bugfix: starred_messages: Update messages in starred narrow.

The commit updates ZT behavior in starred message section
to match the web app. The current behavior involves removing
the message when the user moves out of the starred section.
Fixes #940.

Author: Abhirup-99

tests/model/test_model.py

@@ -1531,7 +1531,10 @@ def test_update_star_status(self, mocker, model, event_op,
         operation, model.server_feature_level = update_message_flags_operation
 
         model.index = dict(messages={msg_id: {'flags': flags_before}
-                                     for msg_id in indexed_ids})
+                                     for msg_id in indexed_ids},
+                           starred_msg_ids=set([msg_id
+                                                for msg_id in indexed_ids
+                                                if 'starred' in flags_before]))
         event = {
             'type': 'update_message_flags',
             'messages': event_message_ids,
@@ -1543,7 +1546,10 @@ def test_update_star_status(self, mocker, model, event_op,
         set_count = mocker.patch('zulipterminal.model.set_count')
 
         model._handle_update_message_flags_event(event)
-
+        assert (model.index['starred_msg_ids']
+                == set([message_id for message_id in model.index['messages']
+                        if 'starred' in
+                        model.index['messages'][message_id]['flags']]))
         changed_ids = set(indexed_ids) & set(event_message_ids)
         for changed_id in changed_ids:
             assert model.index['messages'][changed_id]['flags'] == flags_after

zulipterminal/model.py

@@ -1153,9 +1153,14 @@ def _handle_update_message_flags_event(self, event: Event) -> None:
             if operation == 'add':
                 if flag_to_change not in msg['flags']:
                     msg['flags'].append(flag_to_change)
+                if flag_to_change == 'starred':
+                    self.index['starred_msg_ids'].add(message_id)
             elif operation == 'remove':
                 if flag_to_change in msg['flags']:
                     msg['flags'].remove(flag_to_change)
+                if(message_id in self.index['starred_msg_ids']
+                   and flag_to_change == 'starred'):
+                    self.index['starred_msg_ids'].remove(message_id)
             else:
                 raise RuntimeError(event, msg['flags'])
 

zulipterminal/ui_tools/views.py

@@ -113,7 +113,8 @@ def load_old_messages(self, anchor: int) -> None:
         ids_to_keep = self.model.get_message_ids_in_current_narrow()
         if self.log:
             top_message_id = self.log[0].original_widget.message['id']
-            ids_to_keep.remove(top_message_id)  # update this id
+            if top_message_id in ids_to_keep:
+                ids_to_keep.remove(top_message_id)  # update this id
             no_update_baseline = {top_message_id}
         else:
             no_update_baseline = set()