I am using Change Stream Events to get notified whenever a document is updated/deleted/inserted in a database collection.

But they would be a lot more useful if I they would include the "previous" state of a document. Meaning that within a "deleted" event I could still access the contents of the deleted document and in an "updated" event I could get both versions (before and after) of an updated document.

I am aware that the "updateDescription" describes the keys which have been changed and the latest value, but they don't include what the value was previously.

I got the idea by working with the Document Database Firebase Firestore before. Within their updated/deleted/inserted events they do include both the "before" and "after" state for deleted/updated/created events. (Of course, in the case of deleted and in the case of created the after/before is empty respectively)