Model.deleteMany() and Model.deleteOne() does not return acknowledged

[benghaun]

Do you want to request a feature or report a bug?
This is a bug - or perhaps just inconsistent documentation, I'm not entirely sure which is it.

What is the current behavior?
When calling Model.deleteMany() (or Model.deleteOne()), the return result is { deletedCount: 1 }, and doesn't have the acknowledged property.

If the current behavior is a bug, please provide the steps to reproduce.
Simply call Model.deleteMany() on any model and observe the result. Sample script below:

const mongoose = require('mongoose');

mongoose.connect('mongodb://127.0.0.1:27017', {});

const TestModel = mongoose.model('Test', {
  test: { type: String },
});

const main = async () => {
  console.log('running main');
  const result = await TestModel.deleteMany({});
  console.log(result); // logs { deletedCount: 0 }
};

main()
  .then(() => {
    process.exit(0);
  })
  .catch(err => console.log(err));

What is the expected behavior?
The v6 migration guide states that the result of deleteMany should have both the acknowledged property and the deletedCount property. This is consistent with the TypeScript definitions, which indicate that the result of the deleteMany operation has both deletedCount and acknowledged.

However, the deleteMany API documentation states that only deletedCount is returned, which is consistent with the implementation.

If the intention is to not include acknowledged, then the migration guide and the TypeScript definitions should be updated. If the intention is to include acknowledged, then the implementation and the API documentation should be updated.

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that "latest" is not a version.
Node.js: v14.17.5
Mongoose: v6.1.6
MongoDB: 4.0.22

[Uzlopak]

Well I think it is not wrong.

https://docs.mongodb.com/manual/reference/write-concern/#j-option

So you have to specify the j-option to get the acknowledgement.

[vkarpov15]

This is a bug caused by leftover code from how we handled delete results in Mongoose 5.x. Fix will be in v6.2.4