Remove direction to include virutals in toObject

[iatenine]

Passing {virtuals: true} to toObject does not have the same effect as toJSON{ vrituals: true} Tested on Ubuntu 22.04 and Windows 10 using version "^6.9.2"

Can be replicated with the following model file:

const postSchema = new Schema(
  {
    text: String,
    username: String,
    comments: [{ type: Schema.Types.ObjectId, ref: 'comment' }],
  },
  {
    // replace with toJSON to revert to correct behavior
    toObject: {
      virtuals: true,
    },
  }
);

postSchema.virtual('commentCount').get(function () {
  return this.comments.length;
});

// Initialize our Post model
const Post = model('post', postSchema);

Please correct if I'm using this code erroneously

Summary

Documentation directly states including virtuals can be achieved via the same process for both toJSON and toObject but { virtuals: true } has no impact on toObject

Examples

toJSON response:

{
		"_id": "643631713ac0c3db07a42df3",
		"text": " curabitur dolor purus ut ornare amet imsum elit lacinia blandit",
		"username": "Abaan",
		"comments": [
			"643631713ac0c3db07a42dee"
		],
		"commentCount": 1,
		"id": "643631713ac0c3db07a42df3"
},

toObject response:

{
		"_id": "643631713ac0c3db07a42df3",
		"text": " curabitur dolor purus ut ornare amet imsum elit lacinia blandit",
		"username": "Abaan",
		"comments": [
			"643631713ac0c3db07a42dee"
		]
},

[vkarpov15]

"Pass { virtuals: true } to either
toObject() or toJSON()." means calling JSON.stringify(doc.toObject({ virtuals: true })) or JSON.stringify(doc.toJSON({ virtuals: true })) . Not for setting the schema-level toJSON option.

I think we just need an example of the two different approaches for getting virtuals into JSON.stringify() output: using schema toJSON option, or calling JSON.stringify(doc.toObject({ virtuals: true }))

[iatenine]

@vkarpov15 Could you provide such an example?

All sources I've found including the Mongoose docs and StackOverflow seem to imply the behavior will be the same for both

[vkarpov15]

@iatenine "Could you provide such an example?" <-- I don't understand, can you please clarify?

[iatenine]

@vkarpov15 well if I understand correctly, there's a different way to include virtual for toObject

I get they use a different approach under the hood causing similar, but different, behavior but it's not obvious how virtuals can be achieved without switching to toJson

[hasezoey]

i dont understand what the problem here is, given the following code:

// NodeJS: 18.10.0
// MongoDB: 5.0 (Docker)
// Typescript 4.9.5
import * as mongoose from 'mongoose'; // mongoose@7.0.3

const schema1 = new mongoose.Schema({
  normalProp: String,
});

schema1.virtual('virtProp').get(() => 'hello1');

const model1 = mongoose.model('Test1', schema1);

const doc1 = new model1({ normalProp: 'normal1' });

console.log('1normal', doc1);
console.log('1toJSON virtuals', doc1.toJSON({ virtuals: true }));
console.log('1toObject virtuals', doc1.toObject({ virtuals: true }));

const schema2 = new mongoose.Schema(
  {
    normalProp: String,
  },
  {
    toObject: {
      virtuals: true,
    },
    toJSON: {
      virtuals: true,
    },
  }
);

schema2.virtual('virtProp').get(() => 'hello2');

const model2 = mongoose.model('Test2', schema2);

const doc2 = new model2({ normalProp: 'normal2' });

console.log('2normal', doc2);
console.log('2toJSON', doc2.toJSON());
console.log('2toObject', doc2.toObject());

the output is

1normal { <-- no virtuals expected, because of no options
  normalProp: 'normal1',
  _id: new ObjectId("64479cb47b50cd461a7b3022")
}
1toJSON virtuals {
  normalProp: 'normal1',
  _id: new ObjectId("64479cb47b50cd461a7b3022"),
  virtProp: 'hello1', <-- virtual present because of direct function option
  id: '64479cb47b50cd461a7b3022'
}
1toObject virtuals {
  normalProp: 'normal1',
  _id: new ObjectId("64479cb47b50cd461a7b3022"),
  virtProp: 'hello1', <-- virtual present because of direct function option
  id: '64479cb47b50cd461a7b3022'
}
2normal {
  normalProp: 'normal2',
  _id: new ObjectId("64479cb47b50cd461a7b3023"),
  virtProp: 'hello2', <-- virtual present here because of schema-option
  id: '64479cb47b50cd461a7b3023'
}
2toJSON {
  normalProp: 'normal2',
  _id: new ObjectId("64479cb47b50cd461a7b3023"),
  virtProp: 'hello2', <-- virtual present here because of schema-option
  id: '64479cb47b50cd461a7b3023'
}
2toObject {
  normalProp: 'normal2',
  _id: new ObjectId("64479cb47b50cd461a7b3023"),
  virtProp: 'hello2', <-- virtual present here because of schema-option
  id: '64479cb47b50cd461a7b3023'
}

[elias-soykat]

the virtual feture is something complex compare to other features. the docs also not clear about schema level virtuals.

[hasezoey]

the docs also not clear about schema level virtuals

could you explain what you mean with that? because from what i know there is only one kind of virtual, only different ways to define them

[elias-soykat]

the docs also not clear about schema level virtuals

could you explain what you mean with that? because from what i know there is only one kind of virtual, only different ways to define them

I don't know when i define in modal below code.

{ timestamps: true, versionKey: false, toJSON: { virtuals: true }, toObject: { virtuals: true } }

i get a id property in every documents.

but i don't define it like this.

userSchema.virtual('id')
    .get(function () {
        return this._id
    })

btw i love mongoose <3 i want contribute in this repo. suggest me some issues. thank you.

[hasezoey]

i get a id property in every documents.

the id virtual is added and enabled by default in mongoose, it can be disabled with the schema option id: false, and since you enable virtuals to be output in toJSON / toObject it will show up unless you disable it or manually remove it

[elias-soykat]

okay, thank you

[iatenine]

Thank you @vkarpov15
Knew I needed to understand it better to clarify the wording but didn't have time so glad you were able to correct and merge