Listen for trackpad pinch events in javascript

Desktop browsers do not implement the gesture events, so trackpads on desktop do not register pinch events like they do on mobile devices. However, pinch events come through as wheel events with the ctrl key depressed events 🤷‍♂️

let scale = 1;

document.body.addEventListener("wheel", function(e) {
  if (e.ctrlKey) {
    scale += e.deltaY * -0.01;
  }
});