Test Driven Development
Modified on 06/03/2013 23:58 by Administrator — Categorized as: Test Type
What is test driven development?
Simple put,it is writing unit tests first then write the code that can pass the test. It was discovered by Kent Beck, a good friend of Ward Cunningham, so again we can go to
Wards Wiki
to see multiple points of view. It get's a bit technical at times and the bullet list below is an excerpt from
Test Driven Development on Ward's Wiki
.
Think about what you want to do.
Think about how to test it.
Write a small test. Think about the desired API.
Write just enough code to fail the test.
Run and watch the test fail. (The test-runner, if you're using something like JUnit, shows the "Red Bar"). Now you know that your test is going to be executed.
Write just enough code to pass the test (and pass all your previous tests).
Run and watch all of the tests pass. (The test-runner, if you're using JUnit, etc., shows the "Green Bar"). If it doesn't pass, you did something wrong, fix it now since it's got to be something you just wrote.
If you have any duplicate logic, or inexpressive code, refactor to remove duplication and increase expressiveness -- this includes reducing coupling and increasing cohesion.
Run the tests again, you should still have the Green Bar. If you get the Red Bar, then you made a mistake in your refactoring. Fix it now and re-run.
Repeat the steps above until you can't find any more tests that drive writing new code.