10 years ago I built a little library / test app to support embedded Ruby development with a kind of Fuzx testing. One of the cool features of Ruby is that one

10 years ago I built a little library / test app to support embedded Ruby development with a kind of Fuzx testing. One of the cool features of Ruby is that one thread can raise an exception in another thread. So my library simply allows you to define a set of exceptions, with a distribution across them. The app runs an extra thread in parallel with the main app, and "carpet bombs" the main app with exceptions drawn from the desired distribution. Very useful for checking that the code is resilient to all sorts of real world edge cases you haven't thought of!