It depends a lot on what you work on and how you program. Virtually none of our software has actual coding errors, and when developers write new parts or change them, it’s always very obvious if something breaks. Partly because of how few abstractions we use, partly because of how short we keep our chains. Letting every function live in isolation and almost never being used by multiple parts of the software. Both the lack of abstractions and the lack of reuse is against a lot of principles, and it’s not exactly like we refuse to do either religiously, but the only real principle we have is YAGNI, and if you build and abstraction before you need it you’re never going to pass a code review. As far as code reuse goes, well, in the perfect world it’s sort of stupid to have a lot of duplicate code. In a world where a lot of code is written on a Thursday afternoon by people who are tired, their babies kept them awake, the meetings were horrible, management doesn’t do the right things and so on. Well, in that world it’s almost always better to duplicate code so that it doesn’t eventually become a complicated abstract mess. It shouldn’t, and I’m sure it doesn’t in some places, I’ve just never worked in such a place. I have worked with a lot of people who followed things like clean code religiously and the results were always unwieldy code where even small changes would take weeks to implement. Which is completely counterproductive to what the actual business needs. The benefit of YAGNI is that it mostly applies to tests as well, exactly because it’s basically impossible to make changes without knowing exactly what impact you’re having on the entire system.
What isn’t easy is business logic, and here I think tests are useful. Or at least they can be. Because far too often, the business doesn’t have a clue what they want up front. Even more often the business logic will change so rapidly that tests automated tests become virtually useless since you’re going to rely on acceptance tests anyway.
Like I said, I’m not religious about it. I sometimes write tests, but in my anecdotal experience things like full test-coverage is an insane waste of time over a long period.
What isn’t easy is business logic, and here I think tests are useful. Or at least they can be. Because far too often, the business doesn’t have a clue what they want up front. Even more often the business logic will change so rapidly that tests automated tests become virtually useless since you’re going to rely on acceptance tests anyway.
Like I said, I’m not religious about it. I sometimes write tests, but in my anecdotal experience things like full test-coverage is an insane waste of time over a long period.