webpack.config.js

const path = require("path");

module.exports = {
  entry: "./src/index.js",
  output: {
    path: path.resolve(__dirname, "dist"),
    filename: "index.js",
    libraryTarget: "commonjs2",
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /(node_modules|bower_components)/,
        use: {
          loader: "babel-loader",
        },
      },
      {
        test: /\.css$/,
        use: ["style-loader", "css-loader"],
      },
      // Uncomment below if you need to handle font files
      /*
      {
        test: /\.(woff(2)?|ttf|eot|svg)(\?v=\d+\.\d+\.\d+)?$/,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: '[name].[ext]',
              outputPath: 'fonts/'
            }
          }
        ]
      }
      */
    ],
  },
  externals: {
    react: "commonjs react",
  },
  resolve: {
    extensions: [".js", ".jsx"], // added this line to make sure both .js and .jsx files are transpiled
  },
};