LegacyAssetTest.php

<?php

namespace Drupal\KernelTests\Core\Asset;

use Drupal\KernelTests\KernelTestBase;

/**
 * Tests deprecated asset functions.
 *
 * @group Asset
 * @group legacy
 */
class LegacyAssetTest extends KernelTestBase {
    
    /**
     * Tests the deprecation.
     */
    public function testDeprecatedDrupalFlushCssJs() : void {
        $this->expectDeprecation('_drupal_flush_css_js is deprecated in drupal:10.2.0 and is removed from drupal:11.0.0. Use \\Drupal\\Core\\Asset\\AssetQueryStringInterface::reset() instead. See https://www.drupal.org/node/3358337');
        _drupal_flush_css_js();
    }

}