在我们的办公室里，每天都有这样的对话:

“伙计，我就是喜欢单元测试，我刚刚能够对某些东西的工作方式进行了一系列更改，然后能够通过再次运行测试来确认我没有破坏任何东西……”

细节每天都在变化，但情绪却不变。单元测试和测试驱动开发(TDD)有很多隐藏的和个人的好处，也有很多明显的好处，除非他们自己做，否则你无法真正向他们解释。

但是，忽略这一点，下面是我的尝试!

Unit Tests allows you to make big changes to code quickly. You know it works now because you've run the tests, when you make the changes you need to make, you need to get the tests working again. This saves hours. TDD helps you to realise when to stop coding. Your tests give you confidence that you've done enough for now and can stop tweaking and move on to the next thing. The tests and the code work together to achieve better code. Your code could be bad / buggy. Your TEST could be bad / buggy. In TDD you are banking on the chances of both being bad / buggy being low. Often it's the test that needs fixing but that's still a good outcome. TDD helps with coding constipation. When faced with a large and daunting piece of work ahead writing the tests will get you moving quickly. Unit Tests help you really understand the design of the code you are working on. Instead of writing code to do something, you are starting by outlining all the conditions you are subjecting the code to and what outputs you'd expect from that. Unit Tests give you instant visual feedback, we all like the feeling of all those green lights when we've done. It's very satisfying. It's also much easier to pick up where you left off after an interruption because you can see where you got to - that next red light that needs fixing. Contrary to popular belief unit testing does not mean writing twice as much code, or coding slower. It's faster and more robust than coding without tests once you've got the hang of it. Test code itself is usually relatively trivial and doesn't add a big overhead to what you're doing. This is one you'll only believe when you're doing it :) I think it was Fowler who said: "Imperfect tests, run frequently, are much better than perfect tests that are never written at all". I interpret this as giving me permission to write tests where I think they'll be most useful even if the rest of my code coverage is woefully incomplete. Good unit tests can help document and define what something is supposed to do Unit tests help with code re-use. Migrate both your code and your tests to your new project. Tweak the code till the tests run again.

我参与的很多工作都没有很好地进行单元测试(web应用程序用户交互等)，但即使如此，我们在这个商店里都被测试感染了，当我们把测试束缚住时，我们最高兴。我怎么极力推荐这种方法都不为过。

如果你正在使用NUnit，一个简单而有效的演示就是在他们面前运行NUnit自己的测试套件。看到一个真正的测试套件对代码库进行测试，胜过千言万语……

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)。

最好的说服方式是……找到一个bug，为它写一个单元测试，修复这个bug。

这个特定的错误不太可能再次出现，您可以通过测试来证明它。

如果你做得足够多，其他人很快就会明白。

你想说服谁?工程师还是经理?如果你试图说服你的工程师同事，我认为你最好的办法是迎合他们的愿望，让他们做出高质量的软件。有许多研究表明，它能发现漏洞，如果他们关心做好工作，这对他们来说就足够了。

如果您试图说服管理层，您将很可能不得不做一些成本/收益推理，说明未检测到的缺陷的成本大于编写测试的成本。一定要把不可转化的成本也包括在内，比如失去客户的信心等等。

测试驱动开发中经常被忽略的一个主要部分是可测试代码的编写。乍一看，这似乎是一种妥协，但您会发现可测试代码最终也是模块化的、可维护的和可读的。 如果你仍然需要说服别人，这是一个关于单元测试优点的简单演示。