I find tests to be invaluable especially in times of high churn and lots of changes. First they force me to think of my design in terms of components I can comp

I find tests to be invaluable especially in times of high churn and lots of changes. First they force me to think of my design in terms of components I can compose together into higher level systems, and when I find one of those components or systems is no longer how I want it I can make changes with my test suite telling me what I've broken, and what I haven't broken.