Could there be a formal, "hard test" for asperger's syndrome?

No: Nobody even knows what it is, and the only treatment that works is to learn some new skills which isn't a bad idea for most people. Poorly-coordinated, talk mechanically, good at some academic subjects, focused interests (often strange). Best rx is to learn to say nice things, get guidance reading people, strength / endurance sport, "relationships are more important than being right." has pluses.