Automated metamorphic testing

Usual techniques for automatic test data generation are based on the assumption that a complete oracle will be available during the testing process. However, there are programs for which this assumption is unreasonable. Recently, Chen et al. (1998, 2001) proposed to overcome this obstacle by using known relations over the input data and their unknown expected outputs to seek a subclass of faults inside the program. In this paper, we introduce an automatic testing framework able to check these so-called metamorphic relations. The framework makes use of constraint logic programming techniques to find test data that violate a given metamorphic-relation. Circumstances where it can also prove that the program satisfies this relation are presented. The first experimental results we got with a prototype tool build on the top of the test data generator INKA, show that this methodology can be completely automated.