Add error handling for sqs.list_queue_tags

moto/sqs/responses.py

@@ -474,7 +474,11 @@ class SQSResponse(BaseResponse):
     def list_queue_tags(self):
         queue_name = self._get_queue_name()
 
-        queue = self.sqs_backend.get_queue(queue_name)
+        try:
+            queue = self.sqs_backend.get_queue(queue_name)
+        except QueueDoesNotExist as e:
+            return self._error('AWS.SimpleQueueService.NonExistentQueue',
+                               e.description)
 
         template = self.response_template(LIST_QUEUE_TAGS_RESPONSE)
         return template.render(tags=queue.tags)

tests/test_sqs/test_sqs.py

@@ -1108,6 +1108,26 @@ def test_tags():
     })
 
 
+@mock_sqs
+def test_list_queue_tags_errors():
+    client = boto3.client('sqs', region_name='us-east-1')
+
+    response = client.create_queue(
+        QueueName='test-queue-with-tags',
+        tags={
+            'tag_key_1': 'tag_value_X'
+        }
+    )
+    queue_url = response['QueueUrl']
+
+    client.list_queue_tags.when.called_with(
+        QueueUrl=queue_url + '-not-existing',
+    ).should.throw(
+        ClientError,
+        'The specified queue does not exist for this wsdl version.'
+    )
+
+
 @mock_sqs
 def test_tag_queue_errors():
     client = boto3.client('sqs', region_name='us-east-1')