Bug in Update $set in a Map property

[vvFiCKvv]

Given a schema:

  Country = new mongoose.Schema({
    cities: {
        type: Map,
        of: {
             population: {type: Number}
        }
    });

When
Country.updateOne({_id:""}, {$set: "cities.newyork.population": 10000} ).exec()
throws Mongoose maps only support string keys, got undefined

Bypassing the mongoose works:
Country.collection.update({_id:""}, {$set: "cities.newyork.population": 10000} )
But it is missing schema validation.

By changing the mongoose/lib/schema/map.js function cast = (val, doc, init) => val it's working...
But I am not sure when this should be done in order to create a pull request(maybe when $__schemaType.path ends with ".$*").

P.S I can create a pull request with a failing test in order for anyone to investigate it more.

[vkarpov15]

Which version of Mongoose are you using? On Mongoose v5.9.26, the below script succeeds.

'use strict';
  
const mongoose = require('mongoose');

mongoose.set('debug', true);
mongoose.set('useFindAndModify', false);

const { Schema } = mongoose;

run().catch(err => console.log(err));

async function run() {
  await mongoose.connect('mongodb://localhost:27017/test', {
    useNewUrlParser: true,
    useUnifiedTopology: true
  });

  await mongoose.connection.dropDatabase();

  const CountrySchema = new mongoose.Schema({
    cities: {
        type: Map,
        of: {
             population: {type: Number}
        }
    }
  });
  const Country = mongoose.model('Country', CountrySchema);

  await Country.updateOne({}, { $set: { "cities.newyork.population": 10000 } }).exec()

  console.log('Done');
}

[vvFiCKvv]

Sorry for the late delay, I was in vacations,
I did a little more investigation and it has to do with child schemas and maps.
It was difficult to pinpoint the problem exactly because our schema is complicated.
I should avoid using subschemas, for now, thank you for your involvement.

``it("should work with mongoose", async () => {

    const mongoose = require("mongoose");

    mongoose.set("debug", true);
    mongoose.set("useFindAndModify", false);


    await run();//.catch((err) => console.log(err));

    async function run() {
        await mongoose.connect("mongodb://localhost:27017/test", {
            useNewUrlParser: true,
            useUnifiedTopology: true
        });

        await mongoose.connection.dropDatabase();

        const CountrySchema = new mongoose.Schema({
            cities: {
                type: Map,
                of: {
                    population: { type: Number }
                }
            }
        },
        { strict: "throw", useNestedStrict: true, _id: false, id: false }
        );

        const CountrySuperSchema = new mongoose.Schema({
            country: CountrySchema
        });

        const Country = mongoose.model("Country", CountrySuperSchema);

        let test = await new Country();
        test.save();
        await Country.updateOne({ _id: test._id }, { $set: { "country.cities.newyork.population": 10000 } }).exec();

        console.log("Done");
    }



});