AN APPROACH FOR TESTING WEB SERVICE COMPOSITIONS WHEN INTERNAL MESSAGES ARE UNOBSERVABLE

Usually, Web service compositions are tested by assuming that all the messages exchanged between the services, participating to the composition, are observable. Nevertheless, when services are deployed in an infrastructure which restricts access or when they are deployed on Clouds, this assumption cannot be sustained. Indeed, these environments do not allow extracting the observable reactions of a composition under test (impossibility to install testers or sniffer based tools in the environment). So, this paper proposes a method to check whether a service composition conforms its specification with reference to the ioco test relation, by considering that the internal messages exchanged between the services are hidden but that we can invoke each service one by one (or an exact copy). We propose a method which decomposes an existing test case set according to the operation interleaving that we formalize with a factor denoted the dependency degree. Then, while executing the new test case set, we recover fragments of traces (observable reactions) that are reassembled. With the final traces, we are able to check whether the implemented composition is ioco-conform to its specification in the real environment where is deployed the composition.