tests: Clean up and extend topic links tests in test_messages.

This is a follow-up to b69213808a.
We now actually send messages from the notification_bot, which
is the real usecase for this code.

Also, this cleans up the code and removes needless asserts like
`assertNotEqual(zulip_realm, lear_realm)` making the test easier
to read.

zerver/lib/actions.py

@@ -2046,9 +2046,9 @@ def extract_emails(emails: Iterable[str]) -> List[str]:
     return recipients
 
 def check_send_stream_message(sender: UserProfile, client: Client, stream_name: str,
-                              topic: str, body: str) -> int:
+                              topic: str, body: str, realm: Optional[Realm]=None) -> int:
     addressee = Addressee.for_stream_name(stream_name, topic)
-    message = check_message(sender, client, addressee, body)
+    message = check_message(sender, client, addressee, body, realm)
 
     return do_send_messages([message])[0]
 

zerver/lib/test_classes.py

@@ -463,7 +463,8 @@ class ZulipTestCase(TestCase):
         )
 
     def send_stream_message(self, sender_email: str, stream_name: str, content: str="test content",
-                            topic_name: str="test", sender_realm: str="zulip") -> int:
+                            topic_name: str="test", sender_realm: str="zulip",
+                            recipient_realm: Optional[Realm]=None) -> int:
         sender = get_user(sender_email, get_realm(sender_realm))
 
         (sending_client, _) = Client.objects.get_or_create(name="test suite")
@@ -474,6 +475,7 @@ class ZulipTestCase(TestCase):
             stream_name=stream_name,
             topic=topic_name,
             body=content,
+            realm=recipient_realm,
         )
 
     def get_messages_response(self, anchor: int=1, num_before: int=100, num_after: int=100,

zerver/tests/test_messages.py

@@ -1282,58 +1282,38 @@ class MessageDictTest(ZulipTestCase):
     def test_topic_links_use_stream_realm(self) -> None:
         # Set up a realm filter on 'zulip' and assert that messages
         # sent to a stream on 'zulip' have the topic linkified from
-        # senders in both the 'zulip' and 'lear' realms.  This test is
+        # senders in both the 'zulip' and 'lear' realms as well as
-        # a bit artificial; we really should be sending the message
+        # the notification bot.
-        # from `notification_bot`, no the lear realm, since that's the
-        # actual use case.
         zulip_realm = get_realm('zulip')
-        lear_realm = get_realm('lear')
         url_format_string = r"https://trac.zulip.net/ticket/%(id)s"
         url = 'https://trac.zulip.net/ticket/123'
-        othello = self.example_user('othello')
-        cordelia = self.lear_user('cordelia')
-        stream = get_stream('Denmark', zulip_realm)
         topic_name = 'test #123'
-        recipient = get_stream_recipient(stream.id)
-        sending_client = make_client(name="test suite")
 
         realm_filter = RealmFilter(realm=zulip_realm,
                                    pattern=r"#(?P<id>[0-9]{2,8})",
                                    url_format_string=url_format_string)
-        realm_filter.save()
         self.assertEqual(
             realm_filter.__str__(),
             '<RealmFilter(zulip): #(?P<id>[0-9]{2,8})'
             ' https://trac.zulip.net/ticket/%(id)s>')
 
-        message_from_zulip = Message(
+        def get_message(sender: UserProfile) -> Message:
-            sender=othello,
+            msg_id = self.send_stream_message(sender.email, 'Denmark', 'hello world', topic_name,
-            recipient=recipient,
+                                              sender.realm.string_id, zulip_realm)
-            content='hello world',
+            return Message.objects.get(id=msg_id)
-            date_sent=timezone_now(),
-            sending_client=sending_client,
-            last_edit_time=timezone_now(),
-            edit_history='[]'
-        )
-        message_from_zulip.set_topic_name(topic_name)
-        message_from_zulip.save()
-        message_from_lear = Message(
-            sender=cordelia,
-            recipient=recipient,
-            content='hello world',
-            date_sent=timezone_now(),
-            sending_client=sending_client,
-            last_edit_time=timezone_now(),
-            edit_history='[]'
-        )
-        message_from_lear.set_topic_name(topic_name)
-        message_from_lear.save()
 
-        dct = MessageDict.to_dict_uncached_helper(message_from_zulip)
+        def assert_topic_links(links: List[str], msg: Message) -> None:
-        self.assertEqual(dct[TOPIC_LINKS], [url])
+            dct = MessageDict.to_dict_uncached_helper(msg)
-        dct = MessageDict.to_dict_uncached_helper(message_from_lear)
+            self.assertEqual(dct[TOPIC_LINKS], links)
-        self.assertEqual(dct[TOPIC_LINKS], [url])
+
-        self.assertNotEqual(lear_realm, zulip_realm)
+        # Send messages before and after saving the realm filter from each user.
+        assert_topic_links([], get_message(self.example_user('othello')))
+        assert_topic_links([], get_message(self.lear_user('cordelia')))
+        assert_topic_links([], get_message(self.notification_bot()))
+        realm_filter.save()
+        assert_topic_links([url], get_message(self.example_user('othello')))
+        assert_topic_links([url], get_message(self.lear_user('cordelia')))
+        assert_topic_links([url], get_message(self.notification_bot()))
 
     def test_reaction(self) -> None:
         sender = self.example_user('othello')