locale_library_info_alter

locale_library_info_alter(array &$libraries, $module)

function locale_library_info_alter(array &$libraries, $module) {
  if ($module === 'core' && isset($libraries['jquery.ui.datepicker'])) {
    $libraries['jquery.ui.datepicker']['dependencies'][] = 'locale/drupal.locale.datepicker';
    $libraries['jquery.ui.datepicker']['drupalSettings']['jquery']['ui']['datepicker'] = [
      'isRTL' => NULL,
      'firstDay' => NULL,
    ];
  }

  // When the locale module is enabled, we update the core/drupal library to
  // have a dependency on the locale/translations library, which provides
  // window.drupalTranslations, containing the translations for all strings in
  // JavaScript assets in the current language.
  // @see locale_js_alter()
  if ($module === 'core' && isset($libraries['drupal'])) {
    $libraries['drupal']['dependencies'][] = 'locale/translations';
  }
}