fix: return assignee roster within the lock (NQ-69-01)

custom_components/nestquest/dao_rules.py

@@ -962,14 +962,18 @@ class QuestDefinitionsDao:
 
     async def add_assignee(
         self, definition_id: int, child_id: int
-    ) -> None:
+    ) -> list[ChildRecord]:
         """Assign ``child_id`` to the definition (idempotent).
 
         Validates the assignee inside the same serialized transaction
         as the INSERT (existing and active AT ASSIGNMENT TIME), so a
         child deactivated concurrently cannot become an assignee.
         Assigning an already-assigned child is a no-op, mirroring the
-        composite primary key's storage-level guarantee.  Changes
+        composite primary key's storage-level guarantee.  Returns the
+        definition's assignees read back INSIDE the same transaction
+        that performed the write, so the returned roster is a
+        consistent post-assignment snapshot — a concurrent assign or
+        unassign cannot race it after the write commits.  Changes
         future instances only: already-generated instances and
         completion history are never rewritten here.
         """
@@ -990,6 +994,7 @@ class QuestDefinitionsDao:
                     "ON CONFLICT (definition_id, child_id) DO NOTHING",
                     (definition_id, child_id),
                 )
+                return await self.list_assignees(definition_id)
 
     async def remove_assignee(
         self, definition_id: int, child_id: int

custom_components/nestquest/quest_definitions.py

@@ -348,8 +348,9 @@ async def assign_child(
     active/exists check inside its transaction, and also confirms the
     definition exists.  Assigning an already-assigned child is a no-op
     (no duplicate row).  Returns the definition's assignees read back
-    through the DAO, a consistent post-assignment roster.  Raises
-    ValueError on any rejected argument.  Only the
+    inside the DAO's same transaction, a consistent post-assignment
+    roster (a concurrent assign/unassign cannot race it after the
+    write).  Raises ValueError on any rejected argument.  Only the
     ``quest_definition_assignees`` link is written; existing instances
     and completion history are never touched.
     """
@@ -357,7 +358,7 @@ async def assign_child(
     _validate_child_id(child_id)
     dao = QuestDefinitionsDao(database)
     try:
-        await dao.add_assignee(definition_id, child_id)
+        return await dao.add_assignee(definition_id, child_id)
     except ValueError as error:
         # The DAO names only the child/definition; re-raise so the
         # public contract names the field the caller actually passed.
@@ -367,7 +368,6 @@ async def assign_child(
         if message.startswith("quest definition "):
             raise ValueError(f"definition_id: {message}") from error
         raise
-    return await dao.list_assignees(definition_id)
 
 
 async def unassign_child(

tests/test_quest_definitions.py

@@ -1093,3 +1093,60 @@ def test_assign_and_unassign_leave_instances_and_history_alone(
         return None
 
     _with_db(tmp_path, "assign-unassign-history.db")(_body)
+
+
+def test_concurrent_assign_unassign_returns_consistent_roster(
+    tmp_path,
+) -> None:
+    """A concurrent unassign cannot strip the just-assigned child from
+    the roster that ``assign_child`` returns.
+
+    ``assign_child`` returns the roster read inside the same locked
+    transaction as the INSERT, so the child it assigned is always present
+    in its result — even when an unassign of that same child races.  The
+    pause hook holds ``list_assignees`` mid-flight so the unassign is
+    deterministically queued against the assignment's lock.
+    """
+    async def _body(database, children, rules, definitions, child):
+        created = await create_quest_definition(
+            database, "Brush teeth", _daily_rule(), [child.id], ["morning"]
+        )
+        bo = await children.create("Bo", NOW)
+
+        import custom_components.nestquest.dao_rules as dao_rules
+
+        original_list = dao_rules.QuestDefinitionsDao.list_assignees
+        started = asyncio.Event()
+        release = asyncio.Event()
+
+        async def _pausing_list(self, definition_id):
+            if not started.is_set():
+                started.set()
+                await release.wait()
+            return await original_list(self, definition_id)
+
+        dao_rules.QuestDefinitionsDao.list_assignees = _pausing_list
+        try:
+            assign_task = asyncio.ensure_future(
+                assign_child(database, created.definition.id, bo.id)
+            )
+            await started.wait()
+            unassign_task = asyncio.ensure_future(
+                unassign_child(database, created.definition.id, bo.id)
+            )
+            await asyncio.sleep(0)
+            release.set()
+            assignees, removed = await asyncio.gather(
+                assign_task, unassign_task
+            )
+        finally:
+            dao_rules.QuestDefinitionsDao.list_assignees = original_list
+
+        assert bo.id in [c.id for c in assignees], (
+            "assign_child must return a roster containing the child it "
+            "just assigned, even under a concurrent unassign"
+        )
+        assert removed is True
+        return assignees
+
+    _with_db(tmp_path, "assign-unassign-concurrent.db")(_body)