trigger-event.js

const EVENT_DEFAULTS = {
  bubbles: true
};

export default triggerEvent(element, name, options) {
  const eventInit = Object.assign({}, EVENT_DEFAULTS, getLocation(element), options);
  const event = new getConstructor(name)(name, eventInit);
  element.dispatchEvent(event);
}

function getLocation(element) {
  const rect = element.getBoundingClientRect();
  const X = rect.left + 1;
  const Y = rect.top + 1;
  return {
    target: element,
    pageX: X,
    offsetX: X,
    clientX: X,
    screenX: X + 5,
    pageY: Y,
    offsetY: Y,
    clientY: Y,
    screenY: Y + 95
  };
}

function getConstructor(name) {
  if (name.indexOf('mouse')) {
    return MouseEvent;
  }
  if (name.indexOf('key')) {
    return KeyboardEvent;
  }
  if (name.indexOf('touch')) {
    return TouchEvent;
  }
  return Event;
}