fix: remove unnecessary function

lib/store/inventory.ex

@@ -344,7 +344,7 @@ defmodule Store.Inventory do
   alias Store.Accounts.User
 
   def purchase(%User{} = user, %Product{} = product, product_params) do
-    order = get_user_draft_order(user)
+    order = get_order_draft_by_id(user.id, preloads: [:user, :products])
 
     case order do
       %Order{} ->
@@ -355,13 +355,6 @@ defmodule Store.Inventory do
     end
   end
 
-  defp get_user_draft_order(user) do
-    Order
-    |> where(user_id: ^user.id, status: :draft)
-    |> Repo.one()
-    |> Repo.preload([:user, :products])
-  end
-
   defp handle_existing_order(order, product, product_params) do
     quantity = String.to_integer(product_params["quantity"])
 
@@ -606,8 +599,7 @@ defmodule Store.Inventory do
 
   def get_order_draft_by_id(user_id, opts) when is_list(opts) do
     Order
-    |> where(user_id: ^user_id)
-    |> where(status: :draft)
+    |> where(user_id: ^user_id, status: :draft)
     |> Repo.one()
     |> apply_filters(opts)
   end