bulletproof.rb

class FooError < StandardError; end

module BulletProof
  
  def self.included(base)
    base.extend ClassMethods
  end
  
  # blatantly stolen: http://blog.codefront.net/2008/01/14/retrying-code-blocks-in-ruby-on-exceptions-whatever/
  def retryable(options = {}, &block)
    opts = { :tries => 1, :on => Exception }.merge(options)
    
    retry_exception, retries = opts[:on], opts[:tries]
    
    begin
      return yield
    rescue retry_exception => e
      puts "#{e.class}: #{e.message}"
      retry if (retries -= 1) > 0
      return
    end
    
    yield
  end
  
  module ClassMethods
    def bulletproof(*methods)
      opts = methods.last.is_a?(Hash) ? methods.pop : {}
      tries = opts[:tries] || 1
      
      methods.each do |method|
        define_method :"#{method}_with_bulletproof" do |*args|
          retryable(:tries => tries) do
            send :"#{method}_without_bulletproof", *args
          end
        end
        
        class_eval %Q{
          alias #{method}_without_bulletproof #{method}
          alias #{method} #{method}_with_bulletproof
        }
      end
    end
  end
  
end


class A
  
  include BulletProof
  
  def bar(a,b,c)
    raise FooError, 'bar'
  end
  def baz(a)
    raise 'baz'
  end
  bulletproof :bar, :baz, :tries => 2
  
  
end

a = A.new

a.bar(1,2,3)
a.baz(1)