This is a playground to test JavaScript. It runs a completely standard copy of Node.js on a virtual server created just for you. Every one of npm’s 300,000+ packages are pre-installed, so try it out:
const package = require("@wordpress/scripts/package.json")
console.log( `Package version: ${ package.version }` )
const jestConfig = require("@wordpress/scripts/config/jest-unit.config.js")
console.log( `testRunner: ${ jestConfig.testRunner }` ) // should be "jest-circus/runner".
console.log( 'reporters: ' + JSON.stringify( jestConfig.reporters ) ) // should be an array