Mongoose: Mixed Schema Type does not store Empty Objects.

[AyushG3112]

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

What is the current behavior?
Mixed Schema Type does not store Empty Objects.

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

Here is my Model

const GadgetPositionSchema = new Schema(
  {
    displayScheme: String,
    position: Schema.Types.Mixed,
    updatedOn: Date
  },
  { retainKeyOrder: true }
);

let gadgetPositionModel;

try {
  gadgetPositionModel = mongoose.model('gadgetpositions');
} catch (error) {
  gadgetPositionModel = mongoose.model('gadgetpositions', GadgetPositionSchema);
}

module.exports = gadgetPositionModel;

Here is the save query I run

const gadgetPositionObj = new gadgetPositionModel(); gadgetPositionObj.displayScheme = 'default'; gadgetPositionObj.position = {}; gadgetPositionObj.updatedOn = new Date(); return gadgetPositionObj.save();

What is the expected behavior?
It should save the document as

{
    "_id" : ObjectId("59eda54eb0202d00017820d7"),
    "displayScheme" : "default",
    "position": {}
    "updatedOn" : ISODate("2017-10-23T08:16:14.970Z"),
    "__v" : 0
}

What is the actual behavior?
Currently it saves the document as

{
    "_id" : ObjectId("59eda54eb0202d00017820d7"),
    "displayScheme" : "default",
    "updatedOn" : ISODate("2017-10-23T08:16:14.970Z"),
    "__v" : 0
}

Please mention your node.js, mongoose and MongoDB version.
Node: v6.10.3
MongoDB: v3.4.6
"mongoose": "^4.12.1",

[vkarpov15]

Thanks for the repro instructions, will investigate and fix asap.

[vkarpov15]

Currently by design, set the minimize option to false to turn this behavior off.

const GadgetPositionSchema = new mongoose.Schema(
  {
    displayScheme: String,
    position: mongoose.Schema.Types.Mixed,
    updatedOn: Date
  },
  { retainKeyOrder: true, minimize: false }
);

[AyushG3112]

Might need to fix the docs then, @vkarpov15, because the docs say that mongoose removed empty object from "Schemas". However, my Schema doesn't contain an empty object but the object(model instance) I'm trying to save does.

[vkarpov15]

Can you point me to the docs you're referring to @AyushG3112 ?

[naman1303]

Currently by design, set the minimize option to false to turn this behavior off.

const GadgetPositionSchema = new mongoose.Schema(
  {
    displayScheme: String,
    position: mongoose.Schema.Types.Mixed,
    updatedOn: Date
  },
  { retainKeyOrder: true, minimize: false }
);

Thank you for this. It helped me solve an issue on the similar lines.