On the validation of API execution-sequence to assess the correctness of application upon COTS upgrades deployment

Various regression test selection strategies have been developed to establish the correctness of software systems upon deployment of COTS upgrades. These strategies recommend a smaller regression test suite to be re-executed. We present a process that identifies the patch impact on the system and localizes the source of potential errors without executing the system test suite. The impact is analyzed based on verifying the behavior of affected COTS API execution-sequences. An API execution-sequence is called affected when one or more of the altered functions of the COTS upgrade are part of COTS API execution-sequence that interfaces with application components. A wrapper-based passive test oracle has been developed to check the correctness of the behavior of these execution-sequences. The changed behavior of these execution-sequences reflects the patch impact. A case study has been conducted and the results are encouraging