Rinse and Repeat with TDD
Wed 25 November 2009
I must confess having had a awed love relationship with TDD (Test Driven Development). This is the style where you first write the test cases and then write the code to make them pass. I've always felt awed by it. I have always firmly believed that it is the right way to offer sustainable quality. As someone who hasn't been particularly awed by separate QA teams, I have always imagined TDD to be the silver bullet to offer controlled, sustained, high quality. Well, the silver bullet is a bit of an exaggeration, but sounded nice while I was on a roll :). A number of times I wrote automated test cases post facto. But when the rubber met the road - I didn't ever implement TDD.
Its probably a function of style. I like to write a piece of code and then keep on testing it against different scenarios and often keep on remoulding it substantially. My focus is at this stage on the code structure - the design aspects. Trying to do it with TDD always created a mess. The amount of intense refactoring I do always meant I soon got tired of also simultaneously refactoring the test cases and gave up on them soon.
Anyways, I finally think I found a formula that works - at least for me. I do not write production code in the first pass. I just write prototype code. I keep on playing with it, shaping it, challenging it, cajoling it, recasting it. Until I'm satisfied with the overall structure and internal design. Now when thats done, I rewrite it. Completely. Umm, I copy/paste maybe 40-50% of the code. But this time I write it on a completely new fresh set of files. And I write the test cases before I write the code. I find I can now really write tons of test cases and code quite rapidly. And with the tremendous satisfaction that at the end of the day, I now have the control harness to be able to keep on adding new features without having to continuously worry if I broke something else. With substantially detailed test cases, now I can actually feel quite confident that if I did break something - I'll get to know it. Not next month, not next week, not even tomorrow - in the next few minutes.
So this approach seems to be working for me - the initial efforts have delivered great results and I'm quite satisfied. Now just wondering what to call it - for lack of a better term I shall term it "Rinse and Repeat with TDD".
So if TDD works for you - great. You have one of the most important coding disciplines nailed down. But if you're wanting to try to do TDD but haven't been able to successfully implement it - you may just want to check out the Rinse and Repeat with TDD style. Who knows, you might find it useful too.