Hi Colin,

> And it's an important feature. I work on several packages with
> extensive test suites, and I really like the fact that the enhanced
> test runner doesn't tie up the UI while the tests are running,
> something which can take several minutes, and which I do very
> frequently. This change would slow my development pace to a crawl.

Have you tried the changes? I would guess that if you did you would find the
behavior almost indistinguishable.

> It's also an overstatement to say that running the tests in the
> background is "problematic if any of the tests involve anything Morphic
> related." I run Morphic-related tests in the background all the time
> with no problems.

Well, okay, I should have said that the tests that are problematic involve
interactions with the currently running world. The current test runner
screws up regularly and it's almost impossible to figure out if the test
failed or if this is one of these weird UI interaction problems. That's why
I removed that "feature" - the tests are worthless if they don't give you
convidence in your code and having an error show up is most definitely
nothing to convince me of the quality of my code.

> That's not to say that there *is* no problem, only that we should track
> it down and fix it, rather than remove an important feature. Would it
> be feasible to alter either the problematic tests or Morphic its self
> to work properly in the background? Would it be useful to set up a
> sandbox - some sort of  invisible world with it's own  UI thread - for
> Morphic-related tests?

Sure, the only question is: How much time are willing to invest?! For
example, the Right Way (tm) to deal with this is to give TestRunner its "own
world" in which it could run these tests. Simple as that. It would mean that
any Morphic related tests would just see their own "World" (possibly even
embedded into TestRunner) so if you run these in the background you wouldn't
be affected by any suddenly popping up windows or similar. Alas, I just
don't have time for it...

Cheers,
  - Andreas