Good point, I made the mistake of asking for an implementation rather than talking about what I want to achieve. I don't want the assert module, I just want a tdd framework available.
I got around it initially by just creating my own tests and runner and outputting that:
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
But I mostly didn't want to do my own testing framework. I'm new to node, seems like Vows is popular, but there are several other candidates as well.
I think the trick is just to have an easy way to handle unit testing. If picking one enabled it to be baked in somehow (ctrl-t) that would be great. I'll noddle on it a bit and see what I can come up with.
More than happy to contribute, I've just come from the dark side of 15 years of Microsoft development so I'm still figuring out the landscape. :)