[Python] Performing Collection Queries Within a Transaction: Python vs. Swift

In Python, we can perform queries on collections within a transaction using the following code snippet:

def write_upload_success(filename: str, uid: str, doc_id: str) -> DocumentReference:
db = firestore.client()

transaction = db.transaction()

@firestore.transactional
def transaction_operation(transaction) -> str:
# Query to check if the filename exists
notes_ref = db.collection('users').document(uid).collection('notes')

# Find the largest order number in the existing notes
order_query = notes_ref.order_by('order', direction=firestore.Query.DESCENDING).limit(1).get(transaction=transaction)

max_order_note = None

for note in order_query:
max_order_note = note
break

order = max_order_note.get('order') + 1 if max_order_note else 1

note_ref = notes_ref.document(doc_id)

#
# ...
#

return note_ref

return transaction_operation(transaction)


It appears that Python allows querying collections within a transaction using:

notes_ref.order_by('order', direction=firestore.Query.DESCENDING).limit(1).get(transaction=transaction)


However, I haven't been able to find an equivalent approach in Swift. Is it not possible to perform collection queries within a transaction in Swift?

Thanks.

p/s Almost all AIs will wrongly suggest using transaction.getDocuments in Swift, which this function doesn't exist.

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