From 117cb784973e4d79a56446d3e4a88bb2a52b577e Mon Sep 17 00:00:00 2001 From: Derek Knapp Date: Thu, 15 Feb 2024 23:09:47 -0800 Subject: [PATCH] return Item in cancellation_reasons when transaction fails and return_values=ALL_OLD (#1226) --- docs/transaction.rst | 5 ++++- pynamodb/connection/base.py | 1 + pynamodb/exceptions.py | 1 + .../integration/test_transaction_integration.py | 17 +++++++++++++++++ 4 files changed, 23 insertions(+), 1 deletion(-) diff --git a/docs/transaction.rst b/docs/transaction.rst index d5f6788d5..30c0b2ddd 100644 --- a/docs/transaction.rst +++ b/docs/transaction.rst @@ -94,7 +94,8 @@ Now, say you make another attempt to debit one of the accounts when they don't h condition=( (BankStatement.account_balance >= transfer_amount) & (BankStatement.is_active == True) - ) + ), + return_values=ALL_OLD ) transaction.update( BankStatement(user_id='user2'), @@ -107,6 +108,8 @@ Now, say you make another attempt to debit one of the accounts when they don't h assert e.cause_response_code == 'TransactionCanceledException' # the first 'update' was a reason for the cancellation assert e.cancellation_reasons[0].code == 'ConditionalCheckFailed' + # when return_values=ALL_OLD, the old values can be accessed from the raw_item property + assert BankStatement.from_dynamodb_dict(e.cancellation_reasons[0].raw_item) == user1_statement # the second 'update' wasn't a reason, but was cancelled too assert e.cancellation_reasons[1] is None diff --git a/pynamodb/connection/base.py b/pynamodb/connection/base.py index 3e20255d1..d0181a813 100644 --- a/pynamodb/connection/base.py +++ b/pynamodb/connection/base.py @@ -357,6 +357,7 @@ def _make_api_call(self, operation_name: str, operation_kwargs: Dict) -> Dict: CancellationReason( code=d['Code'], message=d.get('Message'), + raw_item=cast(Optional[Dict[str, Dict[str, Any]]], d.get('Item')), ) if d['Code'] != 'None' else None ) for d in cancellation_reasons diff --git a/pynamodb/exceptions.py b/pynamodb/exceptions.py index 1c78c69f8..822230e3a 100644 --- a/pynamodb/exceptions.py +++ b/pynamodb/exceptions.py @@ -134,6 +134,7 @@ class CancellationReason: """ code: str message: Optional[str] = None + raw_item: Optional[Dict[str, Dict[str, Any]]] = None class TransactWriteError(PynamoDBException): diff --git a/tests/integration/test_transaction_integration.py b/tests/integration/test_transaction_integration.py index 48ef041c8..e247fd851 100644 --- a/tests/integration/test_transaction_integration.py +++ b/tests/integration/test_transaction_integration.py @@ -5,6 +5,7 @@ import pytest from pynamodb.connection import Connection +from pynamodb.constants import ALL_OLD from pynamodb.exceptions import CancellationReason from pynamodb.exceptions import DoesNotExist, TransactWriteError, InvalidStateError @@ -168,6 +169,22 @@ def test_transact_write__error__transaction_cancelled__condition_check_failure(c assert BankStatement.Meta.table_name in exc_info.value.cause.MSG_TEMPLATE +@pytest.mark.ddblocal +def test_transact_write__error__transaction_cancelled__condition_check_failure__return_all_old(connection): + # create a users and a bank statements for them + User(1).save() + + # attempt to do this as a transaction with the condition that they don't already exist + with pytest.raises(TransactWriteError) as exc_info: + with TransactWrite(connection=connection) as transaction: + transaction.save(User(1), condition=(User.user_id.does_not_exist()), return_values=ALL_OLD) + assert exc_info.value.cause_response_code == TRANSACTION_CANCELLED + assert 'ConditionalCheckFailed' in exc_info.value.cause_response_message + assert exc_info.value.cancellation_reasons == [ + CancellationReason(code='ConditionalCheckFailed', message='The conditional request failed', raw_item=User(1).to_dynamodb_dict()), + ] + + @pytest.mark.ddblocal def test_transact_write__error__transaction_cancelled__partial_failure(connection): User(2).delete()