webhooks/clubhouse: Ignore requests with empty request body.

zerver/webhooks/clubhouse/tests.py

@@ -1,3 +1,4 @@
+import json
 from mock import MagicMock, patch
 
 from zerver.lib.test_classes import WebhookTestCase
@@ -193,3 +194,10 @@ class ClubhouseWebhookTest(WebhookTestCase):
         expected_message = u"The type of the story [Add cool feature!](https://app.clubhouse.io/zulip/story/11) was changed from **feature** to **bug**."
         self.send_and_test_stream_message('story_update_change_type', "Add cool feature!",
                                           expected_message)
+
+    @patch('zerver.lib.webhooks.common.check_send_webhook_message')
+    def test_empty_post_request_body_ignore(self, check_send_webhook_message_mock: MagicMock) -> None:
+        payload = json.dumps(None)
+        result = self.client_post(self.url, payload, content_type="application/json")
+        self.assertFalse(check_send_webhook_message_mock.called)
+        self.assert_json_success(result)

zerver/webhooks/clubhouse/view.py

@@ -444,6 +444,13 @@ def api_clubhouse_webhook(
         payload: Dict[str, Any]=REQ(argument_type='body')
 ) -> HttpResponse:
 
+    # Clubhouse has a tendency to send empty POST requests to
+    # third-party endpoints. It is unclear as to which event type
+    # such requests correspond to. So, it is best to ignore such
+    # requests for now.
+    if payload is None:
+        return json_success()
+
     body_func = get_body_function_based_on_type(payload)
     topic_func = get_topic_function_based_on_type(payload)
     topic = topic_func(payload)