trait FileMigrationSetupTrait

trait FileMigrationSetupTrait {
    
    /**
     * Returns information about the file to be migrated.
     *
     * @return array
     *   Array with keys 'path', 'size', 'base_path', and 'plugin_id'.
     */
    protected abstract function getFileMigrationInfo();
    
    /**
     * Prepare the file migration for running.
     */
    protected function fileMigrationSetup() {
        $this->installEntitySchema('file');
        $this->installSchema('file', [
            'file_usage',
        ]);
        $info = $this->getFileMigrationInfo();
        $fs = $this->container
            ->get('file_system');
        // Ensure that the files directory exists.
        $fs->mkdir(dirname($info['path']), NULL, TRUE);
        // Put test file in the source directory.
        file_put_contents($info['path'], str_repeat('*', $info['size']));
        
        /** @var \Drupal\migrate\Plugin\Migration $migration */
        $migration = $this->getMigration($info['plugin_id']);
        // Set the source plugin's source_base_path configuration value, which
        // would normally be set by the user running the migration.
        $source = $migration->getSourceConfiguration();
        $source['constants']['source_base_path'] = $fs->realpath($info['base_path']);
        $migration->set('source', $source);
        $this->executeMigration($migration);
    }
    
    /**
     * Tests a single file entity.
     *
     * @param int $id
     *   The file ID.
     * @param string $name
     *   The expected file name.
     * @param string $uri
     *   The expected URI.
     * @param string $mime
     *   The expected MIME type.
     * @param string $size
     *   The expected file size.
     * @param string $created
     *   The expected creation time.
     * @param string $changed
     *   The expected modification time.
     * @param string $uid
     *   The expected owner ID.
     */
    protected function assertEntity($id, $name, $uri, $mime, $size, $created, $changed, $uid) {
        
        /** @var \Drupal\file\FileInterface $file */
        $file = File::load($id);
        $this->assertInstanceOf(FileInterface::class, $file);
        $this->assertSame($name, $file->getFilename());
        $this->assertSame($uri, $file->getFileUri());
        $this->assertFileExists($uri);
        $this->assertSame($mime, $file->getMimeType());
        $this->assertSame($size, $file->getSize());
        // isPermanent(), isTemporary(), etc. are determined by the status column.
        $this->assertTrue($file->isPermanent());
        $this->assertSame($created, $file->getCreatedTime());
        $this->assertSame($changed, $file->getChangedTime());
        $this->assertSame($uid, $file->getOwnerId());
    }

}