tradein-mvp/backend/tests/test_849_matching_savepoint.py

@@ -300,22 +300,30 @@ class TestSingleSavepointBatchIsolation:
     def test_no_begin_nested_inside_link_listing_to_house(self):
         """Verify that _link_listing_to_house does NOT open its own begin_nested.
 
-        The outer per-row SAVEPOINT (one call per lot in save_listings) is the only
+        As of #1921, save_listings opens exactly 3 sequential (non-nested) SAVEPOINTs
-        SAVEPOINT level allowed. If begin_nested is called more than N lots times,
+        per lot, all at the same level:
-        that indicates a double-nesting.
+          1. upsert-reconcile SAVEPOINT (base.py ~line 500) — isolates INSERT so a
+             UniqueViolation on (source, source_id) can be caught and reconciled via
+             a plain UPDATE without aborting the whole session.
+          2. snapshot SAVEPOINT (base.py ~line 621) — fault-tolerant snapshot write.
+          3. hook SAVEPOINT (base.py ~line 645) — fault-tolerant house-matching hook.
+
+        All three are sequential: each opens only after the previous has already
+        committed or rolled back. None is nested inside another.
+
+        If _link_listing_to_house were to open its own inner begin_nested the count
+        would exceed 3 * len(lots) — that would indicate illegal double-nesting.
         """
         db = _mock_save_db(inserted=True, listing_id=77)
         lots = [_base_lot(source_id=str(i)) for i in range(3)]
 
         save_listings(db, lots)
 
-        # save_listings calls begin_nested once per lot for the snapshot
+        # 3 sequential SAVEPOINTs per lot (upsert-reconcile + snapshot + hook).
-        # and once per lot for the hook — so 2 * len(lots) total.
+        # > 3 * len(lots) would mean an inner SAVEPOINT was opened inside one of them.
-        # If _link_listing_to_house opens an INNER begin_nested too,
+        assert db.begin_nested.call_count == 3 * len(lots), (
-        # the count would be > 2 * len(lots).
+            f"Expected exactly 3 begin_nested per lot "
-        # (snapshot SAVEPOINT + hook SAVEPOINT = 2 per lot, no extra inner)
+            f"(upsert-reconcile + snapshot + hook, all sequential), "
-        assert db.begin_nested.call_count == 2 * len(lots), (
-            f"Expected exactly 2 begin_nested per lot (snapshot + hook outer), "
             f"got {db.begin_nested.call_count} — inner SAVEPOINT may still be present"
         )