Same here in Munich, we've had a course on software-testing in OOP-languages and had to write unit-tests for some modules of jenkins which were graded and eventually merged into master.

That sounds pretty cool. Do you get a choice of what kind of project you want to contribute to?

Sorry - should've been more clear. It's a project written by the staff in Java and Angular. It's been used continuously through the years, evolving each semester with the best contributions being merged. I believe it's a health management service, I haven't taken the course yet.