我最近在我的工作场所经历了完全相同的经历，发现大多数人都知道理论上的好处，但必须具体地向他们推销这些好处，所以下面是我使用的(成功地)要点:

它们在执行负测试(处理意外输入(空指针、越界值等)时节省了时间，因为您可以在单个进程中完成所有这些。 它们在编译时提供关于更改标准的即时反馈。 它们对于测试在正常运行时可能不会公开的内部数据表示非常有用。

还有那个大的…

您可能不需要单元测试，但是当其他人进入并在没有完全理解的情况下修改代码时，它可以捕捉到他们可能犯的许多愚蠢的错误。

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。

单元测试很像去健身房。你知道这对你有好处，所有的争论都有意义，所以你开始锻炼。刚开始有一种冲动，这很好，但几天后你开始怀疑是否值得这样做。你每天花一个小时换衣服，在仓鼠转轮上跑步，你不确定除了腿和手臂疼痛之外，你真的得到了什么。

然后，也许一两周后，就在疼痛消失的时候，一个重要的截止日期开始来临。你需要把醒着的每一个小时都用来完成“有用的”工作，所以你要去掉无关紧要的事情，比如去健身房。你改掉了这个习惯，当截止日期结束的时候，你又回到了起点。如果你设法回到健身房，你会觉得和你第一次去的时候一样酸痛。

You do some reading, to see if you're doing something wrong. You begin feel a little bit of irrational spite toward all the fit, happy people extolling the virtues of exercise. You realize that you don't have a lot in common. They don't have to drive 15 minutes out of the way to go to the gym; there is one in their building. They don't have to argue with anybody about the benefits of exercise; it is just something everybody does and accepts as important. When a Big Deadline approaches, they aren't told that exercise is unnecessary any more than your boss would ask you to stop eating.

所以，回答你的问题，单元测试通常是值得付出努力的，但是所需的努力量对每个人来说都不一样。如果你在一家不重视代码质量的公司处理意大利面条式的代码库，那么单元测试可能需要付出巨大的努力。(许多经理会歌颂单元测试，但这并不意味着他们会在关键时刻支持单元测试。)

如果你正试图将单元测试引入到你的工作中，并且没有看到你所期待的所有阳光和彩虹，不要责怪自己。你可能需要找一份新工作来真正让单元测试为你工作。

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)。

关于这个话题，我写了一篇很大的博客文章。我发现单靠单元测试是不值得的，而且通常在截止日期临近时就会被削减。

与其从“测试后验证”的角度来讨论单元测试，我们应该看看在实现之前编写规范/测试/想法时所发现的真正价值。

这个简单的想法改变了我写软件的方式，我不会回到“旧的”方式。

测试优先开发如何改变了我的生活

当你说“我们的代码库不适合简单的测试”时，这是代码气味的第一个迹象。编写单元测试意味着您通常以不同的方式编写代码，以使代码更具可测试性。在我看来，这是一件好事，因为多年来我在编写代码时看到我必须为其编写测试，这迫使我提出更好的设计。