I've thought a lot about strategies for testing robot code, since existing methods (directly testing hardware and Gazebo simulation) don't seem adequate to me. I'm a big fan of unit-testing and Test Driven Development (I use them extensively in my own projects), and recently I've figured out a way to use the CppUTest framework with C++ robot projects that use WPILib. Step-by-step instructions for getting started are available at this blog post I wrote:
http://www.botbakery.net/2016/03/uni...putest-in.html
Sample code with unit tests and a mock WPILib is here:
https://github.com/althebaker43/frc_cpputest_examples
CppUTest homepage:
https://cpputest.github.io/
For Java projects, a similar strategy that involves the JUnit framework could probably be used.
I know it's pretty late in the season to post this, but perhaps it could be useful for some last-minute code hardening before heading off to your final competitions.
Any feedback is appreciated.