[REG 6->7] Plain fields cannot be assigned in special case (typescript error)

[orgads]

Prerequisites

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

Mongoose version

7.3.0

Node.js version

18.16.0

MongoDB server version

5.x

Typescript version (if applicable)

5.1.3

Description

Directly assigning to fields of a document fails with v7 when the document is generic (special case, see example).

Steps to Reproduce

import { Model } from 'mongoose';

interface ResourceDoc {
  foo: string;
}

type ResourceIdT<ResourceIdField extends string> = {
  [key in ResourceIdField]: string;
}
type ResourceDocWithId<ResourceIdField extends string> = ResourceDoc & ResourceIdT<ResourceIdField>;

class TestClass<
  ResourceType extends string,
  DocT extends ResourceDocWithId<`${ResourceType}Id`>>
{
  constructor(dbModel: Model<DocT>) {
    const resourceDoc = new dbModel();
    resourceDoc.foo = 'bar'; // Type 'string' is not assignable to type 'Require_id<DocT>["foo"]'
  }
}

If I replace `${ResourceType}Id` with 'FooId' then it works.

Expected Behavior

It should work.

[vkarpov15]

As far as I can tell, the script as written should throw an error. ResourceType can be any string, so there's no guarantee that there's a foo property on resourceDoc.

[orgads]

@vkarpov15 Notice that ResourceDocWithId is an intersection of ResourceDoc (which has foo) and ResourceIdT<ResourceIdField> (which adds the id field).

This is caused by Omit. Not sure what has changed between 6 and 7, but #13573 fixes it (but breaks other things 🙄).