Babel Transpilation

Follow these steps to transpile ES6+ JavaScript code to ES5 in order to improve browser compatibility.

1. Use npm init to create a package.json file in the root directory and give it a name and description.

2. Install the Babel command line npm package and add it to the devDependencies property: npm install babel-cli -D

3. Install the Babel preset environment npm package: npm install babel-preset-env -D

4. Add a .babelrc file to the project folder: touch .babelrc

5. In .babelrc, preset your local project’s config to "env".

    {
      "presets": ["env"]
    }
   

6. In package.json, add the script "build": "babel src -d lib". Don’t forget to add a comma after the “test” script.

7. Use npm run build to transpile the code in src and write it to lib.

To check browser compatibility use caniuse.com.