Unit testing?

[xeon]

Has anyone developed a package or some way to implement unit testing (http://en.wikipedia.org/wiki/Unit_testing) ?

Poking around with Sosaria date/time functions I developed a little script to automate correctness checks of my library functions, and, as in other languages I've used this technique of agile programming, I found it most useful.

Having a complete package with some kind of library to quickly implement unit testing would be great. But I can't think of a way to make one which can adapt to any script.