Select of a Map type with select:false not working as expected

[jlvcm]

Prerequisites

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

Mongoose version

6.6.2

Node.js version

16.16.0

MongoDB server version

5.0.3

Typescript version (if applicable)

No response

Description

After version 6.6.2 the select with a + on a field of type Map with select: false does not seem to work as expected, it just does not return the element, i'm not sure but it may be related with this change:

• fix(query): handle select: false on map paths in query results #12467

Steps to Reproduce

const mongoose = require('mongoose');
const { MongoMemoryServer } = require('mongodb-memory-server');

async function main(){
  // Connect to a mongodb server
  await mongoose.connect((await MongoMemoryServer.create({ binary: { version: '5.0.3' } })).getUri());

  // Create the model
  const MyModel = mongoose.model('ModelName', new mongoose.Schema({
    title: String,
   // Create the type we are testing, a Map with `select:false` 
   body: {
      type: Map,
      of: { en: String, pt: String },
      select: false,
    }
  }));
  // Set the body
  await MyModel.create({
    title: "teste",
    body: {
      'A':{'en': 'en test A value', 'pt': 'pt test A value'},
      'B':{'en': 'en test B value', 'pt': 'pt test B value'}
    }
  })
  // Get the all items with the body field.
  console.log(await MyModel.find({}).select('+body').lean());
}

main();

Expected Behavior

We expect the body to be returned:

[
  {
    "_id": new ObjectId("635a471c7cf95eff198f4b2f"),
    title: 'teste',
    "body": {
      "A": {
        "en": "en test A value",
        "pt": "pt test A value"
      },
      "B": {
        "en": "en test B value",
        "pt": "pt test B value"
      }
    }
    __v: 0
  }
]

But on version >=6.6.2 it just returns the title:

[
  {
    _id: new ObjectId("635a471c7cf95eff198f4b2f"),
    title: 'teste',
    __v: 0
  }
]

It seems that the issue requires a type Map, a select with a + and mongoose version >= 6.6.2
we can get the body by changing:

• mongoose to version 6.6.1 or lower
• use type: Object, instead of Map
• remove the + from the select (but not what we want)