Generating test case specifications of web service composition using model checking

Model checking techniques have been widely used in verifying web service compositions to ensure the trustworthiness. However, little research has focused on testing web services. Based on the research of model checking techniques, we propose a model checking based approach for testing web service composition which is described by using the web services choreography description language (WS-CDL). According to worldwide web consortium (W3C) candidate recommendation, the WS-CDL specification provides a language for characterizing interactions between distinct web services using XML. Since the behaviors of web service composition are asynchronous, distributed, low-coupled and platform independent, we employ the guarded automata (GA) model for specifying the composition described in WS-CDL and using the simple promela interpreter (SPIN) model checker for detecting the collaborations of web services. Test cases can be transformed from counterexamples generated by SPIN using adequacy criteria. In this paper we apply the transition coverage criterion for generating counterexamples. To illustrate our approach, we set “E-commerce service system” as an example for demonstrating how test cases can be generated using SPIN for compositions specified in WS-CDL.