make account balance string formatting more rigid

src/ez_lan_manager/pages/Account.py

@@ -1,3 +1,4 @@
+from decimal import Decimal
 from functools import partial
 from typing import Optional
 
@@ -12,7 +13,7 @@ from src.ez_lan_manager.types.User import User
 
 class AccountPage(Component):
     user: Optional[User] = None
-    balance: Optional[int] = None
+    balance: Optional[Decimal] = None
     transaction_history: list[Transaction] = list()
     banking_info_revealer_open: bool = False
     paypal_info_revealer_open: bool = False

src/ez_lan_manager/services/AccountingService.py

@@ -2,6 +2,7 @@ import logging
 from collections.abc import Callable
 from datetime import datetime
 from decimal import Decimal, ROUND_DOWN
+from typing import Optional
 
 from src.ez_lan_manager.services.DatabaseService import DatabaseService
 from src.ez_lan_manager.types.Transaction import Transaction
@@ -65,9 +66,11 @@ class AccountingService:
         return await self._db_service.get_all_transactions_for_user(user_id)
 
     @staticmethod
-    def make_euro_string_from_decimal(euros: Decimal) -> str:
+    def make_euro_string_from_decimal(euros: Optional[Decimal]) -> str:
         """
         Internally, all money values are euros as decimal. Only when showing them to the user we generate a string.
         """
+        if euros is None:
+            return "0.00 €"
         rounded_decimal = str(euros.quantize(Decimal(".01"), rounding=ROUND_DOWN))
         return f"{rounded_decimal} €"