Add helper to display total tax on an order

app/helpers/checkout_helper.rb

@@ -18,20 +18,24 @@ module CheckoutHelper
   end
 
   def display_checkout_admin_and_handling_adjustments_total_for(order)
-    adjustments = order.adjustments.eligible.where('originator_type = ? AND source_type != ? ', 'EnterpriseFee',  'Spree::LineItem' )
-    Spree::Money.new( adjustments.sum( &:amount ) , { :currency => order.currency })
+    adjustments = order.adjustments.eligible.where('originator_type = ? AND source_type != ? ', 'EnterpriseFee', 'Spree::LineItem')
+    Spree::Money.new adjustments.sum(&:amount) , currency: order.currency
   end
 
   def checkout_line_item_adjustments(order)
-    order.adjustments.eligible.where( source_type: "Spree::LineItem")
+    order.adjustments.eligible.where(source_type: "Spree::LineItem")
   end
 
   def checkout_subtotal(order)
-    order.item_total + checkout_line_item_adjustments(order).sum( &:amount )
+    order.item_total + checkout_line_item_adjustments(order).sum(&:amount)
   end
 
   def display_checkout_subtotal(order)
-    Spree::Money.new( checkout_subtotal(order) , { :currency => order.currency })
+    Spree::Money.new checkout_subtotal(order) , currency: order.currency
+  end
+
+  def display_checkout_tax_total(order)
+    Spree::Money.new order.total_tax, currency: order.currency
   end
 
   def checkout_state_options(source_address)

spec/helpers/checkout_helper_spec.rb

@@ -12,4 +12,12 @@ describe CheckoutHelper do
 
     helper.validated_input("test", "foo", type: :email)
   end
+
+  describe "displaying the tax total for an order" do
+    let(:order) { double(:order, total_tax: 123.45, currency: 'AUD') }
+
+    it "retrieves the total tax on the order" do
+      helper.display_checkout_tax_total(order).should == Spree::Money.new(123.45, currency: 'AUD')
+    end
+  end
 end