react-common/packages/react-common-docs/next.config.js

const path = require('path')

const withMDX = require('next-mdx-frontmatter')({
  extension: /\.mdx?$/
})

const e = withMDX({
  pageExtensions: ['js', 'jsx', 'ts', 'tsx', 'md', 'mdx']
})

module.exports = {
  ...e,
  webpack(...args) {
    const oldWebpack = e.webpack(...args)
    const [config, { defaultLoaders, }] = args

    config.module.rules.push({
      test: /\.(ts|tsx)$/,
      include: [path.resolve(__dirname, '../react-common/')],
      use: [defaultLoaders.babel],
    })

    return oldWebpack
  }
}