webpack.config.js

const HtmlWebpackPlugin = require('html-webpack-plugin');
const path = require("path");

module.exports = {
  mode: process.env.NODE_ENV,
  devServer: {
    contentBase: path.resolve(__dirname, 'client'),
    publicPath: path.join(__dirname, '/dist/'),
    compress: true,
    port: 8080,
    proxy: {
      '/': 'http://localhost:3000'
    }
  },
  entry: './client/index.js',
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'bundle.js'
  },
  module: {
    rules: [
      {
        test: /\.jsx?/,
        exclude: /node_modules/,
        loader: "babel-loader",
        query: {
          presets: ["@babel/env", "@babel/react"],
          plugins: [
            "@babel/plugin-proposal-class-properties",
            "@babel/plugin-transform-runtime",
            "@babel/transform-async-to-generator",
          ],
        },
      },
      {
        test: /.(css|scss)$/,
        exclude: /node_modules/,
        use: ["style-loader", "css-loader"],
      },
    ],
  },
  resolve: {
    extensions: [".js", ".jsx", ".css", ".scss"],
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: './client/index.html',
      filename: './index.html'
    })
  ]
};