Express 4 and socket.io share sessions

app.js

var express = require("express");
var path = require("path");
var favicon = require("serve-favicon");
var logger = require("morgan");
var cookieParser = require("cookie-parser");
var bodyParser = require("body-parser");
var session = require("express-session");
var cookie = require("cookie");
var q = require("q");

var routes = require("./routes/index");
var users = require("./routes/users");

var app = express();
var sessionStore = new session.MemoryStore();

// view engine setup
app.set("views", path.join(__dirname, "views"));
app.set("view engine", "jade");

app.use(favicon(path.join(__dirname, "public", "favicon.ico")));
app.use(logger("dev"));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
	extended : true
}));
app.use(cookieParser());
app.use(session({
	name : "connect.sid",
	secret : "abc123",
	cookie : {
		httpOnly : true
	},
	saveUninitialized : true,
	resave : true,
	store : sessionStore
}));
app.use(express.static(path.join(__dirname, "public")));

app.use("/", routes);
app.use("/users", users);

app.use("/abc", function(req, res, next) {
	req.session.views = (req.session.views || 0) + 1;
	res.end(JSON.stringify({
		data : "abc"
	}));
});

// / catch 404 and forward to error handler
app.use(function(req, res, next) {
	var err = new Error("Not Found");
	err.status = 404;
	next(err);
});

// / error handlers

// development error handler
// will print stacktrace
if (app.get("env") === "development") {
	app.use(function(err, req, res, next) {
		res.render("error", {
			message : err.message,
			error : err
		});
	});
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
	res.render("error", {
		message : err.message,
		error : {}
	});
});

var server = require("http").Server(app);
var io = require("socket.io")(server);

module.exports = server;

server.listen(process.env.PORT || 3000, function() {
	console.log("Server listening on port " + (process.env.PORT || 3000));
});

// THIS IS THE PARSER!
function getSession(socket) {
	var defer = q.defer();
	var signedCookies,
		parsedCookies = cookie.parse(socket.handshake.headers.cookie);

	signedCookies = cookieParser.signedCookies(parsedCookies, "abc123");
	signedCookies = cookieParser.JSONCookies(signedCookies);
	sessionStore.get(signedCookies["connect.sid"], function(err, sess) {
		if (err || !sess) {
			defer.reject(err);
			return;
		}
		defer.resolve(sess);
	});
	return defer.promise;
}

// testing...
io.of("/test").on("connection", function(socket) {
	socket.on("message", function(data) {
		getSession(socket).then(console.log);
	});
});