They inspect the brakes here in Virginia for wear but don't do an actual brake test using the electric brake controller.  They do check all of the safety lights.  I have been failed a couple of times on one of my trailers for having backup lights on the rear that was not under control of the truck safety lights switching.   Having a manual backup light switch doesn't work here haha...    So I moved those backup lights to the rear side of the trailer up high using manual control switch and that got passed ok... That actually worked out better for seeing where I was backing into as you can't really see directly behind the trailer anyway.  They also looked at all the safety light lens for the DOT APPROVED numbers.
Roy Ken