Connection autoCreate option behaves differently migrating 5 to 6

[igrunert-atlassian]

Prerequisites

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

Mongoose version

6.8.4

Node.js version

18.13.0

MongoDB server version

4.12.1 (driver)

Typescript version (if applicable)

No response

Description

When upgrading from Mongoose 5.13.15 to 6.8.4, we switched to explicitly setting the autoCreate option to false on the connection. We previously never set the autoCreate option on our Schema objects, so they should default to null (which means use the connection's autoCreate option). Our Schemas instantiate before the connection is created.

We found that in Mongoose 6, the autoCreate commands buffered prior to the connection being created were executed, issuing createCollection commands to the database. This didn't happen previously in Mongoose 5.

Workaround was to explicitly set autoCreate to false on the Schema objects.

Steps to Reproduce

Added to test/connection.test.js

it('with autoCreate = false after schema create', async function() {
    const schema = new Schema({ name: String }, {
      collation: { locale: 'en_US', strength: 1 },
      collection: 'gh8814_Conn'
    });

    const Model = mongoose.model('gh8814_Conn', schema);

    const conn = mongoose.connect(start.uri, {
      autoCreate: false
    });

    await conn;
    await Model.init();

    const res = await mongoose.connection.db.listCollections().toArray();
    assert.ok(!res.map(c => c.name).includes('gh8814_Conn'));
  });

Expected Behavior

Schema with autoCreate: null option set follows the connection's autoCreate option, even if schema is initialized first and the createCollection command is buffered.

[IslandRhythms]

Just to double check, is your assertion suppose to pass or fail?

const mongoose = require('mongoose');

const testSchema = new mongoose.Schema({
  name: String
}, { collation: { locale: 'en_US', strength: 1 }, collection: 'gh8814_Conn' });

const Test = mongoose.model('gh8814_Conn', testSchema);

async function run() {
  await mongoose.connect('mongodb://localhost:27017', { autoCreate: false });
  await Test.init();
  const res = await mongoose.connection.db.listCollections().toArray();
  console.log(res);
  await mongoose.connection.dropDatabase();
};

run();

[igrunert-atlassian]

The assertion fails, and I think the code should be changed to make the test pass.

The gh8814_Conn collection shouldn't be created (following the autoCreate option on the connection).