Test case generation for BPEL-based web service composition using Colored Petri Nets

Web service composition involves a collection of web services; the interaction among the participating services makes the testing of the web service composition significantly complicated. In this paper, we present an approach of test case generation for Business Process Execution Language (BPEL) based web service composition using Colored Petri Net (CPN) which provides a strong formal background for the testing of the BPEL structures. Our approach combines a reachability graph and a control flow graph to generate feasible test cases by reducing the associated time cost. After transforming the BPEL processes into a CPN model, we construct a reachability graph from the model to get all the reachable states. Then a control flow graph is constructed from the reachability graph applying proposed rules to investigate test paths. Finally, test data are generated by solving the constraints of the test paths. A prototype tool has implemented the proposed approach and it is applied on two case studies, demonstrating that the approach is both effective and feasible.