Ali Mesbah, Arie van Deursen. Invariant-based automatic testing of AJAX user interfaces. In 31st International Conference on Software Engineering, ICSE 2009, May 16-24, 2009, Vancouver, Canada, Proceedings. pages 210-220, IEEE, 2009. [doi]
AJAX-based Web 2.0 applications rely on stateful asynchronous client/server communication, and client-side run-time manipulation of the DOM tree. This not only makes them fundamentally different from traditional web applications, but also more error-prone and harder to test.
We propose a method for testing AJAX applications automatically, based on a crawler to infer a flow graph for all (client-side) user interface states. We identify AJAX-specific faults that can occur in such states (related to DOM validity, error messages, discoverability, back-button compatibility, etc.) as well as DOM-tree invariants that can serve as oracle to detect such faults. We implemented our approach in ATUSA, a tool offering generic invariant checking components, a plugin-mechanism to add application-specific state validators, and generation of a test suite covering the paths obtained during crawling. We describe two case studies evaluating the fault revealing capabilities, scalability, required manual effort and level of automation of our approach.