Enhancement: Cast ObjectId to string inside of MongooseMap.

[jhunterkohler]

Enchancment

I am working on a project that uses the MongooseMap type and thought one simple line would help within the get, set, and delete instance methods. We just add a short conversion onto the following functions:

mongoose/lib/types/map.js

Lines 43 to 44 in aef25e0

	get(key, options) {
	options = options || {};

mongoose/lib/types/map.js

Lines 51 to 52 in aef25e0

	set(key, value) {
	checkValidKey(key);

mongoose/lib/types/map.js

Lines 109 to 110 in aef25e0

	delete(key) {
	this.set(key, undefined);

Namely, insert:

if(key instanceof ObjectId) {
    key = key.toString();
}

Also require ObjectId in the header.

mongoose/lib/types/map.js

Lines 2 to 4 in aef25e0

	const Mixed = require('../schema/mixed');
	const deepEqual = require('../utils').deepEqual;

const ObjectId = require('./objectid')

Example

This implicit cast would be more or less expected as ObjectId is so frequently represented as a string. This example just shows a case where data would be stored in conjunction with a list of references. We want to get the data upon user requests, and calling the user id on the Map's hash-table will obviously be faster than a linear scan (or at least less painfull to look at then a toString call every 10 seconds).

const UserSchema = {
    name: String
}

const User = mongoose.model('User', UserSchema);

const GroupSchema = {
    members: {
        type: Map,
        of: { 
            read_receipts: Bool,
            share_location: Bool,
            follow_globals: Bool,
            nickname: String,
            role: {
                type: String
                enum: ['member', 'creator', 'admin']
            },
         }
     }
}

GroupSchema.methods.add
    = function add(userId, role = 'member') {
        this.members.set(userId, { role });
    };

GroupSchema.methods.remove
    = function remove(userId) {
        this.members.delete(userId);
     };

const Group = model('Group', GroupSchema);

TL;DR

Add ObjectId conversion to map so we don't have to think about converting to string. Maintain object relationships with ObjectIds meant to represent other docs.

[vkarpov15]

Fixed by #9938