In my school, sparring is required from white belt on for juniors and from yellow belt on for adults. For the very rare adults who CAN'T spar (like the woman with a brain tumor who is not allowed to get hit, or even jostled hard--EVER), they can do kata, techniques, and self defense only, but will never get to brown belt. Since we spar a great deal, they probably won't get anywhere near that far. This is despite the fact that we do light contact point sparring (although, as I've mentioned before, the Texas definition of "light" appears to be different than most places.)
The only test that includes sparring, however, is our black belt test. Prior to that, sparring in school tournaments is required for juniors; kata in tournaments is required for adults up to purple belt, and sparring and kata are required for brown belts. I guess that covers the testing aspect of sparring. You can't test if you don't compete in the school tournaments.