webpack.development.js

const path = require('path');
const webpack = require('webpack');

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

module.exports = {
  mode: 'development',
  cache: true,
  devtool: 'cheap-module-eval-source-map',
  entry: {
    main: ['@babel/polyfill', path.join(__dirname, 'src/index.jsx')],
  },
  devServer: {
    contentBase: path.join(__dirname, 'src/public'),
    historyApiFallback: true,
    disableHostCheck: true,
    host: process.env.HOST || '0.0.0.0',
    port: process.env.PORT || 8000,
  },
  output: {
    filename: '[name].[hash:8].js',
    path: path.resolve(__dirname, 'build'),
    publicPath: '/',
  },
  plugins: [
    new webpack.HotModuleReplacementPlugin(),
    new HtmlWebpackPlugin({
      template: 'src/public/index.html',
      filename: 'index.html',
    }),
    new MiniCssExtractPlugin({
      filename: '[name].[hash:8].css',
    }),
  ],
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        include: path.resolve(__dirname, 'src'),
        loader: 'babel-loader',
        query: {
          presets: [
            '@babel/preset-react',
            ['@babel/env', { targets: { browsers: ['last 2 versions'] }, modules: false }],
          ],
          plugins: [
            '@babel/plugin-proposal-class-properties',
          ],
        },
      },
      {
        test: /\.css$/,
        use: [
          { loader: MiniCssExtractPlugin.loader },
          { loader: 'css-loader' },
        ],
      },
    ]
  }
}