Mongoose specify optional array of objects

Question

One of the keys in my mongo collection is

    options: [
      new mongoose.Schema(
        {
          answer: {
            type: String,
            required: true,
          },
          value: {
            type: Number,
            min: -10,
            max: 10,
            required: true,
          },
        },
        { _id: false }
      ),
    ],

The issue I'm having here is that options is optional but when there's no options field filled out, the inserted document has options: []

I believe I'm able to solve this normally by putting a default: undefined but I'm not sure how to go about doing this for this array of objects.

Thanks!

Answer 1

In mongoose an empty array is a default value for an array type. You can override it by using default field this way:

let optionsSchema = new mongoose.Schema(
    {
        answer: {
            type: String,
            required: true,
        },
        value: {
            type: Number,
            min: -10,
            max: 10,
            required: true,
        },
    },
    { _id: false });


const RootSchema = new Schema({
    options : {
        type: [optionsSchema],
        default: undefined
    }
})