webhooks: Fix HttpResponse with notify_bot_owner_on_invalid_json.

Apparently, there was a bug in notify_bot_owner_on_invalid_json, where
we didn't reraise the JsonableError.

We fix this with a refactoring that makes the exception layering
clearer as well.

zerver/decorator.py

@@ -348,15 +348,14 @@ def api_key_only_webhook_view(
                 rate_limit_user(request, user_profile, domain='all')
             try:
                 return view_func(request, user_profile, *args, **kwargs)
-            except InvalidJSONError as e:
+            except Exception as err:
-                if not notify_bot_owner_on_invalid_json:
+                if isinstance(err, InvalidJSONError) and notify_bot_owner_on_invalid_json:
-                    raise e
                     # NOTE: importing this at the top of file leads to a
                     # cyclic import; correct fix is probably to move
                     # notify_bot_owner_about_invalid_json to a smaller file.
                     from zerver.lib.webhooks.common import notify_bot_owner_about_invalid_json
                     notify_bot_owner_about_invalid_json(user_profile, webhook_client_name)
-            except Exception as err:
+                else:
                     log_exception_to_webhook_logger(request, user_profile)
                 raise err
 

zerver/tests/test_webhooks_common.py

@@ -52,11 +52,11 @@ class WebhooksCommonTestCase(ZulipTestCase):
 
     def test_notify_bot_owner_on_invalid_json(self)-> None:
         @api_key_only_webhook_view('ClientName', notify_bot_owner_on_invalid_json=False)
-        def my_webhook_raises_exception(request: HttpRequest, user_profile: UserProfile) -> None:
+        def my_webhook_no_notify(request: HttpRequest, user_profile: UserProfile) -> None:
             raise InvalidJSONError("Malformed JSON")
 
         @api_key_only_webhook_view('ClientName', notify_bot_owner_on_invalid_json=True)
-        def my_webhook(request: HttpRequest, user_profile: UserProfile) -> None:
+        def my_webhook_notify(request: HttpRequest, user_profile: UserProfile) -> None:
             raise InvalidJSONError("Malformed JSON")
 
         webhook_bot_email = 'webhook-bot@zulip.com'
@@ -70,7 +70,7 @@ class WebhooksCommonTestCase(ZulipTestCase):
 
         last_message_id = self.get_last_message().id
         with self.assertRaisesRegex(JsonableError, "Malformed JSON"):
-            my_webhook_raises_exception(request)  # type: ignore # mypy doesn't seem to apply the decorator
+            my_webhook_no_notify(request)  # type: ignore # mypy doesn't seem to apply the decorator
 
         # First verify that without the setting, it doesn't send a PM to bot owner.
         msg = self.get_last_message()
@@ -78,7 +78,8 @@ class WebhooksCommonTestCase(ZulipTestCase):
         self.assertNotEqual(msg.content, expected_msg.strip())
 
         # Then verify that with the setting, it does send such a message.
-        my_webhook(request)  # type: ignore # mypy doesn't seem to apply the decorator
+        with self.assertRaisesRegex(JsonableError, "Malformed JSON"):
+            my_webhook_notify(request)  # type: ignore # mypy doesn't seem to apply the decorator
         msg = self.get_last_message()
         self.assertNotEqual(msg.id, last_message_id)
         self.assertEqual(msg.sender.email, self.notification_bot().email)