migration system

untitled/app.py

@@ -1,3 +1,4 @@
+import json
 import os
 import time
 
@@ -67,7 +68,7 @@ class App:
                         continue
                     try:
                         save = persistence.load(save_name)
-                    except persistence.json.JSONDecodeError:
+                    except (json.JSONDecodeError, KeyError):
                         print(
                             "There was an error loading your savefile, it may be corrupt :("
                         )

untitled/migration.py

@@ -0,0 +1,7 @@
+_MIGRATIONS = {}
+
+
+def migrate(data):
+    while data["version"] in _MIGRATIONS:
+        data = _MIGRATIONS[data["version"]](data)
+    return data

untitled/persistence.py

@@ -1,7 +1,7 @@
 import json
 from pathlib import Path
 
-from untitled import PACKAGE_ROOT, model
+from untitled import PACKAGE_ROOT, migration, model
 
 SAVE_FOLDER = PACKAGE_ROOT / "saves"
 
@@ -26,7 +26,7 @@ def load(name, folder=None):
 
     with open(save_file) as f:
         data = json.load(f)
-
+    data = migration.migrate(data)
     save = model.Save.from_dict(data)
 
     return save