Express handlebars server with MongoDB

server.js

const express   = require('express')
const mongoose  = require('mongoose')
const exphbs    = require('express-handlebars')
const bodyParser= require('body-parser')
const path      = require('path')

const PORT      = process.env.PORT || 1279

const app       = express()

const routes    = require('../routes')

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.text());
app.use(bodyParser.json({ type: "application/vnd.api+json" }));
app.use(express.static(path.join(__dirname + '/public')));
app.use(express.static(path.join(__dirname, "js")));

app.engine('.hbs', exphbs({ 
    defaultLayout: 'main',
    extname: '.hbs',
    partialsDir: ['views/partials']

}))
app.set('views' + '' + path.join(__dirname + '/views'))
app.set('view engine', '.hbs')

app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())

app.use(routes)

const DB_URL    = 'mongodb://localhost:27017/your_db'

mongoose.Promise = Promise
if (mongoose.connection.readyState == 0) { 
    mongoose.connect(DB_URL, { useNewUrlParser: true }) 
}

app.listen(PORT, () => {
    console.log(`App listening on port: ${PORT}`)
})