From b5a5219a09851c137b1c4c3a7cf2be2db3be590a Mon Sep 17 00:00:00 2001
From: ajspig <dragon@monstercode.com>
Date: Tue, 18 Aug 2026 13:36:44 -0400
Subject: [PATCH] fix: cascade scope removal through document_sources

---
 src/deriver/queue_manager.py         |  3 +--
 src/deriver/scope_backfill.py        | 11 +++++++----
 tests/deriver/test_scope_backfill.py |  2 +-
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/deriver/queue_manager.py b/src/deriver/queue_manager.py
index e4c8124b..1c19c131 100644
--- a/src/deriver/queue_manager.py
+++ b/src/deriver/queue_manager.py
@@ -478,8 +478,7 @@ class QueueManager:
 
     @staticmethod
     def _is_tenant_work(work_unit_keys: Iterable[str]) -> bool:
-        """True if any claimed work unit is real tenant work, not housekeeping.
-        """
+        """True if any claimed work unit is real tenant work, not housekeeping."""
         for key in work_unit_keys:
             try:
                 if parse_work_unit_key(key).task_type != "reconciler":
diff --git a/src/deriver/scope_backfill.py b/src/deriver/scope_backfill.py
index 81017e28..f602838b 100644
--- a/src/deriver/scope_backfill.py
+++ b/src/deriver/scope_backfill.py
@@ -28,8 +28,7 @@ import logging
 from dataclasses import dataclass
 from typing import Any
 
-from sqlalchemy import select, update
-from sqlalchemy.dialects.postgresql import array
+from sqlalchemy import exists, select, update
 from sqlalchemy.sql.functions import func
 
 from src import crud, models
@@ -441,7 +440,7 @@ async def process_scope_removal(
             all_removed = list(frontier)
 
             # Fail-closed cascade: soft-delete derived documents whose support
-            # (source_ids) intersects anything removed, transitively — a
+            # (document_sources) intersects anything removed, transitively — a
             # deduction resting on removed evidence must leave with it, and so
             # must an induction resting on that deduction.
             while frontier:
@@ -453,7 +452,11 @@ async def process_scope_removal(
                         models.Document.observed == observed,
                         models.Document.level != "explicit",
                         models.Document.deleted_at.is_(None),
-                        models.Document.source_ids.has_any(array(frontier)),
+                        exists().where(
+                            models.DocumentSource.derived_id == models.Document.id,
+                            models.DocumentSource.source_id.in_(frontier),
+                            models.DocumentSource.workspace_name == workspace_name,
+                        ),
                     )
                     .values(deleted_at=func.now())
                     .returning(models.Document.id)
diff --git a/tests/deriver/test_scope_backfill.py b/tests/deriver/test_scope_backfill.py
index 06464c6f..9cca383a 100644
--- a/tests/deriver/test_scope_backfill.py
+++ b/tests/deriver/test_scope_backfill.py
@@ -522,7 +522,7 @@ async def test_removal_cascades_to_dependent_derived_docs_only(
         session_name=None,
         content="unrelated deduction",
         level="deductive",
-        source_ids=["some-other-doc-id-not-removed"],
+        source_ids=[generate_nanoid()],
     )
 
     copy_id, dependent_id, unrelated_id = copy.id, dependent.id, unrelated.id