Testing under the Hood

 Even when a particular test passed at first glance, there might still be things going wrong. You may just not have noticed it, because the User Interface stays quiet; at least for the moment. Things can go wrong in a black box long after you executed the test; hours, days or even weeks later. The longer such problems remain undetected the more effort it takes to fix the problem and repair the damage it caused, especially if the system is already LIVE in production. See also Cheerful Debugging Messages and its Consequences in this blog.

It is not enough to look only at the front-end of an application. You should also watch carefully what’s going on behind the curtains. Give all testers a facility to query the underlying database. A lot of things can go wrong there and remain undetected for too long. It will start hurting only when such data is shared with or passed to other programs using a corresponding interface to read or exchange data. I have seen a lot of things stored inappropriate only to hurt when such data was later used by another program.

I developed an SQL query tool with some extra facilities like an analyser to compare all tables before and after a triggered action.

 How can testers live without such tools? It opens a whole new universe of potential problems just waiting to get reported.