Calculate events bound via jQuery

group_jquery_events.js

function getEvents(sel) {
  return $(sel).toArray().reduce(function(acc, el) {
    var events = $._data(el, 'events');
    if (events) acc.push(events);
    return acc;
  }, []);
}

function calculateEvents(acc, obj) {
  for (key in obj) {
    if (!acc[key]) acc[key] = 0;
    acc[key] += obj[key].length;
  }
  return acc;
}

getEvents("*").reduce(calculateEvents, {})

/*
Object {dragover: 1, click: 43, mousedown: 5, _touchstart: 6, _touchmove: 6…}
_touchend: 5
_touchmove: 6
_touchstart: 6
click: 43
dragover: 1
mousedown: 5
mousemove: 2
mouseout: 1
__proto__: Object
*/