Ron Jacobs was recently down in Australia for the Australian Architecture Forum as well as for an Architecture Council tour in Canberra, Sydney and Melbourne.

Ron Jacobs - Architecture Council

At the councils, Ron delivered a talk on "The Perfect Pattern Storm: Where TDD meets UX and MVP", which provided some insights into how Test Driven Development (TDD) is influencing solution architectures.  His talk pointed out that the test-first mantra was/is having a significant impact in how we design software, in that a lot more thought gets put into making sure that components are testable from the outset.  Sometimes this requires a change in approach, and Ron's example of this was how the 'traditional' Model View Controller pattern gave rise to the Model View Presenter (MVP) derivative.  This evolution allowed the View to be made as simple (and testable) as possible, by delegating the responsibility for handling UI events to a Presenter class, which was then independently testable in isolation from the actual UI technology (web or forms) that was feeding events to the view.

The testability challenge of MVC never occured to me when I was first exposed to the pattern in my SmallTalk80 days at University, as I was too busily immersed in telnet-based multi-player dungeons and drinking beer with various mates (you know who you are).  However, looking back through the lens of Wikipedia, one thing that surprised me was that Kent Beck - the originator of Extreme Programming - was actually a big SmallTalk proponent, and that in fact he'd been thinking of these things all the way back in the mid 90's.  It still boggles my mind that anyone would want to build a payroll system in SmallTalk - even back then - given the demands the environment and runtime made on hardware, but then those were the heady days of computing where anything was possible :)

Anyway - Ron's slides from the Architecture Council tour can be found here.  Enjoy!