babel.config.js

module.exports = function (api) {
  const env = api.env();
  api.cache.using(() => env === 'development');

  return {
    presets: ['@babel/preset-env', '@babel/preset-react'],
    plugins: [
      '@babel/plugin-transform-runtime',
      // Stage 0
      '@babel/plugin-proposal-function-bind',

      // Stage 1
      '@babel/plugin-proposal-export-default-from',
      '@babel/plugin-proposal-logical-assignment-operators',
      ['@babel/plugin-proposal-optional-chaining', { loose: false }],
      ['@babel/plugin-proposal-pipeline-operator', { proposal: 'minimal' }],
      ['@babel/plugin-proposal-nullish-coalescing-operator', { loose: false }],
      '@babel/plugin-proposal-do-expressions',

      // Stage 2
      ['@babel/plugin-proposal-decorators', { legacy: true }],
      '@babel/plugin-proposal-function-sent',
      '@babel/plugin-proposal-export-namespace-from',
      '@babel/plugin-proposal-numeric-separator',
      '@babel/plugin-proposal-throw-expressions',

      // Stage 3
      '@babel/plugin-syntax-dynamic-import',
      '@babel/plugin-syntax-import-meta',
      ['@babel/plugin-proposal-class-properties', { loose: false }],
      '@babel/plugin-proposal-json-strings',
      'react-hot-loader/babel',
    ],
  };
};