minimal setup for the server.js

server.js

const express = require('express')
const bodyParser = require('body-parser')
const mongoose = require('mongoose')
const cors = require('cors')
require('dotenv').config()

const app = express()
const port = process.env.PORT || 5000

// Connect to the database
const options = { useNewUrlParser: true }
mongoose.connect('mongodb://localhost:/mern_boilerplate', options)
 .then(() => console.log('connected successfully'))
 .catch(err => console.log('An error occurred', err))

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

app.listen(port, () => console.log(`server is running on port ${port}))