Angular2 单元测试不使用模拟服务

Question

我正在测试一个显示/隐藏登录/退出按钮的非常简单的组件。

为此，我模拟了我的 AuthService 服务，因为它依赖于 AngularFire2。

我遇到的问题是我的模拟服务 (Mock AuthService) 似乎没有被提供来代替实际的 AuthService。

在测试中应该显示 Facebook 登录按钮，service.isAnonymous 应该是未定义的。在实际服务中，确实如此。但在模拟服务中是 true。这个测试应该会失败。

另外，请注意我正在尝试调用方法 service.test(false);;在模拟服务中，此方法存在并且是public。但是我收到错误:

Property 'test' does not exist on type 'AuthService'.

这表明没有提供我的模拟服务。

您可以在我的测试规范中看到我如何尝试两种方式来提供模拟服务(一种被注释掉):

import { DebugElement } from '@angular/core';
import {
  async,
  inject,
  ComponentFixture,
  TestBed
} from '@angular/core/testing';
import { By } from '@angular/platform-browser';

import { FacebookLoginComponent } from './facebook-login.component';
import { AuthService } from '../shared/auth.service';
import { MockAuthService } from '../shared/testing/auth.service';

describe('FacebookLoginComponent', () => {
  let authService: AuthService;
  let component: FacebookLoginComponent;
  let fixture: ComponentFixture<FacebookLoginComponent>;
  let debugElement: DebugElement;
  let htmlElement: HTMLElement;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [ FacebookLoginComponent ],
      // providers: [{ provide: AuthService, useValue: MockAuthService }]
    })
      .compileComponents();

    TestBed.overrideComponent(FacebookLoginComponent, {
      set: {
        providers: [{ provide: AuthService, useClass: MockAuthService }]
      }
    })
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(FacebookLoginComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should be created', () => {
    expect(component).toBeTruthy();
  });

  it('should show the Facebook login button', inject([ AuthService ], (service: AuthService) => {
    expect(service.isAnonymous).toBeUndefined();

    debugElement = fixture.debugElement.query(By.css('button'));
    htmlElement = debugElement.nativeElement;

    service.test(false);

    expect(htmlElement.textContent).toBe('Facebook Login');
  }));

  it('should show the Logout button', () => {
    debugElement = fixture.debugElement.query(By.css('button'));
    htmlElement = debugElement.nativeElement;

    expect(htmlElement.textContent).toBe('Logout');
  });
});

为了完整性；这是我的模拟服务，MockAuthService:

import { Injectable } from '@angular/core';

@Injectable()
export class MockAuthService {
  public authState: { isAnonymous: boolean, uid: string };

  constructor() {
    this.authState = { isAnonymous: true, uid: '0HjUd9owxPZ5kibvUCN6S2DgB4x1' };
  }

  // public get currentUser(): firebase.User {
  //   return this.authState ? this.authState : undefined;
  // }

  // public get currentUserObservable(): Observable<firebase.User> {
  //   return this.afAuth.authState;
  // }

  public get currentUid(): string {
    return this.authState ? this.authState.uid : undefined;
  }

  public get isAnonymous(): boolean {
    return this.authState ? this.authState.isAnonymous : false;
  }

  public get isAuthenticated(): boolean {
    return !!this.authState;
  }

  // public logout(): void {
  //   this.afAuth.auth.signOut();
  // }

  public test(isAnonymous: boolean) {
    this.authState.isAnonymous = isAnonymous;
  }
}

我不知道如何提供模拟。

更新:

根据目前的答案和评论，我更新了我的模拟测试规范。但是，我仍然遇到同样的问题。

我收到错误消息Property 'test' does not exist on type 'AuthService'。

这表明它仍然没有用模拟代替实际的 authService 服务。

此外，当我添加:

public test(test: boolean): boolean {
  return test;
}

对实际服务测试失败；但不是因为上面的错误，而是因为它应该——没有满足测试的期望。

这是我更新的规范:

import { DebugElement } from '@angular/core';
import {
  async,
  inject,
  ComponentFixture,
  TestBed
} from '@angular/core/testing';
import { By } from '@angular/platform-browser';

import { FacebookLoginComponent } from './facebook-login.component';
import { AuthService } from '../shared/auth.service';
import { MockAuthService } from '../shared/testing/auth.service';

describe('FacebookLoginComponent', () => {
  let authService: AuthService;
  let component: FacebookLoginComponent;
  let fixture: ComponentFixture<FacebookLoginComponent>;
  let debugElement: DebugElement;
  let htmlElement: HTMLElement;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [ FacebookLoginComponent ],
      providers: [{ provide: AuthService, useClass: MockAuthService }]
    }).compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(FacebookLoginComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should be created', () => {
    expect(component).toBeTruthy();
  });

  it('should show the Facebook Login button', inject([ AuthService ], (service: AuthService) => {
    debugElement = fixture.debugElement.query(By.css('button'));
    htmlElement = debugElement.nativeElement;

    expect(htmlElement.textContent).toBe('Facebook Login');
  }));

  it('should show the Logout button', inject([ AuthService ], (service: AuthService) => {
    expect(service.isAnonymous).toBe(true);

    debugElement = fixture.debugElement.query(By.css('button'));
    htmlElement = debugElement.nativeElement;

    service.test(false);

    fixture.detectChanges();

    expect(htmlElement.textContent).toBe('Logout');
  }));
});

Answer 1

beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [ FacebookLoginComponent ],
      // providers: [{ provide: AuthService, useValue: MockAuthService }]
    })
      .compileComponents();

    TestBed.overrideComponent(FacebookLoginComponent, {
      set: {
        providers: [{ provide: AuthService, useClass: MockAuthService }]
      }
    })
  }));

有两个问题。您不需要覆盖组件的提供程序，因为您可以在配置 TestBed 时提供它们。

我假设您已经开始覆盖组件，因为初始配置不起作用。它不起作用，因为您使用的是 useValue 而不是 useClass。

  // providers: [{ provide: AuthService, useValue: MockAuthService }]

应该这样做:

beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [ FacebookLoginComponent ],
      providers: [{ provide: AuthService, useClass: MockAuthService }]
    }).compileComponents();
  }));

编辑:

当使用inject 函数时，您应该使用MockAuthService 作为类型。 TypeScript 应该停止提示。

inject([ AuthService ], (service: MockAuthService) => { /* ... */ });