Extending Test-Driven Development for Robust Web Services

Research and practice show that a large number of Web services are deployed with robustness problems (i.e., presenting unexpected behaviors in the presence of invalid inputs). Test-driven development, particularly suitable for Web service environments, is a software development technique based on predefined test cases that are used during development to validate the desired software improvements or new functionalities. However, building representative test cases is quite difficult and developers often miss the test cases for robustness validation. This paper demonstrates how robustness testing can be integrated in the test driven development process to improve Web services robustness. To demonstrate the proposed approach we have invited experienced developers to implement three different versions of the Web services specified by the standard TPC-App performance benchmark, two following the standard test-driven development process and the other using the approach proposed in this paper. Results suggest that test-driven development coupled with robustness testing is a practical way to prevent the deployment of services with robustness problems.