Do you all ever plan on making a course going over unit testing, and the best way to say, test a game that uses a State Machine?
I doubt we'll make an entire course dedicated to unit testing. It may show up in a best practices guide somewhere down the line, however.
The issue is that TDD works best with complex systems where knock-on effects from changes are common. In most game courses, we try to limit the scope, which means a smaller game, which means little need for test driven development or unit tests.
Still, you should investigate Gut, a Godot library for unit tests in Godot.
I talked with experienced game developers, and the thing is it's quite difficult to find what to test.
When you're working on the large game, I can totally see places that you would want to test and ensure you're not breaking anything.
But when it comes to games, I feel integration testing and benchmarking might be much more beneficial than unit testing on the gameplay side (the engine itself has tests and handles many errors for you).
My biggest problem there is to find code to test that really make a positive difference in your codebase. As always, something that's reality-based and is worth the investment.
I know some cases like unit testing your server code and libraries when many persons use them. But in the kind of stuff we teach at the moment, there's not really a great use for them.