angular depth-first scope traverse from `Scope.$digest`

gistfile1.txt

let next, current = root, target = root
do {
  console.log(current.$$watchers)
  if (!(next = ((current.$$watchers.length && current.$$childHead) ||
                (current !== target && current.$$nextSibling)))) {
    while (current !== target && !(next = current.$$nextSibling)) {
      current = current.$parent;
    }
  }
} while ((current = next));