Mongoose does not clean up modified paths of nested properties and array elements within the nested property after save

[upirr]

Prerequisites

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

Mongoose version

7.3.3

Node.js version

16.18.1

MongoDB server version

4.4

Typescript version (if applicable)

5.1

Description

Mongoose does not clean up modified paths of nested properties and array elements within the nested property after save. It's similar to #13582, only in this case this is nested property with schema that is misbehaving.

Steps to Reproduce

import mongoose from 'mongoose';
import { expect } from 'chai';
​
const TwoElementSchema = new mongoose.Schema({
	elementName: String,
});
​
const TwoNestedSchema = new mongoose.Schema({
	nestedName: String,
	elements: [TwoElementSchema],
});
​
const TwoDocDefaultSchema = new mongoose.Schema({
	docName: String,
	nested: { type: TwoNestedSchema, default: {} },
});
​
const TwoDocNoDefaultSchema = new mongoose.Schema({
	docName: String,
	nested: { type: TwoNestedSchema },
});
​
const TwoDocDefault = mongoose.model('TwoDocDefault', TwoDocDefaultSchema);
const TwoDocNoDefault = mongoose.model('TwoDocNoDefault', TwoDocNoDefaultSchema);
​
describe('mongoose after doc save', () => {
	before(async () => {
		await mongoose.connect('mongodb://localhost:27017/j2-autotests');
	});
​
	describe('modified paths', () => {
​
		it('should all be cleared for nested element with default value', async () => {
			let doc = new TwoDocDefault({ docName: 'MyDocName' });
			doc.nested.nestedName = 'qdwqwd';
			doc.nested.elements.push({ elementName: 'ElementName1' });
			expect(allPaths(doc)).to.not.deep.equal([]);
			doc = await doc.save();
			expect(allPaths(doc)).to.deep.equal([]);
		});
​
		it('should all be cleared for nested element without default value', async () => {
			let doc = new TwoDocNoDefault({ docName: 'MyDocName', nested: {} });
			doc.nested!.nestedName = 'qdwqwd';
			doc.nested!.elements.push({ elementName: 'ElementName1' });
			expect(allPaths(doc)).to.not.deep.equal([]);
			doc = await doc.save();
			expect(allPaths(doc)).to.deep.equal([]);
		});
	});
});
​
const allPaths = (doc: mongoose.Document) => {
	return [doc, ...doc.$getAllSubdocs()].reduce((ary, d: any) => {
		return ary.concat(d.modifiedPaths().map((p: string) => p));
	}, [] as string[]);
};

Expected Behavior

Nested property modifiedPaths() call properly returns []. Nested property subproperty that is defined as documents array call to modifiedPaths() also properly returns [] as a result.

[IslandRhythms]

const mongoose = require('mongoose');

const TwoElementSchema = new mongoose.Schema({
	elementName: String,
});

const TwoNestedSchema = new mongoose.Schema({
	nestedName: String,
	elements: [TwoElementSchema],
});

const TwoDocDefaultSchema = new mongoose.Schema({
	docName: String,
	nested: { type: TwoNestedSchema, default: {} },
});

const TwoDocNoDefaultSchema = new mongoose.Schema({
	docName: String,
	nested: { type: TwoNestedSchema },
});

const TwoDocDefault = mongoose.model('TwoDocDefault', TwoDocDefaultSchema);
const TwoDocNoDefault = mongoose.model('TwoDocNoDefault', TwoDocNoDefaultSchema);

async function run() {
  await mongoose.connect('mongodb://localhost:27017');
  await mongoose.connection.dropDatabase();

  let doc = new TwoDocDefault({ docName: 'MyDocName' });
  doc.nested.nestedName = 'qdwqwd';
	doc.nested.elements.push({ elementName: 'ElementName1' });
	console.log(allPaths(doc).length == [].length); // should be false
	doc = await doc.save();
	console.log(allPaths(doc) == [].length); // should be true
  doc = new TwoDocNoDefault({ docName: 'MyDocName', nested: {} });
  doc.nested.nestedName = 'qdwqwd';
  doc.nested.elements.push({ elementName: 'ElementName1' });
  console.log(allPaths(doc) == [].length); // false
  doc = await doc.save();
  console.log(allPaths(doc) == [].length); // should be true

}

run();


const allPaths = (doc) => {
	return [doc, ...doc.$getAllSubdocs()].reduce((ary, d) => {
		return ary.concat(d.modifiedPaths().map((p) => p));
	}, []);
};