A couple of days ago I stumbled upon this post. Now, I won’t discuss the post itself (which I think is well structured and surely worth a read) but just its title, that states: it’s OK not to write unit tests.
I’ve been working in C# lately: unit testing in a static language is hell. The clutter created by all those interfaces you’re forced to create solely for mocking is enough reason for give testing up… and that’s just the beginning. So yes, if you’re working in C# (and I think it applies to Java too) it is totally OK not to write unit tests: on the contrary, you’ve gotta have a damn good reason to aim for 100% coverage on a C# project. And by damn good I mean the customer is paying for it because, honestly, maintaining those tests is gonna be a huge waste of time, and you better make sure you can bill that time to someone.
Things change big time when talking about a dynamic language, like ruby. Testing in ruby is so easy that it’s a waste not to do it. Tools are also much better than their .NET counterparts (think RSpec). You still have problems, especially during refactoring, but personally I didn’t feel like throwing my test suite away each time I had to break something. If it’s OK not to write unit tests in ruby? That depends on your situation, but surely the cost of testing is much lower.
Because that’s the point, and that’s what it made me think about the title in the first place: testing has a cost and it’s much higher than what the so-called agile mentors often promise… maybe because the “implementation details” – and the deadlines involved – are usually to be fulfilled by someone else. Telling someone that the cost of testing is lower than the cost of problems due to not testing is lying: it varies greatly according to the situation.
So of course it’s OK not to write unit tests. I wonder how we got to the point that somebody has to argument that. I feel like agile has acquired this silver bullet status and we know how much management love those… let’s stop this before bad things happen – the one who has to maintain the next enterprise behemoth with 2k+ tests that break at every gust of wind might be you.