Tests define intent. Usually when you craft something, you have an idea of what you want going in. You may even draw it, and in the case of construction project

Tests define intent. Usually when you craft something, you have an idea of what you want going in. You may even draw it, and in the case of construction projects, fully 3d render it. Tests are the programmer equivalent, they define a contract you expect from your functions, which can then help you shape the function itself.