def test__transactional___call__failure():
from google.api_core import exceptions
from google.cloud.firestore_v1.base_transaction import _EXCEED_ATTEMPTS_TEMPLATE
to_wrap = mock.Mock(return_value=mock.sentinel.result, spec=[])
wrapped = _make__transactional(to_wrap)
txn_id = b"only-one-shot"
transaction = _make_transaction_pb(txn_id, max_attempts=1)
# Actually force the ``commit`` to fail.
exc = exceptions.Aborted("Contention just once.")
firestore_api = transaction._client._firestore_api
firestore_api.commit.side_effect = exc
# Call the __call__-able ``wrapped``.
with pytest.raises(ValueError) as exc_info:
wrapped(transaction, "here", there=1.5)
err_msg = _EXCEED_ATTEMPTS_TEMPLATE.format(transaction._max_attempts)
assert exc_info.value.args == (err_msg, )
assert transaction._id is None
assert wrapped.current_id == txn_id
assert wrapped.retry_id == txn_id
# Verify mocks.
to_wrap.assert_called_once_with(transaction, "here", there=1.5)
firestore_api.begin_transaction.assert_called_once_with(
request={
"database": transaction._client._database_string,
"options": None
},
metadata=transaction._client._rpc_metadata,
)
firestore_api.rollback.assert_called_once_with(
request={
"database": transaction._client._database_string,
"transaction": txn_id,
},
metadata=transaction._client._rpc_metadata,
)
firestore_api.commit.assert_called_once_with(
request={
"database": transaction._client._database_string,
"writes": [],
"transaction": txn_id,
},
metadata=transaction._client._rpc_metadata,
)
async def __call__(self, transaction, *args, **kwargs):
"""Execute the wrapped callable within a transaction.
Args:
transaction
(:class:`~google.cloud.firestore_v1.transaction.Transaction`):
A transaction to execute the callable within.
args (Tuple[Any, ...]): The extra positional arguments to pass
along to the wrapped callable.
kwargs (Dict[str, Any]): The extra keyword arguments to pass
along to the wrapped callable.
Returns:
Any: The result of the wrapped callable.
Raises:
ValueError: If the transaction does not succeed in
``max_attempts``.
"""
self._reset()
for attempt in range(transaction._max_attempts):
result = await self._pre_commit(transaction, *args, **kwargs)
succeeded = await self._maybe_commit(transaction)
if succeeded:
return result
# Subsequent requests will use the failed transaction ID as part of
# the ``BeginTransactionRequest`` when restarting this transaction
# (via ``options.retry_transaction``). This preserves the "spot in
# line" of the transaction, so exponential backoff is not required
# in this case.
await transaction._rollback()
msg = _EXCEED_ATTEMPTS_TEMPLATE.format(transaction._max_attempts)
raise ValueError(msg)