app.js

// dependencies
const express = require('express');
const routes = require('./routes/index');
const bodyParser = require('body-parser');
const passport = require('passport');
const mongoose = require('mongoose');
const User = require('./models/user');

const app = express();

// use static authenticate method of model in LocalStrategy
passport.use(User.createStrategy());

// use static serialize and deserialize of model for passport session support
passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());

// parse json
app.use(bodyParser.json());

// use sessions
app.use(require('express-session')({
  secret: 'secret123',
  resave: false,
  saveUninitialized: false
}));

// Connect Passport to express
app.use(passport.initialize());
app.use(passport.session());

// mongoose
mongoose.connect('mongodb://localhost/express-mongo-passport', (err) => {
  if (err) {
    console.log('Error connecting to database', err);
  } else {
    console.log('Connected to database!');
  }
});

app.use('/', routes);

app.listen(3000, () => console.log('Listening on http://localhost:3000'));