使用 Jasmine 监视构造函数

2022-01-11 00:00:00 jasmine javascript spy

我正在使用 Jasmine 测试是否创建了某些对象并在它们上调用了方法.

I am using Jasmine to test if certain objects are created and methods are called on them.

我有一个 jQuery 小部件，它创建翻转计数器对象并在它们上调用 setValue 方法.翻转计数器的代码在这里:https://bitbucket.org/cnanney/apple-style-flip-counter/src/13fd00129a41/js/flipcounter.js

I have a jQuery widget that creates flipcounter objects and calls the setValue method on them. The code for flipcounter is here: https://bitbucket.org/cnanney/apple-style-flip-counter/src/13fd00129a41/js/flipcounter.js

翻转计数器是使用以下方法创建的:

The flipcounters are created using:

var myFlipCounter = new flipCounter("counter", {inc: 23, pace: 500});

我想测试是否创建了翻转计数器并在它们上调用了 setValue 方法.我的问题是我如何在这些对象被创建之前监视它们?我是否监视构造函数并返回假对象?示例代码真的很有帮助.谢谢你的帮助！:)

I want to test that the flipcounters are created and the setValue method is called on them. My problem is that how do I spy on these objects even before they are created? Do I spy on the constructor and return fake objects? Sample code would really help. Thanks for your help! :)

更新:

我试过像这样监视 FlipCounter:

I've tried spying on the flipCounter like this:

myStub = jasmine.createSpy('myStub');
spyOn(window, 'flipCounter').andReturn(myStub);

//expectation
expect(window.flipCounter).toHaveBeenCalled();

然后通过flipCounter测试setValue调用:

Then testing for the setValue call by flipCounter:

spyOn(myStub, 'setValue');

//expectation
expect(myStub.setValue).toHaveBeenCalled();

初始化flipCounter 的第一个测试很好，但是对于测试setValue 调用，我得到的只是setValue() 方法不存在"错误.我这样做对吗?谢谢！

the first test for initializing flipCounter is fine, but for testing the setValue call, all I'm getting is a 'setValue() method does not exist' error. Am I doing this the right way? Thanks!

推荐答案

flipCounter 只是另一个函数，即使它也恰好构造了一个对象.因此你可以这样做:

flipCounter is just another function, even if it also happens to construct an object. Hence you can do:

var cSpy = spyOn(window, 'flipCounter');

得到一个间谍，并对其进行各种检查或说:

to obtain a spy on it, and do all sorts of inspections on it or say:

var cSpy = spyOn(window, 'flipCounter').andCallThrough();
var counter = flipCounter('foo', options);
expect(cSpy).wasCalled();

但是，这似乎有点过头了.这样做就足够了:

However, this seems overkill. It would be enough to do:

var myFlipCounter = new flipCounter("counter", options);
expect(myFlipCounter).toBeDefined();
expect(myFlipCounter.getValue(foo)).toEqual(bar);

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