TAD Happier

Yesterday afternoon, it was not going well. Trying to write visualisation code, I was getting some unexpected null links. It was difficult code and tricky design, and I'd not been doing any test first work.

This morning, I aggressively changed it so that it could have tests. Test After Development, or TAD for short. Yes, I found the error (out by one). Code is testable. New feature added as a test first. Much happier.