I think this should stop. In it's place, developers can have a pet open-source project, which they submit with their application. The point is that the same project can be submitted for a hundred applications if needed, saving the candidate dozens or hundreds of hours of wasted time.
They could put that time into the project instead and even if they don't get a single offer, the open source community benefits, and the candidate got to do something interesting rather than convert roman numerals or aggregate an array.
I seriously wonder if we should all boycott dev tests. If they give a test, just give them a github link and say "Please review this as a good example of my work.". If they can't review code that isn't tied to a silly question maybe they are not worth working for.
I say this having done some such tests recently myself. (To be fair one of them said a Github submission is OK, I just didn't feel my Github was good enough at the time.). I kind of feel bad contributing to the madness!