This guide will take you through on how to use nodemon to build api which is simply to create a web app with node.js + express.js in a babel environment. Often we need to use babel to increase readability of our code. And nodemon was used to watch and re-build the project and serve it consistently.

Nodemon to build api

As a prerequisite, you will have to install the node.js and npm/yarn in your environment. I will be using yarn as it will make the . package maintenance easy. But I have included the npm command as well for your convenience.

First, initiate the project with

yarn init
--------npm--------
npm init

Then install the project dependencies. I have run following in the terminal to install express(https://expressjs.com/), babel and nodemon(https://nodemon.io/).

yarn add express
yarn add --dev babel-preset-env
yarn add --dev nodemon

--------npm--------
npm install express
npm --save-dev babel-preset-env
yarn --save-dev nodemon

The babel-preset-env will install the presets es2015, es2016, es2017 along with some other(http://babeljs.io/docs/plugins/#presets). After that, you can add the script to start nodemon in the package.json.

 "scripts": {
   "start": "nodemon src/app.js --exec babel-node --presets babel-preset-env"
 },

Here babel-node is provided with the babel-cli. More of its usages are in the official doc: http://babeljs.io/docs/usage/cli/
Now all are set. We need to add the app.js file which I have specified in the script above. Create a filesrc/app.js and add the hello world code mentioned below.

import express from 'express'

const app = express();

app.get('/', function (req, res) {
 res.send('Hello World!')
});

app.listen(3000, function () {
 console.log('Example app listening on port 3000!')
});

Then run the app you have build. Run yarn start on the terminal. You will see an output like below in the terminal.

$ yarn start
yarn start v0.27.5
$ nodemon src/app.js --exec babel-node --presets babel-preset-env
[nodemon] 1.12.1
[nodemon] to restart at any time, enter `rs`
[nodemon] watching: *.*
[nodemon] starting `babel-node src/app.js --presets babel-preset-env`
Example app listening on port 3000!

The github link for the above project is: https://github.com/sandaruny/node-express-babel