webpack.common.js

const {CleanWebpackPlugin} = require('clean-webpack-plugin');
const HtmlWebPackPlugin = require('html-webpack-plugin');
const PreloadWebpackPlugin = require('preload-webpack-plugin');
const webpack = require('webpack'); 
const path = require('path');

module.exports = {
  entry: {
    main: './src/index.js'
  },
  output: {
    filename: '[name].[chunkhash:8].js',
    path: path.resolve('./dist'),
    publicPath: '/'
  },
  optimization: {
    splitChunks: {
      cacheGroups: {
        vendors: {
          test: /[\\/]node_modules[\\/]/i,
          chunks: 'all'
        },
        commons: {
          name: 'commons',
          chunks: 'initial',
          minChunks: 2
        }
      }
    },
    runtimeChunk: {
      name: 'runtime'
    }
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /(node_modules)/,
        use: [{ loader: 'babel-loader' }]
      },
      {
        test: /\.s(a|c)ss$/,
        use: [
          {
            loader: 'style-loader'
          },
          {
            loader: 'css-loader'
          },
          {
            loader: 'sass-loader'
          }
        ]
      }
    ]
  },
  plugins: [
    new webpack.ProgressPlugin(),
    new HtmlWebPackPlugin({
      template: 'index.html'
    }),
    new CleanWebpackPlugin(),
    new PreloadWebpackPlugin({
      rel: 'preload',
      include: 'initial'
      // include: ['main', 'vendors']
    })
  ]
};