The way I've always approached this dilemma is to set up my testing framework and tooling so unit tests are possible, and then write them as I find bugs in earl

The way I've always approached this dilemma is to set up my testing framework and tooling so unit tests are possible, and then write them as I find bugs in early ad hoc testing. I know its very anti-TDD to write tests from a reactionary perspective, but I find this is a good way to gradually get test coverage where it is needed while still being able to prototype the parts of the side project that are interesting.