vows is a solid unit testing library for Node.js, but the syntax is tedious.
I've written a thin abstraction called vows-fluent which makes the API chainable.
And I've written another abstraction, [vows-is] which builds on vows-fluent and exposes a BDD style syntax.
An example would be
var is = require("vows-is");
is.suite("testing is fun").batch()
.context("is testing fun?")
.topic.is("yes")
.vow.it.should.equal("yes")
.suite().run({
reporter: is.reporter
});
More examples.