babel.config.js

// The source code including full typescript support is available at: 
// https://github.com/shakacode/react_on_rails_demo_ssr_hmr/blob/master/babel.config.js

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

  const changesOnDefault = {
    presets: [
      [
        '@babel/preset-react',
        {
          development: !isProductionEnv,
          useBuiltIns: true,
          runtime: 'automatic'
        }
      ]
    ].filter(Boolean),
    plugins: [
      // Enable React Refresh (Fast Refresh) only when webpack-dev-server is running (HMR mode)
      // This prevents React Refresh from trying to connect when using static compilation
      !isProductionEnv && process.env.WEBPACK_SERVE && 'react-refresh/babel',
      isProductionEnv && ['babel-plugin-transform-react-remove-prop-types',
        {
          removeImport: true
        }
      ]
    ].filter(Boolean),
  }

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

  return resultConfig
}