Getting started with Babel
Installation
Make sure latest node.js
installed and npm
updated.
Init package.json
:
npm init -y
Install babel
:
npm install --save-dev babel-cli babel-preset-env
Install polyfill:
npm install --save babel-polyfill
Configure
Create .babelrc
:
{
"presets": ["env"]
}
Add entry to scripts
section of package.json
file:
"babel": "babel src -d dist"
Create html and js
Create src
folder for source files and dist
for transpiled output.
Create file src/index.js
written in ES2015:
const greetings = `Hello World!`;
document.body.innerHTML += greetings;
Create index.html
:
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Babel Sample</title>
</head>
<body>
<script src="node_modules/babel-polyfill/dist/polyfill.min.js"></script>
<script src="dist/index.js"></script>
</body>
</html>
Run babel
npm run babel
Load webpage
Open index.html
and see output
Debug
Open debugger (Ctrl-Shift-I in Chrome) and navigate to source code, inspect output
Adding source maps
Modify entry in scripts
section of package.json
file to produce source maps:
"babel": "babel src -d dist -s"
Watching source files
Modify entry in scripts
section of package.json
file to watch for changes:
"babel": "babel src -d dist -w"