add models and unit test

app/models/pega_table.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class PegaTable < ApplicationRecord
+  # Validate presence of essential fields
+  validates :uuid, presence: true
+  validates :veteranfirstname, presence: true
+  validates :veteranlastname, presence: true
+  validates :response, presence: true
+
+  validate :validate_response_format
+
+  private
+
+  def validate_response_format
+    return if response.blank?
+
+    response_hash = JSON.parse(response)
+    unless response_hash['status'].present? && [200, 403, 500].include?(response_hash['status'].to_i)
+      errors.add(:response, 'must contain a valid HTTP status code (200, 403, 500)')
+    end
+  rescue JSON::ParserError
+    errors.add(:response, 'must be a valid JSON format')
+  end
+end

spec/factories/pega_tables.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :pega_table do
+    uuid { 'c47bec59-02c7-43e4-a0f7-acf287a32a97' }
+    veteranfirstname { 'John' }
+    veteranlastname { 'Doe' }
+
+    trait :with_valid_response do
+      response { '{"status": 200}' }
+    end
+
+    trait :with_invalid_response do
+      response { '{"status": 400}' }
+    end
+
+    trait :with_invalid_json_response do
+      response { 'invalid_json' }
+    end
+  end
+end

spec/models/pega_table_spec.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe PegaTable, type: :model do
+  describe 'validations' do
+    it { is_expected.to validate_presence_of(:uuid) }
+    it { is_expected.to validate_presence_of(:veteranfirstname) }
+    it { is_expected.to validate_presence_of(:veteranlastname) }
+    it { is_expected.to validate_presence_of(:response) }
+
+    context 'custom validations' do
+      it 'ensures response contains a valid HTTP status code' do
+        # Test case for valid status code (200)
+        pega_table = build(:pega_table, :with_valid_response)
+        expect(pega_table).to be_valid
+
+        # Test case for invalid status code (400)
+        pega_table = build(:pega_table, :with_invalid_response)
+        pega_table.valid?
+        expect(pega_table.errors[:response]).to include('must contain a valid HTTP status code (200, 403, 500)')
+
+        # Test case for invalid JSON format
+        pega_table = build(:pega_table, :with_invalid_json_response)
+        pega_table.valid?
+        expect(pega_table.errors[:response]).to include('must be a valid JSON format')
+      end
+    end
+  end
+end