Properly handle websocket transport errors and recovery (#1897)

Author: beagold

changes/1897.bugfix.md

@@ -0,0 +1,2 @@
+Properly handle websocket transport errors and recover
+- Additionally, errors will now include additional information

hikari/errors.py

@@ -41,6 +41,7 @@
     "InternalServerError",
     "ShardCloseCode",
     "GatewayConnectionError",
+    "GatewayTransportError",
     "GatewayServerClosedConnectionError",
     "GatewayError",
     "MissingIntentWarning",
@@ -176,6 +177,14 @@ def is_standard(self) -> bool:
         return (self.value // 1000) == 1
 
 
+@attrs.define(auto_exc=True, repr=False, slots=False)
+class GatewayTransportError(GatewayError):
+    """An exception thrown if an issue occurs at the transport layer."""
+
+    def __str__(self) -> str:
+        return f"Gateway transport error: {self.reason!r}"
+
+
 @attrs.define(auto_exc=True, repr=False, slots=False)
 class GatewayConnectionError(GatewayError):
     """An exception thrown if a connection issue occurs."""

hikari/impl/shard.py

@@ -210,10 +210,10 @@ async def send_json(self, data: data_binding.JSONObject) -> None:
 
     def _handle_other_message(self, message: aiohttp.WSMessage, /) -> typing.NoReturn:
         if message.type == aiohttp.WSMsgType.TEXT:
-            raise errors.GatewayError("Unexpected message type received TEXT, expected BINARY")
+            raise errors.GatewayTransportError("Unexpected message type received TEXT, expected BINARY")
 
         if message.type == aiohttp.WSMsgType.BINARY:
-            raise errors.GatewayError("Unexpected message type received BINARY, expected TEXT")
+            raise errors.GatewayTransportError("Unexpected message type received BINARY, expected TEXT")
 
         if message.type == aiohttp.WSMsgType.CLOSE:
             close_code = int(message.data)
@@ -229,7 +229,8 @@ def _handle_other_message(self, message: aiohttp.WSMessage, /) -> typing.NoRetur
             raise errors.GatewayConnectionError("Socket has closed")
 
         # Assume exception for now.
-        raise errors.GatewayError("Unexpected websocket exception from gateway") from self._ws.exception()
+        reason = f"{message.data!r} [extra={message.extra!r}, type={message.type}]"
+        raise errors.GatewayTransportError(reason) from self._ws.exception()
 
     async def _receive_and_check_text(self) -> str:
         message = await self._ws.receive()
@@ -920,6 +921,9 @@ async def _keep_alive(self) -> None:
             except errors.GatewayConnectionError as ex:
                 self._logger.warning("failed to communicate with server, reason was: %r. Will retry shortly", ex.reason)
 
+            except errors.GatewayTransportError as ex:
+                self._logger.error("encountered transport error. Will try to reconnect shorty", exc_info=ex)
+
             except errors.GatewayServerClosedConnectionError as ex:
                 if not ex.can_reconnect:
                     self._logger.info(

tests/hikari/impl/test_shard.py

@@ -269,7 +269,7 @@ def test__handle_other_message_when_message_type_is_unknown(self, transport_impl
         exception = Exception("some error")
         transport_impl._ws.exception = mock.Mock(return_value=exception)
 
-        with pytest.raises(errors.GatewayError, match="Unexpected websocket exception from gateway") as exc_info:
+        with pytest.raises(errors.GatewayTransportError) as exc_info:
             transport_impl._handle_other_message(stub_response)
 
         assert exc_info.value.__cause__ is exception