Cover alternative invoice template with specs

spec/services/invoice_renderer_spec.rb

@@ -3,13 +3,18 @@ require 'spec_helper'
 describe InvoiceRenderer do
   let(:service) { described_class.new }
 
-  it "creates a PDF invoice" do
+  it "creates a PDF invoice with two different templates" do
     order = create(:completed_order_with_fees)
     order.bill_address = order.ship_address
     order.save!
 
     result = service.render_to_string(order)
-
     expect(result).to match /^%PDF/
+
+    allow(Spree::Config).to receive(:invoice_style2?).and_return true
+
+    alternative = service.render_to_string(order)
+    expect(alternative).to match /^%PDF/
+    expect(alternative).to_not eq result
   end
 end