smarm/tests/cluster_remote_send.rs

//! RFC 010 c9 — remote `Name` sends: the outbound seam and the single
//! inbound name-resolution seam, cross-process.
//!
//! Two node processes each run the integrated `cluster::start`. The
//! *receiver* registers a `String` inbox under a name and exposes it (and
//! registers a second name it does NOT expose); the *sender* waits for
//! `node_up`, then sends. Facts cross as stdout lines: `LISTENING <addr>`,
//! `MEMBER-UP <name>`, `GOT <payload>`, `SEND-RESULT <case> <verdict>`.
//! Roles park forever afterwards (retractable-state trap); the parent
//! SIGKILLs via `Drop`.
//!
//! What is asserted at each end (roadmap-binding):
//! - cross-node name-send delivers the payload;
//! - an unexposed name is unreachable — the receiver's inbox stays empty
//!   even though the name IS registered locally;
//! - a wrong type hash is a decode failure at the receiver, never a
//!   misroute — the `String` inbox does not see a `u64` delivered under a
//!   made-up hash, nor a `u64` under `u64`'s hash;
//! - a send to a disconnected (never-connected) node fails locally with
//!   `NotConnected`, and `Ok(())` means only "handed to the transport".
//!
//! Timing note for the "stays empty" assertions: they are proven by
//! ORDERING, not by waiting — the sender emits the negative-case frames
//! BEFORE the positive one on the same connection (in-order stream), so when
//! the receiver has seen the positive payload, the negatives have already
//! been processed and refused. No sleep-and-hope.
#![cfg(feature = "cluster")]

mod common;

use common::{maybe_child, spawn_node, Node};
use smarm::cluster::envelope::NodeMeta;
use smarm::cluster::expose::expose;
use smarm::cluster::membership::{subscribe, NodeEvent};
use smarm::cluster::remote::{send_remote_raw, RemoteName, RemoteSendError};
use smarm::cluster::{start, Config, StaticSeeds};
use smarm::{channel, register, Name};
use std::time::Duration;

const ROLES: &[(&str, fn())] = &[("receiver", role_receiver), ("sender", role_sender)];

const INBOX: Name<String> = Name::new("c9.inbox");
const HIDDEN: Name<String> = Name::new("c9.hidden");

fn base_config(name: &str, seeds: Vec<(String, String)>) -> Config {
    Config {
        node_name: name.to_string(),
        meta: NodeMeta {
            role: "c9".to_string(),
            region: "local".to_string(),
        },
        listen_addr: "127.0.0.1:0".to_string(),
        strategy: Box::new(StaticSeeds::new(seeds)),
    }
}

/// Receiver: register + expose INBOX; register HIDDEN unexposed **in a
/// separate actor** (one actor holds one channel per message type — a
/// second `register` of the same `M` on one actor silently replaces the
/// first, closing it); print every payload that lands in either.
fn role_receiver() {
    smarm::run(|| {
        let cluster = start(base_config("recv", vec![])).expect("listener binds");
        println!("LISTENING {}", cluster.local_addr());

        // HIDDEN's holder: its own actor, so its String channel does not
        // displace INBOX's on the root actor.
        let (hidden_ready_tx, hidden_ready_rx) = channel::<()>();
        smarm::spawn(move || {
            let (hid_tx, hid_rx) = channel::<String>();
            register(HIDDEN, hid_tx).unwrap();
            hidden_ready_tx.send(()).unwrap();
            loop {
                match hid_rx.recv() {
                    Ok(s) => println!("GOT-HIDDEN {s}"),
                    Err(_) => break,
                }
            }
        });
        hidden_ready_rx.recv().unwrap();

        let (in_tx, in_rx) = channel::<String>();
        register(INBOX, in_tx).unwrap();
        expose(INBOX);
        println!("READY");
        loop {
            match in_rx.recv() {
                Ok(s) => println!("GOT {s}"),
                Err(_) => break,
            }
        }
        loop {
            smarm::sleep(Duration::from_secs(3600));
        }
    });
}

/// Sender: connect to recv, wait for node_up, then in this ORDER on the one
/// connection: hidden-name send, wrong-hash sends (two flavours), then the
/// positive send. Plus a send to a node that is not connected at all.
fn role_sender() {
    let recv_addr = std::env::var("SMARM_RECV_ADDR").expect("SMARM_RECV_ADDR");
    smarm::run(move || {
        let _cluster = start(base_config("send", vec![("recv".to_string(), recv_addr)]))
            .expect("listener binds");
        let events = subscribe().expect("manager is up");
        loop {
            match events.rx.recv() {
                Ok(NodeEvent::NodeUp(info)) if info.name == "recv" => break,
                Ok(_) => continue,
                Err(_) => panic!("manager gone"),
            }
        }
        println!("MEMBER-UP recv");

        // Not connected: purely local knowledge, no frame leaves.
        let ghost: RemoteName<String> = RemoteName::new("nowhere", INBOX);
        let r = smarm::cluster::remote::send(ghost, "lost".to_string());
        println!(
            "SEND-RESULT not-connected {}",
            match r {
                Err(RemoteSendError::NotConnected(_)) => "NotConnected",
                Ok(()) => "Ok",
                Err(_) => "OtherErr",
            }
        );

        // Unexposed name at the peer: the frame goes (local knowledge can't
        // know the peer's exposed set) and the peer refuses it.
        let hidden: RemoteName<String> = RemoteName::new("recv", HIDDEN);
        let r = smarm::cluster::remote::send(hidden, "should not land".to_string());
        println!(
            "SEND-RESULT hidden {}",
            if r.is_ok() { "Ok" } else { "Err" }
        );

        // Wrong hash, two flavours: (a) a u64 payload under a made-up hash
        // (unknown type at the peer); (b) a u64 payload under u64's real
        // hash against a String-typed name (decoder known, wrong channel).
        // Both are raw sends — the typed API cannot express them, by design.
        let bogus = 0xdead_beef_u64;
        let r = send_remote_raw(
            "recv",
            "c9.inbox",
            bogus,
            &smarm::cluster::envelope::encode_payload(&7u64).unwrap(),
        );
        println!(
            "SEND-RESULT wrong-hash-unknown {}",
            if r.is_ok() { "Ok" } else { "Err" }
        );
        let r = send_remote_raw(
            "recv",
            "c9.inbox",
            smarm::cluster::expose::type_hash::<u64>(),
            &smarm::cluster::envelope::encode_payload(&7u64).unwrap(),
        );
        println!(
            "SEND-RESULT wrong-hash-known {}",
            if r.is_ok() { "Ok" } else { "Err" }
        );

        // Positive: last on the stream, so its arrival proves the negatives
        // were already processed.
        let inbox: RemoteName<String> = RemoteName::new("recv", INBOX);
        let r = smarm::cluster::remote::send(inbox, "hello from send".to_string());
        println!(
            "SEND-RESULT positive {}",
            if r.is_ok() { "Ok" } else { "Err" }
        );

        loop {
            smarm::sleep(Duration::from_secs(3600));
        }
    });
}

fn wait_send_result(node: &mut Node, case: &str) -> String {
    let prefix = format!("SEND-RESULT {case} ");
    let line = node.wait_line(&prefix, |l| l.starts_with(&prefix));
    line[prefix.len()..].to_string()
}

#[test]
fn remote_name_send_delivers_and_refusals_never_misroute() {
    maybe_child(ROLES);

    let mut recv = spawn_node("receiver", &[]);
    let addr = recv.wait_listening();
    recv.wait_line("READY", |l| l == "READY");

    let mut send = spawn_node("sender", &[("SMARM_RECV_ADDR", &addr)]);
    send.wait_line("MEMBER-UP recv", |l| l == "MEMBER-UP recv");

    // Local-knowledge-only failure for an unknown node.
    assert_eq!(wait_send_result(&mut send, "not-connected"), "NotConnected");
    // Every frame-bearing send is Ok — Ok means "handed to the transport",
    // nothing about what the peer does with it (RFC §3, documented here).
    assert_eq!(wait_send_result(&mut send, "hidden"), "Ok");
    assert_eq!(wait_send_result(&mut send, "wrong-hash-unknown"), "Ok");
    assert_eq!(wait_send_result(&mut send, "wrong-hash-known"), "Ok");
    assert_eq!(wait_send_result(&mut send, "positive"), "Ok");

    // The positive payload lands...
    recv.wait_line("GOT hello from send", |l| l == "GOT hello from send");
    // ...and, by stream ordering, every negative before it was refused: no
    // GOT for the wrong-hash frames, no GOT-HIDDEN at all. The transcript
    // up to this point is the proof.
    let transcript = recv.transcript();
    let gots: Vec<&str> = transcript
        .iter()
        .map(|s| s.as_str())
        .filter(|l| l.starts_with("GOT"))
        .collect();
    assert_eq!(
        gots,
        ["GOT hello from send"],
        "exactly one delivery, the exposed one"
    );
}