Integrating static and dynamic analysis to improve the comprehension of existing Web applications

Web applications are today becoming more and more interactive and dynamic: the pages rendered in a browser on the client side can be dynamically built by server pages according to the user inputs or requests. Moreover, even pieces of code (e.g., client-side scripts) can be dynamically generated. The comprehension of such applications, needed to effectively perform maintenance or testing, may be very hard. Indeed, for highly dynamic Web applications, static analysis is likely to give only an imprecise and approximate picture, thus, also dynamic analysis is required to gain a proper understanding of complex and dynamic application behavior. This paper presents the integration and the enhancement of two existing Web application reverse engineering tools: one, WARE, performing static analysis, the other, WANDA, dynamic analysis. In particular, the paper shows how the integrated toolkit can be used to identify equivalence classes from groups of dynamically built client pages, with the aim of improving comprehension. To validate the proposed approach, results from a case study are presented and discussed.