WordNet (r) 3.0 (2006):

reality check
    n 1: an occasion on which one is reminded of the nature of
         things in the real world; "this program is intended as a
         reality check for CEOs"; "after all those elaborate
         productions, I felt in need of a reality check"

The Jargon File (version 4.4.7, 29 Dec 2003):

reality check
 n.

    1. The simplest kind of test of software or hardware; doing the equivalent
    of asking it what 2 + 2 is and seeing if you get 4. The software equivalent
    of a smoke test.

    2. The act of letting a real user try out prototype software. Compare 
    sanity check.


The Free On-line Dictionary of Computing (30 December 2018):

reality check

    The simplest kind of functional test of software or
   hardware; doing the equivalent of asking it what 2 + 2 is and
   seeing if it says four.  The software equivalent of a smoke
   test.  A reality check may include letting a real user try out
   prototype software.

   A sanity check is even more basic, the equivalent of checking
   that the above addition was implemented with an addition operator
   rather than subtraction.

   (2007-03-15)