bugfix: model: Add updated message_ids to their new topic's set.

Prior to this commit, if a message's topic was changed, the
corresponding `message_id` was not added to the new topic's set
under the "topic_msg_ids" key of the model's index. This commit
adds the updated `message_id` to that set, ensuring the
accuracy of the new topic's set.

Tests updated.

Author: prah23

tests/model/test_model.py

@@ -1646,7 +1646,7 @@ def test_notify_users_enabled(
                         },
                     },
                     "topic_msg_ids": {
-                        10: {"old subject": {2}},
+                        10: {"new subject": {1}, "old subject": {2}},
                     },
                     "edited_messages": {1},
                     "topics": {10: []},
@@ -1679,7 +1679,7 @@ def test_notify_users_enabled(
                         },
                     },
                     "topic_msg_ids": {
-                        10: {"old subject": set()},
+                        10: {"new subject": {1, 2}, "old subject": set()},
                     },
                     "edited_messages": {1},
                     "topics": {10: []},
@@ -1710,10 +1710,10 @@ def test_notify_users_enabled(
                         },
                     },
                     "topic_msg_ids": {
-                        10: {"old subject": {1, 2}},
+                        10: {"new subject": set(), "old subject": {1, 2}},
                     },
                     "edited_messages": {1},
-                    "topics": {10: ["old subject"]},
+                    "topics": {10: ["new subject", "old subject"]},
                 },
                 False,
                 id="Message content is updated",
@@ -1744,7 +1744,7 @@ def test_notify_users_enabled(
                         },
                     },
                     "topic_msg_ids": {
-                        10: {"old subject": {2}},
+                        10: {"new subject": {1}, "old subject": {2}},
                     },
                     "edited_messages": {1},
                     "topics": {10: []},
@@ -1774,10 +1774,10 @@ def test_notify_users_enabled(
                         },
                     },
                     "topic_msg_ids": {
-                        10: {"old subject": {1, 2}},
+                        10: {"new subject": set(), "old subject": {1, 2}},
                     },
                     "edited_messages": {1},
-                    "topics": {10: ["old subject"]},
+                    "topics": {10: ["new subject", "old subject"]},
                 },
                 False,
                 id="Some new type of update which we don't handle yet",
@@ -1808,7 +1808,7 @@ def test_notify_users_enabled(
                         },
                     },
                     "topic_msg_ids": {
-                        10: {"old subject": {1, 2}},
+                        10: {"new subject": {3}, "old subject": {1, 2}},
                     },
                     "edited_messages": set(),
                     "topics": {10: []},  # This resets the cache
@@ -1842,7 +1842,7 @@ def test_notify_users_enabled(
                         },
                     },
                     "topic_msg_ids": {
-                        10: {"old subject": {1, 2}},
+                        10: {"new subject": {3}, "old subject": {1, 2}},
                     },
                     "edited_messages": set(),
                     "topics": {10: ["new subject", "old subject"]},
@@ -1876,7 +1876,7 @@ def test_notify_users_enabled(
                         },
                     },
                     "topic_msg_ids": {
-                        10: {"old subject": {2}},
+                        10: {"new subject": {1}, "old subject": {2}},
                     },
                     "edited_messages": {1},
                     "topics": {10: ["new subject", "old subject"]},
@@ -1908,10 +1908,10 @@ def test__handle_update_message_event(
                 for message_id in [1, 2]
             },
             "topic_msg_ids": {
-                10: {"old subject": {1, 2}},
+                10: {"new subject": set(), "old subject": {1, 2}},
             },
             "edited_messages": set(),
-            "topics": {10: ["old subject"]},
+            "topics": {10: ["new subject", "old subject"]},
         }
         mocker.patch(MODEL + "._update_rendered_view")
 

zulipterminal/model.py

@@ -1399,6 +1399,11 @@ def _handle_update_message_event(self, event: Event) -> None:
                             msg_id
                         )
 
+                    # Add the msg_id to the new topic's set, if the set has
+                    # already been initiated.
+                    if new_subject in self.index["topic_msg_ids"][stream_id]:
+                        self.index["topic_msg_ids"][stream_id][new_subject].add(msg_id)
+
                 # Update and re-render indexed messages.
                 indexed_msg = self.index["messages"].get(msg_id)
                 if indexed_msg: