webhooks/bitbucket: Support empty push payloads with no user info.

zerver/webhooks/bitbucket/fixtures/force_push_without_user_info.json

@@ -0,0 +1,15 @@
+{
+    "canon_url": "https://bitbucket.org/",
+    "commits":[],
+    "repository":{
+        "name": "Repository name",
+        "absolute_url": "kolaszek/repository-name/",
+        "fork": false,
+        "is_private": true,
+        "scm": "git",
+        "owner": "kolaszek",
+        "website": ""
+    },
+    "truncated": false,
+    "user_uuid": "387gs94h-2lk0-4sdb-b23f-71234rhty871"
+}

zerver/webhooks/bitbucket/tests.py

@@ -61,6 +61,13 @@ class BitbucketHookTests(WebhookTestCase):
         self.api_stream_message(self.TEST_USER_EMAIL, fixture_name, self.EXPECTED_TOPIC,
                                 expected_message)
 
+    def test_bitbucket_on_force_push_event_without_user_info(self) -> None:
+        fixture_name = 'force_push_without_user_info'
+        self.url = self.build_webhook_url(payload=self.get_body(fixture_name))
+        expected_message = u"Someone [force pushed](https://bitbucket.org/kolaszek/repository-name/)"
+        self.api_stream_message(self.TEST_USER_EMAIL, fixture_name, self.EXPECTED_TOPIC,
+                                expected_message)
+
     @patch('zerver.webhooks.bitbucket.view.check_send_webhook_message')
     def test_bitbucket_on_push_event_filtered_by_branches_ignore(self, check_send_webhook_message_mock: MagicMock) -> None:
         fixture_name = 'push'

zerver/webhooks/bitbucket/view.py

@@ -36,7 +36,7 @@ def api_bitbucket_webhook(request: HttpRequest, user_profile: UserProfile,
         # a useful message :/
         subject = repository['name']
         content = (u"%s [force pushed](%s)"
-                   % (payload['user'],
+                   % (payload.get('user', 'Someone'),
                       payload['canon_url'] + repository['absolute_url']))
     else:
         branch = payload['commits'][-1]['branch']