Here's how you can use express.js' handle() to call routes directly. YMMV.

expressdirect.js

var express = require('express');

var app = express();

app.get('/your/route/here',function(req, res){
  res.send('hello world');
});

function request(method,route,cb) {
  app.handle({
      method: method,
      url: route
  },{
      finish: null,
      on: function (type,fn) {
        if (type == 'finish') {
          this.finish = fn;
        }
      },
      setHeader: function () {
        
      },
      end: function (buffer,encoding) {
        cb(null,buffer.toString(encoding));
        
        this.finish();
      }
  },function (err) {
      cb(err);
  });
}

request('get','/your/route/here',function (err,result) {
  if (err) throw err;
  
  console.log('got: ' + result);
})