webpack.config.js

//project based on https://medium.com/@BrodaNoel/how-to-create-a-react-component-and-publish-it-in-npm-668ad7d363ce
var path = require('path');
module.exports = {
  mode: 'production',
  entry: './src/index.jsx',
  output: {
    path: path.resolve(__dirname, 'build'),
    filename: 'index.js',
    libraryTarget: 'commonjs2', // THIS IS THE MOST IMPORTANT LINE! :mindblow: I wasted more than 2 days until realize this was the line most important in all this guide.
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        include: path.resolve(__dirname, 'src'),
        exclude: /(node_modules|bower_components|build)/,
        use: {
          loader: 'babel-loader',
        },
      },
    ],
  },
  externals: {
    'react': 'commonjs react',
    'react-dom' : 'commonjs react-dom'
  }
};