Check for `Element` prevents correctly working under jsdom · Issue #72 · que-etc/resize-observer-polyfill · GitHub
Under a jsdom environment Element is not an Object. if (typeof Element === 'undefined' || !(Element instanceof Object)) { return; } https://github.com/que-etc/resize-observer-polyfill/blob/master/src/ResizeObserverSPI.js#L76 Probably sim...