Problematic typing of _id when using .select() in TypeScript about mongoose HOT 2 OPEN

import * as mongoose from 'mongoose';


interface RawUserDocument {
  email: string;
  passwordHash: string;
  name: string;
  username: string;
  profileImageURL: string;
  following: mongoose.Types.ObjectId[];
  followers: mongoose.Types.ObjectId[];
}

const userSchema = new mongoose.Schema<RawUserDocument>({
  email: { type: String, required: true, unique: true, index: true },
  passwordHash: { type: String, required: true },
  name: { type: String, required: true, index: true },
  username: { type: String, required: true, unique: true, index: true },
  profileImageURL: {
    type: String,
    required: true,
  },
  following: [{ type: mongoose.Schema.Types.ObjectId, ref: "User" }],
  followers: [{ type: mongoose.Schema.Types.ObjectId, ref: "User" }]
});

const User = mongoose.model<RawUserDocument>("User", userSchema);

const getUserByID = async <
  Fields extends keyof RawUserDocument = keyof RawUserDocument
>(
  id: string,
  options?: {
    fields: Fields[];
  }
): Promise<undefined> => {
  if (options?.fields) {
    const test1: { _id: mongoose.Types.ObjectId } | null = await User.findById(
      id
    ).select(options.fields.join(" "));
    const test2: { _id: mongoose.Types.ObjectId } | null = await User.findById(
      id
    ).select<Pick<RawUserDocument, Fields>>(options.fields.join(" "));
  }
};


// Narrowing the unknown type still doesn't work

// const getUserByID = async <
//   Fields extends keyof Omit<RawUserDocument, "_id"> = keyof Omit<
//     RawUserDocument,
//     "_id"
//   >
// >(
//   id: string,
//   options?: {
//     fields: Fields[];
//   }
// ): Promise<undefined> => {
//   if (options?.fields) {
//     const test1: { _id: mongoose.Types.ObjectId } | null = await User.findById(
//       id
//     ).select(options.fields.join(" "));
//     let test2: { _id: mongoose.Types.ObjectId } | null = null;
//     const test3 = await User.findById(id).select<Pick<RawUserDocument, Fields>>(
//       options.fields.join(" ")
//     );
//     // Still a type conflict here, despite establishing that the _id is in fact an ObjectID
//     if (test3 && test3._id instanceof mongoose.Types.ObjectId) test2 = test3;
//   }
// };