Fix df.signal not propagated into child sub-orchestrations

src/client.rs

@@ -94,6 +94,42 @@ fn get_duroxide_client() -> Result<&'static Client, String> {
     })
 }
 
+async fn list_running_descendants(client: &Client, root_instance_id: &str) -> Vec<String> {
+    let tree = match client.get_instance_tree(root_instance_id).await {
+        Ok(tree) => tree,
+        Err(e) => {
+            warning!(
+                "pg_durable: failed to inspect instance tree for signal fan-out (root={}): {:?}",
+                root_instance_id,
+                e
+            );
+            return vec![];
+        }
+    };
+
+    let mut descendants = Vec::new();
+    for child_instance_id in tree.all_ids {
+        if child_instance_id == root_instance_id {
+            continue;
+        }
+
+        match client.get_instance_info(&child_instance_id).await {
+            Ok(info) if info.status.eq_ignore_ascii_case("running") => {
+                descendants.push(child_instance_id);
+            }
+            Ok(_) => {}
+            Err(e) => {
+                warning!(
+                    "pg_durable: failed to inspect child instance status for signal fan-out (child={}): {:?}",
+                    child_instance_id, e
+                );
+            }
+        }
+    }
+
+    descendants
+}
+
 /// Start a durable function via the shared PostgreSQL store.
 pub fn start_durable_function(
     function_name: &str,
@@ -141,6 +177,21 @@ pub fn raise_external_event(instance_id: &str, event_name: &str, data: &str) ->
             .raise_event(instance_id, event_name, data)
             .await
             .map_err(|e| format!("Failed to raise event: {e:?}"))?;
+
+        for child_instance_id in list_running_descendants(client, instance_id).await {
+            if let Err(e) = client
+                .raise_event(&child_instance_id, event_name, data)
+                .await
+            {
+                warning!(
+                    "pg_durable: failed to fan out signal '{}' to child instance {}: {:?}",
+                    event_name,
+                    child_instance_id,
+                    e
+                );
+            }
+        }
+
         Ok(())
     })
 }

tests/e2e/sql/23_signal_in_race.sql

@@ -0,0 +1,72 @@
+-- Tests: df.signal propagation into wait_for_signal inside df.race branch
+SET SESSION AUTHORIZATION df_e2e_user;
+
+DROP TABLE IF EXISTS test_signal_race_log;
+CREATE TABLE test_signal_race_log (
+    id SERIAL PRIMARY KEY,
+    branch TEXT NOT NULL,
+    data JSONB,
+    created_at TIMESTAMPTZ DEFAULT now()
+);
+
+CREATE TEMP TABLE _test_signal_race_state (instance_id TEXT);
+
+INSERT INTO _test_signal_race_state
+SELECT df.start(
+    df.race(
+        df.seq(
+            df.wait_for_signal('approve', 12) |=> 'sig',
+            'INSERT INTO test_signal_race_log (branch, data) VALUES (''signal'', $sig::jsonb)'
+        ),
+        df.seq(
+            df.sleep(8),
+            'INSERT INTO test_signal_race_log (branch, data) VALUES (''sleep'', ''{}''::jsonb)'
+        )
+    ),
+    'test-signal-in-race'
+);
+
+SELECT pg_sleep(2);
+
+DO $$
+DECLARE
+    v_instance_id TEXT;
+BEGIN
+    SELECT instance_id INTO v_instance_id FROM _test_signal_race_state;
+    PERFORM df.signal(v_instance_id, 'approve', '{"approved": true}');
+END $$;
+
+DO $$
+DECLARE
+    v_instance_id TEXT;
+    v_status TEXT;
+BEGIN
+    SELECT instance_id INTO v_instance_id FROM _test_signal_race_state;
+    SELECT df.wait_for_completion(v_instance_id, 25) INTO v_status;
+
+    IF v_status != 'completed' THEN
+        RAISE EXCEPTION 'TEST FAILED [signal-in-race]: expected completed, got %', v_status;
+    END IF;
+
+    IF NOT EXISTS (
+        SELECT 1
+        FROM test_signal_race_log
+        WHERE branch = 'signal'
+          AND (data->>'timed_out')::boolean = false
+          AND (data->'data'->>'approved')::boolean = true
+    ) THEN
+        RAISE EXCEPTION 'TEST FAILED [signal-in-race]: signal branch did not receive approve event';
+    END IF;
+
+    IF EXISTS (SELECT 1 FROM test_signal_race_log WHERE branch = 'sleep') THEN
+        RAISE EXCEPTION 'TEST FAILED [signal-in-race]: sleep branch unexpectedly won race';
+    END IF;
+
+    RAISE NOTICE 'TEST PASSED: signal_in_race';
+END $$;
+
+DROP TABLE _test_signal_race_state;
+DROP TABLE test_signal_race_log;
+
+RESET SESSION AUTHORIZATION;
+SELECT 'TEST PASSED' AS result;