問題描述

我在一個大型 Angular 應(yīng)用程序上工作，最初我們通過使用 $provide 來模擬服務(wù)進行了很多測試.但是，我們現(xiàn)在在測試中使用了很多 Jasmine Spies，以便對服務(wù)進行存根和監(jiān)視.

I work on a large Angular App and initially we done a lot of our tests by using $provide to mock services. However we now have a lot of Jasmine Spies in our tests in order to stub and spy on services.

即

spyOn(myService, 'myMethod').andReturn 'myValue'

我們真的應(yīng)該為此使用 $provide，還是在某些情況下監(jiān)視服務(wù)是最好的方法?

Should we really be using $provide for this or are there cases where spying on a service is the best approach?

在 Angular 測試中，他們使用間諜來監(jiān)視 Jquery 我將其視為外部服務(wù).

In the Angular Tests they use spies for spying on Jquery which I would see as an external service.

spyOn(jq.prototype, 'on');

$provide 似乎更多地用于內(nèi)部服務(wù).

$provide seems to be used more for internal services.

  module(function($provide){
    $provide.provider('$exceptionHandler', $ExceptionHandlerProvider);
  });

還有一個 Jasmine createSpy 函數(shù)，但現(xiàn)在我認為 $provide 應(yīng)該始終優(yōu)先于它.

There is also a Jasmine createSpy function but now I'm thinking that $provide should always take precedence over that.

對此的任何見解或幫助將不勝感激.

Any insights or help in this would be appreciated.

推薦答案

根據(jù)我自己的(有限的)經(jīng)驗，我會說做任何方法:

From my own (limited) experience, I would say do whatever approach makes:

• 測試代碼更簡單/更清晰/更短
• 限制關(guān)于您的測試在內(nèi)部執(zhí)行的代碼的假設(shè).
• 減少其副作用(例如運行實際的 Ajax 請求)
• 在條款或運行時間方面盡可能縮短測試時間.

通常 spyOn 方法會起作用，為了完成上述操作，我想從服務(wù)/工廠中存根單個方法.如果我需要模擬整個服務(wù)/工廠，請使用 $provide.

Usually the spyOn approach works when, in order to do the above, I would like to stub a single method from a service / factory. If I need to mock an entire service / factory, then use $provide.

我想到了一些需要其中之一的特定情況:

A few specific cases come to mind that require one or the other:

• 如果您正在測試一項服務(wù)，然后要從該服務(wù)中存根其他方法，您必須使用 spyOn

為了確保稍后不會在被測代碼中引入額外的依賴項，$provide 增加了一些保護.說，如果你想確保 ServiceA 只需要 ServiceB 中的 myMethod，那么 $provide 我認為會是走的路，好像 ServiceA 在測試期間從 ServiceB 調(diào)用任何未定義的方法，都會引發(fā)錯誤.

To ensure that extra dependencies aren't introduced later in the code under test, than $provide adds a bit more protection. Say, if you want to ensure that ServiceA only requires myMethod from ServiceB, then $provide I think would be the way to go, as if ServiceA calls any undefined methods from ServiceB during the test, errors would be raised.

$provide.provider('ServiceB', {
    myMethod: function() {}
});

app.factory('myFactory', function() {
  return function(option) {
    // Do something here
  }
});

myFactory(option);

var myFactorySpy = jasmine.createSpy();
$provide.provider('myFactory', myFactorySpy);

expect(myFactorySpy).toHaveBeenCalledWith(option);