fix: Use SENTINEL as default value for cart_update (#168)

Otherwise discount will be removed

Author: sveneberth

src/viur/shop/modules/api.py

@@ -155,12 +155,12 @@ def cart_add(
         self,
         *,
         parent_cart_key: str | db.Key = None,
-        cart_type: CartType = None,
-        name: str = None,
-        customer_comment: str = None,
-        shipping_address_key: str | db.Key = None,
-        shipping_key: str | db.Key = None,
-        discount_key: str | db.Key = None,
+        cart_type: CartType = SENTINEL,
+        name: str = SENTINEL,
+        customer_comment: str = SENTINEL,
+        shipping_address_key: str | db.Key = SENTINEL,
+        shipping_key: str | db.Key = SENTINEL,
+        discount_key: str | db.Key = SENTINEL,
         **kwargs,
     ):
         """
@@ -206,12 +206,12 @@ def cart_update(
         self,
         *,
         cart_key: str | db.Key,
-        cart_type: CartType = None,  # TODO: necessary?
+        cart_type: CartType = SENTINEL,  # TODO: necessary?
         name: str = None,
-        customer_comment: str = None,
-        shipping_address_key: str | db.Key = None,
+        customer_comment: str = SENTINEL,
+        shipping_address_key: str | db.Key = SENTINEL,
         shipping_key: str | db.Key = SENTINEL,
-        discount_key: str | db.Key = None,  # TODO: use sentinel?
+        discount_key: str | db.Key = SENTINEL,
         **kwargs,
     ):
         """

src/viur/shop/modules/cart.py

@@ -15,6 +15,7 @@
 from ..services import EVENT_SERVICE, Event
 from ..skeletons.article import ArticleAbstractSkel
 from ..skeletons.cart import CartItemSkel, CartNodeSkel
+from ..types.response import make_json_dumpable
 
 logger = SHOP_LOGGER.getChild(__name__)
 
@@ -438,7 +439,7 @@ def cart_update(
     ) -> SkeletonInstance_T[CartNodeSkel] | None:
         if not isinstance(cart_key, db.Key):
             raise TypeError(f"cart_key must be an instance of db.Key")
-        if not isinstance(cart_type, (CartType, type(None))):
+        if cart_type is not SENTINEL and not isinstance(cart_type, (CartType, type(None))):
             raise TypeError(f"cart_type must be an instance of CartType")
         if parent_cart_key is not SENTINEL and not isinstance(parent_cart_key, (db.Key, type(None))):
             raise TypeError(f"parent_cart_key must be an instance of db.Key")
@@ -654,6 +655,7 @@ def freeze_cart(
             "vat": cart_skel["vat"],
             "total_quantity": cart_skel["total_quantity"],
             "shipping": cart_skel["shipping"],
+            "discount": make_json_dumpable(cart_skel["discount"]),
         }
         cart_skel["is_frozen"] = True
         cart_skel.write()