In good software design, they say that testing is very important. Suppose you are writing software for a message board. You write tests to define how the system is expected to respond to actions like "new messages", "erase messages", "like messages". This is because, as you add more features, it's easy to make an unintended mistake to the code. So the tests protect you, who in this case is the programmer. It protects you from future change, some coming from the outside, some coming from oneself.
In good software design, it's possible that about half the work is actually testing.
One of the reasons I appreciate Buddhism is it's emphasis on testing. The Buddha didn't just proclaim, "I am the Buddha, all powerful, you must listen to me." In the Kalama Sutta and the sutta teaching his son, Rahula, he gives tests to judge whether something is useful or wise. He specifically says not to base your evaluation on your preferences or logic alone. First, he asks you to look at the results. Was it harmful or helpful? Is it praised by wise people, who may be able to see your blind spots? These are tests. Unlike tests at school that are meant to be stressful, these are tests that protect you.
