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验证Mockito和PowerMock是否捕获到异常

[英]Verify that exception was caught with Mockito and PowerMock

原文 2013-07-09 14:08:19 9 4 java/ junit/ mockito/ powermock

Is there any way to verify that exception was caught? 有没有办法验证异常是否被捕获？ I mean that in my method there is a situation when I should catch the exception and in test I want to verify that exception was really caught. 我的意思是在我的方法中有一种情况，我应该捕获异常，在测试中，我想验证异常是否真正被捕获。

4 个解决方案

I think the answer is no -- perhaps you could pull it off with some intense reflection wrangling, but if so I don't think it would be worth your time. 我认为答案是否定的 - 或许你可以通过一些激烈的反思争论来解决这个问题，但如果是这样的话，我认为这不值得你花时间。

But I think (without seeing your method), you can probably still get full coverage on your method: 但我认为（没有看到你的方法），你仍然可以完全覆盖你的方法：

If your method takes any action after catching the exception, assert or verify that those actions happened. 如果您的方法在捕获异常后采取任何操作，则断言或验证这些操作是否发生。
If no action happens after catching the exception, assert or verify that whatever actions were supposed to happen but were cut off by the exception, didn't happen. 如果在捕获异常后没有发生任何操作，则断言或验证应该发生的任何操作但被例外中断，都没有发生。
Finally, (again, not seeing your method I don't know exactly what you're dealing with) if your method is void, and nothing happens after catching the exception, and the last line of logic is what can throw the exception, then consider making your method return a boolean, have it return false if the exception is caught and true otherwise. 最后，（再次，没有看到你的方法我不知道你正在处理什么）如果你的方法是无效的，并且在捕获异常后没有任何反应，最后一行逻辑是什么可以抛出异常，那么考虑让你的方法返回一个布尔值，如果异常被捕获则返回false，否则返回true。 Then in your test, make a scenario that should cause the exception to be thrown and caught, and test that the method returns false. 然后在测试中，创建一个应该引发异常并捕获异常的场景，并测试该方法返回false。

Hard to give any advice without any example. 没有任何例子，很难给出任何建议。 But if the exception wouldn't be caught it would went up till it reaches the test and the test would fail, because an exception was thrown. 但是如果异常没有被捕获，它会一直运行直到达到测试并且测试失败，因为抛出异常。 I know that doesn't verify that it was caught in a specific block but just that it was caught at all. 我知道这不会验证它是否被捕获在特定块中，而只是它被捕获了。

What does that exception do in your program if it is not caught? 如果没有捕获，那么您的程序中的异常会怎样？ If it causes the program to crash, you can just run your Act part of the test within a try {} block. 如果它导致程序崩溃，您可以在try {}块中运行您的Act部分测试。 If it throws an exception you can catch it and fail the test. 如果它抛出异常，你可以捕获它并且不通过测试。

Another option, if the cacught exception causes a method to be called, say printToLog() you can verfiy that the method was indeed called with the correct parameters (using mockito). 另一种选择，如果cacught异常导致调用方法，比如printToLog（），你可以确认该方法确实是用正确的参数调用的（使用mockito）。

You should be able to mock the element that you want to throw the exception, so that it does throw the exception and then check that there were no calls to other methods that would be invoked if no exception had occurred. 您应该能够模拟要抛出异常的元素，以便它抛出异常，然后检查在没有发生异常的情况下没有调用其他方法。

Also check the state is as expected when an exception is thrown. 还会在抛出异常时检查状态是否符合预期。