Allow class listeners

changes/1661.enhancement.md

@@ -0,0 +1 @@
+Allow class listeners

hikari/impl/event_manager_base.py

@@ -421,7 +421,7 @@ def consume_raw_event(
     def subscribe(
         self, event_type: typing.Type[typing.Any], callback: event_manager_.CallbackT[typing.Any], *, _nested: int = 0
     ) -> None:
-        if not inspect.iscoroutinefunction(callback):
+        if not (inspect.iscoroutinefunction(callback) or inspect.iscoroutinefunction(callback.__call__)):
             raise TypeError("Cannot subscribe a non-coroutine function callback")
 
         # `_nested` is used to show the correct source code snippet if an intent
@@ -620,8 +620,8 @@ async def _invoke_callback(
         try:
             await callback(event)
         except Exception as ex:
-            # Skip the first frame in logs, we don't care for it.
-            trio = type(ex), ex, ex.__traceback__.tb_next if ex.__traceback__ is not None else None
+            # Skip the first frame in logs if it exists, as it means it wasn't our fault
+            trio = (type(ex), ex, ex.__traceback__.tb_next) if ex.__traceback__ else ex
 
             if base_events.is_no_recursive_throw_event(event):
                 _LOGGER.error(

tests/hikari/impl/test_event_manager_base.py

@@ -601,6 +601,18 @@ async def test_handle_dispatch_invokes_when_consumer_not_enabled(self, event_man
         consumer.callback.assert_not_called()
         error_handler.assert_not_called()
 
+    def test_subscribe_when_class_call(self, event_manager):
+        class Foo:
+            async def __call__(self) -> None:
+                ...
+
+        foo = Foo()
+        event_manager._check_event = mock.Mock()
+
+        event_manager.subscribe(member_events.MemberCreateEvent, foo)
+
+        assert event_manager._listeners[member_events.MemberCreateEvent] == [foo]
+
     def test_subscribe_when_callback_is_not_coroutine(self, event_manager):
         def test():
             ...