add string presence type for optional unique columns

app/models/employee.rb

@@ -22,6 +22,9 @@
 class Employee < ApplicationRecord
   include ActsAsLoginable
 
+  attribute :inn, :string_presence
+  attribute :passport_number, :string_presence
+
   validates :first_name, :last_name, presence: true
   validates :inn, :passport_number, uniqueness: true, allow_blank: true
 

app/models/student.rb

@@ -24,6 +24,10 @@
 class Student < ApplicationRecord
   include ActsAsLoginable
 
+  attribute :inn, :string_presence
+  attribute :passport_number, :string_presence
+  attribute :ticket_number, :string_presence
+
   validates :first_name, :last_name, presence: true
   validates :inn, :passport_number, :ticket_number, uniqueness: true, allow_blank: true
 

config/initializers/active_record.rb

@@ -0,0 +1 @@
+require 'custom_types/string_presence_type'

lib/custom_types/string_presence_type.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+class StringPresenceType < ActiveRecord::Type::String
+  def cast_value(value)
+    value = value.presence if value.is_a?(String)
+    super(value)
+  end
+end
+
+ActiveRecord::Type.register :string_presence, StringPresenceType

spec/models/employee_spec.rb

@@ -56,6 +56,20 @@
     include_examples :changes_records_count_of, described_class, by: 1
     include_examples :changes_records_count_of, LoginRecord, by: 1
 
+    context 'with inn and passport_number as empty strings' do
+      let(:create_params) do
+        super().merge inn: '', passport_number: ''
+      end
+
+      include_examples :creates_record do
+        let(:expected_record_attrs) do
+          create_params.except(:login_record).merge(inn: nil, passport_number: '', allowed_services: match_array([1, 2]))
+        end
+      end
+      include_examples :changes_records_count_of, described_class, by: 1
+      include_examples :changes_records_count_of, LoginRecord, by: 1
+    end
+
     context 'with optional attributes' do
       let(:create_params) do
         super().merge middle_name: 'Jamesovich',

spec/models/student_spec.rb

@@ -56,6 +56,25 @@
     include_examples :changes_records_count_of, described_class, by: 1
     include_examples :changes_records_count_of, LoginRecord, by: 1
 
+    context 'with inn, ticket_number and passport_number as empty strings' do
+      let(:create_params) do
+        super().merge inn: '', passport_number: '', ticket_number: ''
+      end
+
+      include_examples :creates_record do
+        let(:expected_record_attrs) do
+          create_params.except(:login_record).merge(
+            inn: nil,
+            passport_number: '',
+            ticket_number: '',
+            allowed_services: match_array([1, 2])
+          )
+        end
+      end
+      include_examples :changes_records_count_of, described_class, by: 1
+      include_examples :changes_records_count_of, LoginRecord, by: 1
+    end
+
     context 'with optional attributes' do
       let(:create_params) do
         super().merge middle_name: 'Jamesovich',