Angular - Jasmine 单元测试的模拟 Promise 方法 [英] Angular - mock Promise method for Jasmine unit test

问题描述

  public onSubmit(registerData: RegisterDataModel): void {
    this.registrationService.registerWithEmailAndPassword(registerData).then((msg: string[]) =>
      this.router.navigate(['/completeSignUp']).then(() => {
        msg.forEach(singleMessage => this.notificationService.primary(singleMessage));
      }))
      .catch((msg) => msg.forEach(singleMessage => {
        this.notificationService.danger(singleMessage);
      }));
  }

我想测试我的方法中是否调用了 router.navigate.现在我想模拟我的 service.registerWithEmailAndPasswort Promise 但不知何故我无法模拟它.

I want to test if router.navigate is called in my method. Now I want to mock my service.registerWithEmailAndPasswort Promise but somehow I cannot mock it.

//Stubs
const routerStub: Router = jasmine.createSpyObj('Router', ['navigate']);
const registryStub: RegistrationService = jasmine.createSpyObj('RegistrationService', ['registerWithEmailAndPassword']);

单元测试

  it('should navigate on promise - success', () => {
    (<jasmine.Spy>registryStub.registerWithEmailAndPassword).and.callThrough();
    const spy = (<jasmine.Spy>routerStub.navigate);
    component.onSubmit({username: null, email: null, password: null, passwordConfirm: null, termsAndCondition: null});
    expect(spy).toHaveBeenCalledWith(['/completeSignUp']);
  });

出现的错误是:TypeError: Cannot read property 'then' of undefined有人如何正确模拟这项服务吗?

The Error that is appearing is: TypeError: Cannot read property 'then' of undefined Does anyone how to proper mock this service?

我也尝试过模拟这样的承诺:

I have also tried to mock the promise like:

    (<jasmine.Spy>registryStub.registerWithEmailAndPassword)
  .and.returnValue(new Promise(() => Promise.resolve()));

但它仍然让我失望:

Expected spy Router.navigate to have been called with [ [ '/completeSignUp' ] ] but it was never called.

推荐答案

正如 Silicon Soul 提到的，你肯定需要用返回值模拟 router.navigate 承诺，否则它将进入 Promise.reject().通过添加 (<jasmine.Spy>routerStub.navigate).and.returnValue(Promise.resolve()); 单元测试应该没问题.最终的单元测试应如下所示:

As silicon Soul mentioned you need definately mock the router.navigate promise with a returnvalue as otherwise it will ent into a Promise.reject(). By adding (<jasmine.Spy>routerStub.navigate).and.returnValue(Promise.resolve()); the unit test should be ok. The final unit test should look like:

  it('should navigate on promise - success', fakeAsync(() => {
    const spy = (<jasmine.Spy>routerStub.navigate).and.returnValue(Promise.resolve());
    (<jasmine.Spy>registryStub.registerWithEmailAndPassword).and.returnValue(Promise.resolve(['test']));
    component.onSubmit({username: 'test', email: 'test', password: 'test', passwordConfirm: 'test', termsAndCondition: true});

    tick();
    expect(spy).toHaveBeenCalledWith(['/completeSignUp']);
  }));

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