Static DOM event dependency analysis for testing web applications

The number and complexity of JavaScript-based web applications are rapidly increasing, but methods and tools for automatically testing them are lagging behind, primarily due to the difficulty in analyzing the subtle interactions between the applications and the event-driven execution environment. Although static analysis techniques have been routinely used on software written in traditional programming languages, such as Java and C++, adapting them to handle JavaScript code and the HTML DOM is difficult. In this work, we propose the first constraint-based declarative program analysis procedure for computing dependencies over program variables as well as event-handler functions of the various DOM elements, which is crucial for analyzing the behavior of a client-side web application. We implemented the method in a software tool named JSDEP and evaluated it in ARTEMIS, a platform for automated web application testing. Our experiments on a large set of web applications show the new method can significantly reduce the number of redundant test sequences and significantly increase test coverage with minimal overhead.