searches haystack for needle and returns array of tree nodes from correct path

pathfinder.js

function pathfinder(needle, haystack, child = haystack, parent, result = [], path = [], paths = [[[haystack]]], siblingIndex = 0, depthIndex = 0, rootIndex, onRoot) {

  let iterable = []; 

  if (Object.prototype.toString.call(child) === '[object Array]') {
    iterable = child;
  } else if (Object.prototype.toString.call(child) === '[object Object]') {
    iterable = Object.keys(child);
  }


  if (onRoot === true) { 
    paths.push(paths[0]);
  } 

  if (depthIndex > 0) {
    let path = paths[rootIndex].slice();
    path.push(child); 
//     paths[rootIndex].push(path);
    console.log(path, paths)
//     console.log('root', rootIndex, 'depth', depthIndex, 'sibling', siblingIndex, paths[rootIndex])
  }

  if (child === needle) {
    result.push(paths[rootIndex]);
  }

  for (let i = 0; i < iterable.length; i++) {
    pathfinder(
      needle, 
      haystack,
      child.hasOwnProperty(iterable[i]) ? child[iterable[i]] : iterable[i], 
      child,
      result,
      path,
      paths, 
      i, 
      depthIndex + 1, 
      depthIndex === 0 ? i : rootIndex, 
      rootIndex === undefined
    );
  }

  return [].concat.apply([], result);

}

var f = {
  "a": "a",
  "b": "b",
  "b2": null,
  "b3": ["b3.0", "b3.1", "b3.2"],
  "c": {
    "c1": [
      "c1.1", 
      "c1.2",
      "c1.3",
      "c1.4",
      {
        "c2": "fake",
        "c2b": [
          "c2b.a", 
          "c2b.b", 
          "c2b.c", 
          false,
          {
            "c4": "needle"
          }
        ]
      },
      {
        "c3": "false"
      }
    ]
  },
  "d": {
    "d1": {
      "d2": "d2",
      "d3": {
        "d4": {
          "d5": [
            "d6.0",
            {
              "d7": "this is d7"
            }
          ]
        }
      }
    }
  },
  "e": "e is null"
};

var res = pathfinder('needle', f);

console.log(res);

// console.log(res.length === 6, 'res should have 6 nodes');
// console.log(res.filter(n => typeof n === 'object').length === res.length, 'nodes can only be objects');
// console.log(JSON.stringify(res[0]) === JSON.stringify(f), 'first node should be root object');
// console.log(JSON.stringify(res[res.length - 1]) === JSON.stringify({c4: 'needle'}), 'last node should be needle object');

/*

// result
[
  // root level path container
  [
    // individual path array
    [{}, {}, {}, result]
  ]
]

*/