--TEST-- ReflectionClass::isSubclassOf() - non-existent class error --FILE-- <?php class A {} $rc = new ReflectionClass('A'); var_dump($rc->isSubclassOf('X')); ?> --EXPECTF-- Fatal error: Uncaught exception 'ReflectionException' with message 'Class X does not exist' in %s:5 Stack trace: #0 %s(5): ReflectionClass->isSubclassOf('X') #1 {main} thrown in %s on line 5