src/plugins/swcMinifyPlugin.ts


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/*
 * Copyright (c) 2023 Kristóf Marussy <kristof@marussy.com>
 *
 * SPDX-License-Identifier: MIT
 */

import type { Plugin } from '@docusaurus/types';
import TerserPlugin from 'terser-webpack-plugin';

/**
 * A Docusarus plugin that replaces the built-in Javascript minifier with swc.
 *
 * See
 * https://github.com/facebook/docusaurus/issues/4765#issuecomment-1679863984
 * but we use swc instead of esbuild.
 *
 * @returns The Docusarus plugin.
 */
export default function swcMinifyPlugin(): Plugin {
  return {
    name: 'kris-swc-minify-plugin',
    configureWebpack: (config) => ({
      mergeStrategy: {
        'optimization.minimizer': 'replace',
      },
      optimization: {
        minimizer: config.optimization.minimizer?.map((plugin) => {
          // `instanceof` seems to be broken, because a different version of
          // `TerserPlguin` is coming from Docusaurus than the one we import.
          if (plugin.constructor.name === TerserPlugin.name) {
            return new TerserPlugin({
              minify: TerserPlugin.swcMinify,
            });
          }
          return plugin;
        }),
      },
    }),
  };
}