unb-server 2.0.3

unb inbound server: Node, request/subscribe handlers, catalog, relay orchestration, accept
Documentation
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mod common;

use std::time::Duration;

use common::{connect_nodes, ghost_establish, start};
use futures_util::StreamExt;
use schemars::JsonSchema;
use serde::Deserialize;
use serde_json::{json, Value};
use unb::{handler, Handler, HandlerError, Reply, Request};
use unb_client::{dial_transport, pair};
use unb_core::{Detail, DiscoverEvent, Kind, Scope};
use unb_runtime::{ClientError, Wire};
use unb_server::Node;

#[derive(Deserialize, JsonSchema)]
struct Probe {}

#[handler]
async fn chess(_request: Request<Probe>) -> Result<Reply<Value>, HandlerError> {
    Ok(Reply::new(json!({})))
}

#[handler]
async fn weather(_request: Request<Probe>) -> Result<Reply<Value>, HandlerError> {
    Ok(Reply::new(json!({})))
}

#[tokio::test(flavor = "multi_thread")]
async fn discover_streams_a_local_node_catalog_then_a_done_response() {
    let node =
        Node::builder("hub")
            .service(chess.describe(
                json!({ "one_line": "a chess game", "input_schema": {"from": "string"} }),
            ))
            .insecure_accept_declared_peer_identities()
            .build()
            .unwrap();
    let url = start(node).await;
    let wire = Wire::open(dial_transport(&url).await.unwrap());
    common::ready_client(&wire).await;

    let mut stream = wire
        .client_session()
        .start(
            "/hub",
            Kind::Discover,
            unb_core::Envelope::encode_payload(&json!({ "detail": "index", "scope": "local" })),
            None,
            Default::default(),
        )
        .await
        .unwrap();
    let catalog = stream
        .next()
        .await
        .unwrap()
        .expect("expected a node_catalog event");
    assert_eq!(catalog.kind, Kind::Event);
    let payload = catalog.payload_json();
    assert_eq!(payload["type"], "node_catalog");
    assert_eq!(payload["node"], "hub");
    assert_eq!(payload["subjects"][0]["subject"], "chess");
    assert_eq!(payload["subjects"][0]["target_path"], "/hub/chess");
    assert_eq!(payload["subjects"][0]["one_line"], "a chess game");
    assert!(
        payload["subjects"][0].get("input_schema").is_none(),
        "index detail omits schemas"
    );
    let done = stream
        .next()
        .await
        .unwrap()
        .expect("expected a terminal done");
    assert_eq!(done.kind, Kind::Response);
    assert_eq!(done.payload_json()["type"], "done");
    let mut stream = wire
        .client_session()
        .start(
            "/hub",
            Kind::Discover,
            unb_core::Envelope::encode_payload(&json!({ "detail": "full", "scope": "local" })),
            None,
            Default::default(),
        )
        .await
        .unwrap();
    let full = stream.next().await.unwrap().unwrap();
    assert_eq!(
        full.payload_json()["subjects"][0]["metadata"]["input_schema"]["from"],
        "string",
        "full detail carries schemas"
    );
}

#[tokio::test(flavor = "multi_thread")]
async fn discover_catalog_yields_typed_events_and_ends_on_done() {
    let node = Node::builder("hub")
        .service(chess.describe(json!({ "one_line": "a chess game" })))
        .insecure_accept_declared_peer_identities()
        .build()
        .unwrap();
    let url = start(node).await;
    let wire = Wire::open(dial_transport(&url).await.unwrap());
    common::ready_client(&wire).await;

    let mut catalog = wire
        .discover_catalog("/hub", Detail::Index, Scope::Local)
        .await
        .unwrap();
    let mut events = Vec::new();
    while let Some(event) = catalog.next().await {
        events.push(event);
    }

    assert!(
        matches!(events.first(), Some(DiscoverEvent::NodeCatalog { node, .. }) if node.as_str() == "hub"),
        "first event is the local node catalog: {events:?}"
    );
    assert!(
        matches!(events.last(), Some(DiscoverEvent::Done { .. })),
        "the stream ends with the done marker: {events:?}"
    );
    let catalogs = events
        .iter()
        .filter(|event| matches!(event, DiscoverEvent::NodeCatalog { .. }))
        .count();
    assert_eq!(catalogs, 1, "local scope yields exactly one node catalog");
}

#[tokio::test(flavor = "multi_thread")]
async fn connected_discovery_observes_exact_atomic_catalog_revisions() {
    let owner = Node::builder("mutable-owner")
        .insecure_accept_declared_peer_identities()
        .build()
        .unwrap();
    let observer = Node::builder("observer")
        .insecure_accept_declared_peer_identities()
        .build()
        .unwrap();
    connect_nodes(&observer, "mutable-owner", &owner).await;

    owner.add_service(chess).await.unwrap();
    assert!(observer
        .reachable_names()
        .contains(&"mutable-owner".to_string()));
    let added = observer
        .discover_events(Detail::Full, Scope::Reachable)
        .await;
    assert!(added.iter().any(|event| matches!(
        event,
        DiscoverEvent::NodeCatalog { node, revision: 1, subjects, .. }
            if node == "mutable-owner"
                && subjects.len() == 1
                && subjects[0]["subject"] == "chess"
                && subjects[0]["target_path"] == "/mutable-owner/chess"
                && subjects[0]["operations"]["unary"].is_object()
    )));

    owner.remove_subject("chess").await.unwrap();
    assert!(observer
        .reachable_names()
        .contains(&"mutable-owner".to_string()));
    let removed = observer
        .discover_events(Detail::Full, Scope::Reachable)
        .await;
    assert!(removed.iter().any(|event| matches!(
        event,
        DiscoverEvent::NodeCatalog { node, revision: 2, subjects, .. }
            if node == "mutable-owner" && subjects.is_empty()
    )));
}

#[tokio::test(flavor = "multi_thread")]
async fn discover_streams_node_scoped_catalogs_with_no_cross_node_dedup() {
    let owner_a = Node::builder("owner-a")
        .service(weather.describe(json!({ "one_line": "forecasts a" })))
        .insecure_accept_declared_peer_identities()
        .build()
        .unwrap();
    let owner_b = Node::builder("owner-b")
        .service(weather.describe(json!({ "one_line": "forecasts b" })))
        .insecure_accept_declared_peer_identities()
        .build()
        .unwrap();
    let relay = Node::builder("relay-1")
        .insecure_accept_declared_peer_identities()
        .build()
        .unwrap();

    connect_nodes(&relay, "owner-a", &owner_a).await;
    connect_nodes(&relay, "owner-b", &owner_b).await;

    let (client_side, relay_server) = pair();
    relay.serve_transport(relay_server).await;
    let client = Wire::open(client_side);
    common::ready_client(&client).await;

    let mut stream = common::stream(
        &client,
        "/relay-1",
        Kind::Discover,
        json!({ "detail": "index" }),
    )
    .await;

    let mut catalogs: Vec<(String, Vec<String>)> = Vec::new();
    loop {
        let frame = stream
            .next()
            .await
            .unwrap()
            .expect("stream ended without a terminal done");
        if frame.kind == Kind::Response {
            assert_eq!(frame.payload_json()["type"], "done");
            break;
        }
        let payload = frame.payload_json();
        if payload["type"] == "node_catalog" {
            let node = payload["node"].as_str().unwrap_or_default().to_string();
            let subjects: Vec<String> = payload["subjects"]
                .as_array()
                .into_iter()
                .flatten()
                .filter_map(|entry| entry["subject"].as_str().map(str::to_string))
                .collect();
            catalogs.push((node, subjects));
        }
    }

    let nodes: Vec<&String> = catalogs.iter().map(|(node, _)| node).collect();
    assert!(nodes.contains(&&"relay-1".to_string()), "{catalogs:?}");
    assert!(nodes.contains(&&"owner-a".to_string()), "{catalogs:?}");
    assert!(nodes.contains(&&"owner-b".to_string()), "{catalogs:?}");

    let weather_owners = catalogs
        .iter()
        .filter(|(_, subjects)| subjects.iter().any(|s| s == "weather"))
        .count();
    assert_eq!(
        weather_owners, 2,
        "two nodes own weather; discovery is node-scoped and emits both (no dedup): {catalogs:?}"
    );
}

#[tokio::test(flavor = "multi_thread")]
async fn discover_partial_ok_warns_on_a_timed_out_neighbor_and_still_finishes() {
    let relay = Node::builder("relay")
        .insecure_accept_declared_peer_identities()
        .max_activations(0)
        .build()
        .unwrap();
    let (relay_side, ghost_side) = pair();
    let ghost = Wire::open(ghost_side);
    let (connected, ()) = tokio::join!(
        relay.connect_transport("ghost", relay_side),
        ghost_establish(&ghost, "ghost")
    );
    connected.unwrap();
    let _ghost = ghost;

    let (client_side, relay_server) = pair();
    relay.serve_transport(relay_server).await;
    let client = Wire::open(client_side);
    common::ready_client(&client).await;

    let mut stream = client
        .client_session()
        .start(
            "/relay",
            Kind::Discover,
            unb_core::Envelope::encode_payload(&json!({ "timeout_ms": 150, "mode": "partial_ok" })),
            None,
            Default::default(),
        )
        .await
        .unwrap();

    let mut saw_warning = false;
    loop {
        let frame = stream
            .next()
            .await
            .unwrap()
            .expect("stream ended without a done");
        let payload = frame.payload_json();
        if frame.kind == Kind::Response {
            assert_eq!(payload["type"], "done");
            break;
        }
        if payload["type"] == "warning" {
            assert_eq!(payload["node"], "ghost");
            saw_warning = true;
        }
    }
    assert!(
        saw_warning,
        "partial_ok surfaces a warning for the timed-out neighbor"
    );
}

#[tokio::test(flavor = "multi_thread")]
async fn discover_strict_fails_the_stream_on_a_timed_out_neighbor() {
    let relay = Node::builder("relay")
        .insecure_accept_declared_peer_identities()
        .max_activations(0)
        .build()
        .unwrap();
    let (relay_side, ghost_side) = pair();
    let ghost = Wire::open(ghost_side);
    let (connected, ()) = tokio::join!(
        relay.connect_transport("ghost", relay_side),
        ghost_establish(&ghost, "ghost")
    );
    connected.unwrap();
    let _ghost = ghost;

    let (client_side, relay_server) = pair();
    relay.serve_transport(relay_server).await;
    let client = Wire::open(client_side);
    common::ready_client(&client).await;

    let mut stream = client
        .client_session()
        .start(
            "/relay",
            Kind::Discover,
            unb_core::Envelope::encode_payload(&json!({ "timeout_ms": 150, "mode": "strict" })),
            None,
            Default::default(),
        )
        .await
        .unwrap();

    loop {
        let frame = match stream.next().await {
            Err(ClientError::Protocol { code, .. }) => {
                assert_eq!(code, unb_core::ErrorCode::PeerUnreachable);
                return;
            }
            Ok(Some(frame)) => frame,
            other => panic!("stream ended without a terminal error: {other:?}"),
        };
        if frame.kind == Kind::Error {
            assert_eq!(frame.payload_json()["code"], "PEER_UNREACHABLE");
            return;
        }
        assert_eq!(
            frame.kind,
            Kind::Event,
            "only events precede the strict error"
        );
    }
}

#[tokio::test(flavor = "multi_thread")]
async fn discover_does_not_deadlock_when_the_fan_out_exceeds_the_input_channel() {
    let relay = Node::builder("relay")
        .insecure_accept_declared_peer_identities()
        .build()
        .unwrap();
    let mut ghosts = Vec::new();
    for index in 0..80 {
        let name = format!("ghost-{index}");
        let ghost = Node::builder(&name)
            .insecure_accept_declared_peer_identities()
            .build()
            .unwrap();
        connect_nodes(&relay, &name, &ghost).await;
        ghosts.push(ghost);
    }

    let (client_side, relay_server) = pair();
    relay.serve_transport(relay_server).await;
    let client = Wire::open(client_side);
    common::ready_client(&client).await;

    let mut stream = client
        .client_session()
        .start(
            "/relay",
            Kind::Discover,
            unb_core::Envelope::encode_payload(&json!({ "timeout_ms": 150, "mode": "partial_ok" })),
            None,
            Default::default(),
        )
        .await
        .unwrap();

    let done = tokio::time::timeout(Duration::from_secs(10), async {
        loop {
            let frame = stream
                .next()
                .await
                .unwrap()
                .expect("stream ended without a done");
            if frame.kind == Kind::Response {
                return frame.payload_json()["type"] == "done";
            }
        }
    })
    .await
    .expect("a fan-out wider than the input channel must still terminate, not deadlock");
    assert!(done);
}