PseudoColumns can mask columns with default values, useful when joining tables in ActiveRecord

pseudo_columns.rb

module PseudoColumns
  extend ActiveSupport::Concern

  module ClassMethods
    # Specify the columns in {name => default_value} format
    def pseudo_columns(columns = {})
      columns.each do |k, v|
        define_method(k) do
          attributes.fetch(__method__.to_s, v)
        end
      end
    end
  end
end