Session.js

const cookie = require('cookie-signature');
const uid = require('uid-safe');

function SessionMiddleWare(cookieKey, cookieLength, secretKey) {
  const sessionStore = {}
  
  const destroy = (key) => {
    delete sessionStore[key];
  }
  return async (req, res, next) => {
    let signedCookie = req.cookies[cookieKey];
    if (signedCookie != undefined) {
      const unsignedCookie = cookie.unsign(signedCookie, secretKey);
      if (unsignedCookie && sessionStore[unsignedCookie] != undefined) {
        req.session = sessionStore[unsignedCookie] || {
          "destroy": destroy.bind(this, unsignedCookie)
        };
        return next();
      }
    }

    const unsignedCookie = await uid(cookieLength);
    signedCookie = cookie.sign(unsignedCookie, secretKey);
    sessionStore[unsignedCookie] = {
      "destroy": destroy.bind(this, unsignedCookie)
    };
    req.session = sessionStore[unsignedCookie];
    res.cookie(cookieKey, signedCookie, {});
    next();
  }
}

module.exports = SessionMiddleWare;