You can check diagnostic codes stored on the ECU. If the MAF is sending voltage out of spec then the ECU will notice, but if the signal is within spec but at the wrong time then the ECU can't tell the difference.
Otherwise, remove the MAF and bench test according to FSM procedures. Even these procedures are not perfect.
If still not convinced, swap in a known good MAF.
you can do a field test if you have an ohm meter. Just make sure there is continuity across all pins. Any breaks indicate a bad AFM.
The results of the ohm test I ran on my known good AFMs. The numbers are slightly different between the two, but that shouldn't be much of a problem. Basically, if there is a no connect between any of the pins, then you have a problem.