Function traverseEnterLeave

docs/lib/react.js:9033–9052

* Traverses the ID hierarchy and invokes the supplied `cb` on any IDs that * should would receive a `mouseEnter` or `mouseLeave` event. * * Does not invoke the callback on the nearest common ancestor because nothing * "entered" or "left" that element.

(from, to, fn, argFrom, argTo)

 * "entered" or "left" that element.
 */
function traverseEnterLeave(from, to, fn, argFrom, argTo) {
  var common = from && to ? getLowestCommonAncestor(from, to) : null;
  var pathFrom = [];
  while (from && from !== common) {
    pathFrom.push(from);
    from = from._nativeParent;
  }
  var pathTo = [];
  while (to && to !== common) {
    pathTo.push(to);
    to = to._nativeParent;
  }
  var i;
  for (i = 0; i < pathFrom.length; i++) {
    fn(pathFrom[i], true, argFrom);
  }
  for (i = pathTo.length; i-- > 0;) {
    fn(pathTo[i], false, argTo);
  }
}

module.exports = {
  isAncestor: isAncestor,