TestClassAttributeClassOnly.php

<?php

declare (strict_types=1);
namespace Drupal\router_test\Controller;

use Drupal\Core\Controller\ControllerBase;
use Symfony\Component\Routing\Attribute\Route;

/**
 * Test controller: class-only #[Route] with bare __invoke().
 */
class TestClassAttributeClassOnly extends ControllerBase {
  
  /**
   * Provides test content.
   */
  public function __invoke() : array {
    return [
      '#markup' => 'Testing class-only #[Route] with bare __invoke()',
    ];
  }

}