Jasmine.js测试-监视window.navigator.userAgent [英] Jasmine.js Testing - spy on window.navigator.userAgent

问题描述

我需要找到更改userAgent值的方法.我尝试spyOn window.navigator.userAgent.但这无济于事.

I need to find the way to change userAgent value. I tried to spyOn the window.navigator.userAgent. But that's not helping.

JS :

@Injectable()
export class DetectBrowserService {
  browserIE: boolean;
  constructor() {
    this.browserIE = this.detectExplorer();
  }

  public detectExplorer() {
    const brows = window.navigator.userAgent;
    const msie = brows.indexOf('MSIE ');
    if (msie > 0) {
      // IE 10 or older => return version number
      return true;
    }
  }
}

规范:

it('should test window.navigator.userAgent', () => {
  const wind = jasmine.createSpy('window.navigator.userAgent');
  wind.and.returnValue('1111');
  detectBrowserService = TestBed.get(DetectBrowserService);
  console.log(window.navigator.userAgent);
});

我本来是1111，但是获得了有关我的浏览器的真实信息.

I was expecting 1111, but got the real info about my browser.

推荐答案

userAgent是window.navigator上的只读/常量属性. jasmine.createSpy通常用于在方法和NOT属性上创建间谍.

userAgent is a read-only/constant property on window.navigator. And jasmine.createSpy is generally used to create spies on methods and NOT properties.

现在，我尝试直接执行window.navigator.userAgent = '1111';，因为在测试中可以轻松访问window.navigator.但我收到一个错误消息:

Now, I tried directly doing window.navigator.userAgent = '1111'; as window.navigator would simply be accessible in my tests. But I was getting an error saying:

[ts] Cannot assign to 'userAgent' because it is a constant or a read-only property. (property) NavigatorID.userAgent: string

[ts] Cannot assign to 'userAgent' because it is a constant or a read-only property. (property) NavigatorID.userAgent: string

因此，唯一的选择是使用旧的__defineGetter__.这就是我在这里所做的:

So the only option was to use the good old __defineGetter__. So that's what I did here:

it('should test window.navigator.userAgent', () => {
  window.navigator['__defineGetter__']('userAgent', function(){
    return '1111' // Return whatever you want here
  });
  detectBrowserService = TestBed.get(DetectBrowserService);
  console.log(window.navigator.userAgent);
});

它有效:

希望这会有所帮助！

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