[regularfry]

I find it utterly bizarre that this should still be a current topic of contention. Running unit tests against a local database was a norm in Rails a decade ago, because the framework made it trivial to set up.

Yes, there were knock-on performance questions that wanted answering - how do you avoid the database setup costs for those tests that don't care about it, for instance, the "fast Rails test" movement was a big thing - but by and large those were solved problems by the time I stopped writing Rails code professionally around the 5.1 era.

The answer is, of course, no, you don't spin up an entire instance of Oracle to run a single unit test. You run against a local instance, and you use whatever tricks your-RDBMS-of-choice gives you to make resetting the test tables to a known-good state extremely fast. That way you can have your tests running continuously, giving you fast feedback as you develop, only suffering db overheads when you actually need to run tests that hit it.

If your chosen stack makes it difficult to do this, it's worth asking why.