Add a missing return type for event_auth.

Author: clokep

mypy.ini

@@ -142,6 +142,9 @@ disallow_untyped_defs = True
 [mypy-synapse.crypto.*]
 disallow_untyped_defs = True
 
+[mypy-synapse.event_auth]
+disallow_untyped_defs = True
+
 [mypy-synapse.events.*]
 disallow_untyped_defs = True
 

synapse/event_auth.py

@@ -763,7 +763,9 @@ def get_named_level(auth_events: StateMap[EventBase], name: str, default: int) -
         return default
 
 
-def _verify_third_party_invite(event: EventBase, auth_events: StateMap[EventBase]):
+def _verify_third_party_invite(
+    event: EventBase, auth_events: StateMap[EventBase]
+) -> bool:
     """
     Validates that the invite event is authorized by a previous third-party invite.