I've added a couple of features to https://github.com/LucHermitte/vim-UT
vim-UT is a unit testing framework for vim scripts, that displays assertion failures in quick-quick window.
The plugin is meant to be simple to use and lightweight. So far the syntax was mainly dedicated, and restricted, to test the result of vim functions and expressions.
Assert 1 > 2
Assert s:foo > s:Bar(g:var + 28) / strlen("foobar")
debug AssertTxt (s:foo > s:Bar(g:var+28)
\, s:foo." isn't bigger than s:Bar(".g:var."+28)")
AssertEquals!('a', 'a')
AssertDiffers('a', 'a')
let dict = {}
AssertIs(dict, dict)
AssertIsNot(dict, dict)
AssertMatch('abc', 'a')
As