Google Apps Script has made the switch to Chrome V8 JavaScript Engine. You can now write your Google Scripts and GSuite addons directly in ES6 but with a few caveats.
Historically, Apps Script has been powered by Mozilla’s Rhino JavaScript interpreter. While Rhino provided a convenient way for Apps Script to execute developer scripts, it also tied Apps Script to a specific JavaScript version (ES5). Apps Script developers can’t use more modern JavaScript syntax and features in scripts using the Rhino runtime.
To address this concern, Apps Script is now supported by the V8 runtime that powers Chrome and Node.js. You can migrate existing scripts to V8 in order to take advantage of the modern JavaScript syntax and features.
This page describes the new features enabled by V8 and how you can enable V8 for use in your scripts. Migrating scripts to V8 describes steps for migrating existing scripts to use the V8 runtime.
Developers have been waiting a while for the new Google Apps Script runtime, since 2018 in fact, but it’s now here. The new runtime not only allows developers to use modern JavaScript syntax but when announced in 2018 also comes with a a tenfold (x10) faster execution. Follow the link to the developer docs for the full migration guide.
