Hi please allow skins to also be tested to make sure they work. Just like extension can be tested using mwext-testextension script skins should also have its own test by both being able to have dependencies or just on its own.
??? I think we misunderstood :) That was a question :P What tests should run for skins? Skins itself (at least the ones I know) doesn't provide any unit tests, so running unit tests on them would be pointless. Ok, there is one test, SideBarTest from which we could, maybe, benefit. But I'm not sure, if we should create unit tests for each skin to run this test on it.
Sure, the test group extensions runs some generic tests, mostly structure tests, see:
Skins doesn't have these generic tests (only the one I mentioned before, SideBarTest.