prototype plugin pattern idea to make middleware less magical

request.js

function Request(req, res) {
  this.upstream = request
  this.downstream = response
}

Request.prototype = {
  start: function() {
    // kick off the default chain of handlers
  },

  // other built-in methods
}

Request.prototype.myPlugin = function(next) {
  // custom logic based on this.upstream / this.downstream

  next()
}

require("http").createServer(function(req, res) {
  new Request(req, res).start()
})