raise exeption on notifications error (#256)

Co-authored-by: Saimon Michelson <saimon.michelson@gmail.com>

Author: saimonation

cterasdk/asynchronous/core/notifications.py

@@ -6,7 +6,7 @@
 from .base_command import BaseCommand
 from ...common import Object
 from ...lib import CursorResponse
-from ...exceptions import ClientResponseException
+from ...exceptions import ClientResponseException, NotificationsError
 
 
 class Notifications(BaseCommand):
@@ -26,11 +26,16 @@ async def get(self, cloudfolders=None, cursor=None, max_results=None):
 
         :returns: An asynchronous iterator
         :rtype: cterasdk.asynchronous.core.iterator.CursorAsyncIterator
+        :raises: cterasdk.exceptions.NotificationsError
         """
         param = await self._create_parameter(cloudfolders, cursor)
         param.max_results = max_results if max_results is not None else 2000
         logging.getLogger('cterasdk.metadata.connector').debug('Listing updates.')
-        return CursorResponse(await self._core.v2.api.post('/metadata/list', param))
+        response = await self._core.v2.api.post('/metadata/list', param)
+        if response is not None:
+            return CursorResponse(response)
+        logging.getLogger('cterasdk.metadata.connector').error('An error occurred while trying to retrieve notifications.')
+        raise NotificationsError(cloudfolders, cursor)
 
     async def _create_parameter(self, cloudfolders, cursor):
         param = Object()

cterasdk/exceptions.py

@@ -30,6 +30,12 @@ def __init__(self, error_object):
         super().__init__('An error occurred while processing the HTTP request.', error_object)
 
 
+class NotificationsError(CTERAException):
+
+    def __init__(self, cloudfolders, cursor):
+        super().__init__('An error occurred while trying to retrieve notifications.', cloudfolders=cloudfolders, cursor=cursor)
+
+
 class ObjectNotFoundException(CTERAException):
 
     def __init__(self, message, object_ref, **kwargs):