> I suppose that assert() can still be used. The new
> version would I have to figure out that it runs in
> the context of test/unit. In that context its behavior
> would be compatible with test/unit.
>
> The other contexts that assert() should support are:
>   - production => throw an exception
>   - debugging  => start an irb session
>   - custom     => invoke some user provided assert failure handler

I like this the best of all I've seen so far.