babel.config.js

const aliases = require('./aliases.config');
const resolveAlias = require('./resolveAlias');

module.exports = {
  presets: [
    [
      '@babel/preset-env',
      {
        modules: process.env.BABEL_ENV === 'esm' ? false : 'commonjs',
      },
    ],
    '@babel/preset-react',
    '@babel/preset-typescript',
  ],
  env: {
    debug: {
      sourceMaps: 'inline',
      retainLines: true,
    },
    esm: {
      plugins: [['@babel/plugin-transform-runtime', { useESModules: true }]],
    },
    development: {
      plugins: [
        [
          'module-resolver',
          {
            // https://github.com/tleunen/babel-plugin-module-resolver/issues/338
            // There seem to be a bug with module-resolver under mono-repo setup:
            // It doesn't resolve paths correctly when using root/alias combo, so we
            // use this function instead.
            // Will return undefined if not found in which case module-resolver will
            // fallback on its default behaviour.
            resolvePath: source => resolveAlias(source, aliases),
          },
        ],
      ],
    },
  },
};