findOneAndUpdate returning both "before" and "after" document

[MDrooker]

Hi-
Trying to be efficient in some upsert operations..
So for new documents inserted, its not a problem because I know its "updatedExisting = false.

But when Im actually doing a true update, it would be great to get the old document and the new document from Mongo.
I can probably just calculate it, but trying to find out is there an option in Mongoose that returns both old and new documents at the same time?

Thanks

[vkarpov15]

Unfortunately not. The MongoDB server only returns the document before or the document after; no way to get the MongoDB server to return both. Your best bet would be to get the document before, and then calculate the updated document.