Mongoose Multiple Level Populate with Refpath - node.js

Question

I'm trying to use Mongoose populate() feature with a nested path but WITH refpath:
Child schema:
let child = new Schema({
item: {
type: Schema.Types.ObjectId,
required: true,
refPath: "itemType",
},
itemType: {
type: String,
required: true,
enum: ["typeA", "typeB"],
},
});
Parent schema:
let parent = new Schema({
children: [child],
});
After building my models, I run a query:
let mQuery1 = Parent.find().populate({
/* Type 1, does not populate at all. */ path: "children",
populate: { path: "item" },
});
This just does nothing.
let mQuery2 = Parent.find().populate({
path: "children",
populate: [
{ path: "item", model: "typeA" },
{ path: "item", model: "typeB" },
],
});
And this query ends up populating one type of the fields and the others not(e.g, populates typeA and returns null for typeB(s)).
So my question is, how do I come about populating nested fields that utilise refPath?
Cheers.

Answer 1

I've found the answer, thought I would share
you won't need to populate model like this:
<br>
let mQuery2 = Parent.find().populate({<br>
path: "children",<br>
populate: [<br>
{ path: "item", model: "typeA" },<br>
{ path: "item", model: "typeB" },<br>
],<br>
});<br>
but just:
<br>
let mQuery2 = Parent.find().populate({ <br>
path: "children", populate: <br>
{path: "item"}<br>
})<br>
However, in your posting route, you must have itemType with the value of either typeA or typeB. The respective model will then be populated automatically. I also managed to pass the chosen model to the itemType automatically on the backend only so no one needs to manually key in the model name.
here's the link that has helped me with this issue:
https://github.com/Automattic/mongoose/issues/7273