Populate array inside object in mongoose

Question

I have a company model which looks like this:

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const CompanySchema = new Schema(
  {
    companyName: String,
    settings: {
      type: {
        priceVisible: Boolean,
        allowPickupAddressAddition: Boolean,
        paymentMethodsAvailable: [
          { type: Schema.Types.ObjectId, ref: "PaymentMethod" },
        ],
      },
    },    
  }
);

const Company = mongoose.model("Company", CompanySchema);

module.exports = Company;

And I want to populate the values store in paymentMethodsAvailable array. Here is relevant controller code:

const company = await Company.findOne({ _id: id }).populate([
      {
        path: "settings",
        populate: [{path: "paymentMethodsAvailable"}]
      },
    ]);

But this doesn't work as expected. I can see that it might be trying to populate settings object, and fails there. Is there a way in which I can tell mongoose to populate settings.paymentMethodsAvailable ?

Answer 1

You should notice The type Key:

type is a special property in Mongoose schemas. When Mongoose finds a nested property named type in your schema, Mongoose assumes that it needs to define a SchemaType with the given type.

• If the type is a nested property of settings, the Mongoose schema should be:

const CompanySchema = new mongoose.Schema({
    companyName: String,
    settings: {
        type: {
            type: {
                priceVisible: Boolean,
                paymentMethodsAvailable: [{ type: mongoose.Schema.Types.ObjectId, ref: 'PaymentMethod' }],
            },
        },
    },
});

// seed
const [p1] = await PaymentMethod.create([{ name: 'a' }, { name: 'b' }]);
const [c1] = await Company.create([
  {
    companyName: 'c-a',
    settings: {
      type: {
        priceVisible: true,
        paymentMethodsAvailable: [p1],
      },
    },
  },
]);

// populate
const company = await Company.findOne({ _id: c1?._id }).populate('settings.type.paymentMethodsAvailable');
console.log(util.inspect(company?.toObject(), false, null));

The populate path is settings.type.paymentMethodsAvailable.

Output:

{
  settings: {
    type: {
      priceVisible: true,
      paymentMethodsAvailable: [
        {
          _id: new ObjectId("64abce807233874fe5733d10"),
          name: 'a',
          __v: 0
        }
      ],
      _id: new ObjectId("64abce807233874fe5733d15")
    }
  },
  _id: new ObjectId("64abce807233874fe5733d14"),
  companyName: 'c-a',
  __v: 0
}

• If the type is not a nested property of settings, the Mongoose schema is like yours:

const CompanySchema = new mongoose.Schema({
    companyName: String,
    settings: {
        type: {
            priceVisible: Boolean,
            paymentMethodsAvailable: [{ type: mongoose.Schema.Types.ObjectId, ref: 'PaymentMethod' }],
        },
    },
});

// seed
const [p1] = await PaymentMethod.create([{ name: 'a' }, { name: 'b' }]);
const [c1] = await Company.create([
  {
    companyName: 'c-a',
    settings: {
      priceVisible: true,
      paymentMethodsAvailable: [p1],
    },
  },
]);

// populate
const company = await Company.findOne({ _id: c1?._id }).populate('settings.paymentMethodsAvailable');
console.log(util.inspect(company?.toObject(), false, null));

The populate path is settings.paymentMethodsAvailable.

Output:

{
  _id: new ObjectId("64abd00acd28f4120a317c2e"),
  companyName: 'c-a',
  settings: {
    priceVisible: true,
    paymentMethodsAvailable: [
      {
        _id: new ObjectId("64abd00acd28f4120a317c2a"),
        name: 'a',
        __v: 0
      }
    ],
    _id: new ObjectId("64abd00acd28f4120a317c2f")
  },
  __v: 0
}