Use Estonian reference number format instead of ISO 11649

test/models/billing/reference_no/base_test.rb

@@ -0,0 +1,29 @@
+require 'test_helper'
+
+# https://www.pangaliit.ee/settlements-and-standards/reference-number-of-the-invoice
+class ReferenceNoBaseTest < ActiveSupport::TestCase
+  def test_generates_random_base
+    assert_not_equal Billing::ReferenceNo::Base.generate, Billing::ReferenceNo::Base.generate
+  end
+
+  def test_randomly_generated_base_conforms_to_standard
+    base = Billing::ReferenceNo::Base.generate
+    format = /\A\d{1,19}\z/
+    assert_match format, base.to_s
+  end
+
+  def test_generates_check_digit_for_a_given_base
+    assert_equal 3, Billing::ReferenceNo::Base.new('1').check_digit
+    assert_equal 7, Billing::ReferenceNo::Base.new('1234567891234567891').check_digit
+  end
+
+  def test_returns_string_representation
+    base = Billing::ReferenceNo::Base.new('1')
+    assert_equal '1', base.to_s
+  end
+
+  def test_normalizes_non_string_values
+    base = Billing::ReferenceNo::Base.new(1)
+    assert_equal '1', base.to_s
+  end
+end

test/models/billing/reference_no_test.rb

@@ -0,0 +1,13 @@
+require 'test_helper'
+
+class ReferenceNoTest < ActiveSupport::TestCase
+  def test_returns_format_regexp
+    format = /\A\d{2,20}\z/
+    assert_equal format, Billing::ReferenceNo::REGEXP
+  end
+
+  def test_generated_reference_number_conforms_to_format
+    reference_no = Billing::ReferenceNo.generate
+    assert_match Billing::ReferenceNo::REGEXP, reference_no
+  end
+end

test/models/registrar_test.rb

@@ -6,7 +6,7 @@ class RegistrarTest < ActiveSupport::TestCase
   end
 
   def test_valid
-    assert @registrar.valid?
+    assert @registrar.valid?, proc { @registrar.errors.full_messages }
   end
 
   def test_invalid_without_name
@@ -55,8 +55,28 @@ class RegistrarTest < ActiveSupport::TestCase
     assert_equal 'Main Street, New York, New York, 12345', @registrar.address
   end
 
-  def test_reference_number_generation
-    @registrar.validate
-    refute_empty @registrar.reference_no
+  def test_validates_reference_number_format
+    @registrar.reference_no = '1'
+    assert @registrar.invalid?
+
+    @registrar.reference_no = '11'
+    assert @registrar.valid?
+
+    @registrar.reference_no = '1' * 20
+    assert @registrar.valid?
+
+    @registrar.reference_no = '1' * 21
+    assert @registrar.invalid?
+
+    @registrar.reference_no = '1a'
+    assert @registrar.invalid?
+  end
+
+  def test_disallows_non_unique_reference_numbers
+    registrars(:bestnames).update!(reference_no: '1234')
+
+    assert_raises ActiveRecord::RecordNotUnique do
+      registrars(:goodnames).update!(reference_no: '1234')
+    end
   end
 end