Don't understand error

Question

I am attempting to add authentication to my node.js/express.js/react.js application.

My directory structure is as follows:

application
    server.js
    www
    js
       app.js
       sessions.js

I add these two lines to server.js

var express = require('express'),
    app = express(),
    path = require('path'),
    http = require('http').Server(app),
    io = req

let sessions = require('./www/js/sessions');
app.use(sessions);

I run node server.js I see a new message I have not seen before:

$ node server.js 
express-session deprecated req.secret; provide secret option www/js/sessions.js:16:22

and then in the browser when I connect to I get this error. If I remove the two lines above from server.js the program runs fine:

In the browser, I see exception:

TypeError: passport.initialize is not a function
   at module.exports.passport (/home/idf/Documents/js/react-trader/www/js/sessions.js:18:56)
   at Layer.handle [as handle_request] (/home/idf/Documents/js/react-trader/node_modules/express/lib/router/layer.js:95:5)
   at trim_prefix (/home/idf/Documents/js/react-trader/node_modules/express/lib/router/index.js:312:13)
   at /home/idf/Documents/js/react-trader/node_modules/express/lib/router/index.js:280:7
   at Function.process_params (/home/idf/Documents/js/react-trader/node_modules/express/lib/router/index.js:330:12)
   at next (/home/idf/Documents/js/react-trader/node_modules/express/lib/router/index.js:271:10)
   at expressInit (/home/idf/Documents/js/react-trader/node_modules/express/lib/middleware/init.js:33:5)
   at Layer.handle [as handle_request] (/home/idf/Documents/js/react-trader/node_modules/express/lib/router/layer.js:95:5)
   at trim_prefix (/home/idf/Documents/js/react-trader/node_modules/express/lib/router/index.js:312:13)
   at /home/idf/Documents/js/react-trader/node_modules/express/lib/router/index.js:280:7

I can't tell from the error if it is complaining that it can't find sessions.js , or if it is failing to find an npm requirement. I did install express-session and I see it in the package.json so not sure...

{
  "name": "TraderWS",
  "version": "1.0.0",
  "description": "Trader Workstation",
  "main": "server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Me",
  "license": "MIT",
  "dependencies": {
    "babel-loader": "^6.2.10",
    "babel-preset-es2015": "^6.22.0",
    "babel-preset-react": "^6.22.0",
    "body-parser": "^1.16.1",
    "connect-redis": "^3.2.0",
    "express": "^4.12.3",
    "express-session": "^1.15.1",
    "griddle-react": "^0.7.1",
    "react": "^15.4.2",
    "rx": "^4.0.7",
    "socket.io": "^1.3.5",
    "webpack": "^2.2.1"
  }
}

Answer 1

This may or may not help anyone else.

Initially the problem was that I was not passing a passport to sessions. This fixed that problem:

let usersService = require('./service/users');
let bodyParser = require('./middleware/bodyParser');
let passport = require('./config/passport');
let sessions = require('./middleware/sessions')(passport); // was missing parameter passport

Then I had another problem in that I had code below with the commented out version, and that caused an error because there was no secret. Once I actually entered a string secret, the problem went away

'use strict';

const session = require('express-session');

let config = {
    //secret: process.env.SESSION_SECRET,
    secret: 'keyboard cat',
    saveUninitialized: false,
    resave: false
};

if (process.env.REDIS_URL) {
    const RedisStore = require('connect-redis')(session);
    config.store = new RedisStore({ url: process.env.REDIS_URL });
}

let expressSession = session(config);

module.exports = passport => [expressSession, passport.initialize(), passport.session()];