Wrong Options Used in Model.$__handleSave

[makinde]

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

What is the current behavior?
When you try to save a document that has no changes, mongoose will run a Model.exists() query to make sure the document is in the DB (I don't know why this is done, but that's a different story). That query is done with a subset of the options that were passed to Document.save() call, not the original options. This breaks my middleware because Model.exists() triggers a Document.findOne() middleware, but the extra options that I have passed in are not sent with this new query.

The relevant line is 316 in lib/model.js.

    } else {
      this.constructor.exists(this.$__where(), saveOptions)
        .then((documentExists)=>{
          if (!documentExists) throw new DocumentNotFoundError(this.$__where(),this.constructor.modelName);

          this.$__reset();
          callback();
        })
        .catch(callback);
      return;
    }

saveOptions there is a stripped down version of the original options passed in. I think options should be used there, or something similar to it.

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

const doc = new MyModel({name: 'john'});
await doc.save({ customOpt: 1 }); // works
await doc.save({ customOpt: 1 }); // customOpt isn't passed to the Model.exists query

This seems like a far fetched case. But I ran into this by having a Document.save() call inside a session.withTransaction() call. withTransaction would then rerun the function after a TransientTransactionError, triggering this edge case where the document is saved twice.

What is the expected behavior?
The custom options should be passed through to the Model.exists() method.

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that "latest" is not a version.
Node: 12.14.0
Mongoose: 5.9.6
MongoDB: 4.2.3

[AbdelrahmanHafez]

This will be fixed by #8097

I'll dig some more into this and see if we can have a fix for this before v6.0.

[AbdelrahmanHafez]

Reproduction script:

// 8739
'use strict';

const mongoose = require('mongoose');
const { Schema } = mongoose;
const assert = require('assert');

mongoose.connect('mongodb://localhost:27017/test', { useNewUrlParser: true, useUnifiedTopology: true });

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

let optionInMiddleware;

userSchema.pre('findOne', function(next) {
  optionInMiddleware = this.getOptions().customOption;

  return next();
});

const User = mongoose.model('User', userSchema);


async function run() {
  await User.deleteMany();

  const user = await User.create({ name: 'Hafez' });

  await user.save({ customOption: 'test' });

  assert.equal(optionInMiddleware, 'test');

  console.log('Done.');
}


run().catch(console.error);