Improve failed_checkout_spec by making calculator decorator line_items_for work with new Stock::Package

app/models/spree/calculator_decorator.rb

@@ -1,7 +1,6 @@
 module Spree
   Calculator.class_eval do
 
-
     private
 
     # Given an object which might be an Order or a LineItem (amongst
@@ -9,10 +8,11 @@ module Spree
     def line_items_for(object)
       if object.respond_to? :line_items
         object.line_items
+      elsif object.respond_to? :order
+        object.order.line_items
       else
         [object]
       end
     end
-
   end
 end

spec/models/spree/calculator/flat_percent_item_total_spec.rb

@@ -6,11 +6,18 @@ describe Spree::Calculator::FlatPercentItemTotal do
 
   before { calculator.stub :preferred_flat_percent => 10 }
 
-  it "should compute amount correctly for a single line item" do
+  it "computes amount correctly for a single line item" do
     calculator.compute(line_item).should == 1.0
   end
 
   context "extends LocalizedNumber" do
     it_behaves_like "a model using the LocalizedNumber module", [:preferred_flat_percent]
   end
+
+  it "computes amount correctly for a given Stock::Package" do
+    order = double(:order, line_items: [line_item] )
+    package = double(:package, order: order)
+
+    calculator.compute(package).should == 1.0
+  end
 end