Implement this: WithFallbackConcern

sample.rb

# frozen_string_literal: true

FactoryBot.define do
  factory :sample do
    identifier { SecureRandom.uuid }
    traceability_sample { 'AA123456789' }
    traceability_batch { nil }
  end
end

sample_spec.rb

# frozen_string_literal: true

require 'rails_helper'

describe Sample, type: :model do
  let(:sample) { FactoryBot.build(:sample) }

  context '#with_fallback' do
    it 'has a functional with_fallback methods' do
      expect(sample).to respond_to(:traceability_sample)
      expect(sample.traceability_sample).to eq('AA123456789')

      expect(sample).to respond_to(:traceability_batch)
      expect(sample.traceability_batch).to be_nil

      expect(sample).not_to respond_to(:traceability_license)

      expect(
        sample.with_fallback(
          :traceability_license,
          :traceability_batch,
          :traceability_sample
        )
      ).to eq('AA123456789')
    end
  end
end

with_fallback_concern.rb

# frozen_string_literal: true
#
# Implement #with_fallback to use this as 
# obj.with_fallback(meth_1, meth_2, ...)
# where the first valid method that does not
# return nil is returned
# sample.traceability_sample => "AA123456789"
# sample.traceability_batch => nil
# sample.traceability_license => NoMethodError
# sample.with_fallback(:traceability_sample, :traceability_batch, :traceability_license) => "AA123456789"
#
module WithFallbackConcern
  extend ActiveSupport::Concern

  def with_fallback
    raise StandardError, 'not implemented'
  end
end