Wrong values after simple query on mongodb since 6.2.1

[nazarkulyk]

Hallo,

i found some regression in 6.2.1 version. It did worked all times till including 6.2.0 version.

MongoDB Data:

{ _id: 60817c815a30530098dd0d6f
name : "Morgen Star New"
details: Object
  prospectorDetails: Object
    name: "Günter Lüschen 10"
  exhibitorDetails: Object
    name: "Günter Lüschen 20"
}

Output from mongoose 6.2.1 and higher:

{ _id: new ObjectId("60817c815a30530098dd0d6f"),
  name: 'Günter Lüschen 20',
  details: {
    prospectorDetails: { name: 'Günter Lüschen 10' },
    exhibitorDetails: { name: 'Günter Lüschen 20' }
  }
}

Output from mongoose 6.2.0 and lower:

{ _id: new ObjectId("60817c815a30530098dd0d6f"),
  name: 'Morgen Star New',
  details: {
    prospectorDetails: { name: 'Günter Lüschen 10' },
    exhibitorDetails: { name: 'Günter Lüschen 20' }
  }
}

Mongoose >= 6.2.1 breaks "name" attribute of root object.

Schema:

export const HorseSchema = new Schema<Horse>(
  {
    name: { type: SchemaTypes.String, required: false, index: true }
  },
  { strict: false, strictQuery: false }
);

[jeanbmar]

Exact same problem. Mongoose goes nuts when a nested property uses the same name as a top level property with strict: false.
Doesn't happen when doing toObject() afterward.
It's a critical breaking issue imo.

[IslandRhythms]

Modify this script to reproduce your bug.

const mongoose = require('mongoose');

const testSchema = new mongoose.Schema({
    name: String,
    details: {
        person: {
            name: String
        }
    }
}, {strict: false, strictQuery: false});

const Test = mongoose.model('Test', testSchema);

async function run() {
    await mongoose.connect('mongodb://localhost:27017');
    await mongoose.connection.dropDatabase();

    await Test.create({
        name: 'Foo',
        details: {
            person: {
                name: 'Bar'
            }
        }
    });

    console.log(await Test.findOne())
}

run();

[jeanbmar]

@IslandRhythms here it is:

const mongoose = require('mongoose');

const testSchema = new mongoose.Schema(
  {
    name: String,
  },
  { strict: false }
);

const Test = mongoose.model('Test', testSchema);

async function run() {
  await mongoose.connect('mongodb://localhost:27017');
  await mongoose.connection.dropDatabase();

  await Test.create({
    name: 'Foo',
    details: {
      person: {
        name: 'Bar',
      },
    },
  });

  const test = await Test.findOne({}).exec();
  console.log(test.name); // <--------- prints Bar instead of Foo
}
run();

[nazarkulyk]

There is realy issue with mongoos >=2.6.1

There are two documents in collention. One returns wrong "name":

The difference is "key" order on Mongo DB self in collection. If attribute is last one, what happends in your case @IslandRhythms then everything works as expected, but if in document attribute is before nested - it takes last one.
See screenshots

[nazarkulyk]

I definitively can reproduce it if i create object on Mongoo DB manualy. So the Object looks like:

{"_id":{"$oid":"62309a639c0470bef6c6febd"},"name":"Full Name","person":{"firstName":{"name":"first Name"},"lastName":{"name":"last Name"}}}

After that:

const test1 = await Test.findOne({}).exec();
console.log(test1);
const test2 = await Test.findOne({}).select('name').exec();
console.log(test2);

Output is:

❯ node src/test.js
Mongoose: tests.findOne({}, { projection: {} })
{
  _id: new ObjectId("62309a639c0470bef6c6febd"),
  name: 'last Name',
  person: {
    firstName: { name: 'first Name' },
    lastName: { name: 'last Name' }
  }
}
Mongoose: tests.findOne({}, { projection: { name: 1 } })
{ _id: new ObjectId("62309a639c0470bef6c6febd"), name: 'Full Name' }

[nazarkulyk]

Here is even better script to reproduce. There is not "name" filled on create. But we get it if query:

const mongoose = require('mongoose');

const testSchema = new mongoose.Schema(
  {
    name: String
  },
  { strict: false, strictQuery: false }
);

const Test = mongoose.model('Test', testSchema);

async function run() {
  await mongoose.connect('mongodb://localhost:27017');
  await mongoose.connection.dropDatabase();

  await Test.create({
    details: {
      person: {
        name: 'Bar'
      }
    }
  });

  console.log(await Test.findOne());
}

run();

Result:

❯ node src/test.js
{
  _id: new ObjectId("62309efc4de374c11812fbbe"),
  details: { person: { name: 'Bar' } },
  name: 'Bar',
  __v: 0
}

[IslandRhythms]

@jeanbmar Your script does not reproduce it.
@nazarkulyk Your script reproduces it.

const mongoose = require('mongoose');

const testSchema = new mongoose.Schema(
  {
    name: String
  },
  { strict: false, strictQuery: false }
);

const Test = mongoose.model('Test', testSchema);

async function run() {
  await mongoose.connect('mongodb://localhost:27017');
  await mongoose.connection.dropDatabase();

  await Test.create({
    details: {
      person: {
        name: 'Bar'
      }
    }
  });

  console.log(await Test.findOne());
}

run();

[vkarpov15]

This issue was introduced when we fixed #11309 with d7649f2. Sorry for the trouble - the fix will be in v6.2.8.