Page "Sanity testing" Paragraph 12

Another, possibly more common usage of ' sanity test ' is to denote checks which are performed within program code, usually on arguments to functions or returns therefrom, to see if the answers can be assumed to be correct.

The more complicated the routine, the more important that its response be checked.

The trivial case is checking to see that a file opened, written to, or closed, did not fail on these activities – which is a sanity check often ignored by programmers.

But more complex items can also be sanity-checked for various reasons.