多年来，我一直试图说服人们，他们需要为自己的代码编写单元测试。无论他们是先编写测试(如TDD)还是在编写功能之后，我总是试图向他们解释对代码进行单元测试的所有好处。几乎没有人反对我。你不能否认一些显而易见的事情，任何聪明的人都会看到单元测试和TDD的好处。

单元测试的问题在于它需要行为上的改变，而要改变人们的行为是非常困难的。用语言，你会让很多人同意你的观点，但你不会看到他们做事的方式有太多变化。

你必须通过行动来说服人们。你的个人成功会比你的争论吸引更多的人。如果他们看到你不只是在谈论单元测试或TDD，而是在做你鼓吹的事情，而且你是成功的，人们就会试图模仿你。

You should also take on a lead role because no one writes unit test right the first time, so you may need to coach them on how to do it, show them the way, and the tools available to them. Help them while they write their first tests, review the tests they write on their own, and show them the tricks, idioms and patterns you've learned through your own experiences. After a while, they will start seeing the benefits on their own, and they will change their behavior to incorporate unit tests or TDD into their toolbox.

改变不会在一夜之间发生，但只要有一点耐心，你就可能实现你的目标。

当涉及到重构或重写一段代码时，单元测试也特别有用。如果您有良好的单元测试覆盖率，您就可以满怀信心地进行重构。如果没有单元测试，通常很难确保您没有破坏任何东西。

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。

Unit testing helps a lot in projects that are larger than any one developer can hold in their head. They allow you to run the unit test suite before checkin and discover if you broke something. This cuts down a lot on instances of having to sit and twiddle your thumbs while waiting for someone else to fix a bug they checked in, or going to the hassle of reverting their change so you can get some work done. It's also immensely valuable in refactoring, so you can be sure that the refactored code passes all the tests that the original code did.

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。

我在几年前发现了TDD，从那时起我就使用它编写了所有我喜欢的项目。我估计，TDD一个项目所花费的时间与牛仔式地组合一个项目所花费的时间大致相同，但我对最终产品的信心增加了，以至于我忍不住有一种成就感。

我还觉得它改进了我的设计风格(更面向界面，以防我需要一起模拟东西)，而且，正如顶部的绿色帖子所写的，它有助于“编码便秘”:当你不知道接下来要写什么，或者你有一个令人生畏的任务摆在你面前时，你可以写小一点的。

最后，我发现到目前为止，TDD最有用的应用是在调试中，如果仅仅因为您已经开发了一个询问框架，那么您就可以用它来刺激项目以可重复的方式产生错误。