A colleague just showed Eclipse functionality where you could run a piece of a junit test, just a method, even when another method in the same unit test class was uncompilable. He also showed where Eclipse could build just the minimum that was absolutely necessary to run the test if you were starting fresh having never compiled the project before - so maybe it compiles the 10 truly necessary classes instead of 1000+.
I see that IDEA allows to switch out the compile with either the Eclipse or Eclipse Embedded compilers. Is there some way to accomplish what he was showing by switching to one of the Eclipse compilers and changing some other settings? I take it one or both of these alternative compilers can accomplish the above - is that part of why they are available?