Tool and Dataset for Tracking the Adoption of Classes in JavaScript Software from 2015 to 2020

Tool and Dataset for Tracking the Adoption of Classes in JavaScript Software from 2015 to 2020

JavaScript is the most popular language on GitHub with over 18% of pull requests and over 40% of pushes on GitHub containing JavaScript in the beginning of 2021. In 2015, user definable classes were added to JavaScript as many developers were using other techniques to create classes. This major change to a very popular programming language has not been rigorously studied. In this paper we provide an overview of how developers have integrated these new classes. We created a tool that would detect both these legacy classes as well as the new classes and used it on mined NPM packages as well as general GitHub repositories. While many projects did not use ES6 classes, many also did not use any form of class either. Projects that used classes tended to have more new classes than legacy classes though there are still several projects that still have legacy classes.