SocketIO + Passport + Cookie-Sessions

middleware.js

/*
 This is just a hacky approach to get things moving, as passport-socketio library
 does not support cookie-sessions.
*/

var Promise = require("bluebird");
var passport = require("passport");
var session = require("cookie-session");

var sessionConfig = {
    secret: "secret-goes-here",
    resave: false,
    saveUninitialized: true,
    name: "cookie-name-goes-here",
    signed: true
};
var configuredSessionMiddleware = session(sessionConfig);

var parseCookieSession = function(socket) {
    var dummyRequest = {
        headers: {
            cookie: socket.request.headers.cookie || ''
        }
    };
    var dummyResponse = {};

    return new Promise(function(resolve, reject){
      var passportProperty = passport._key;
      var userProperty = passport._userProperty;
      
      configuredSessionMiddleware(dummyRequest, dummyResponse, function(error){
        if(error) { return reject(error); }
        if(!dummyRequest.session[passportProperty]) { return reject("Authentication data not provided"); }
        if(!dummyRequest.session[passportProperty][userProperty]) { return reject("User data not provided"); }
        var userId = dummyRequest.session[passportProperty][userProperty];
        return resolve(userId);
      });
    });
};

var getUserData = function(userId) {
    return new Promise(function(resolve, reject){
        passport.deserializeUser(userId, function(err, user) {
            if (err) { return reject(err);}
            if (!user) { return reject("User not found"); }
            resolve(user);
        });
    });
};

var assignUserToSocket = function(socket, user)
{ socket.request.user = user; };

module.exports = function(socket, next) {
  Promise.resolve(socket)
      .then(parseCookieSession)
      .then(getUserData)
      .then(function(user) {
          assignUserToSocket(socket, user);
      })
      .then(function() { next(); })
      .catch(function(error){
          next(new Error('unable to authorise'));
      });
  };
};