[TeMPOraL]

Yes. You write a function ApplyFooToBar(), and then unit tests that check that, when supplied with right Foos, the function indeed applies those Foos to the Bar. It's not a very intellectually challenging work.

If anything, the challenge is with all the boilerplate surrounding the test, because you can't just write down what the test checks themselves - you need to assemble data, assemble expected result, which you end up DRY-ing into support modules once you have 20 tests needing similar pre-work, and then there's lots of other bullshit to deal with at the intersection between your programming language, your test framework, and your modularization strategy.