Add schema migrations for index

src/tests/test_backup_restore.py

@@ -45,11 +45,11 @@ def test_backup_restore_workflow(monkeypatch):
 
         vault.save_index({"passwords": {"temp": {}}})
         backup_mgr.restore_latest_backup()
-        assert vault.load_index() == data2
+        assert vault.load_index()["passwords"] == data2["passwords"]
 
         vault.save_index({"passwords": {}})
         backup_mgr.restore_backup_by_timestamp(1111)
-        assert vault.load_index() == data1
+        assert vault.load_index()["passwords"] == data1["passwords"]
 
         backup1.unlink()
         current = vault.load_index()

src/tests/test_migrations.py

@@ -0,0 +1,34 @@
+import sys
+from pathlib import Path
+import pytest
+from cryptography.fernet import Fernet
+
+sys.path.append(str(Path(__file__).resolve().parents[1]))
+
+from password_manager.encryption import EncryptionManager
+from password_manager.vault import Vault
+from password_manager.migrations import LATEST_VERSION
+
+
+def setup(tmp_path: Path):
+    key = Fernet.generate_key()
+    enc_mgr = EncryptionManager(key, tmp_path)
+    vault = Vault(enc_mgr, tmp_path)
+    return enc_mgr, vault
+
+
+def test_migrate_v0_to_v1(tmp_path: Path):
+    enc_mgr, vault = setup(tmp_path)
+    legacy = {"passwords": {"0": {"website": "a", "length": 8}}}
+    enc_mgr.save_json_data(legacy)
+    data = vault.load_index()
+    assert data["schema_version"] == LATEST_VERSION
+    assert data["passwords"] == legacy["passwords"]
+
+
+def test_error_on_future_version(tmp_path: Path):
+    enc_mgr, vault = setup(tmp_path)
+    future = {"schema_version": LATEST_VERSION + 1, "passwords": {}}
+    enc_mgr.save_json_data(future)
+    with pytest.raises(ValueError):
+        vault.load_index()

src/tests/test_portable_backup.py

@@ -54,7 +54,7 @@ def test_round_trip_across_modes(monkeypatch):
 
             vault.save_index({"pw": 0})
             import_backup(vault, backup, path)
-            assert vault.load_index() == data
+            assert vault.load_index()["pw"] == data["pw"]
 
 
 def test_corruption_detection(monkeypatch):
@@ -113,4 +113,5 @@ def test_import_over_existing(monkeypatch):
 
         vault.save_index({"v": 2})
         import_backup(vault, backup, path)
-        assert vault.load_index() == {"v": 1}
+        loaded = vault.load_index()
+        assert loaded["v"] == 1