#[tokio::test]
async fn hid_roundtrip() {
    use lesavka_common::lesavka::*;
    use lesavka_server::RelaySvc; // export the struct in lib.rs
    let svc = RelaySvc::default();
    let (mut cli, srv) = tonic::transport::Channel::balance_channel(1);
    tokio::spawn(
        tonic::transport::server::Server::builder()
            .add_service(relay_server::RelayServer::new(svc))
            .serve_with_incoming(srv),
    );

    let (mut tx, mut rx) = relay_client::RelayClient::new(cli)
        .stream()
        .await
        .unwrap()
        .into_inner();
    tx.send(HidReport {
        data: vec![0, 0, 4, 0, 0, 0, 0, 0],
    })
    .await
    .unwrap();
    assert!(rx.message().await.unwrap().is_none()); // nothing echoed yet
}