huskies: merge 906

server/src/crdt_state/state/mod.rs

@@ -29,6 +29,13 @@ mod tests;
 
 pub use init::init;
 
+/// Subscribe to CRDT state-transition events.
+///
+/// Returns `None` if the CRDT layer has not been initialised yet.
+pub fn subscribe() -> Option<broadcast::Receiver<super::types::CrdtEvent>> {
+    statics::CRDT_EVENT_TX.get().map(|tx| tx.subscribe())
+}
+
 pub(super) use apply::{apply_and_persist, emit_event};
 pub(super) use indices::{
     rebuild_active_agent_index, rebuild_agent_throttle_index, rebuild_gateway_project_index,

server/src/crdt_state/state/tests.rs

@@ -94,6 +94,59 @@ fn rebuild_index_maps_story_ids() {
     assert!(index.contains_key("20_story_b"));
 }
 
+/// Regression for story 906: `subscribe()` and `emit_event()` must share the
+/// same broadcast channel.  Previously they referenced two separate
+/// `CRDT_EVENT_TX` statics (one in `types.rs`, one in `state/statics.rs`),
+/// so events fired into one channel and subscribers listened on the other —
+/// no Matrix stage-transition notifications fired post-CRDT migration.
+#[tokio::test(flavor = "current_thread")]
+async fn subscribe_receives_stage_transition_events() {
+    use super::super::types::CrdtEvent;
+    use super::super::write::write_item;
+
+    crate::crdt_state::init_for_test();
+
+    let mut rx = super::subscribe().expect("subscribe must return Some after init_for_test");
+
+    // Insert a new item — emit_event fires with from_stage=None.
+    write_item(
+        "906_story_subscribe",
+        "1_backlog",
+        Some("Subscribe Wiring"),
+        None,
+        None,
+        None,
+        None,
+        None,
+        None,
+        None,
+    );
+
+    let evt: CrdtEvent = rx.try_recv().expect("expected CrdtEvent on insert");
+    assert_eq!(evt.story_id, "906_story_subscribe");
+    assert!(evt.from_stage.is_none());
+    assert_eq!(evt.to_stage, "1_backlog");
+
+    // Update stage — emit_event fires again with the real from_stage.
+    write_item(
+        "906_story_subscribe",
+        "2_current",
+        None,
+        None,
+        None,
+        None,
+        None,
+        None,
+        None,
+        None,
+    );
+
+    let evt: CrdtEvent = rx.try_recv().expect("expected CrdtEvent on stage change");
+    assert_eq!(evt.story_id, "906_story_subscribe");
+    assert_eq!(evt.from_stage.as_deref(), Some("1_backlog"));
+    assert_eq!(evt.to_stage, "2_current");
+}
+
 #[tokio::test]
 async fn init_and_write_read_roundtrip() {
     let tmp = tempfile::tempdir().unwrap();