webpack.config.js

const path = require("path");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const htmlWebpackPlugin = new HtmlWebpackPlugin({
  template: path.join(__dirname, "./example/src/index.html"),
  filename: "./index.html"
});

module.exports = {
  entry: path.join(__dirname, "./example/src/app.js"),
  output: {
    path: path.join(__dirname, "example/dist"),
    filename: "bundle.js"
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        use: "babel-loader",
        exclude: /node_modules/
      },
      {
        test: /\.css$/,
        use: [
          "style-loader",
          {
            loader: "css-loader",
            options: {
              modules: true
            }
          }
        ]
      },
      {
        test: /\.sass$/,
        use: [
          "style-loader",
          {
            loader: "css-loader",
            options: {
              modules: true
            }
          },
          "sass-loader"
        ]
      }
    ]
  },
  plugins: [htmlWebpackPlugin],
  resolve: {
    extensions: [".js", ".jsx"]
  },
  devServer: {
    port: 3001
  }
};