javascript - 错误: Expected spy create to have been called

Question

我正在 Angular 7 中为 Component with async service 编写单元测试用例并收到此错误:

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

这是我的组件:

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);
            });
        }
  }

单元测试用例:

  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();
  })
  ));

我尝试在 beforeEach 中移动 spy 减速，但仍然给出相同的错误。

如何修复这个错误？

谢谢!

Answer 1

预期已调用的 spy 创建不是错误，而是失败的测试。

发生这种情况是因为您没有使用 callThrough();也可以在你的 spy 上。

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

    myService = TestBed.get(GuestUserService);
    mySpy = spyOn(myService, 'create').and.callThrough(); //callThrough()

    spyOn(router, 'navigate');

    spyOn(component, 'submitRegistrationForm').and.callThrough(); //callThrough()


    component.submitRegistrationForm();

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

    expect(component.submitRegistrationForm).toHaveBeenCalled();

    expect(myService).toBeDefined();
    expect(mySpy).toBeDefined();
    expect(mySpy).toHaveBeenCalledTimes(1); 
    expect(router.navigate).toHaveBeenCalled();
  })
  ));