Someone please explain how I can use unit testing or test driven development w/ codeigniter

[eluser]Unknown[/eluser]
Under my controllers directory I created a folder called testcases.
I am using the codeigniter cli interface for running my tests.

I just started with codeigiter, I assume I can place phpunit tests in this directory and run the tests via a script.

But while boot straping into a new project I have something to get going.