twig_tweak/tests/twig_tweak_test/twig_tweak_test.module

<?php

/**
 * @file
 * Primary module hooks for Twig Tweak test module.
 */

/**
 * Implements hook_page_bottom().
 */
function twig_tweak_test_page_bottom(array &$page_bottom) {
  $page_bottom['twig_tweak_test']['#theme'] = 'twig_tweak_test';
}

/**
 * Implements hook_theme().
 */
function twig_tweak_test_theme() {
  return ['twig_tweak_test' => ['variables' => []]];
}

/**
 * Prepares variables for twig-tweak-test template.
 */
function template_preprocess_twig_tweak_test(&$vars) {
  $vars['node'] = $node = Drupal::routeMatch()->getParameter('node');
}