什么时候应该使用$提供与在我的角度JS单元测试茉莉花间谍 [英] When should I use $provide versus Jasmine Spies in my Angular JS Unit tests

问题描述

我在一个大角度应用工作，首先我们通过使用$提供模拟服务做了很多我们的测试。但是，我们现在有很多在我们的测试茉莉花间谍，以存根和窥探的服务。

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'

我们应该真正使用$提供此还是有哪里上的服务的间谍是最好的方法？案例

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

在他们使用的间谍为<一期角测试href=\"https://github.com/angular/angular.js/blob/ccd4227cfe2e12b8a9b7f6a7a18b210fd799677c/test/ng/directive/aSpec.js#L68\"相对=nofollow>间谍jQuery的，我会看到作为一个外部服务。

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

spyOn(jq.prototype, 'on');

<一个href=\"https://github.com/angular/angular.js/blob/6476aed7626fa7b4adefa99c5cb4a86ed371835c/test/ng/exceptionHandlerSpec.js\"相对=nofollow> $提供似乎是内部服务被使用了。

$provide seems to be used more for internal services.

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

还有一个茉莉花createSpy功能，但现在我在想，$提供应始终以precedence了这一点。

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

在这个任何见解或帮助将是AP preciated。

Any insights or help in this would be appreciated.

推荐答案

从我自己的（有限）的经验，我会说尽一切办法使：

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

• 测试code简单/更清晰/短


• 限制什么的code你的测试内部做的假设。


• 降低其副作用的影响（如实际运行Ajax请求）


• 保持试验尽可能短，在字词或运行时间。

通常 spyOn 办法工作时，为了做到上述情况，我想从存根服务/工厂一个方法。如果我需要模拟一个完整的服务/工厂，然后用 $提供。

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.

一个少数特定情况下会想到需要一个或另一个：

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

• 如果你正在测试一项服务，然后存根从该服务的其他方法，你将不得不使用 spyOn

要确保额外的依赖并不被测后来在code出台，比 $提供更增添了一点保障。也就是说，如果你想确保 ServiceA 只要求 myMethod的从 ServiceB ，然后 $提供我觉得这是要走的路，仿佛 ServiceA 要求从任何未定义的方法 ServiceB 在测试过程中，错误将得到提升。

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() {}
});

如果你想嘲笑一个工厂，返回的函数，因此：

If you want to mock a factory that returns a function, so:

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

哪个用作

myFactory(option);

然后，以验证某些code调用 myFactory（选购件）我觉得没有办法，然后使用 $提供来嘲弄工厂。

Then to verify that some code calls myFactory(option) I think there is no alternative then to use $provide to mock the factory.

只是顺便说说，他们不是互相排斥的选项。您可以使用 $提供然后还有涉及间谍。在previous例如，如果您想验证工厂被称为一个选项，您可能需要：

Just by the way, they're not mutually-exclusive options. You can use $provide and then still have spies involved. In the previous example, if you want to verify the factory was called with an option, you might have to:

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

和随后在适当的点上的测试

And then in the test at the appropriate point:

expect(myFactorySpy).toHaveBeenCalledWith(option);

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