Add Registry model

#623

app/models/registrar.rb

@@ -99,7 +99,7 @@ class Registrar < ActiveRecord::Base
   # rubocop:disable Metrics/AbcSize
   def issue_prepayment_invoice(amount, description = nil)
     vat_rate = if local_vat_payer?
-                 Setting.registry_vat_prc
+                 Registry.instance.vat_rate
                else
                  if vat_no.blank?
                    self.vat_rate
@@ -114,7 +114,6 @@ class Registrar < ActiveRecord::Base
       payment_term: 'prepayment',
       description: description,
       currency: 'EUR',
-      vat_rate: Setting.registry_vat_prc,
       vat_rate: vat_rate,
       seller_name: Setting.registry_juridical_name,
       seller_reg_no: Setting.registry_reg_no,

app/models/registry.rb

@@ -0,0 +1,11 @@
+class Registry
+  include Singleton
+
+  def vat_rate
+    Setting.registry_vat_prc
+  end
+
+  def legal_address_country
+    Country.new(Setting.registry_country_code)
+  end
+end

config/application.rb

@@ -15,7 +15,7 @@ require 'rails/all'
 # you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 
-module Registry
+module DomainNameRegistry
   class Application < Rails::Application
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers

test/models/registry_test.rb

@@ -0,0 +1,16 @@
+require 'test_helper'
+
+class RegistryTest < ActiveSupport::TestCase
+  def setup
+    @registry = Registry.send(:new)
+  end
+
+  def test_implements_singleton
+    assert_equal Registry.instance.object_id, Registry.instance.object_id
+  end
+
+  def test_vat_rate
+    Setting.registry_vat_prc = 0.2
+    assert 0.2, @registry.vat_rate
+  end
+end