Pair Programming and Pair Testing

Our programmers here at iMeta now wax lyrical about pair programming and it’s easy to see why. The quality of code coming through to the test team now is exceptional. There’s very few fix-fail episodes and the programmers seem over the moon with how great pair programming is fairing. Sure, there were teething issues and some programmers didn’t feel the groove when pairing but these were soon overcome and they moved forward.

It got me thinking though about whether or not testers should be pairing when writing test cases. And my conclusion is that they should. It brought back memories of when I used to have to send test cases off for peer review at a previous company. I too had to review other peoples tests. It did often become a chore but more importantly was that is missed the point. And here’s why:

• The review was more a sanity check on formatting, spelling, ensuring every step had an expected result, test case length was ok, etc
  
• It became a chore so often it ended up being a skim read.
• The person reviewing often didn’t have the same product knowledge. This meant the test cases weren’t reviewed regarding how well they tested the application.

And so I sat down with a fellow tester on an after work development project and did some pair test case writing to start with. It was incredible. The thought patterns and processes we entered were remarkable. As a pair we wrote simple, clean and to the point tests. Those pointless steps or ideas were left out. During the tester not doing the main writing would then spawn a mind map charting all of the ideas so that we didn’t miss any.

The tests were succinct and short in a high level guidance way (i.e. no detailed steps). We kept every single test DRY (don’t repeat yourself) extrapolating all setup, preconditions and data out to separate excel documents. It truly was a great experience as each of us brought a different outlook to the table. But more than that we bounced ideas off of each other. In terms of time spent it might appear that we were doubling but the quality of the output was incredible.

So how about actual pair testing?

The next step was to actually see if we could do some pair testing. And we could. This too brought some amazing side effects. We raised more important defects. We generated new and interesting exploratory ideas to run all managed through a mind map. We had to do so little admin to the test cases that we were both truly surprised with how good they were.

It felt like we’d covered more of the system in less of the time. But we also covered a lot more of the system than we had test cases for. This was because as we got to a step, one or both of us would highlight that the documentation hadn’t mentioned this, or the test case didn’t consider this factor yada yada.

The whole process has left me thinking more and more of us should consider pair testing. Maybe as a short trial process for one day a week. Maybe as a permanent idea. Believe me, the tests, the testing and the camaraderie are all enviable positive effects of pairing up. Let’s not just leave the pairing to the programmers. Let’s help take testing to a new level too.