如何在 Angular 中測試單元測試 void 函數？

Question

我是 angular 的新手，我正在測試我的 Login 組件，它是這樣的。它有一個handleLogin()函數，它是無效的。它重定向到另一個函數，如下所示。

如何測試此功能？ 它重定向到一些其他函數，該函數也重定向到其他地方。 如何測試這么復雜的功能。

Answer 1

由於涉及一個服務並且您應該“UNIT”測試該組件，所以您應該模擬該服務並期望在您調用組件上的handleLogin方法時調用它的方法。

像這樣的東西：

import { LoginComponent } from './login.component';
import { LoginService } from '../../services/login.service';
import { AuthenticationService } from './auth.service';

describe('Component: Login', () => {

  let component: LoginComponent;
  let service: LoginService;
  let spy: any;

  beforeEach(() => {
    service = new LoginService();
    component = new LoginComponent(service);
  });

  afterEach(() => {
    service = null;
    component = null;
  });

  describe('Method: handleLogin', () => {

    it('should call the `redirectToAuth` method on the `LoginService`', () => {
      spy = spyOn(service, 'redirectToAuth');
      component.handleLogin();
      expect(spy).toHaveBeenCalled();
    });

  });

});

Answer 2

it('should not be called redirect after login function', () => {
  const loginService = TestBed.inject(LoginService);
  const authService = TestBed.inject(AuthenticationService);
  spyOn(authService, 'isLoggedIn').and.returnValue(false);  // FALSE
  component.ngOnInit();
  expect(loginSerive.redirectAfterLogin).not.toHaveBeenCalled();
}

it('should be called redirect after login function', () => {
  const loginService = TestBed.inject(LoginService);
  const authService = TestBed.inject(AuthenticationService);
  spyOn(authService, 'isLoggedIn').and.returnValue(true); 
  component.ngOnInit();
  expect(loginSerive.redirectAfterLogin).toHaveBeenCalled();
}

it('should be called redirectToAuth function', () => {
  const loginService = TestBed.inject(LoginService);
  spyOn(loginService, 'redirectToAuth').and.callFake; 
  component. handleLogin();
  expect(loginSerive.redirectToAuth).toHaveBeenCalled();
}