class NoHelpTest

class NoHelpTest extends KernelTestBase {
  use HttpKernelUiHelperTrait;
  use UserCreationTrait;
  
  /**
   * Modules to install.
   *
   * Use one of the test modules that do not implement hook_help().
   *
   * @var array
   */
  protected static $modules = [
    'help',
    'menu_test',
    'user',
    'system',
  ];
  
  /**
   * The user who will be created.
   *
   * @var \Drupal\user\Entity\User|false
   */
  protected $adminUser;
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();
    $this->installEntitySchema('user');
    $this->adminUser = $this->createUser([
      'access help pages',
    ]);
    $this->setCurrentUser($this->adminUser);
  }
  
  /**
   * Ensures modules not implementing help do not appear on admin/help.
   */
  public function testMainPageNoHelp() : void {
    $this->drupalGet('admin/help');
    $this->assertSession()
      ->statusCodeEquals(200);
    $this->assertSession()
      ->pageTextContains('Module overviews are provided by modules');
    $this->assertFalse(\Drupal::moduleHandler()->hasImplementations('help', 'menu_test'), 'The menu_test module does not implement hook_help');
    // Make sure the test module menu_test does not display a help link on
    // admin/help.
    $this->assertSession()
      ->pageTextNotContains(\Drupal::service('extension.list.module')->getName('menu_test'));
    // Ensure that the module overview help page for a module that does not
    // implement hook_help() results in a 404.
    $this->drupalGet('admin/help/menu_test');
    $this->assertSession()
      ->statusCodeEquals(404);
  }

}