Merge pull request #1930 from matrix-org/travis/msc/tombstone-notif

MSC1930: Add a push rule for m.room.tombstone events

proposals/1930-tombstone-notifications.md

@@ -0,0 +1,40 @@
+# Proposal to add a default push rule for m.room.tombstone events
+
+Currently users are unaware of when a room becomes upgraded, leaving them potentially in the old room
+without knowing until they visit the room again. By having a notification for when the room is upgraded,
+users are able to ensure they are able to stay relevant in rooms by joining the upgraded room.
+
+
+## Proposal
+
+A new default override rule is to be added which is similar to `@room` notifications:
+
+```json
+{
+    "rule_id": ".m.rule.tombstone",
+    "default": true,
+    "enabled": true,
+    "conditions": [
+        {
+            "kind": "event_match",
+            "key": "type",
+            "pattern": "m.room.tombstone"
+        }
+    ],
+    "actions": [
+        "notify",
+        {
+            "set_tweak": "highlight",
+            "value": true
+        }
+    ]
+}
+```
+
+
+## Tradeoffs
+
+Clients could calculate this on their own and show some sort of "room upgraded" notification instead,
+however by doing it this way it means that all clients would need to be aware of room upgrades. Having
+a default push rule means that clients get this notification for free. Clients which want a more diverse
+UX can still do so by ignoring this push rule locally.