Analyzing real-world JavaScript web applications is a challenging task. On top of understanding the semantics of JavaScript, it requires modeling of web documents, platform objects, and interactions between them. Not only JavaScript itself but also its usage patterns are extremely dynamic. Most of web applications load JavaScript code dynamically, which makes pure static analysis approaches inapplicable.

In this talk, we present our attempts to analyze JavaScript web applications in the wild mostly statically using various approaches. From pure JavaScript programs to JavaScript web applications using platform-specific libraries, we explain technical challenges in analyzing each of them and how we built an open-source analysis framework for JavaScript, SAFE, that addresses the challenges incrementally.