jscefr: A Framework to Evaluate the Code Proficiency for JavaScript

In this paper, we present jscefr (pronounced jes-cee-fer), a tool that detects the use of different elements of the JavaScript (JS) language, effectively measuring the level of proficiency required to comprehend and deal with a fragment of JavaScript code in software maintenance tasks. Based on the pycefr tool, the tool incorporates JavaScript elements and the well-known Common European Framework of Reference for Languages (CEFR) and utilizes the official ECMAScript JavaScript documentation from the Mozilla Developer Network. jscefr categorizes JS code into six levels based on proficiency. jscefr can detect and classify 138 different JavaScript code constructs. To evaluate, we apply our tool to three JavaScript projects of the NPM ecosystem, with interesting results. A video demonstrating the tool's availability and usage is available at https://youtu.be/Ehh-Prq59Pc.