Migrator.php

<?php

declare (strict_types=1);

/*
 * This file is part of PHPUnit.
 *
 * (c) Sebastian Bergmann <sebastian@phpunit.de>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace PHPUnit\TextUI\XmlConfiguration;

use PHPUnit\Runner\Version;
use PHPUnit\Util\Xml\Loader as XmlLoader;
use PHPUnit\Util\Xml\XmlException;

/**
 * @no-named-arguments Parameter names are not covered by the backward compatibility promise for PHPUnit
 *
 * @internal This class is not covered by the backward compatibility promise for PHPUnit
 */
final class Migrator {
    
    /**
     * @throws Exception
     * @throws MigrationException
     * @throws XmlException
     */
    public function migrate(string $filename) : string {
        $origin = (new SchemaDetector())->detect($filename);
        if (!$origin->detected()) {
            throw new Exception('The file does not validate against any known schema');
        }
        if ($origin->version() === Version::series()) {
            throw new Exception('The file does not need to be migrated');
        }
        $configurationDocument = (new XmlLoader())->loadFile($filename);
        foreach ((new MigrationBuilder())->build($origin->version()) as $migration) {
            $migration->migrate($configurationDocument);
        }
        $configurationDocument->formatOutput = true;
        $configurationDocument->preserveWhiteSpace = false;
        return $configurationDocument->saveXML();
    }

}