sync: 鍚屾灞€鍩熺綉鏈€鏂颁唬鐮?(source master @ b69568e4)

offline-backend-20260512/backend/tests/test_migration_graph.py

@@ -14,4 +14,24 @@ def test_migration_graph_has_unique_revisions_and_one_head() -> None:
 
     revisions = list(scripts.walk_revisions())
     assert len({revision.revision for revision in revisions}) == len(revisions)
-    assert len(scripts.get_heads()) == 1
+    assert scripts.get_heads() == ["20261020_01"]
+    assert scripts.get_revision("20261020_01").down_revision == (
+        "20261019_01",
+        "20261014_02",
+    )
+    assert scripts.get_revision("20261019_01").down_revision == "20261015_01"
+    assert scripts.get_revision("20261014_02").down_revision == "20261014_01"
+    assert scripts.get_revision("20261014_01").down_revision == "20261009_01"
+    assert scripts.get_revision("20261009_01").down_revision == "20261006_01"
+
+    assert scripts.get_revision("20260916_02").down_revision == "20260916_01"
+    assert scripts.get_revision("20260916_03").down_revision == (
+        "20260916_02",
+        "20260909_01",
+        "20260914_01",
+    )
+    assert scripts.get_revision("20260920_02").down_revision == (
+        "20260920_01",
+        "20260916_03",
+    )
+    assert scripts.get_revision("20261015_01").down_revision == "20260920_02"