Metamorphic Relation Prioritization for Effective Regression Testing
This work addresses the efficiency and cost issues in regression testing for software developers and testers, representing an incremental improvement in testing methodologies.
The paper tackles the problem of inefficient regression testing in metamorphic testing by proposing fault-based and coverage-based approaches to prioritize metamorphic relations, showing that these approaches significantly outperform ad-hoc methods in fault detection effectiveness and reduce test cases and time to detect faults.
Metamorphic testing (MT) is widely used for testing programs that face the oracle problem. It uses a set of metamorphic relations (MRs), which are relations among multiple inputs and their corresponding outputs to determine whether the program under test is faulty. Typically, MRs vary in their ability to detect faults in the program under test, and some MRs tend to detect the same set of faults. In this paper, we propose approaches to prioritize MRs to improve the efficiency and effectiveness of MT for regression testing. We present two MR prioritization approaches: (1) fault-based and (2) coverage-based. To evaluate these MR prioritization approaches, we conduct experiments on three complex open-source software systems. Our results show that the MR prioritization approaches developed by us significantly outperform the current practice of executing the source and follow-up test cases of the MRs in an ad-hoc manner in terms of fault detection effectiveness. Further, fault-based MR prioritization leads to reducing the number of source and follow-up test cases that needs to be executed as well as reducing the average time taken to detect a fault, which would result in saving time and cost during the testing process.