Question

我有一个独立的班需要测试角度。我不知道如何才能为它注入模拟服务。

我尝试使用TestBed来依赖注入服务。但这不起作用。

// user-setting.ts, class I want to test
constructor(private config: UserSettingDefault, private userSettingsService: UserSettingsService) { }

// user-setting.spec.ts, I try to use TestBed to inject, but failed
class UserSettingsServiceMock {

}

fdescribe('UserSetting', () => {
  let userSettingsService: UserSettingsServiceMock

  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        { provide: UserSettingsService, useClass: UserSettingsServiceMock },
      ],
    });

    userSettingsService = TestBed.get(UserSettingsService);
  });

  it('should create an instance', () => {
    const config = { app: 'user', type: 'search', id: 'embeded-link' };
    const userSetting = new UserSetting(config, userSettingsService);
    expect(userSetting).toBeTruthy();
  });
});

我希望我可以为UserSetting创建一个新实例。但是抛出一些错误：

ERROR in src/app/core/user/user-settings/user-setting.spec.ts(25,49): error TS2345: Argument of type 'UserSettingsServiceMock' is not assignable to parameter of type 'UserSettingsService'.
  Property 'language' is missing in type 'UserSettingsServiceMock'.

Answer 1

因此，如果要在组件中模拟服务，则必须提供该服务的虚拟框架（即，您需要在该模拟注入依赖项中编写模拟方法和变量，这些都是组件正在使用的）。您将收到错误消息，因为必须在组件中使用userSettingsService.language。因此，您还需要模拟该值。

class UserSettingsServiceMock {
language = {};
}

如何在角单元测试中测试独立的类？

1 个答案: