Code Coverage-Based Failure Proximity without Test Oracles

Failure indexing technique plays an important role in modern software maintenance. It can facilitate duplicated failure removal, failure assignment, etc. Failure proximity is a crucial part that underpins failure indexing techniques. It is comprised of two components: a fingerprinting function extracting failure signatures from failures and a distance function computing pairwise distances between failures. Failure proximity usually assumes the existence of test oracle. However, in many real-life application domains, test oracles do not always exist. Hence, the applicability of existing failure proximity techniques is limited. In our paper, we focus on investigating how to apply metamorphic testing on code coverage-based failure proximity without test oracles. In our approach, instead of using the testing results of failure, the results of violation or non-violation for metamorphic test groups are used. Specifically, the fingerprinting function extracts signatures from metamorphic slices rather than execution slices and the distance function computes the pairwise distance between violations rather than between failures. Thereby, the applicability of failure proximity is extended to the situations without test oracles. The experimental results on 50 two-fault mutants show that the quality of proximity matrix obtained through our approach is statistical comparable to traditional code coverage-based failure proximity with test oracle.