Model-based automated testing of JavaScript Web applications via longer test sequences

JavaScript has become one of the most widely used languages for Web development. Its dynamic and event-driven features make it challenging to ensure the correctness of Web applications written in JavaScript. A variety of dynamic analysis techniques have been proposed which are, however, limited in either coverage or scalability. In this paper, we propose a simple, yet effective, model-based automated testing approach to achieve a high code-coverage within the time budget via testing with longer event sequences. We implement our approach as an open-source tool LJS, and perform extensive experiments on 21 publicly available benchmarks. On average, LJS is able to achieve 86.5% line coverage in 10 minutes. Compared with JSDEP, a state-of-the-art breadth-first search based automated testing tool enriched with partial order reduction, the coverage of LJS is 11%–19% higher than that of JSDEP on real-world large Web applications. Our empirical findings support that proper longer test sequences can achieve a higher code coverage in JavaScript Web application testing.