View source  
  <?php
use Drupal\Core\Extension\Extension;
use Drupal\Core\Routing\RouteMatchInterface;
function system_test_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.system_test':
      $output = '';
      $output .= '<h3>' . t('Test Help Page') . '</h3>';
      $output .= '<p>' . t('This is a test help page for the system_test module for the purpose of testing if the "Help" link displays properly.') . '</p>';
      return $output;
  }
}
function system_test_modules_installed($modules) {
  if (\Drupal::state()
    ->get('system_test.verbose_module_hooks')) {
    foreach ($modules as $module) {
      drupal_set_message(t('hook_modules_installed fired for @module', array(
        '@module' => $module,
      )));
    }
  }
}
function system_test_modules_uninstalled($modules) {
  if (\Drupal::state()
    ->get('system_test.verbose_module_hooks')) {
    foreach ($modules as $module) {
      drupal_set_message(t('hook_modules_uninstalled fired for @module', array(
        '@module' => $module,
      )));
    }
  }
}
function system_test_system_info_alter(&$info, Extension $file, $type) {
  
  static $test;
  if (($dependencies = \Drupal::state()
    ->get('system_test.dependencies')) || $test) {
    if ($file
      ->getName() == 'module_test') {
      $info['hidden'] = FALSE;
      $info['dependencies'][] = array_shift($dependencies);
      \Drupal::state()
        ->set('system_test.dependencies', $dependencies);
      $test = TRUE;
    }
    if ($file
      ->getName() == 'common_test') {
      $info['hidden'] = FALSE;
      $info['version'] = '8.x-2.4-beta3';
    }
  }
  
  if ($file
    ->getName() == 'system_dependencies_test') {
    $info['hidden'] = FALSE;
  }
  if (in_array($file
    ->getName(), array(
    'system_incompatible_module_version_dependencies_test',
    'system_incompatible_core_version_dependencies_test',
    'system_incompatible_module_version_test',
    'system_incompatible_core_version_test',
  ))) {
    $info['hidden'] = FALSE;
  }
  if ($file
    ->getName() == 'requirements1_test' || $file
    ->getName() == 'requirements2_test') {
    $info['hidden'] = FALSE;
  }
  if ($file
    ->getName() == 'system_test') {
    $info['hidden'] = \Drupal::state()
      ->get('system_test.module_hidden', TRUE);
  }
}
function system_test_page_attachments(array &$page) {
  
  $frontpage = \Drupal::state()
    ->get('system_test.front_page_output') ?: 0;
  if ($frontpage && \Drupal::service('path.matcher')
    ->isFrontPage()) {
    drupal_set_message(t('On front page.'));
  }
}
function _system_test_first_shutdown_function($arg1, $arg2) {
  
  \Drupal::state()
    ->set('_system_test_first_shutdown_function', array(
    $arg1,
    $arg2,
  ));
  drupal_register_shutdown_function('_system_test_second_shutdown_function', $arg1, $arg2);
}
function _system_test_second_shutdown_function($arg1, $arg2) {
  
  \Drupal::state()
    ->set('_system_test_second_shutdown_function', array(
    $arg1,
    $arg2,
  ));
  
  throw new Exception('Drupal is <blink>awesome</blink>.');
}
function system_test_filetransfer_info() {
  return array(
    'system_test' => array(
      'title' => t('System Test FileTransfer'),
      'class' => 'Drupal\\system_test\\MockFileTransfer',
      'weight' => -10,
    ),
  );
}
function system_test_module_preinstall($module) {
  \Drupal::state()
    ->set('system_test_preinstall_module', $module);
}
function system_test_module_preuninstall($module) {
  \Drupal::state()
    ->set('system_test_preuninstall_module', $module);
}