Sanity testing

A sanity test or sanity check is a basic test to quickly evaluate whether a claim or the result of a calculation can possibly be true. It is a simple check to see if the produced material is rational (that the material's creator was thinking rationally, applying sanity). The point of a sanity test is to rule out certain classes of obviously false results, not to catch every possible error. A rule-of-thumb may be checked to perform the test. The advantage of a sanity test, over performing a complete or rigorous test, is speed.

In arithmetic, for example, when multiplying by 9, using the divisibility rule for 9 to verify that the sum of digits of the result is divisible by 9 is a sanity test—it will not catch every multiplication error, however it's a quick and simple method to discover many possible errors.

In computer science, a sanity test is a very brief run-through of the functionality of a computer program, system, calculation, or other analysis, to assure that part of the system or methodology works roughly as expected. This is often prior to a more exhaustive round of testing.

A sanity test can refer to various orders of magnitude and other simple rule-of-thumb devices applied to cross-check mathematical calculations. For example:

In software development, the sanity test (a form of software testing which offers "quick, broad, and shallow testing") determines whether it is possible and reasonable to proceed with further testing.

Software sanity tests are synonymous with smoke tests. A sanity or smoke test determines whether it is possible and reasonable to continue testing. It exercises the smallest subset of application functions needed to determine whether the systems are accessible and the application logic is responsive. If the sanity test fails, it is not reasonable to attempt more rigorous testing. Sanity tests are ways to avoid wasting time and effort by quickly determining whether an application is too flawed to merit any rigorous testing. Many companies run sanity tests on an automated build as part of their software development life cycle.

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