Persist generic object references

tests/test_reconciliation_persistence.py

@@ -203,7 +203,7 @@ class AppliedStatePersistenceTests(unittest.TestCase):
 
 
 class SchemaMigrationTests(unittest.TestCase):
-    def test_version_one_database_is_migrated_to_version_two(self):
+    def test_version_one_database_is_migrated_to_version_three(self):
         with tempfile.TemporaryDirectory() as directory:
             path = Path(directory) / "state.sqlite3"
             connection = sqlite3.connect(path)
@@ -230,10 +230,29 @@ class SchemaMigrationTests(unittest.TestCase):
                         """
                     )
                 }
+                reference_columns = {
+                    table: {
+                        row[1]
+                        for row in store.connection.execute(
+                            f"PRAGMA table_info({table})"
+                        )
+                    }
+                    for table in (
+                        "observations",
+                        "desired_state",
+                        "applied_state",
+                    )
+                }
 
-        self.assertEqual(version, 2)
+        self.assertEqual(version, 3)
         self.assertIn("desired_state", tables)
         self.assertIn("applied_state", tables)
+        self.assertTrue(
+            all(
+                "references_json" in columns
+                for columns in reference_columns.values()
+            )
+        )
 
 
 if __name__ == "__main__":