FileUrlTest.php

<?php

namespace Drupal\Tests\file\Kernel;

use Drupal\Core\File\FileSystemInterface;

/**
 * Tests the file url.
 *
 * @group file
 */
class FileUrlTest extends FileManagedUnitTestBase {
    
    /**
     * Tests public files with a different host name from settings.
     */
    public function testFilesUrlWithDifferentHostName() {
        $test_base_url = 'http://www.example.com/cdn';
        $this->setSetting('file_public_base_url', $test_base_url);
        $filepath = \Drupal::service('file_system')->createFilename('test.txt', '');
        $directory_uri = 'public://' . dirname($filepath);
        \Drupal::service('file_system')->prepareDirectory($directory_uri, FileSystemInterface::CREATE_DIRECTORY);
        $file = $this->createFile($filepath, NULL, 'public');
        $url = $file->createFileUrl(FALSE);
        $expected_url = $test_base_url . '/' . basename($filepath);
        $this->assertSame($url, $expected_url);
    }

}