On the Analysis of Spectrum-based Fault Localization

Spectrum-based fault localization (SBFL) has been widely studied due to its simplicity and effectiveness. However, it still has some challenging problems. The application of SBFL in the absence of test oracle and the selection of the most effective risk evaluation formulas are amongst the most critical problems. In this thesis, we are going to address these two problems. Currently, all existing SBFL techniques have assumed the existence of a test oracle. Otherwise, the program spectrum will not be associated with the testing result of failed or passed, and as a consequence, there will be insufficient information to perform the risk evaluation. However, in many real-world applications, it is very common that test oracles do not exist, and hence SBFL cannot be applied in such situations. Therefore, in this thesis, we propose a novel concept of metamorphic slice resulted from the integration of metamorphic testing and program slicing, to alleviate the oracle problem for SBFL. In our approach, instead of using the program slice and the testing result of failed or passed for an individual test case, metamorphic slice and the testing result of violation or non-violation of a metamorphic relation are used. Since we need not to know the execution result for an individual test case, the existence of test oracle is no longer a prerequisite to SBFL. Experimenta