webpack.config.js

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

const isProduction = process.env.NODE_ENV === 'production';

const config = {
  entry: './src/index.js',
  output: {
    path: path.resolve(__dirname, 'dist'),
  },
  devServer: {
    open: true,
    host: 'localhost',
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: 'index.html',
    }),
  ],
  module: {
    rules: [
      {
        test: /\.m?js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env'],
          },
        },
      },
      {
        test: /\.scss$/,
        use: ['style-loader', 'css-loader', 'sass-loader', 'postcss-loader'],
      },
      {
        test: /\.(eot|svg|ttf|woff|woff2|png|jpg|gif)$/i,
        type: 'asset',
      },
    ],
  },
};

module.exports = () => {
  if (isProduction) {
    config.mode = 'production';
  } else {
    config.mode = 'development';
  }
  return config;
};