Domain name validator

app/models/domain.rb

@@ -5,6 +5,8 @@ class Domain < ActiveRecord::Base
   belongs_to :technical_contact, class_name: 'Contact'
   belongs_to :admin_contact, class_name: 'Contact'
 
+  validates :name, domain_name: true
+
   class << self
     def check_availability(domains)
       res = []

app/validators/domain_name_validator.rb

@@ -0,0 +1,10 @@
+class DomainNameValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    ok = value =~ /\A[a-zA-Z0-9][a-zA-Z0-9-]{0,61}[a-zA-Z0-9]\.ee\z/
+    ok &&= !(value[2] == '-' && value[3] == '-')
+
+    unless ok
+      record.errors[attribute] << (options[:message] || 'invalid format')
+    end
+  end
+end

config/initializers/load_validators.rb

@@ -0,0 +1 @@
+Dir[File.join(Rails.root, "app", "validators", "*.rb")].each {|x| require x }

spec/models/domain_spec.rb

@@ -10,5 +10,17 @@ describe Domain do
   it 'creates a resource' do
     d = Fabricate(:domain)
     expect(d.name).to_not be_nil
+
+    invalid = ['a.ee', "#{'a' * 64}.ee", 'ab.eu', 'test.ab.ee', '-test.ee', '-test-.ee', 'test-.ee', 'te--st.ee']
+
+    invalid.each do |x|
+      expect(Fabricate.build(:domain, name: x).valid?).to be false
+    end
+
+    valid = ['ab.ee', "#{'a' * 63}.ee", 'te-s-t.ee']
+
+    valid.each do |x|
+      expect(Fabricate.build(:domain, name: x).valid?).to be true
+    end
   end
 end