为什么使用jasmine的运行和waitFor函数是必要的？ [英] Why is using jasmine's runs and waitFor function necessary?

问题描述

我正在测试一段异步代码，其内容如下所示：

I'm testing an asynchronous piece of code with something that looks like this:

randomService.doSomething().then(function() {
    console.log('I completed the operation!');
});

令人惊讶（对我而言）我发现它只是成功（即显示console.log输出）当包装在jasmine的中运行函数时，如下所示：

Surprisingly (to me) I've found that it only succeeds (ie console.log output is shown) when wrapped inside jasmine's runs function, like so:

var isDone = false;

runs(function() {
    randomService.doSomething().then(function(data) {
        console.log('I completed the operation!');
        isDone = true;
    });
});

waitsFor(function() {
    return isDone;
}, 'Operation should be completed', 1000);

据我了解，我认为 waitsFor 只是为了延迟代码，换句话说我会使用它，如果我有更多的代码，我必须延迟，直到异步调用完成后 - 换句话说，我会认为我没有理由使用运行和 waitsFor 因为这段代码后没有任何内容，对吧？这是我从阅读这个问题得到的印象：茉莉花运行和等待什么实际上做了什么？但显然我在某些时候已经把自己搞砸了。

As I understood it, I thought waitsFor was only to delay the code, in other words I would use it if I had more code that I had to delay until after the asynchronous call completed - in other words, I would have thought that there'd be no reason for me to use runs and waitsFor since there's nothing that comes after this bit of code, right? That's the impression I got from reading this question: What do jasmine runs and waitsFor actually do? but obviously I've gotten myself mixed up at some point.

有没有人对此有任何想法？

Does anyone have any thoughts on this?

编辑：
这是一个有更多细节问题的Plunker：
http://plnkr.co/edit/3qnuj5N9Thb2UdgoxYaD?p=preview

注意第一个测试总是通过，第二个测试总是通过测试失败了。
另外，我确定我之前应该提到这个，但这是使用angularJS和Jasmine 1.3。

Note how the first test always passes, and the second test fails as it should. Also, I'm sure I should have mentioned this before, but this is using angularJS, and Jasmine 1.3.

推荐答案

<我觉得我发现了这个问题。以下是文章： http：// blogs.lessthandot.com/index.php/webdev/uidevelopment/javascript/testing-asynchronous-javascript-w-jasmine/

基本上这是必要的，因为Jasmine在完成测试之前不等待异步调用完成。根据这篇文章，如果一个调用需要足够长的时间并且稍后会有更多的测试，那么先前测试中的异步回调中的 expect 语句最终可以完全在另一个测试中执行，原始测试完成后。

Essentially it's necessary because Jasmine doesn't wait for the asynchronous calls to finish before it completes a test. According to the article, if a call takes long enough and there are more tests later, an expect statement in an asynchronous callback in a previous test could finally execute in a different test entirely, after the original test completed.

使用运行和等待解决问题，因为他们强迫茉莉等待 waitsFor 完成，然后再进行下一次测试;这是一个没有实际意义的点，但是因为显然Jasmine 2.0以比1.3更好的方式处理异步测试，淘汰运行和 waitsFor 。

Using runs and waitsFor solve the problem because they force jasmine to wait for the waitsFor to finish before proceeding to the next test; This is a moot point however because evidently Jasmine 2.0 addresses asynchronous testing in a better way than 1.3, obsoleting runs and waitsFor.

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