They are also a word of encouragement to whoever sees your code for the first time because he needs to make a change in it, five years from now. "Look, this co

They are also a word of encouragement to whoever sees your code for the first time because he needs to make a change in it, five years from now. "Look, this code looks strange to you, you would have done it differently, and you are afraid you might break things you don't even know exist. But fear not, there are tests, they run, and they will guide you." It's always relieve to find that some random old crap is actually well tested.