hook is not of type Query

[frederik-b]

Do you want to request a feature or report a bug?
Bug

What is the current behavior?
this context in hooks are not of type Query anymore

If the current behavior is a bug, please provide the steps to reproduce.

query hook:

mySchema.pre('findOneAndUpdate', async function setDefaultOptions(this: any) {
  console.log(this instanceof Query) // false, used to be true up to mongoose 5.4.22
})

call findOneAndUpdate

await model(message.messageType).findOneAndUpdate({_id: {$exists: false}}, newMessage, {upsert: true})

What is the expected behavior?

behaviour should not change between minor versions of mongoose
query hooks should be of type Query

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that "latest" is not a version.
mongoose 5.5.6 is broken (and earlier)
mongoose 5.4.22 is the last tested working version

# mongod --version                       
db version v4.0.9

[vkarpov15]

The below script runs as expected for me, this instanceof mongoose.Query === true :

const assert = require('assert');
const mongoose = require('mongoose');
mongoose.set('debug', true);
mongoose.set('useFindAndModify', false);

const GITHUB_ISSUE = `gh7790`;
const connectionString = `mongodb://localhost:27017/${ GITHUB_ISSUE }`;
const { Schema } = mongoose;

run().then(() => console.log('done')).catch(error => console.error(error.stack));

async function run() {
  await mongoose.connect(connectionString);
  await mongoose.connection.dropDatabase();

  const mySchema = new Schema({ name: String });

  mySchema.pre('findOneAndUpdate', async function setDefaultOptions() {
    console.log(this instanceof mongoose.Query); // true
  });

  const Model = mongoose.model('Test', mySchema);

  await Model.findOneAndUpdate({_id: {$exists: false}}, { name: 'test' }, {upsert: true});
}

Can you modify the above script to demonstrate your issue? Also, why does your function accept this as a parameter? That might contribute to the issue, although I'm not familiar with TypeScript.

[frederik-b]

I managed to create a (rather large) test script by reducing everything to the absolute minimum untill I found the problematic code section.
It is definitely https://www.npmjs.com/package/mongoose-delete, which breaks it.

I created a repo with my "reduced" test setup here: https://github.com/frederik-b/mongoosetest .

So it's not a bug with mongoose itself, it's rather that mongoose-delete breaks something which it didn't break in the previous versions.