fix GetTopicAttributes exception (localstack#9310)

bentsku · web-flow · commit 106f5e06fc41 · 2023-10-07T11:37:51.000+02:00
diff --git a/localstack/services/sns/provider.py b/localstack/services/sns/provider.py
@@ -112,6 +112,9 @@ def _get_topic(arn: str, context: RequestContext) -> Topic:
     def get_topic_attributes(
         self, context: RequestContext, topic_arn: topicARN
     ) -> GetTopicAttributesResponse:
+        # get the Topic from moto manually first, because Moto does not handle well the case where the ARN is malformed
+        # (raises ValueError: not enough values to unpack (expected 6, got 1))
+        moto_topic_model = self._get_topic(topic_arn, context)
         moto_response: GetTopicAttributesResponse = call_moto(context)
         # TODO: fix some attributes by moto, see snapshot
         # DeliveryPolicy
@@ -120,7 +123,6 @@ def get_topic_attributes(
         # TODO: very hacky way to get the attributes we need instead of a moto patch
         # see the attributes we need: https://docs.aws.amazon.com/sns/latest/dg/sns-topic-attributes.html
         # would need more work to have the proper format out of moto, maybe extract the model to our store
-        moto_topic_model = self._get_topic(topic_arn, context)
         for attr in vars(moto_topic_model):
             if "success_feedback" in attr:
                 key = camelcase_to_pascal(underscores_to_camelcase(attr))
diff --git a/tests/aws/services/sns/test_sns.py b/tests/aws/services/sns/test_sns.py
@@ -112,6 +112,11 @@ def test_create_topic_with_attributes(self, sns_create_topic, snapshot, aws_clie
 
         snapshot.match("get-attrs-nonexistent-topic", e.value.response)
 
+        with pytest.raises(ClientError) as e:
+            aws_client.sns.get_topic_attributes(TopicArn="test-topic")
+
+        snapshot.match("get-attrs-malformed-topic", e.value.response)
+
     @markers.aws.validated
     def test_tags(self, sns_create_topic, snapshot, aws_client):
 
diff --git a/tests/aws/services/sns/test_sns.snapshot.json b/tests/aws/services/sns/test_sns.snapshot.json
@@ -1,6 +1,6 @@
 {
   "tests/aws/services/sns/test_sns.py::TestSNSTopicCrud::test_create_topic_with_attributes": {
-    "recorded-date": "24-08-2023, 22:30:43",
+    "recorded-date": "06-10-2023, 20:11:02",
     "recorded-content": {
       "get-topic-attrs": {
         "Attributes": {
@@ -75,6 +75,17 @@
           "HTTPHeaders": {},
           "HTTPStatusCode": 404
         }
+      },
+      "get-attrs-malformed-topic": {
+        "Error": {
+          "Code": "InvalidParameter",
+          "Message": "Invalid parameter: TopicArn Reason: An ARN must have at least 6 elements, not 1",
+          "Type": "Sender"
+        },
+        "ResponseMetadata": {
+          "HTTPHeaders": {},
+          "HTTPStatusCode": 400
+        }
       }
     }
   },
