I learned unit testing early at UCDavis. My professor would take in assignments via ssh, run them, if it failed, it would "echo F" for grade.
In the future I'm hoping to run their tests inside Valgrind to check for memory leaks, enable the various sanitizers, etc., and I also need to figure out a way to check for conformance with my code formatting standard, but for right now it gives students perfect knowledge of what their grade will be when they submit.
That said, I spent a lot of time building extracurricular websites in my spare time, which was also a huge leg up in my future career.