How to setup an Express server in a MERN environment

October 12, 2020

Initialize your project

npm init -y

This creates your package.json. Edit the description as you wish and change “main”: “server.js”

npm install the required dependencies

express - Node.js web application framework
bcryptjs - hashing passwords
jsonwebtoken - JWT handling
config - for global variables
express-validator - request body management
mongoose - elegant mongodb object modeling for node.js

npm i express bcryptjs jsonwebtoken config express-validator mongoose

npm install the required dev dependencies

nodemon - node server monitor
concurrently - Run multiple commands concurrently

npm i -D nodemon concurrently

enable ES6 modules instead of CommonJS

install the Babel dev dependencies:

npm install -D @babel/core @babel/cli @babel/node @babel/preset-env

Create a .babelrc file in the project root:

{
  "presets": ["@babel/preset-env"]
}

Modify package.json, add at the top:

  "type": "module",

modify “scripts” in package.json

  "scripts": {
    "start": "node server.js",
    "server": "nodemon server.js"
  },

Create basic express server

Create server.js in the project root:

import express from "express"

const app = express()

app.get("/", (_, res) => res.json({ salutation: "Hello" }))

const PORT = process.env.PORT || 5000
app.listen(PORT, () => console.log(`server started on port ${PORT}`))

Start the dev server:

npm run server

> reactContacts@1.0.0 server /home/darvat/dev/react/reactContacts
> nodemon server.js

[nodemon] 2.0.4
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node server.js`
server started on port 5000

If you now hit localhost:5000 and check devtools in chrome, you will get a proper json response:

We have successfuly created an express server that listens on port 5000 and sends you a json response when you hit the webroot.

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