Customizing Babel Config

Default Configuration

The default configuration of babel is done by using package.json to use the file within the @rails/webpacker package.

json

{
  "babel": {
    "presets": [
      "./node_modules/@rails/webpacker/package/babel/preset.js"
    ]
  }
}

Customizing the Babel Config

This example shows how you can create an object and apply additional presets and plugins on top of the default.

React Configuration

To use this example file,

yarn add react react-dom @babel/preset-react
yarn add --dev @pmmmwh/react-refresh-webpack-plugin react-refresh

// babel.config.js
module.exports = function (api) {
  const defaultConfigFunc = require('@rails/webpacker/package/babel/preset.js')
  const resultConfig = defaultConfigFunc(api)
  const isProductionEnv = api.env('production')

  const changesOnDefault = {
    presets: [
      [
        '@babel/preset-react',
        {
          development: isDevelopmentEnv || isTestEnv,
          useBuiltIns: true
        } 
      ],
      isProductionEnv && ['babel-plugin-transform-react-remove-prop-types', 
        { 
          removeImport: true 
        }
      ]
    ].filter(Boolean),
    plugins: [
      process.env.WEBPACK_SERVE && 'react-refresh/babel'
    ].filter(Boolean),
  }

  resultConfig.presets = [...resultConfig.presets, ...changesOnDefault.presets]
  resultConfig.plugins = [...resultConfig.plugins, ...changesOnDefault.plugins ]

  return resultConfig
}