SpEL2JS Parser

spel2js is a JavaScript library designed to parse and evaluate Spring Expression Language (SpEL) expressions within a defined context. Its primary purpose is to allow single-page applications to mirror server-side authorization logic, reducing duplication and inconsistencies in UI-related permissions. The library provides a JavaScript implementation of the SpEL parser, aiming to mimic the behavior documented for Spring Framework. It exports a singleton object containing `StandardContext` for creating evaluation contexts (which manage `authentication` and `principal` objects) and `SpelExpressionEvaluator` for compiling and executing SpEL expressions. The latest published version is 0.2.9, but significant development activity appears to have ceased around 2016 (judging by the release notes and `bower` references), indicating it is not actively maintained. It targets Node.js environments `>=8` but its age suggests potential compatibility challenges with modern JavaScript ecosystems and build tools.