Refactor registrars

#765

test/models/registrar/code_test.rb

@@ -0,0 +1,29 @@
+require 'test_helper'
+
+class RegistrarCodeTest < ActiveSupport::TestCase
+  def setup
+    @registrar = registrars(:bestnames).dup
+  end
+
+  def test_registrar_is_invalid_without_code
+    @registrar.code = ''
+    assert @registrar.invalid?
+  end
+
+  def test_special_code_validation
+    @registrar.code = 'CID'
+    assert @registrar.invalid?
+    assert_includes @registrar.errors.full_messages, 'Code is forbidden'
+  end
+
+  def test_cannot_be_changed_once_registrar_is_created
+    registrar = registrars(:bestnames)
+    registrar.update!(code: 'new-code')
+    refute_equal 'new-code', registrar.code
+  end
+
+  def test_normalization
+    @registrar.code = 'with spaces:and:colon.'
+    assert_equal 'WITHSPACESANDCOLON.', @registrar.code
+  end
+end