Employers are allowed to test for skills directly related to the job they are applying for.
When I applied for a cashiering job back in college, they were allowed to test my math skills. They were not allowed to give a math test to the guy applying to stock shelves.
I’m in favor of aptitude tests, they weed out a lot of the “administrative passers” who got their degrees without actually learning anything.
Yes, when I was in college and got a proofreading job at a law firm, they did give a proofreading test first.