webpack.config.js

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

module.exports = {
  entry: {
    app: './src/index.js',
    vendor: ['react', 'react-dom'],
  },
  output: {
    path: path.resolve(__dirname, 'static'),
    filename: '[name].bundle.js',
    publicPath: '/',
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
        },
      },
      {
        test: /\.jsx$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
        },
      },
      {
        test: /\.css$/,
        use: ['style-loader', 'css-loader'],
      },
      {
        test: /\.scss$/,
        use: [
          'style-loader',
          'css-loader',
          'sass-loader',
        ],
      },
    ]
  },
  optimization: {
    splitChunks: {
      cacheGroups: {
        vendor: {
          chunks: 'initial',
          name: 'vendor',
          test: 'vendor',
          enforce: true,
        },
      }
    },
    runtimeChunk: false,
  },
  plugins: [new HtmlWebpackPlugin({
    template: './src/index.html',
    filename: 'index.html',
    inject: 'body',
  })],
  devServer: {
    port: 8000,
    contentBase: 'static',
    proxy: {
      '**': {
        target: 'http://[::1]:4000',
      },
      // '/socket.io': {
      //   target: 'http://localhost:4000',
      //   ws: true,
      // },
    },
    historyApiFallback: true,
  },
  devtool: 'source-map',
};