If you have no idea what the usage is you are already doomed. However tests helps, whenever there is a regression you should write a test so that the same thin

If you have no idea what the usage is you are already doomed. However tests helps, whenever there is a regression you should write a test so that the same thing wont regress again. Writing code is not like in real life where herd mentally usually saves your life. Go ahead and improve the code, what helps is tests... but also at least logging errors, and throwing errors. Tests and errors go hand in hand. Errors are not your enemy, errors helps you improve the program.