Can't save values for particular keys of Map

[holem]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

8.9.0

Node.js version

22.9

MongoDB server version

8.0.1

Typescript version (if applicable)

No response

Description

For the field of Map type - if key in format "[number]" (number in square brackets) or "[number" (number preceded by square bracket) then it's not saving.

Steps to Reproduce

const ThingSchema = new mongoose.Schema({
  nums: { type: Map, of: [{ type: Number }], default: new Map() },
});
const Thing = mongoose.model("Thing", ThingSchema);

const thing = new Thing();

thing.nums.set("[0]", [1]);
thing.nums.set("[111]", [2]);
thing.nums.set("[,]", [3]);
thing.nums.set("[!]", [4]);
thing.nums.set("[111-]", [5]);
thing.nums.set("[-111]", [6]);
thing.nums.set("111]", [7]);
thing.nums.set("[111", [8]);
thing.nums.set("111", [9]);
thing.nums.set("0", [10]);

console.log("thing.nums", user.nums);
await thing.save();

const thing2 = await Thing.findById(thing._id.toString());
console.log("thing2.nums", thing2.nums);

output:

thing.nums Map(10) {
  '[0]' => [ 1 ],
  '[111]' => [ 2 ],
  '[,]' => [ 3 ],
  '[!]' => [ 4 ],
  '[111-]' => [ 5 ],
  '[-111]' => [ 6 ],
  '111]' => [ 7 ],
  '[111' => [ 8 ],
  '111' => [ 9 ],
  '0' => [ 10 ]
}
thing2.nums Map(7) {
  '0' => [ 10 ],
  '111' => [ 9 ],
  '111]' => [ 7 ],
  '[!]' => [ 4 ],
  '[,]' => [ 3 ],
  '[-111]' => [ 6 ],
  '[111-]' => [ 5 ]
}

Expected Behavior

All values ​​for all string keys are preserved.

[vkarpov15]

I'm unable to repro. Given the following script:

'use strict';

import mongoose from 'mongoose';

console.log('Mongoose version', mongoose.version);

const ThingSchema = new mongoose.Schema({
  nums: { type: Map, of: [{ type: Number }], default: new Map() },
});
const Thing = mongoose.model("Thing", ThingSchema);

const thing = new Thing();

thing.nums.set("[0]", [1]);
thing.nums.set("[111]", [2]);
thing.nums.set("[,]", [3]);
thing.nums.set("[!]", [4]);
thing.nums.set("[111-]", [5]);
thing.nums.set("[-111]", [6]);
thing.nums.set("111]", [7]);
thing.nums.set("[111", [8]);
thing.nums.set("111", [9]);
thing.nums.set("0", [10]);

await mongoose.connect('mongodb://127.0.0.1:27017/mongoose_test');

console.log("thing.nums", thing.nums);
await thing.save();

const thing2 = await Thing.findById(thing._id.toString());
console.log("thing2.nums", thing2.nums);

I get the following output:

$ node gh-15125.mjs 
Mongoose version 8.9.0
thing.nums Map(10) {
  '[0]' => [ 1 ],
  '[111]' => [ 2 ],
  '[,]' => [ 3 ],
  '[!]' => [ 4 ],
  '[111-]' => [ 5 ],
  '[-111]' => [ 6 ],
  '111]' => [ 7 ],
  '[111' => [ 8 ],
  '111' => [ 9 ],
  '0' => [ 10 ]
}
thing2.nums Map(10) {
  '0' => [ 10 ],
  '111' => [ 9 ],
  '[0]' => [ 1 ],
  '[111]' => [ 2 ],
  '[,]' => [ 3 ],
  '[!]' => [ 4 ],
  '[111-]' => [ 5 ],
  '[-111]' => [ 6 ],
  '111]' => [ 7 ],
  '[111' => [ 8 ]
}

Can you please try running the above script and see if you get the same result?