hephaestus/crates/heph-core/tests/convergence.rs

//! Op-log + merge convergence (tech-spec §12, slice 8b–8d). Two local replicas
//! (distinct origins) exchange ops; we assert they converge, that ambiguous
//! scalar merges surface as conflicts, and that concurrent body edits *merge*
//! through the yrs text CRDT instead of clobbering with last-writer-wins. No
//! network yet — we hand ops across directly.

use heph_core::{
    Attention, Clock, LocalStore, NewNode, NewTask, Op, Store, SyncCursors, TaskState,
};
use std::sync::atomic::{AtomicI64, Ordering};
use std::sync::Arc;

#[derive(Clone)]
struct StepClock(Arc<AtomicI64>);
impl StepClock {
    fn new(ms: i64) -> Self {
        StepClock(Arc::new(AtomicI64::new(ms)))
    }
    fn set(&self, ms: i64) {
        self.0.store(ms, Ordering::SeqCst);
    }
}
impl Clock for StepClock {
    fn now_ms(&self) -> i64 {
        self.0.load(Ordering::SeqCst)
    }
}

/// The shared canonical user both replicas adopt — the §13 model where every
/// device of one human carries the same owner id.
const OWNER: &str = "canonical-user";

fn replica(now: i64) -> (LocalStore, StepClock) {
    let c = StepClock::new(now);
    let mut s = LocalStore::open_in_memory(Box::new(c.clone())).unwrap();
    s.adopt_owner(OWNER).unwrap();
    (s, c)
}

/// Push every op from `src` (after `cursor`) into `dst`, in HLC order.
fn sync_one_way(src: &dyn Store, dst: &mut dyn Store, cursor: Option<&str>) -> Option<String> {
    let ops: Vec<Op> = src.ops_since(cursor).unwrap();
    let mut last = cursor.map(str::to_string);
    for op in &ops {
        dst.apply_op(op).unwrap();
        last = Some(op.hlc.clone());
    }
    last
}

#[test]
fn sync_cursors_default_empty_then_advance_per_direction() {
    let (mut a, _ca) = replica(1000);
    const HUB: &str = "https://hub.example";

    assert_eq!(a.sync_state(HUB).unwrap(), SyncCursors::default());

    // Advancing only the push cursor leaves pull untouched, and vice versa.
    a.record_sync(HUB, Some("hlc-push-1"), None).unwrap();
    a.record_sync(HUB, None, Some("hlc-pull-1")).unwrap();
    assert_eq!(
        a.sync_state(HUB).unwrap(),
        SyncCursors {
            last_pushed_hlc: Some("hlc-push-1".into()),
            last_pulled_hlc: Some("hlc-pull-1".into()),
        }
    );

    // A second peer is tracked independently.
    a.record_sync("other", Some("x"), None).unwrap();
    assert_eq!(
        a.sync_state(HUB).unwrap().last_pushed_hlc.as_deref(),
        Some("hlc-push-1")
    );
}

#[test]
fn owner_sub_gate_claims_first_then_requires_match() {
    // Single-tenant gate (§13): the first sub claims the owner; only that sub
    // is authorized thereafter.
    let (mut a, _ca) = replica(1000);
    assert!(a.authorize_owner_sub("sub-alice").unwrap(), "first claims");
    assert!(a.authorize_owner_sub("sub-alice").unwrap(), "same sub ok");
    assert!(
        !a.authorize_owner_sub("sub-mallory").unwrap(),
        "a different identity must be rejected"
    );
    // Still bound to the original after a rejection.
    assert!(a.authorize_owner_sub("sub-alice").unwrap());
}

#[test]
fn online_round_trip_propagates_a_node() {
    let (mut a, _ca) = replica(1000);
    let (mut b, _cb) = replica(1000);

    let n = a
        .create_node(NewNode::doc("Roof", "shingles need work"))
        .unwrap();
    sync_one_way(&a, &mut b, None);

    let on_b = b.get_node(&n.id).unwrap().expect("node reached B");
    assert_eq!(on_b.title, "Roof");
    assert_eq!(on_b.body.as_deref(), Some("shingles need work"));
}

#[test]
fn apply_is_idempotent() {
    let (mut a, _ca) = replica(1000);
    let (mut b, _cb) = replica(1000);
    let n = a.create_node(NewNode::doc("X", "y")).unwrap();

    // Apply all of A's ops to B twice — second pass is a no-op.
    sync_one_way(&a, &mut b, None);
    let again: Vec<Op> = a.ops_since(None).unwrap();
    for op in &again {
        assert!(
            !b.apply_op(op).unwrap(),
            "re-applying {} mutated B",
            op.op_type
        );
    }
    assert_eq!(b.get_node(&n.id).unwrap().unwrap().title, "X");
}

#[test]
fn offline_divergent_scalar_edits_converge_with_a_conflict() {
    // A creates a task; B learns it. Then both go offline and set a different
    // do_date. After exchanging, both converge to the higher-HLC value and each
    // records a conflict for the discarded value.
    let (mut a, ca) = replica(1000);
    let (mut b, cb) = replica(1000);

    let task = a
        .create_task(NewTask {
            title: "Renew passport".into(),
            attention: Some(Attention::Orange),
            ..Default::default()
        })
        .unwrap();
    sync_one_way(&a, &mut b, None);

    // Divergent offline edits. B's edit is later (higher physical time) → wins.
    ca.set(2000);
    a.set_task_state(&task.node_id, TaskState::Done).unwrap();
    cb.set(3000);
    b.set_task_attention(&task.node_id, Attention::Red).unwrap();
    // Give each a distinct do_date too (the conflicting field).
    // (set_task_* above already produced task.set ops snapshotting scalars.)

    // Exchange the divergent ops.
    sync_one_way(&a, &mut b, None);
    sync_one_way(&b, &mut a, None);

    // Both replicas converge to identical task scalars.
    let ta = a.get_task(&task.node_id).unwrap().unwrap();
    let tb = b.get_task(&task.node_id).unwrap().unwrap();
    assert_eq!(ta, tb, "replicas did not converge: {ta:?} vs {tb:?}");
    // B wrote last (t=3000) → its attention=red wins on both.
    assert_eq!(ta.attention, Some(Attention::Red));

    // Each replica surfaced the divergence as a conflict (not silently merged).
    assert!(
        !a.conflicts_list().unwrap().is_empty(),
        "A recorded no conflict"
    );
    assert!(
        !b.conflicts_list().unwrap().is_empty(),
        "B recorded no conflict"
    );
}

#[test]
fn concurrent_body_edits_merge_via_crdt() {
    // Both replicas edit *different regions* of a shared body offline. The text
    // CRDT merges both edits — neither is lost to last-writer-wins, and no
    // conflict is enqueued.
    let (mut a, ca) = replica(1000);
    let (mut b, cb) = replica(1000);

    let n = a.create_node(NewNode::doc("Note", "Hello world")).unwrap();
    sync_one_way(&a, &mut b, None);

    // A inserts in the middle; B appends at the end.
    ca.set(2000);
    a.update_node(&n.id, None, Some("Hello brave world".into()))
        .unwrap();
    cb.set(2500);
    b.update_node(&n.id, None, Some("Hello world!".into()))
        .unwrap();

    sync_one_way(&a, &mut b, None);
    sync_one_way(&b, &mut a, None);

    let ba = a.get_node(&n.id).unwrap().unwrap().body;
    let bb = b.get_node(&n.id).unwrap().unwrap().body;
    assert_eq!(ba, bb, "bodies did not converge");
    assert_eq!(ba.as_deref(), Some("Hello brave world!")); // both edits survive
    assert!(
        a.conflicts_list().unwrap().is_empty() && b.conflicts_list().unwrap().is_empty(),
        "body merges must not enqueue conflicts"
    );
}

#[test]
fn links_are_an_or_set() {
    // A and B each add a different link to the same node; both survive.
    let (mut a, ca) = replica(1000);
    let (mut b, cb) = replica(1000);

    let src = a.create_node(NewNode::doc("src", "")).unwrap();
    let d1 = a.create_node(NewNode::doc("d1", "")).unwrap();
    sync_one_way(&a, &mut b, None);
    let d2 = b.create_node(NewNode::doc("d2", "")).unwrap();
    sync_one_way(&b, &mut a, None);

    ca.set(2000);
    a.add_link(&src.id, &d1.id, heph_core::LinkType::Blocks)
        .unwrap();
    cb.set(2000);
    b.add_link(&src.id, &d2.id, heph_core::LinkType::Blocks)
        .unwrap();

    sync_one_way(&a, &mut b, None);
    sync_one_way(&b, &mut a, None);

    let dsts_a: Vec<String> = a
        .outgoing_links(&src.id)
        .unwrap()
        .into_iter()
        .filter(|l| l.link_type == heph_core::LinkType::Blocks)
        .map(|l| l.dst_id)
        .collect();
    let mut dsts_b: Vec<String> = b
        .outgoing_links(&src.id)
        .unwrap()
        .into_iter()
        .filter(|l| l.link_type == heph_core::LinkType::Blocks)
        .map(|l| l.dst_id)
        .collect();
    let mut sorted_a = dsts_a.clone();
    sorted_a.sort();
    dsts_b.sort();
    assert_eq!(sorted_a, dsts_b, "link sets did not converge");
    assert!(dsts_b.contains(&d1.id) && dsts_b.contains(&d2.id));
}

#[test]
fn tombstones_propagate_and_are_monotonic() {
    let (mut a, _ca) = replica(1000);
    let (mut b, _cb) = replica(1000);
    let n = a.create_node(NewNode::doc("doomed", "")).unwrap();
    sync_one_way(&a, &mut b, None);

    a.tombstone_node(&n.id).unwrap();
    sync_one_way(&a, &mut b, None);

    assert!(b.get_node(&n.id).unwrap().unwrap().tombstoned);
    // Tombstoned nodes drop out of search/next on B.
    assert!(b.search("doomed").unwrap().is_empty());
}