throwIfOrphans: true and input array elements order

[lkallas]

Consider a tree with 4 elements like this:

{
  "id": "root",
  "parent_id": null,
  "bar": "bar",
  "children": [
    {
      "id": "2",
      "parent_id": "root",
      "foo": "bar",
      "children": []
    },
    {
      "id": "1",
      "parent_id": "root",
      "foo": "bar",
      "children": [
        {
          "id": "1-1",
          "parent_id": "1",
          "foo": "bar",
          "children": []
        }
      ]
    }
  ]
}

As you may see there is multi level nesting in this tree.

When I break this tree into individual elements and try to build it with option throwIfOrphans: true it will throw. It should not, because there are actually no orphans.

This issue comes from the order of items in the array passed into the arrayToTree function.

To reproduce:

const tree = arrayToTree(
  [
    { id: '2', parent_id: 'root', foo: 'bar' },
    { id: '1-1', parent_id: '1', foo: 'bar' },
    { id: '1', parent_id: 'root', foo: 'bar' },
    { id: 'root', parent_id: null, bar: 'bar' },
  ],
  {
    id: 'id',
    parentId: 'parent_id',
    childrenField: 'children',
    dataField: null,
    throwIfOrphans: true,
  },
);

Results:

Error: The items array contains orphans that point to the following parentIds: [1]. These parentIds do not exist in the items array. Hint: prevent orphans to result in an error by passing the following option: { throwIfOrphans: false }

Now when you change the order of elements in the array it will not throw:

const tree = arrayToTree(
  [
    { id: '2', parent_id: 'root', foo: 'bar' },
    { id: '1', parent_id: 'root', foo: 'bar' },
    { id: '1-1', parent_id: '1', foo: 'bar' },
    { id: 'root', parent_id: null, bar: 'bar' },
  ],
  {
    id: 'id',
    parentId: 'parent_id',
    childrenField: 'children',
    dataField: null,
    throwIfOrphans: true,
  },
);

Meaning that the input array order matters. The error is misleading in this particular case.

[philipstanislaus]

Thanks for this outstanding bug report. I'll get back to you shortly!

[philipstanislaus]

Fixed, released in v1.7.1. Thanks for your help!