I'm looking for some tools for testing vim scripts. Either vim scripts that

• do unit/functional testing, or
• classes for some other library (eg Python's unittest module) that make it convenient to
  • run vim with parameters that cause it to do some tests on its environment, and
  • determine from the output whether or not a given test passed.

I'm aware of a couple of vim scripts that do unit testing, but they're sort of vaguely documented and may or may not actually be useful:

vim-unit:

• purports "To provide vim scripts with a simple unit testing framework and tools"
• first and only version (v0.1) was released in 2004
• documentation doesn't mention whether or not it works reliably, other than to state that it is "fare [sic] from finished".

unit-test.vim:

• This one also seems pretty experimental, and may not be particularly reliable.
• May have been abandoned or back-shelved: last commit was in 2009-11 (> 6 months ago)
• No tagged revisions have been created (ie no releases)

So information from people who are using one of those two existent modules, and/or links to other, more clearly usable, options, are very welcome.