fix: suppress UPDATE callbacks for objects deleted in the same transaction (#205)

src/fastapi_toolsets/models/watched.py

@@ -231,6 +231,13 @@ class EventSession(AsyncSession):
                     k: v for k, v in field_changes.items() if k not in transient_ids
                 }
 
+        # Suppress updates for deleted objects (row is gone, refresh would fail).
+        if deletes and field_changes:
+            deleted_ids = {id(o) for o, _ in deletes}
+            field_changes = {
+                k: v for k, v in field_changes.items() if k not in deleted_ids
+            }
+
         # Suppress updates for newly created objects (CREATE-only semantics).
         if creates and field_changes:
             create_ids = {id(o) for o in creates}

tests/test_models.py

@@ -1041,6 +1041,25 @@ class TestTransientObject:
         assert len(creates) == 1
         assert len(deletes) == 1
 
+    @pytest.mark.anyio
+    async def test_update_then_delete_suppresses_update_callback(self, mixin_session):
+        """UPDATE callback is suppressed when the object is also deleted in the same transaction."""
+        obj = WatchedModel(status="initial", other="x")
+        mixin_session.add(obj)
+        await mixin_session.commit()
+
+        _test_events.clear()
+
+        obj.status = "changed"
+        await mixin_session.flush()
+        await mixin_session.delete(obj)
+        await mixin_session.commit()
+
+        updates = [e for e in _test_events if e["event"] == "update"]
+        deletes = [e for e in _test_events if e["event"] == "delete"]
+        assert updates == []
+        assert len(deletes) == 1
+
 
 class TestPolymorphism:
     """Event dispatch with STI (Single Table Inheritance)."""