TestAttributes.php

<?php

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

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

/**
 * Test controller for method-level Route attributes.
 */
class TestAttributes extends ControllerBase {
  public function attributeMethod() : array {
    return [
      '#markup' => 'Testing method with a Route attribute',
    ];
  }
  public function allProperties() : array {
    return [
      '#markup' => 'Testing route with all properties',
    ];
  }

}