webpack.config.js

const path = require('path');

const HtmlWebpackPlugin = require('html-webpack-plugin');
const ScriptExtHtmlWebpackPlugin = require('script-ext-html-webpack-plugin');
const ExtraWatchWebpackPlugin = require('extra-watch-webpack-plugin');
const ZipPlugin = require('zip-webpack-plugin');
const TerserPlugin = require('terser-webpack-plugin');

module.exports = env => {
  const isProd = env === 'prod';

  process.env.NODE_ENV = isProd ? 'production' : 'development';

  const plugins = [
    new HtmlWebpackPlugin({
      template: './index.html',
      minify: {
        removeComments: true,
        removeAttributeQuotes: true,
        removeScriptTypeAttributes: true,
        removeTagWhitespace: true,
        collapseWhitespace: true,
        minifyCSS: true,
        inlineSource: '.(js|ts)$',
      },
      svgoConfig: {
        removeViewBox: true,
        removeDimensions: false,
        convertTransform: true,
        cleanupNumericValues: {
          floatPrecision: 1,
        },
        convertPathData: {
          floatPrecision: 1,
        },
      },
    }),
    new ExtraWatchWebpackPlugin({
      files: ['levels/*.svg', 'assets/*.svg'],
    }),
  ];

  if (isProd) {
    plugins.push(
      new ScriptExtHtmlWebpackPlugin({
        inline: 'bundle',
      }),
    );
    plugins.push(new ZipPlugin({ filename: 'bundle.zip' }));
  }

  return {
    entry: './src/index.ts',
    module: {
      rules: [
        {
          test: /\.ts?$/,
          use: ['ts-loader', 'webpack-conditional-loader'],
          exclude: /node_modules/,
        },
      ],
    },
    resolve: {
      extensions: ['.ts', '.js'],
    },
    output: {
      filename: 'bundle.js',
      path: path.resolve(__dirname, 'dist'),
    },
    plugins,
    devtool: isProd ? false : 'source-map',
    optimization: {
      minimizer: [
        new TerserPlugin({
          terserOptions: {
            mangle: {
              properties: {
                keep_quoted: true,
              },
            },
          },
        }),
      ],
    },
  };
};

console.log('process.env.NODE_ENV', process.env.NODE_ENV);