SymJS: Automatic Symbolic Testing of JavaScript Web Applications

We present SymJS, a comprehensive framework for auto-matic testing of client-side JavaScript Web applications. The tool contains a symbolic execution engine for JavaScript, and an automatic event explorer for Web pages. With-out any user intervention, SymJS can automatically dis-cover and explore Web events, symbolically execute the as-sociated JavaScript code, refine the execution based on dy-namic feedbacks, and produce test cases with high coverage. The symbolic engine contains a symbolic virtual machine, a string-numeric solver, and a symbolic executable DOM model. SymJS’s innovations include a novel symbolic virtual machine for JavaScript Web, symbolic+dynamic feedback directed event space exploration, and dynamic taint analy-sis for enhancing event sequence construction. We illustrate the effectiveness of SymJS on standard JavaScript bench-marks and various real-life Web applications. On average SymJS achieves over 90 % line coverage for the benchmark programs, significantly outperforming existing methods