Closing the Loop: Towards a Complete Metamorphic Testing Pipeline

Metamorphic Testing (MT) address the test oracle problem, which arises when there are no practical means to verify the outputs of the System Under Test (SUT). Instead of just verifying individual input-output combinations, MT assesses the relations between pairs of these combinations during consecutive SUT executions; these relations are known as Metamorphic Relations (MRs). MRs delineate how outputs should adapt based on input changes. Automating MR generation is challenging because of the intrinsic connection between MRs and the SUT’s domain. Furthermore, the relevance of MRs can be contingent upon specific data. Motivated by this, our research focuses on facilitating the generation and selection of MRs, defining their applicability by establishing constraints and shedding light on the factors influencing MR outcomes. Our goal is to equip testers with methods and tools that optimise the application of the MT approach.