How to start TDD/BDD PHP CodeIgniter

I have been reading about TDD/BDD for quite a while now but I could never figure out how to implement it in a project.

This is a simplified version of the project I am currently working :

A website that lets people signup, post used books for sale. People that needs these books can search for books posted for sale close-by and send an email message to the seller via the websi开发者_如何学运维te.

This is being written in CodeIgniter with me as the only developer working on it. For this scenario, can you please tell me how exactly would I go about testing - where to begin with and what would be tested.

I've been wanting to do this for quite a while, I kind of understand the concept, but the actual implementation eludes me, many thanks!

The unit tester that shipped with the last version of CI I used was poor, it just checked true or not.

I found this interesting project which seemed to be maintained up to last year at least:

http://jensroland.com/projects/toast/

Maybe there is something there to help you get started, maybe in the readme files - if not here is the original post where this idea seems to have emanated from.

http://codeigniter.com/forums/viewthread/76703

You could start off by checking your models bring back an expected set of values. ie assert true that "get first 10 books" actually brings back 10 records - this means setting up a test database however, and being able to set up (fill with test data) and tear down that database at will. That is a bit of a bind, but in an MVC situation when starting with TDD it might be the easiest to get your head round.

TDD (ie the idea of developing test/code in that order) makes the most sense when creating your own classes - which you might think of as "helpers" in a typical CI setup.