gateway: allow nullable seq but invalidate if received

litecord/gateway/schemas.py

@@ -121,7 +121,7 @@ RESUME_SCHEMA = {
             "schema": {
                 "token": {"type": "string", "required": True},
                 "session_id": {"type": "string", "required": True},
-                "seq": {"type": "number", "required": True},
+                "seq": {"type": "number", "required": True, "nullable": True},
             },
         }
     },

litecord/gateway/websocket.py

@@ -958,6 +958,12 @@ class GatewayWebsocket:
     async def handle_6(self, payload: Dict[str, Any]):
         """Handle OP 6 Resume."""
         payload = validate(payload, RESUME_SCHEMA)
+
+        # HACK: this is a hack for discord.js that attempts to resume
+        # with a null sequence.
+        if data["seq"] is None:
+            return await self.invalidate_session(False)
+
         data = payload["d"]
         token, sess_id, seq = data["token"], data["session_id"], data["seq"]