middleware to attach raw request body, as a promise, to express request

gistfile1.js

function attachRawBody(req, res, next) {
    var body = '';
    req.rawBody = Q.defer();
    req.on('data', function(chunk) {
        body += chunk;
    });
    req.on('end', function() {
        req.rawBody.resolve(body);
    });
    next();
}