A test case reduction method for semantic based web services

Web Services are the basic building blocks for every e-business applications now-a-days. They provide efficient reusability mechanism, thereby reducing the development time and cost. Mostly the source code of web services is unavailable to other developers who use these services. The manual effort spent by them in testing these web services is very large in order to increase the interoperability. Thus automated testing needs to be developed for testing these Web Services, which is possible by adding semantics to Web Service Description Language (WSDL). Also the test case reduction technique is very much required for regression testing. This paper generates test cases for Web Services using reduction techniques Pair-Wise Testing (PWT) and Orthogonal Array Testing (OAT) and compares the two techniques. The structure of Web Services is specified using UML diagrams. The pre and post conditions for the service rule are specified using Object Constraint Language (OCL). The framework developed by this paper transforms this into WSDL-S specifications. These specifications are parsed and transformed into structured DOM tree. Test data with different factors, levels and strengths are generated for PWT and OAT techniques. Test data set generated by this framework would satisfy the constraints of the WSDL. The test cases are then developed based on the data generated, documented in XML based test files called Web Service Test Specifications (WSTS) and executed. The number of test cases required by general testing, PWT, OAT are compared and the better testing technique for testing Web Services is determined.