Merge branch 'main' into jam-test

Author: dakshina99

.DS_Store

@@ -12,6 +12,8 @@ def validorder(order: Order):
             net += item.amount
         elif item.type == "product":
             net -= item.amount * item.quantity
+        elif item.type == "shipping":
+            net -= item.amount
         else:
             return "Invalid item type: %s" % item.type