feat: add durable store conformance harness

tests/test_durable_store_conformance.py

@@ -0,0 +1,42 @@
+import unittest
+
+from user_engine.adapters.local import InMemoryUserEngineStore, SCHEMA_VERSION
+from user_engine.migrations import (
+    LATEST_SCHEMA_VERSION,
+    USER_ENGINE_RECORD_COUNT_KEYS,
+    USER_ENGINE_STORE_RECORD_TYPES,
+    migration_manifest,
+    validate_migration_manifest,
+)
+from user_engine.testing.store_conformance import (
+    assert_user_engine_migration_contract,
+    assert_user_engine_store_conformance,
+)
+
+
+class DurableStoreConformanceTests(unittest.TestCase):
+    def test_migration_manifest_is_ordered_and_provider_safe(self):
+        assert_user_engine_migration_contract(self)
+
+        manifest = migration_manifest()
+
+        self.assertEqual(validate_migration_manifest(), ())
+        self.assertEqual(manifest[-1].version, LATEST_SCHEMA_VERSION)
+        self.assertIn("users", USER_ENGINE_STORE_RECORD_TYPES)
+        self.assertIn("pending_outbox_events", USER_ENGINE_RECORD_COUNT_KEYS)
+
+    def test_local_schema_version_uses_latest_manifest_version(self):
+        store = InMemoryUserEngineStore()
+
+        store.migrate()
+
+        self.assertEqual(SCHEMA_VERSION, LATEST_SCHEMA_VERSION)
+        self.assertEqual(store.schema_version, LATEST_SCHEMA_VERSION)
+        self.assertTrue(store.ready)
+
+    def test_in_memory_store_satisfies_durable_store_contract(self):
+        assert_user_engine_store_conformance(self, InMemoryUserEngineStore)
+
+
+if __name__ == "__main__":
+    unittest.main()