Test-Driven Web Application Development in Java

Today, software availability as well as adaptability has a strong impact on application development. Together with the success of the Internet technology, it is often necessary to offer a web-based software solution. For Java development, J2EE builds a bridge from traditional towards web application development. Java Server Pages and Servlets allow the implementation of web sites with dynamic content. Anyway, it is still possible to apply well-tried programming paradigms, e.g. the Model-View-Controller (MVC) paradigm. With regard to software quality as well as adaptability, application development is affected more and more by advanced testing techniques. Especially unit testing provides a powerful technique to develop new functionality as well as to extend and reuse existing parts. This is also strengthened by the success of agile processes that force test-driven development. From there, application code grows up with unit tests from scratch on. For Java, JUnit has become the defacto standard unit test environment. Nevertheless, test-driven web application development requires broadening the unit test approach. Considering the special requirements of web application development, both the scope of the unit tests as well as the JUnit framework itself have to be extended to enable a test-driven development. In this paper, we present an approach to customize the unit test cycle as well as the JUnit framework towards a test-driven web application development.