slack_bolt.middleware.middleware_error_handler API documentation

class CustomMiddlewareErrorHandler(MiddlewareErrorHandler):
    def __init__ (self, logger: Logger, func: Callable[..., Optional[BoltResponse]]):
        self.func = func
        self.logger = logger
        self.arg_names = get_arg_names_of_callable(func)

    def handle(
        self,
        error: Exception,
        request: BoltRequest,
        response: Optional[BoltResponse],
    ):
        kwargs: Dict[str, Any] = build_required_kwargs(
            required_arg_names=self.arg_names,
            logger=self.logger,
            error=error,
            request=request,
            response=response,
            next_keys_required=False,
        )
        returned_response = self.func(**kwargs)
        if returned_response is not None and isinstance(returned_response, BoltResponse):
            assert response is not None, "response must be provided when returning a BoltResponse from an error handler"
            response.status = returned_response.status
            response.headers = returned_response.headers
            response.body = returned_response.body

class DefaultMiddlewareErrorHandler(MiddlewareErrorHandler):
    def __init__ (self, logger: Logger):
        self.logger = logger

    def handle(
        self,
        error: Exception,
        request: BoltRequest,
        response: Optional[BoltResponse],
    ):
        message = f"Failed to run a middleware (error: {error})"
        self.logger.exception(message)

class MiddlewareErrorHandler(metaclass=ABCMeta):
    @abstractmethod
    def handle(
        self,
        error: Exception,
        request: BoltRequest,
        response: Optional[BoltResponse], # TODO: why is this optional
    ) -> None:
        """Handles an unhandled exception.

        Args:
            error: The raised exception.
            request: The request.
            response: The response.
        """
        raise NotImplementedError()

@abstractmethod
def handle(
    self,
    error: Exception,
    request: BoltRequest,
    response: Optional[BoltResponse], # TODO: why is this optional
) -> None:
    """Handles an unhandled exception.

    Args:
        error: The raised exception.
        request: The request.
        response: The response.
    """
    raise NotImplementedError()