ExceptionConverter doesn't respect converted error message

[bravik]

I try to convert exceptions with ExceptionConverterInterface like this:

class DomainExceptionConverter implements ExceptionConverterInterface
{
    public function convertException(Throwable $exception): Throwable
    {
        if ($exception instanceof NotEnabledTransitionException) {
            $message = "";
            foreach ($exception->getTransitionBlockerList() as $blocker) {
                $message .= $blocker->getMessage() . "; ";
            }
            $message = rtrim($message, "; ");

            return new PermissionDeniedError($message);
        }
}

However the resulting message in GraphQL error comes from original exception and not from converted one. It seems like a defenitely not expected behavior / bug.

It comes from Error\ErrorHandler:

    private function treatExceptions(array $errors, bool $throwRawException): array
    {
        //...

            // recreate a error with converted exception
            $errorWithConvertedException = new GraphQLError(
                $error->getMessage(),         // Here the original message is passed
                $error->nodes,
                $error->getSource(),
                $error->getPositions(),
                $error->path,
                $rawException
            );

         // ...
    }

I suppose it should look like:

             $errorWithConvertedException = new GraphQLError(
                $rawException && $rawException->getMessage() ?? $error->getMessage(),         
                // ...
            );

I've actually do not understand at all why the converted message is treated as 'previous' and not the main error.

Q	A
Bug report?	yes
Feature request?	no
BC Break report?	no
RFC?	no
Version/Branch	0.13.2