grpc.aio.ServerInterceptor is incompatible with async RPC methods

The grpc.aio.ServerInterceptor is currently annotated using grpc.RpcMethodHandler. However the interface for grpc.RpcMethodHandler is not compatible with async RPC methods. The correct stub for an async version would make use of Awaitable and AsyncIterator:

class RpcMethodHandler(abc.ABC, Generic[_TRequest, _TResponse]):
    request_streaming: bool
    response_streaming: bool

    # XXX: not clear from docs whether this is optional or not
    request_deserializer: _Deserializer[_TRequest] | None

    # XXX: not clear from docs whether this is optional or not
    response_serializer: _Serializer[_TResponse] | None

    unary_unary: Callable[[_TRequest, ServicerContext], Awaitable[_TResponse]] | None

    unary_stream: Callable[[_TRequest, ServicerContext], AsyncIterator[_TResponse]] | None

    stream_unary: Callable[[Iterator[_TRequest], ServicerContext], Awaitable[_TResponse]] | None

    stream_stream: Callable[[Iterator[_TRequest], ServicerContext], AsyncIterator[_TResponse]] | None

Examinez stubs/grpcio/grpc/aio/init.pyi autour des lignes 374-383 et comparez l’annotation de l’interceptor avec la forme de async RpcMethodHandler décrite dans l’issue. Examinez la pull request ouverte #15497 ; c’est terminé lorsque le stub accepte les méthodes RPC asynchrones utilisant Awaitable et AsyncIterator sans entrer en conflit avec l’interface de handler existante.