简而言之——是的。它们值得你付出每一分努力……在某种程度上。在一天结束的时候，测试仍然是代码，并且很像典型的代码增长，您的测试最终将需要重构，以便可维护和可持续。有一大堆的陷阱!当涉及到单元测试时，但是没有什么，我的意思是没有什么比丰富的单元测试集更能让开发人员更自信地进行更改了。

I'm working on a project right now.... it's somewhat TDD, and we have the majority of our business rules encapuslated as tests... we have about 500 or so unit tests right now. This past iteration I had to revamp our datasource and how our desktop application interfaces with that datasource. Took me a couple days, the whole time I just kept running unit tests to see what I broke and fixed it. Make a change; Build and run your tests; fix what you broke. Wash, Rinse, Repeat as necessary. What would have traditionally taken days of QA and boat loads of stress was instead a short and enjoyable experience.

提前准备，一点点额外的努力，当你不得不开始摆弄核心特性/功能时，它会给你带来十倍的回报。

我买了这本书——它是xUnit测试知识的圣经——它可能是我书架上被引用最多的书之一，我每天都在查阅它:链接文本

One of the best things about unit testing is that your code will become easier to test as you do it. Preexisting code created without tests is always a challenge because since they weren't meant to be unit-tested, it's not rare to have a high level of coupling between classes, hard-to-configure objects inside your class - like an e-mail sending service reference - and so on. But don't let this bring you down! You'll see that your overall code design will become better as you start to write unit-tests, and the more you test, the more confident you'll become on making even more changes to it without fear of breaking you application or introducing bugs.

There are several reasons to unit-test your code, but as time progresses, you'll find out that the time you save on testing is one of the best reasons to do it. In a system I've just delivered, I insisted on doing automated unit-testing in spite of the claims that I'd spend way more time doing the tests than I would by testing the system manually. With all my unit tests done, I run more than 400 test cases in less than 10 minutes, and every time I had to do a small change in the code, all it took me to be sure the code was still working without bugs was ten minutes. Can you imagine the time one would spend to run those 400+ test cases by hand?

当涉及到自动化测试——无论是单元测试还是验收测试——每个人都认为编写可以手动完成的代码是浪费精力，有时这是真的——如果你计划只运行一次测试的话。自动化测试最好的部分是，您可以毫不费力地运行它们几次，并且在第二次或第三次运行之后，您所浪费的时间和精力已经得到了补偿。

最后一个建议是，不仅要对代码进行单元测试，还要先进行测试(详见TDD和BDD)。

我在其他任何答案中都没有看到这一点，但我注意到的一件事是，我可以更快地调试。你不需要通过正确的步骤序列深入到你的应用程序中，只发现你犯了一个布尔错误，需要重新做一遍。使用单元测试，您可以直接进入正在调试的代码。

单元测试适用于QA人员或你的经理，而不是你;所以绝对不值得。

您应该专注于编写正确的代码(不管这意味着什么)，而不是测试用例。让其他人去担心吧。

单元测试的全部意义在于使测试变得简单。这是自动的。“make test”就完成了。如果您面临的问题之一是难以测试代码，那么这就是使用单元测试的最佳理由。

就在今天，我不得不更改一个类，之前已经为其编写了单元测试。 测试本身写得很好，包括我甚至没有想过的测试场景。 幸运的是，所有测试都通过了，我的更改很快得到了验证，并自信地放到了测试环境中。