preact.config.js

const webpack = require('webpack');
const { GitRevisionPlugin } = require('git-revision-webpack-plugin');
import tailwindcss from 'tailwindcss';
import postcssCustomMedia from 'postcss-custom-media';
import optionalChaining from '@babel/plugin-proposal-optional-chaining';
import nullishOperator from '@babel/plugin-proposal-nullish-coalescing-operator';
/**
 * Function that mutates original webpack config.
 * Supports asynchronous changes when promise is returned.
 *
 * @param {object} config - original webpack config.
 * @param {object} env - options passed to CLI.
 * @param {WebpackConfigHelpers} helpers - object with useful helpers when working with config.
 **/
export default function (config, env, helpers) {
  const htmlWebpackPlugin = helpers.getPluginsByName(
    config,
    'HtmlWebpackPlugin',
  )[0];
  Object.assign(htmlWebpackPlugin.plugin.options.minify, {
    removeComments: false,
    collapseWhitespace: false,
  });
  htmlWebpackPlugin.plugin.options.preload = false;
  htmlWebpackPlugin.plugin.options.favicon = false;

  if (env.isProd) {
    config.devtool = false; // disable sourcemaps
    config.output.publicPath = './';
    // config.plugins.push(
    // 	new CommonsChunkPlugin({
    // 		name: 'vendor',
    // 		minChunks: ({ resource }) => /node_modules/.test(resource)
    // 	})
    // );
  }
  const babelLoader = helpers.getLoadersByName(config, 'babel-loader');
  for (const result of babelLoader) {
    console.log(result.loader.options);
    result.loader.options.plugins.push(optionalChaining);
    result.loader.options.plugins.push(nullishOperator);
  }
  const results = helpers.getLoadersByName(config, 'postcss-loader');
  for (const result of results) {
    result.loader.options.postcssOptions.plugins = [
      postcssCustomMedia,
      tailwindcss('./tailwind.config.js'),
      ...result.loader.options.postcssOptions.plugins,
    ];
  }

  const gitRevisionPlugin = new GitRevisionPlugin({
    commithashCommand: 'rev-parse --short HEAD',
  });
  config.plugins.push(
    new webpack.DefinePlugin({
      __COMMITHASH__: JSON.stringify(gitRevisionPlugin.commithash()),
    }),
  );
}