderFormFetchService);
        fixture = TestBed.createComponent(OrderListComponent);
        component = fixture.componentInstance;
        orderListStub = [{
          'id': '5c18e74dd5ab9332cc473c94',
          'createdAt': '2018-12-18T12:25:49.507Z',
          'updatedAt': '2018-12-18T12:25:49.507Z',
          'name': 'apple',
          'website': 'www.apple.com',
          'secsId': ''
        }];
        spyOn(orderFormFetchService, 'getorders').and.returnValue(Observable.of(orderListStub));
        fixture.detectChanges();
      });

      it('should create', () => {
        expect(component).toBeDefined();
        expect(component).toBeTruthy();
        expect(fixture).toBeDefined();
        expect(orderFormFetchService).toBeDefined();
      });

     it('check order list ', () => {
      console.log(orderFormFetchService.getorders()); // -> undefined
      expect(component.orderList).toBeDefined();
      //  expect(component.orderList).toEqual(orderListStub);
      });

Code in OrderListComponent is as follows,

export class OrderListComponent   extends BaseComponent implements OnInit {

  defaultQuery = {website: null, name: null};
  orderList: any;
  query = _.clone(this.defaultQuery);
  date: Date;

  constructor(private orderFormFetchService: OrderFormFetchService) { super(); }

  ngOnInit() {
    this.date = new Date();
    this.getOrderList();
  }

  getOrderList(): void {
    this.orderFormFetchService.getOrders()
      .subscribe((res: Response) => {
        if (_.isArray(res)) {
          this.orderList = _.orderBy(res, [order => order.name.toLowerCase()], ['asc']);
        } else {
          this.orderList = [res];
        }
      });
  }
  }

Please help