Actually, I've written tests for half of that problem: Parsing ABC text into an internal format. That is a very clear problem and one just needs a representative set of input files (I now have around 500 of them -- the tests still run in less than a minute. It's true that I haven't been able to figure out a useful way to have an automated test for the drawing part. Here's my project: http://code.google.com/p/abcjs/