Find ancestors by parent traversal

getAncestors.js

var lodash = require('lodash')

var getAncestors = function(node, nodes) {
  var ancestors = []
  var ancestor = node

  while (ancestor) {
    ancestors.unshift(ancestor)
    ancestor = lodash.find(nodes, {id: ancestor.parent})
  }

  return ancestors
}

var ancestors = getAncestors([
  {id: 1, parent: null},
  {id: 2, parent: 1},
  {id: 3, parent: 1},
  {id: 4, parent: 3}
])