webpack.config.js

const path = require("path");

module.exports = {
  entry: './client/index.js',
  output: {
    path: path.resolve(__dirname,"./build"),
    filename:'bundle.js'
  },
  mode: process.env.NODE_ENV,
  module: {
      rules: [
          {
            test: /jsx?$/,
            exclude: /node_modules/,
            use: {
                loader: "babel-loader",
                options: {
                  presets: ["@babel/preset-env", "@babel/preset-react"],
                },
              }
          },
          {
            test: /css?$/,
            use: [
              // Creates `style` nodes from JS strings
              "style-loader",
              // Translates CSS into CommonJS
              "css-loader",
            ],
          },
          {
            test: /\.jpg$/,
            use: 'url-loader'
          },
      ]
  },
  resolve : {
    extensions: ['.js', '.jsx']
  },
  devServer: {
    publicPath: '/build/',
    contentBase: path.join(__dirname, 'public/'),
    port: 8080
  }
};