webpack.config.js

const HtmlWebPackPlugin = require("html-webpack-plugin");
const CopyPlugin = require('copy-webpack-plugin');
const path = require('path');

module.exports = {
    module: {
        rules: [
            {
                test: /\.(js|jsx)$/,
                exclude: /node_modules/,
                use: {
                    loader: "babel-loader"
                }
            },
            {
              test: /\.html$/,
              use: [
                {
                  loader: "html-loader"
                }
              ]
            },
            {
              test: /\.css$/,
              use: ['style-loader', 'css-loader']
            }
        ]
    },
    plugins: [
      new HtmlWebPackPlugin({
        template: "./src/index.html",
        filename: "./index.html"
      }),
      new CopyPlugin({
        patterns: [
          { from: 'assets/pixels', to: 'assets/pixels' },
          { from: 'assets/tiles', to: 'assets/tiles' }
        ],
      })
    ],
    resolve: {
      extensions: [".js", ".jsx"]
    },
    devtool: 'cheap-module-eval-source-map',
    devServer: {
      contentBase: path.join(__dirname, 'public')
    }
};