mapping_test.rb

class MappingTest
  MAPPING = {
    passengers: ->(hash) { hash[:customer_info][:person_name] },
    flight_ticket_selling_carrier: :extract_services,
  }
  
  def results
    response = api_call
    res = {}
    MAPPING.each do |attribute, extraction|
      res[attribute] = if extraction.respond_to?(:call)
                         extraction.call(response) # call proc or lambda
                       else
                         send(response) # call method defined on the class
                       end
    end
    res
  end
end