test changing visibility improperly

moto/sqs/models.py

@@ -6,21 +6,14 @@ import re
 from moto.core import BaseBackend
 from moto.core.utils import camelcase_to_underscores, get_random_message_id
 from .utils import generate_receipt_handle, unix_time_millis
-
+from .exceptions import (
+    ReceiptHandleIsInvalid,
+    MessageNotInflight
+)
 
 DEFAULT_ACCOUNT_ID = 123456789012
 
 
-class MessageNotInflight(Exception):
-    description = "The message referred to is not in flight."
-    status_code = 400
-
-
-class ReceiptHandleIsInvalid(Exception):
-    description = "The receipt handle provided is not valid."
-    status_code = 400
-
-
 class Message(object):
     def __init__(self, message_id, body):
         self.id = message_id

moto/sqs/responses.py

@@ -3,6 +3,10 @@ from jinja2 import Template
 from moto.core.responses import BaseResponse
 from moto.core.utils import camelcase_to_underscores
 from .models import sqs_backend
+from .exceptions import (
+    MessageNotInflight,
+    ReceiptHandleIsInvalid
+)
 
 MAXIMUM_VISIBILTY_TIMEOUT = 43200
 
@@ -46,11 +50,14 @@ class QueueResponse(BaseResponse):
                 MAXIMUM_VISIBILTY_TIMEOUT
             ), dict(status=400)
 
-        sqs_backend.change_message_visibility(
-            queue_name=queue_name,
-            receipt_handle=receipt_handle,
-            visibility_timeout=visibility_timeout
-        )
+        try:
+            sqs_backend.change_message_visibility(
+                queue_name=queue_name,
+                receipt_handle=receipt_handle,
+                visibility_timeout=visibility_timeout
+            )
+        except (ReceiptHandleIsInvalid, MessageNotInflight) as e:
+            return "Invalid request: {}".format(e.description), dict(status=e.status_code)
 
         template = Template(CHANGE_MESSAGE_VISIBILITY_RESPONSE)
         return template.render()