Nonexisiting parents should not be created after export/import

[arthabus]

Context:
Firestore has a concept of "non-exisitng" nodes in path

For example "collection/nonexsitingdoc/subcollection/doc1"
It's possible to create a doc1 where "nonexsitingdoc" will not existing - in such case firestore UI in browser shows it as greyed out.

Expected behavior

Library doesn't create "nonexsisting" docs after export/import

Actual behavior

Library creates docs that are "nonexsisting" after export/import

Steps to reproduce the behavior

1. Create a doc under the following path without creating intermediate docs/collections:
   "collection/nonexsitingdoc/subcollection/doc1"
2. Export the whole collection
3. Clean up database
4. Import it back

My usecase

I have a collection of client with the counter in production like this:

Clients: users/{userId}/clients
Client counter: users/{userId}/clients/-counter-doc-/-conter-col-/counter

Both -counter-doc- and -conter-col- don't exisit in the database which is expected

But after exporting and importing to the dev project (for debug and troubleshooting) the lib creates both -counter-doc- and -conter-col-

Now when I fetch client list it also returns -conter-col- document as a client which breaks the internal logic.

[cuong0993]

Why need to keep that orphan child collection?
This lib handles the "nonexsisting" document as an empty document.
In JSON file, I believe there is no way to distinguish an empty parent document and a "nonexsisting" parent document.

[arthabus]

@cuong0993 ok got you, firebase does distinguish them somehow thoughm, specifically in their admin UI.

I guess it should be possible to store a flag inside of that empty json and then skip creation of such docs/collections on import.

As to why, I've described my use case above, I basically store counter for the number of clients inside of the clients collection.

[cuong0993]

Maybe you can change this line to check if documentData is empty the skip set document (all empty documents will be not existed) https://github.com/cuong0993/node-firestore-import-export/blob/7b98376476b3b70eb0609577e837342dec2a24ef/src/lib/import.ts#L89

[arthabus]

@cuong0993 thanks bro! I'll give it a try