message send: Introduce dataclass to wrap user-notifications variables.

We will in later commits, extend this class to contain methods
to determine if a message is notifiable or not, but for now
we only turn it into a dict and pass it on.

zerver/lib/actions.py

@@ -110,6 +110,7 @@ from zerver.lib.message import (
     update_first_visible_message_id,
     wildcard_mention_allowed,
 )
+from zerver.lib.notification_data import UserMessageNotificationsData
 from zerver.lib.pysa import mark_sanitized
 from zerver.lib.queue import queue_json_publish
 from zerver.lib.realm_icon import realm_icon_url
@@ -1979,7 +1980,8 @@ def do_send_messages(
                 user_id in send_request.wildcard_mention_user_ids and "wildcard_mentioned" in flags
             )
             users.append(
-                dict(
+                asdict(
+                    UserMessageNotificationsData(
                         id=user_id,
                         flags=flags,
                         mentioned=("mentioned" in flags),
@@ -1990,6 +1992,7 @@ def do_send_messages(
                         sender_is_muted=(user_id in send_request.muted_sender_user_ids),
                     )
                 )
+            )
 
         if send_request.message.is_stream_message():
             # Note: This is where authorization for single-stream

zerver/lib/notification_data.py

@@ -0,0 +1,20 @@
+from dataclasses import dataclass
+from typing import List
+
+
+@dataclass
+class UserMessageNotificationsData:
+    id: int
+    flags: List[str]
+    mentioned: bool
+    online_push_enabled: bool
+    stream_push_notify: bool
+    stream_email_notify: bool
+    wildcard_mention_notify: bool
+    sender_is_muted: bool
+
+    def __post_init__(self) -> None:
+        if self.mentioned:
+            assert "mentioned" in self.flags
+        if self.wildcard_mention_notify:
+            assert "wildcard_mentioned" in self.flags