Test case selection for regression testing of applications using web services based on WSDL specification changes

There is much enthusiasm around web services in today´s world. Web Services take the advantage of internet to communicate between two electronic devices connected via a network. Testing a Web Service is a challenge as the Service Requester does not have the source code and somehow needs to fully test the impact of changes on his application. Regression testing verifies the integrity of the application and makes sure that the changes have not introduced new software errors. Our approach involves the parsing of the WSDL XML file to extract information regarding the operation name, input message and output message. Both the original and changed XML files for the web service are parsed to extract their respective information from the port type and message element of WSDL. Then, we generate a hash table form the extracted information for both the original and delta WSDL. We pass the hash tables to a Comparator as input, which then compares the hash tables and generates the operation changes as output. In the last step test cases are selected for regressing testing of the changed web service based upon the changes in operations provided by the comparator.