webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');

module.exports = {
  mode: process.env.NODE_ENV,
  entry: [path.resolve(__dirname, './client/index.js')],
  output: {
    path: path.resolve(__dirname, 'build'),
    filename: 'bundle.js',
    chunkFilename: '[id].js',
    publicPath: '/',
  },
  resolve: {
    extensions: ['.js', '.jsx'],
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        // loader: 'babel-loader',
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-react', '@babel/preset-env'],
          },
        },
      },
      {
        test: /\.css$/,
        use: [
          'style-loader',
          'css-loader',
        ],
      },
      {
        test: /\.(png|jpe?g|gif)$/,
        loader: 'url-loader?limit=10000&name=img/[name].[ext]',
      },
    ],
  },
  plugins: [
    new CleanWebpackPlugin(),
    new HtmlWebpackPlugin({
      template: `${__dirname}/client/index.html`,
      filename: 'index.html',
      inject: 'body',
    }),
  ],
  devServer: {
    publicPath: '/build',
    proxy: {
      '/': 'http://localhost:3000',
    },
    hot: true,
  },
};