Mongoose Schema with nested optional object

Question

Using the following schema:

{
  data1: String,
  nested: {
    nestedProp1: String,
    nestedSub: [String]
  }
}

When I do new MyModel({data1: 'something}).toObject() shows the newly created document like this:

{
  '_id' : 'xxxxx',
  'data1': 'something',
  'nested': {
    'nestedSub': []
  }
}

I.e. the nested document is created with the empty array.

How do I make "nested" to be fully optional - i.e. not created at all if it is not provided on the input data?

I do not want to use a separate schema for the "nested", no need of that complexity.

Answer 1

The following schema satisfies my original requirements:

{
  data1: String,
  nested: {
    type: {
       nestedProp1: String,
       nestedSub: [String]
    },
    required: false
  }
}

With this, new docs are created with "missing" subdocument, if one is not specified.