webpack.config.js

const path = require('path');
const webpack = require('webpack');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin')

module.exports = {
  entry: './src/js/App.js',
  output: {
    path: path.resolve(__dirname, 'public'),
    filename: 'js/bundle.js'
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        include: [path.resolve(__dirname, 'src/js')],
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: [["@babel/preset-env", {
              "useBuiltIns": "usage",
              corejs: 3
            }]],
            plugins: ['@babel/plugin-proposal-class-properties']
          }
        }
      },
      {
        test: /\.css$/,
        use: [MiniCssExtractPlugin.loader, "css-loader"],
      }
    ]
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: 'css/styles.css'
    }),
    new webpack.HotModuleReplacementPlugin(),
    new HtmlWebpackPlugin({
      filename: 'index.html',
      template: 'src/index.html'
    })
  ],
  devtool: 'source-map',
  mode: 'development'
};