问预期间谍导航已被[帐户]调用，但从未被调用

EN

 deleteRecord(id) {
    this.http.delete('/api/accounts/' + id)
    .subscribe(res => {
        if (res['status'] == "FAILURE") {
          console.log("failure");
        } else {
          console.log("API responded success"); //this is printed
          this.router.navigate([ '/accounts' ]); // I want to test this
        }
      }, (err) => {
           console.log(err);
      }
    );
  }

  routerStub = {
      navigate: jasmine.createSpy('navigate'),
    };

    TestBed.configureTestingModule({
      imports:[RouterTestingModule,FormsModule,ReactiveFormsModule,HttpClientTestingModule,RouterTestingModule.withRoutes([{ path: 'accountsList', component: AccountsListComponent}])],
      declarations: [ AccountDetailComponent,AccountsListComponent ],
      schemas:[CUSTOM_ELEMENTS_SCHEMA]
    })


it ('should delete account, if account exist and take back to accountsList page', ()=> {
    let spyOnDelete = spyOn (component,'deleteRecord').and.callThrough();
    fixture.detectChanges();
    component.record.AccountID = "account";
    fixture.detectChanges();
    let deleteButtonDOM = fixture.debugElement.query(By.css('#deletebtn'));
    deleteButtonDOM.triggerEventHandler('click',null);
    fixture.detectChanges();
    expect(spyOnDelete).toHaveBeenCalled(); //passes
    const req = _HttpTestingController.expectOne('/api/accounts/'+ component.record.AccountID);
    expect(req.request.method).toBe("DELETE");
    req.flush({status:"SUCCESS"});
    expect(routerStub.navigate).toHaveBeenCalledWith('accounts');//fails???

  })