make modifiedPaths safer.

[zzztttkkk]

Summary

helpers.common.modifiedPaths is a recursion function.

when user call db.updateOne({key: badValue}), the badValue will cause a endless recursion call. but it is impossible to check user's input. so I think we can check the recursion level , it will be helpful for debugging.

Examples

async function updateDoc(){
    const count = collectionA.countDocuments({}); // miss an `await`, will cause a endless recursion call.
    await collectionB.updateOne({key: count}, {upsert: true});
}

[Uzlopak]

Will this not work?

Suggested change

	function modifiedPaths(update, path, result, recursion=null) {
	function modifiedPaths(update, path, result, recursion={count: 0, raw: {update, path}}) {

[Uzlopak]

Maybe create a new MongooseError?

[zzztttkkk]

I was just worried that it would cause a circular reference.

I will make a new commit tomorrow.

[Uzlopak]

Dont worry, I just think a new MongooseRecursionError or something like that would be nicer.

[vkarpov15]

Agree that this should at least be a MongooseError. Not sure it is worth it to create a new recursion error.

[vkarpov15]

Couple of suggestions. Also, can you please add a test case for this?

[vkarpov15]

Agree that this should at least be a MongooseError. Not sure it is worth it to create a new recursion error.

[vkarpov15]

I think this is a bit brittle. Admittedly we're unlikely to have depth >= 1024 unless there's an infinite recursion. But I think a better approach would be to use a WeakSet or WeakMap to track what objects we've seen in the recursion, similar to how getIndexes() does it.

[zzztttkkk]

@vkarpov15
Hi,the new commit is waiting a review.

[vkarpov15]

Minor nitpick: this ---- is a bit messy. But I'll clean that up after merging, no need for that to be a blocker.