Safari’s weird mousemove — the event fires when hitting modifier keys `ctrlKey`, `shiftKey`, `altKey`, and `metaKey` https://matthewspencer.github.io/mouse-move-in-safari/

1-log-mousemove.js

document.addEventListener('mousemove', function (event) {
  console.log(event.type);
}, false);

2-check-for-position-change.js

var lastClientX;
var lastClientY;

document.addEventListener('mousemove', function (event) {
  if (lastClientX === event.clientX && lastClientY === event.clientY) {
    return;
  }

  lastClientX = event.clientX;
  lastClientY = event.clientY;
}, false);