Type Analysis for JavaScript

Abstract

Abstract. JavaScript is the main scripting language for Web browsers, and it is essential to modern Web applications. Programmers have started using it for writing complex applications, but there is still little tool support available during development. We present a static program analysis infrastructure that can infer detailed and sound type information for JavaScript programs using abstract interpretation. The analysis is designed to support the full language as defined in the ECMAScript standard, including its peculiar object model and all built-in functions. The analysis results can be used to detect common programming errors -or rather, prove their absence, and for producing type information for program comprehension. Preliminary experiments conducted on real-life JavaScript code indicate that the approach is promising regarding analysis precision on small and medium size programs, which constitute the majority of JavaScript applications. With potential for further improvement, we propose the analysis as a foundation for building tools that can aid JavaScript programmers.

Determining dynamic coupling in JavaScript using object type inference

“…They consider subtyping for objects based on implementation (a subtype must contain all members of its supertype), whereas we formulated equivalence between types based on having the same interface. Jensen et al describe a type analysis for JavaScript based on abstract interpretation, with the goal of checking for the absence of common programming errors, and to provide type information for program comprehension [15]. The abstract domain for TAJS is more complex than ours and models all possible primitive data types, while our approach focuses on object types.…”

JSConTest: Contract-Driven Testing and Path Effect Inference for JavaScript.

“…JSConTest is inspired by, but complementary to work on type analysis for JavaScript [JMT09,HT10b,HT09]. The focus of these works is to determine the type safety of JavaScript programs by static analysis (abstract interpretation and constraintbased analysis, respectively).…”

Javanni: A Verifier for JavaScript

“…Originally developed by Netscape as a scripting language for lightweight web programming, JavaScript has rapidly become one of the most widely used programming languages 3 for the web. Its popularity has greatly exceeded its primary target-client-side web programming for nonprofessionals-and the language is now routinely used to develop large applications, such as Google Docs and Google Maps, and even some critical software such as on-line banking.…”

“…The focus of most related approaches to JavaScript verification [1,3] is restricted to standard type analysis. In contrast, Javanni supports full functional correctness properties; to our knowledge, this kind of support is available only in another quite recent work based on separation logic [2].…”