The only test I'm aware of is the gigantic GRE computer Science test (which I believe used to be available three times a year). But that's hardly efficient, unless you're very familiar with a lot of the subjects on the exam. Excelsior will give incremental credits relative to the score on the exam (I believe it can go up to 30 credits).
I'm sorry I cannot find the table that showed subjects awarded relative to scoring. but I'm pretty sure Discrete Mathematics was one that was achieved with a score on lower end of the accepted score range.
https://www.excelsior.edu/Excelsior_...d_Examinations
Still this exam is overkill. I've run a quick search on ACE and the only thing that came up was an ACT class, not what you're looking for I suppose.