A helper method to simplify deprecations.

deprecation_helpers.rb

module DeprecationHelpers
  def deprecated_in_favor_of(new_method_name)
    warning = "[DEPRECATION] '##{deprecated_method_name}' "
    warning << "has been deprecated.\n"
    warning << "Please use '##{new_method_name.to_s}' instead."
    logger.warn(warning)
  end
      
  protected
  def deprecated_method_name
    /`(.*)'/.match(caller[1]).captures[0].to_sym rescue nil
  end 
end 

deprecation_helpers_test.rb

require File.dirname(__FILE__) + '/../../test_helper'              
require 'deprecation_helpers' 
    
class DeprecationHelpersTest < ActiveSupport::TestCase             
  include DeprecationHelpers
  context "#deprecated_in_favor_of" do                             
    setup do                                                       
      def foo                                                      
        deprecated_in_favor_of(:bar)                               
      end
    end
    should "log a deprecation warning" do                          
      logger.expects(:warn).with(includes("[DEPRECATION]"))        
      foo
    end
    should "include the name of the deprecated method" do
      logger.expects(:warn).with(includes("foo"))
      foo
    end
    should "include the name of the new method if one exists" do
      logger.expects(:warn).with(includes("bar"))
      foo
    end
  end
end