Satisfying Test Preconditions through Guided Object Selection

A random testing strategy can be effective at finding faults, but may leave some routines entirely untested if it never gets to call them on objects satisfying their preconditions. This limitation is particularly frustrating if the object pool does contain some precondition-satisfying objects but the strategy, which selects objects at random, does not use them. The extension of random testing described in this article addresses the problem. Experimentally, the resulting strategy succeeds in testing 56% of the routines that the pure random strategy missed; it tests hard routines 3.6 times more often; although it misses some of the faults detected by the original strategy, it finds 9.5% more faults overall; and it causes negligible overhead.