如何对Angular2中调用window.location.href的函数进行单元测试答案

【问题标题】：How to unit-test a function that calls window.location.href in Angular2如何对Angular2中调用window.location.href的函数进行单元测试
【发布时间】：2016-07-22 08:45:03
【问题描述】：

我有这个功能需要测试：

login(): void {
    this.userService.setSessionAndDateOnlogin();
    this.loginService.getLogin()
      .subscribe(
        octopusUrl => window.location.href = octopusUrl);
  }

我使用 window.location.href 导航到外部 URL。

这是我的测试：

it('login function should call the setSessionAndDateOnLogin function from the userservice and\
   subscribe to the  getLogin function of the loginService.',
    fakeAsync(
      inject(
        [LoginComponent, LoginService, UserService],
        (loginComponent: LoginComponent, loginService: LoginService, userService: UserService) => {
          spyOn(userService, 'setSessionAndDateOnlogin');
          loginComponent.login();
          expect(userService.setSessionAndDateOnlogin).toHaveBeenCalled();
        })
    )
  );

当我运行此测试时，我收到以下错误：

您的一些测试重新加载了整个页面！

所以我尝试模拟窗口对象：

import { window } from '@angular/platform-browser/src/facade/browser';
...
class MockWindow {
  location: {
    href: ''
  };
}
...
beforeEach(() => addProviders([
    ...
    { provide: window, useClass: MockWindow }
  ]));

这没有改变，错误仍然存在。

有人有解决这个问题的办法吗？

【问题讨论】：

标签： unit-testing angular jasmine window.location

【解决方案1】：

Window 是一个接口，不能被注入。你应该使用 OpaqueToken

import {Injectable, OpaqueToken, Inject} from '@angular/core';

export const WindowToken = new OpaqueToken('Window');
export const SomeServiceWithWindowDependencyToken = new OpaqueToken('SomeServiceWithWindowDependency');

export function _window(): Window {
  return window;
}


export class SomeServiceWithWindowDependency {
  private window: Window;

  constructor(@Inject(WindowToken) window: Window) {
    this.window = window;
  }
}

然后在测试中

describe('SomeServiceWithWindowDependency', () => {
  beforeEach(() => {
    let mockWindow: any = {
      location: {
        hostname: ''
      }
    };
    TestBed.configureTestingModule({
      providers: [
        {provide: WindowToken, useValue: mockWindow},
        {provide: SomeServiceWithWindowDependencyToken, useClass: SomeServiceWithWindowDependency}
      ]
    });
  });
  it('should do something', inject([SomeServiceWithWindowDependencyToken, WindowToken], (tested: SomeServiceWithWindowDependency, window: Window) => {
    window.location.hostname = 'localhost';
    expect(tested.someMethod()).toBe('result');
  }));
});

记得配置app模块使用真实的window对象

@NgModule({
 declarations: [
    ...
  ],
  imports: [
    ...
  ],
  providers: [
    ...
    {provide: WindowToken, useFactory: _window},
  ],
  bootstrap: [AppComponent]
})
export class AppModule {
}

【讨论】：