webpack.config.cjs

const path = require('path');

module.exports = function (env = {}) {
  return {
    mode: env.mode || 'development',
    entry: './src/index.js',
    devtool: 'eval-cheap-module-source-map',
    devServer: {
      static: [
        {
          directory: path.join(__dirname, 'data'),
          publicPath: '/data',
        },
        // {
        //   directory: path.join(__dirname, 'public'),
        //   publicPath: '/public',
        // },
        {
          directory: path.join(__dirname, 'view'),
          publicPath: '/view',
        },
        {
          directory: path.join(__dirname, 'src'),
          publicPath: '/src',
        },
      ],
      hot: true,
    },
    output: {
      path: path.resolve(__dirname, 'public'),
      filename: 'bundle.js',
      publicPath: '/',
      clean: true,
    },
    // resolve: {
    //   extensions: ['.js'],
    // },
    module: {
      rules: [{
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: [
              [
                '@babel/preset-env',
                {
                  "targets": "> 0.25%, not dead",
                  "useBuiltIns": "usage",
                  "corejs": "3.8.3",
                }
              ]
            ]
          }
        }
      }]
    }
  };
};