spee.ch/webpack/webpack.client.config.js

const Path = require('path');
const webpack = require('webpack');
const nodeExternals = require('webpack-node-externals');
const ExtractCssChunks = require('extract-css-chunks-webpack-plugin');
const createModuleAliases = require('../utils/createModuleAliases.js');

const SCSS_ROOT = Path.resolve(__dirname, '../client/scss/');
const CLIENT_ROOT = Path.resolve(__dirname, '../client/');
const CUSTOM_CLIENT_ROOT = Path.resolve(__dirname, '../site/custom/');

const customAliases = createModuleAliases();

module.exports = (env, argv) => {
  const isDev = argv.mode === 'development';

  return {
    mode: isDev ? 'development' : 'production',
    target: 'web',
    entry : [
      'webpack-hot-middleware/client',
      //'webpack/hot/dev-server',
      '@babel/polyfill',
      'whatwg-fetch',
      './client/src/index.js',
    ],
    output: {
      path      : Path.resolve(__dirname, '../public/bundle'),
      publicPath: '/bundle/',
      filename  : 'bundle.js',
    },
    module: {
      rules: [
        {
          test: /\.jsx?$/,
          exclude: /(node_modules|bower_components)/,
          use: {
            loader: 'babel-loader',
          },
        },
        {
          test: /\.scss$/,
          use: [
            {
              loader: ExtractCssChunks.loader,
            },
            'css-loader',
            'sass-loader',
          ]
        },
        {
          test: /\.(png|jpg|gif|otf|ttf|svg)$/,
          use : [
            {
              loader : 'url-loader',
              options: {
                limit: 8192,
                name : '[name]-[hash].[ext]',
              },
            },
          ],
        },
      ],
    },
    resolve: {
      modules: [
        CUSTOM_CLIENT_ROOT,
        CLIENT_ROOT,
        SCSS_ROOT,
        'node_modules',
        __dirname,
      ],
      alias     : customAliases,
      extensions: ['.js', '.jsx', '.scss', '.json'],
    },
    plugins: [
      ...(isDev ? [new webpack.HotModuleReplacementPlugin()] : []),
      new ExtractCssChunks({
        filename: 'style.css', // '[name].css',
      })
    ],
  };
}