graphical unit test

Always thought that unit test is not suitable for graphical programming, because most of the unit test package only provide ascii text output but graphical programming can simply tell a module is right or wrong but text output only. therefore i been ignoring unit test most of the time.

recently i came accross a game engine called facepunch, by the famous gary mod auther. i downloaded the incomplete engine i try it myself and i discover a test program in the bin folder, guess what it does? it is a unit test tool, it tests most of the aspect of the engine, and it provide visual feedback to veryfy the result! from that moment i know i'm completely wrong all this time :(

and recently i been working on force fill algorithm to simplify swarm/group/collective path finding, after wasted 2 weeks on it, i decided to create a visual unit test tool from scratch. so this tool doesn't serve as a test platform, it will be my prototyping/play group for me :) in fact this is common in certain nature development such as web development, they call it build by spec.