I'm bit confusing. I have a branch of Silly with a few improvements. One begin able to differentiate from a test failure from a test error (on the same way that xunit/junit does).

So, the test code works fine using the boring, old assert expression that throws an AssertError (ie, if is a AssertError, count as failed test. Anything else it's count as test error). However, there it's a big problem... All assert libraries (or at least the active & updated assert libraries) throws a simple Exception or extends from Exception. Not from AssertError.
Why ? Not should they use AssertError to throw that assertion has failed ?