Over 3000 lines of test code in our new MVC project so far and counting. That's over 60% of the number of lines of application code! We've noticed a lot of time being spent on writing tests for our web application code but we wouldn't have it any other way.
Our tests make our applications robust and ensure changes don't break/change existing functionality; this hopefully keeps our customers happy. This in turn means development reduce the time spent on fixing bugs and have more time to spend on developing exciting new features/projects; this hopefully keeps the development team happy too :)
