Power Of Tdd

why can't I feel the driven power of TestDrivenDevelopment?

I think it's helpful, but I cannot drive my development.

People who say that typically have not given up old habits, particularily the amount of editing permitted before passing all tests.

Start with this UncleBob Blog (UncleBlog?;):

http://www.butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd

It says...

• You are not allowed to write any production code unless it is to make a failing unit test pass.
• You are not allowed to write any more of a unit test than is sufficient to fail; and compilation failures are failures.
• You are not allowed to write any more production code than is sufficient to pass the one failing unit test.

Note the frequent use of "not allowed to write any more". That means you must make the smallest edit possible to achieve one of the three goals in the cycle. Write the smallest test that can fail, edit the least code to pass the test, and refactor in the smallest jumps possible to pass all tests.

This incredibly high granularity - one aspect of the TestInfected style - forces out most possibilities for bugs or bad design. The need to run the debugger or research advanced designs goes down. So your velocity goes up, even when it just feels like you are doing many small trivial things.

--PhlIp