Referring more to smaller places like my own - few hundred employees with ~20 person IT team (~10 developers).
I read enough about testing that it seems industry standard. But whenever I talk to coworkers and my EM, it’s generally, “That would be nice, but it’s not practical for our size and the business would allow us to slow down for that.” We have ~5 manual testers, so things aren’t considered “untested”, but issues still frequently slip through. It’s insurance software so at least bugs aren’t killing people, but our quality still freaks me out a bit.
I try to write automated tests for my own code, since it seems valuable, but I avoid it whenever it’s not straightforward. I’ve read books on testing, but they generally feel like either toy examples or far more effort than my company would be willing to spend. Over time I’m wondering if I’m just overly idealistic, and automated testing is more of a FAANG / bigger company thing.
Sometimes you’d use defensive programming (type checker, exception handling, null safeguards, fallback/optional values) which can be argued as a sort of in-place testing, so testing can be not as beneficial to your projects’ robustness as the readability of their core business logic. And some languages would lean more heavily towards defensive programming (e.g. Go, Scala or well written Typescript) and some would rely more on tests but also be designed in a way that makes testing really easy as they seek to keep things loosely coupled (Elixir or Clojure).
Also if your language doesn’t have a quality REPL to reliably test things manually, there is a relatively high chance you debugging process is causing you to waste more time than having a good test coverage.
I think even in languages that do a lot at compile time (Rust, Haskell, etc.) it’s still standard practice to write tests. Maybe not as many tests as e.g. Python or JavaScript or Ruby. But still some.
I work in silicon verification and even where things are fully formally verified we still have some tests. (Generally because the formal verification might have mistakes or omissions, and occasionally there are subtle differences between formal and simulation.)
What the fuck