webpack.config.js

// eslint-disable-next-line
const path = require("path");

// eslint-disable-next-line
module.exports = {
  mode: "production",
  entry: "./index.js",
  output: {
    path: path.resolve("dist"),
    filename: "index.js",
    libraryTarget: "commonjs2",
  },
  module: {
    rules: [
      {
        test: /\.css$/,
        use: [{ loader: "style-loader" }, { loader: "css-loader" }],
      },
      {
        test: /\.js$/,
        exclude: /node_modules/,
        loader: "babel-loader",
      },
      {
        test: /\.jsx?$/,
        exclude: /node_modules/,
        loader: "babel-loader",
        query: {
          presets: ["@babel/preset-react"],
        },
      },
    ],
  },
  externals: {
    react: {
      commonjs: "react",
      commonjs2: "react",
      amd: "React",
      root: "React",
    },
    "react-dom": {
      commonjs: "react-dom",
      commonjs2: "react-dom",
      amd: "ReactDOM",
      root: "ReactDOM",
    },
  },
  resolve: {
    alias: {
      "react-router-dom": path.resolve("./node_modules/react-router-dom"),
    },
  },
};