model/api_types: Handle add/remove subscription events.

This commit adds event handling code for newly added/removed
subscriptions. To store the stream subscriptions which are being updated
in the event, a new field named "subscriptions" is added to the
SubscriptionEvent class.

Co-authored-by: Abhirup Pal <abhiruppalmethodist@gmail.com>
Co-authored-by: Vishwesh Pillai <vishwesh103@gmail.com>

Author: theViz343

tests/model/test_model.py

@@ -4310,6 +4310,70 @@ def test__handle_subscription_event_subscribers_one_user_multiple_streams(
             new_subscribers = model._subscribed_streams[stream_id]["subscribers"]
             assert new_subscribers == expected_subscribers
 
+    @pytest.mark.parametrize(
+        "event, action",
+        [
+            case(
+                {
+                    "type": "subscription",
+                    "op": "add",
+                    "subscriptions": [
+                        {
+                            "name": "Stream 10",
+                            "date_created": 1472047124,
+                            "invite_only": False,
+                            "color": "#b0a5fd",
+                            "pin_to_top": False,
+                            "stream_id": 10,
+                            "is_muted": False,
+                            "audible_notifications": False,
+                            "description": "A description of stream 10",
+                            "rendered_description": "A description of stream 10",
+                            "desktop_notifications": False,
+                            "stream_weekly_traffic": 0,
+                            "push_notifications": False,
+                            "message_retention_days": 30,
+                            "email_address": "stream10@example.com",
+                            "email_notifications": False,
+                            "wildcard_mentions_notify": False,
+                            "subscribers": [1001, 11, 12],
+                            "history_public_to_subscribers": True,
+                            "is_announcement_only": True,
+                            "stream_post_policy": 0,
+                            "is_web_public": True,
+                            "first_message_id": None,
+                        }
+                    ],
+                },
+                "add",
+            ),
+            case(
+                {
+                    "type": "subscription",
+                    "op": "remove",
+                    "subscriptions": [
+                        {
+                            "name": "Stream 10",
+                            "stream_id": 10,
+                        }
+                    ],
+                },
+                "remove",
+            ),
+        ],
+    )
+    def test__handle_subscription_event_add_remove_subscription(
+        self, mocker, model, event, action
+    ):
+        if action == "add":
+            model._subscribe_to_streams = mocker.Mock()
+            model._handle_subscription_event(event)
+            model._subscribe_to_streams.assert_called_once()
+        else:
+            model._unsubscribe_from_streams = mocker.Mock()
+            model._handle_subscription_event(event)
+            model._unsubscribe_from_streams.assert_called_once()
+
     @pytest.mark.parametrize(
         "person, event_field, updated_field_if_different",
         [

zulipterminal/api_types.py

@@ -438,6 +438,18 @@ class SubscriptionPeerAddRemoveEvent(TypedDict):
     user_ids: List[int]  # NOTE: replaces 'user_id' in ZFL 35
 
 
+class SubscriptionAddEvent(TypedDict):
+    type: Literal["subscription"]
+    op: Literal["add"]
+    subscriptions: List[Subscription]
+
+
+class SubscriptionRemoveEvent(TypedDict):
+    type: Literal["subscription"]
+    op: Literal["remove"]
+    subscriptions: List[RemovedSubscription]
+
+
 # -----------------------------------------------------------------------------
 # See https://zulip.com/api/get-events#typing-start and -stop
 class _TypingEventUser(TypedDict):
@@ -532,6 +544,8 @@ class UpdateDisplaySettingsEvent(TypedDict):
     UpdateMessagesLocationEvent,
     ReactionEvent,
     SubscriptionUpdateEvent,
+    SubscriptionAddEvent,
+    SubscriptionRemoveEvent,
     SubscriptionPeerAddRemoveEvent,
     TypingEvent,
     UpdateMessageFlagsEvent,

zulipterminal/model.py

@@ -1308,6 +1308,9 @@ def make_reduced_stream_data(stream: Subscription) -> StreamData:
             new_visual_notified_streams
         )
 
+        self.normalize_and_cache_message_retention_text()
+        self.normalize_date_created_field()
+
     def _unsubscribe_from_streams(
         self, subscriptions: List[RemovedSubscription]
     ) -> None:
@@ -1487,7 +1490,7 @@ def get_stream_by_id(streams: List[StreamData], stream_id: int) -> StreamData:
                         self.visual_notified_streams.add(stream_id)
                     else:
                         self.visual_notified_streams.discard(stream_id)
-        elif event["op"] in ("peer_add", "peer_remove"):
+        elif event["op"] == "peer_add" or event["op"] == "peer_remove":
             # NOTE: ZFL 35 commit was not atomic with API change
             #       (ZFL >=35 can use new plural style)
             if "stream_ids" not in event or "user_ids" not in event:
@@ -1505,6 +1508,14 @@ def get_stream_by_id(streams: List[StreamData], stream_id: int) -> StreamData:
                     else:
                         for user_id in user_ids:
                             subscribers.remove(user_id)
+        elif event["op"] == "add":
+            self._subscribe_to_streams(event["subscriptions"])
+            self.controller.view.left_panel.update_stream_view()
+            self.controller.update_screen()
+        elif event["op"] == "remove":
+            self._unsubscribe_from_streams(event["subscriptions"])
+            self.controller.view.left_panel.update_stream_view()
+            self.controller.update_screen()
 
     def _handle_typing_event(self, event: Event) -> None:
         """