refactor(ws): Clean up websocket listener DI handling

Clean up some rough edges in the websocket listener DI handling

Author: provinzkraut

litestar/handlers/websocket_handlers/_utils.py

@@ -141,10 +141,17 @@ def create_handler_signature(callback_signature: Signature) -> Signature:
     return callback_signature.replace(parameters=new_params)
 
 
-def create_stub_dependency(src: AnyCallable) -> Provide:
+def create_stub_dependency(src: AnyCallable | None) -> Provide:
     """Create a stub dependency, accepting any kwargs defined in ``src``, and
     wrap it in ``Provide``
     """
+    if src is None:
+
+        async def empty_stub() -> None:
+            return None
+
+        return Provide(empty_stub)
+
     src = unwrap_partial(src)
 
     @wraps(src)

litestar/handlers/websocket_handlers/listener.py

@@ -203,11 +203,9 @@ def __init__(
             connection_lifespan or self.default_connection_lifespan
         )
 
-        if self.on_accept:
-            listener_dependencies["on_accept_dependencies"] = create_stub_dependency(self.on_accept)
+        listener_dependencies["on_accept_dependencies"] = create_stub_dependency(self.on_accept)
 
-        if self.on_disconnect:
-            listener_dependencies["on_disconnect_dependencies"] = create_stub_dependency(self.on_disconnect)
+        listener_dependencies["on_disconnect_dependencies"] = create_stub_dependency(self.on_disconnect)
 
         super().__init__(
             path=path,
@@ -376,8 +374,8 @@ def __init__(self, owner: Router) -> None:
         self._owner = owner
 
     def to_handler(self) -> WebsocketListenerRouteHandler:
-        on_accept = self.on_accept if self.on_accept != WebsocketListener.on_accept else None
-        on_disconnect = self.on_disconnect if self.on_disconnect != WebsocketListener.on_disconnect else None
+        on_accept = self.on_accept if type(self).on_accept != WebsocketListener.on_accept else None
+        on_disconnect = self.on_disconnect if type(self).on_disconnect != WebsocketListener.on_disconnect else None
 
         handler = WebsocketListenerRouteHandler(
             dependencies=self.dependencies,