function testFolderConstructChild() { $orig = File::$class_for_file_extension; File::$class_for_file_extension['gif'] = 'FileTest_MyCustomFile'; $folder1 = $this->objFromFixture('Folder', 'folder1'); $fileID = $folder1->constructChild('myfile.gif'); $file = DataObject::get_by_id('File', $fileID); $this->assertEquals('FileTest_MyCustomFile', get_class($file)); File::$class_for_file_extension = $orig; }