I have an autism formal test next month, but have no idea what to expect? I've been down the mental health route and it was them who referred me. I can't bare anyone walking by me or being touched, I feel like I will whack them one! Let's hope he/she doesn't shake my hand! I haven't seen my friends in the flesh for over 2 years, I can't be in the same room as them. This has been since childhood, you guys are welcome to look at my profile and and click on the link to my blog, it's tough to explain here and the blog explains me better :)
It varies a bit, but you may have a one hour session when you are asked questions about your history, childhood etc, and then another hour-long session with an ADOS-2 practical test with some props, card tests and so on. It's all fairly simple, since it's roughly the same process for adults and children.
I don't really have this experience, but if you don't want to shake hands, just don't and say you don't want to. If anyone can understand, they should.