I think the same test should be used for spurs. Also an unnecessary "aid". I personally do use a whip for driving but I rarely need to use it on the horse. Mostly I just tap the side of the shafts to get their attention. Similarly with riding, only a touch of the whip should be necessary if at all. Why whack them?
I do not think that a whip is necessary. If you have a trained horse, it should jump without "encouragement" because it knows what you want from it, and knows it's job. If you believe that you have to ride with a whip, then your horse needs more training. The horse does not need to be whipped for not knowing what to do, or possibly being afraid.
interesting facts an eager horse won't need an aid but some need a bit of encouragement not to be used as punishment
A horse will work best, for a rider he/she can trust. I imagine its the same with jumping, a horse will run or jump without incouragement with that old whip.