I'm having a trouble while mocking Google Cloud Storage Client in Python.
I've tried a couple solutions, but none of them seems to be working in my case. This is what I've tried: Unit testing Mock GCS Python unittest.mock google storage - how to achieve exceptions.NotFound as side effect How to Mock a Google API Library with Python 3.7 for Unit Testing So basically I have a class for downloading the decoded GCS object. This is the class that I want to test:
class Extract:
def __init__(self, storage_client: storage.Client) -> None:
self.client = storage_client
@retry.Retry(initial=3.0, maximum=60.0, deadline=240.0)
def _get_storage_object(self, bucket: str, blob: str) -> bytes:
bucket_obj = self.client.get_bucket(bucket)
blob_obj = bucket_obj.blob(blob)
data = blob_obj.download_as_bytes(timeout=60)
return data
def get_decoded_blob(self, bucket: str, blob: str) -> Union[dict, list]:
raw_blob = self._get_storage_object(bucket=bucket, blob=blob)
decoded_blob = decode_data(raw_blob)
return decoded_blob
And this last version of code for unit testing of the class.
def decode_data(data: bytes) -> List[Dict[str, Any]]:
decoded_blob = data.decode('utf-8')
decoded_data = ast.literal_eval(decoded_blob)
return decoded_data
class TestExtract:
@pytest.fixture()
@mock.patch('src.pipeline.extract.storage', spec=True)
def storage_client(self, mock_storage):
mock_storage_client = mock_storage.Client.return_value
mock_bucket = mock.Mock()
mock_bucket.blob.return_value.download_as_bytes.return_value = 'data'.encode('utf-8')
mock_storage_client.bucket.return_value = mock_bucket
return mock_storage_client
def test_storage_client(self, storage_client):
gcs = extract.Extract(storage_client)
output = gcs._get_storage_object('bucket', 'blob')
assert output == b'data'
The error for the above code is that mock does not return return_value which was assigned in the fixture. Instead, it returns the MagicMock object as below: AssertionError: assert <MagicMock na...806039010368'> == b'data'
Anyone can help me in this case?
