webpack.config.js

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

const htmlWebpackPluginConfig = new HtmlWebpackPlugin({
  template: './client/app/index.html',
  filename: 'index.html',
  inject: 'body',
});

const extractSassPlugin = new ExtractTextPlugin({
  filename: '[name].[contenthash].css',
  disable: process.env.NODE_ENV === 'development',
});

module.exports = {
  entry: './client/app/index.js',
  output: {
    path: path.resolve('dist'),
    filename: '[name].[chunkhash].js',
  },
  plugins: [htmlWebpackPluginConfig, extractSassPlugin],
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        use: 'babel-loader',
        exclude: /node_modules/,
      },
      {
        test: /\.scss$/,
        use: [
          {
            loader: 'style-loader',
          },
          {
            loader: 'css-loader',
          },
          {
            loader: 'sass-loader',
          },
        ],
      },
      {
        test: /\.html$/,
        use: {
          loader: 'html-loader',
        },
      },
    ],
  },
};