Harden 'Client.list_subscriptions' against keys omitted by backend.

Author: tseaver

gcloud/pubsub/client.py

@@ -128,7 +128,7 @@ def list_subscriptions(self, page_size=None, page_token=None,
         topics = {}
         subscriptions = [Subscription.from_api_repr(resource, self,
                                                     topics=topics)
-                         for resource in resp['subscriptions']]
+                         for resource in resp.get('subscriptions', ())]
         return subscriptions, resp.get('nextPageToken')
 
     def topic(self, name, timestamp_messages=False):

gcloud/pubsub/test_client.py

@@ -175,6 +175,27 @@ def test_list_subscriptions_with_paging(self):
         self.assertEqual(req['query_params'],
                          {'pageSize': SIZE, 'pageToken': TOKEN1})
 
+    def test_list_subscriptions_w_missing_key(self):
+        PROJECT = 'PROJECT'
+        CREDS = _Credentials()
+
+        CLIENT_OBJ = self._makeOne(project=PROJECT, credentials=CREDS)
+
+        RETURNED = {}
+        # Replace the connection on the client with one of our own.
+        CLIENT_OBJ.connection = _Connection(RETURNED)
+
+        # Execute request.
+        subscriptions, next_page_token = CLIENT_OBJ.list_subscriptions()
+        # Test values are correct.
+        self.assertEqual(len(subscriptions), 0)
+        self.assertEqual(next_page_token, None)
+        self.assertEqual(len(CLIENT_OBJ.connection._requested), 1)
+        req = CLIENT_OBJ.connection._requested[0]
+        self.assertEqual(req['method'], 'GET')
+        self.assertEqual(req['path'], '/projects/%s/subscriptions' % PROJECT)
+        self.assertEqual(req['query_params'], {})
+
     def test_list_subscriptions_with_topic_name(self):
         from gcloud.pubsub.subscription import Subscription
         PROJECT = 'PROJECT'