DocumentReference.get() uses wrong Firestore database when multiple databases are configured

[devmaxime]

When using the Firebase Admin SDK in Node.js with multiple Firestore databases, DocumentReference instances do not retain their originating database context.

As a result, calling .get() on a reference may silently query the wrong database, depending on which database was most recently used. This leads to confusing and inconsistent behavior.

The only way to guarantee correct behavior is to manually reconstruct the reference using the correct Firestore instance every time:

await db2.collection('users').doc(docRef.id).get();

DocumentReference should retain a reference to the Firestore instance it was created from, so that .get() always uses the correct database. At minimum, using .get() in the wrong context should throw a clear error.

Environment: Node.js 20 and "firebase-admin": "^12.2.0"
Setup: one initialized app, multiple Firestore databases via getFirestore(app, db)

[ehsannas]

Thanks for reporting @devmaxime. I'll take a look

[ehsannas]

Hmm... I'm seeing that behavior. I see the DocumentReference maintaining the reference to the correct firestore instance.

[ehsannas]

I was using the @google-cloud/firestore dependency. I'll try using firebase-admin next.

[ehsannas]

I don't see that behavior in the firebase-admin package either:

[ehsannas]

@devmaxime can you provide a reproduction code?