Assessing the Effectiveness of Input and Output Coverage Criteria for Testing Quantum Programs

Quantum programs implement quantum algorithms solving complex computational problems. Testing such programs is challenging due to the inherent characteristics of Quantum Computing (QC), such as the probabilistic nature and computations in superposition. However, automated and systematic testing is needed to ensure the correct behavior of quantum programs. To this end, we present an approach called Quito (QUantum InpuT Output coverage) consisting of three coverage criteria defined on the inputs and outputs of a quantum program, together with their test generation strategies. Moreover, we define two types of test oracles, together with a procedure to determine the passing and failing of test suites with statistical analyses. To evaluate the cost-effectiveness of the three coverage criteria, we conducted experiments with five quantum programs. We used mutation analysis to determine the coverage criteria' effectiveness and cost in terms of the number of test cases. Based on the results of mutation analysis, we also identified equivalent mutants for quantum programs.