transaction.rb

class Transaction
  attr_accessor :amount, :success
  
  def initialize(amount, success)
    @amount  = amount
    @success = success
  end
  
  def success?
    @success
  end
  
  def to_money
    if success?
      a = amount
      a.to_f / 100
    else
      0
    end
  end
  
  def self.credit(amount, success)
    new(-amount, success)
  end
end