babel.config.js

/* eslint-disable no-undef */
const productionPlugins = [
  // ['babel-plugin-react-remove-properties', { properties: ['data-test-id'] }],
];

module.exports = function getBabelConfig(api) {
  const useESModules = api.env(['stable', 'rollup']);

  const presets = [
    [
      '@babel/preset-env',
      {
        bugfixes: true,
        browserslistEnv: process.env.BABEL_ENV || process.env.NODE_ENV,
        debug: process.env.MUI_BUILD_VERBOSE === 'true',
        modules: useESModules ? false : 'commonjs',
        shippedProposals: api.env('modern'),
      },
    ],
    [
      '@babel/preset-react',
      {
        runtime: 'automatic',
      },
    ],
    '@babel/preset-typescript',
  ];

  const plugins = [
    // Need the following 3 proposals for all targets in .browserslistrc.
    // With our usage the transpiled loose mode is equivalent to spec mode.
    ['@babel/plugin-proposal-class-properties', { loose: true }],
    ['@babel/plugin-proposal-private-methods', { loose: true }],
    ['@babel/plugin-proposal-private-property-in-object', { loose: true }],
    ['@babel/plugin-proposal-object-rest-spread', { loose: true }],
    [
      '@babel/plugin-transform-runtime',
      {
        useESModules,
        // corejs: false,
        // helpers:true,
        // regenerator: true,
        // any package needs to declare 7.4.4 as a runtime dependency. default is ^7.0.0
        version: '^7.4.4',
      },
    ],
  ];

  if (process.env.NODE_ENV === 'production') {
    plugins.push(...productionPlugins);
  }

  return {
    assumptions: {
      noDocumentAll: true,
    },
    // comments: false,
    presets,
    plugins,
    ignore: [/@babel[\\|/]runtime/], // Fix a Windows issue.
    overrides: [
      {
        exclude: /\.test\.(js|ts|tsx)$/,
        plugins: ['@babel/plugin-transform-react-constant-elements'],
      },
    ],
  };
};