Unexpected error executing a lean query and passing the result of the query to a function that accepts a variable of that interface type.

[nikzanda]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

8.10.2

Node.js version

20.10.0

MongoDB server version

6.0.2

Typescript version (if applicable)

5.7.2

Description

I have a model Post that references the model User. The User model includes an embedded field, addresses, which is overridden by the type UserDocumentOverrides using Types.DocumentArray<AddressInstance>. For some reason, this override causes a typing error when performing a lean query on the Post model and passing the query result to a function that expects a parameter of type IPost[].

Steps to Reproduce

Reproduction link here.

P.S. If I locally comment out line 21 of the user.ts file, the error disappears. However, for some reason, on StackBlitz, the error remains.

Expected Behavior

As a workaround, I can manually infer the type during the query .lean<IPost[]>(). However, I don't expect this type of error and having to manually specify the typing.

[vkarpov15]

The following looks like it fixes the issue:

type UserDocumentOverrides = {
  addresses: Types.DocumentArray<IAddress>;
};

You just need to pass the raw document interface to Types.DocumentArray, not the hydrated document interface

[nikzanda]

The following looks like it fixes the issue:

type UserDocumentOverrides = {
addresses: Types.DocumentArray;
};
You just need to pass the raw document interface to Types.DocumentArray, not the hydrated document interface

I'm not sure if this is the correct solution. I tried to further complicate the code by adding virtual fields to address and a document override field:

This forces me to type address in Types.DocumentArray as IAddress & IAddressDocumentOverrides & IAddressVirtuals, otherwise a function that accepts AddressInstance as a parameter returns an error if I pass user.addresses. This, in my opinion, is not very elegant to look at or to write:

Additionally, the same error for which I opened this issue remains:

[vkarpov15]

In that case, try the following. Does this work for you?

import {
  HydratedArraySubdocument,
} from 'mongoose';
import addressSchema, {
  IAddress,
  IAddressDocumentOverrides,
  IAddressVirtuals,
} from './embedded/address';

type UserDocumentOverrides = {
  addresses: Types.DocumentArray<
    HydratedArraySubdocument<
      IAddress,
      IAddressDocumentOverrides & IAddressVirtuals
    >
  >;
};

[nikzanda]

Sorry, but the solution you provided to me is not working. I have updated the repository, and you can see that the described error remains the same. Furthermore, your solution is very similar to the initial code I wrote: I typed addresses as Types.DocumentArray<AddressInstance>, where AddressInstance is a HydratedSingleSubdocument, whereas you used HydratedArraySubdocument.