at_tools-8.x-3.x-dev/at_theme_generator/at_theme_generator.install

<?php

/**
 * @file
 * AT Theme Generator install file.
 */

use Drupal\at_theme_generator\File\DirectoryOperations;

/**
 * Implements hook_install().
 */
function at_theme_generator_install() {
  $list_info = \Drupal::service('theme_handler')->listInfo();
  $theme = 'at_generator';

  // Check if the old at_generator is installed.
  if (array_key_exists($theme, $list_info)) {
    // Check if the old generator theme is default, if so replace with Bartik.
    // Users sometimes made the mistake of setting the old generator theme as
    // default which totally borks their site, we use this module install to
    // to try and fix that issue for them.
    if ($theme == \Drupal::service('theme_handler')->getDefault()) {
      \Drupal::service('theme_handler')->setDefault('bartik');
      \Drupal::messenger()->addStatus(t('Bartik set as default theme.'));
    }
    // Now uninstall it.
    \Drupal::service('theme_installer')->uninstall([$theme]);
  }
  // Now remove the old generator theme.
  $gen_path = \Drupal::service('extension.list.theme')->getPath($theme);
  if (!empty($gen_path)) {
    $directoryOperations = new DirectoryOperations();
    $directoryOperations->directoryRemove($gen_path);
    \Drupal::messenger()->addStatus(t('Old at_generator theme has been removed, please use the new Theme Generator tab in Appearance settings.'));
  }
}

/**
 * Assign "administer at_theme_generator" permission to roles currently assigned the "administer themes" permission.
 */
function at_theme_generator_update_8001() {
  if ($roles = user_roles(FALSE, 'administer themes')) {
    foreach ($roles as $rid => $role) {
      user_role_grant_permissions($rid, ['administer at_theme_generator']);
    }
  }
}