What are the goals of Unit Testing?

• Test each part (unit) of the code in isolation.

• Create tests that retain their value over time.

• Create much larger regression tests that help demonstrate that the entire system still works (or not) after changes.

• In the XP view, if a program feature lacks an automated test it is assumed that it doesn't work.

• Unit tests ensure that we don't break one another's code.

• Reinforcement of the philosophy of working backwards.

• Test first, by intention.

• Write new code only when you have a test that doesn't work.

• Write code as if someone has already written the hard method for you, and you just have to send the message.

• Write the code you want to see without worrying about the infrastructure that supports it.

• Testing affects the system design. Don't put code in places that are hard to test.