No windscreen, no wipers or windscreen washers

A windscreen wiper or washer control missing is a fail. (This refers to the switch)

If the wiper control then is fitted, but the wipers are not, then you can't test that part so the next part is a fail because the wiper(s) are missing, but

If the windscreen washers are not fitted at the time of test, then that becomes a pass and advise because there is no reason for rejection for washer(s) missing, and I don't think you can fail them for not supplying insufficient liquid because they are not fitted, then 

There is no reason for rejection for a windscreen not fitted, (I stand to be corrected), but VOSA or is that DVLSA now might take the same view as with opening windscreens and if that screen is open at the time of test, then the vehicle has passed because adequate view is available, and washers and wipers are not required without a windscreen