core_extensions.rb

class Object
  # Useage:
  # @user.name.or("blank")
  # if @user's name is nil or "", returns "blank", otherwise returns the name
  def or(value)
    (respond_to?(:empty?) ? empty? : !self) ? value : self
  end
end

core_extensions_test.rb

require File.dirname(__FILE__) + '/../test_helper'

class CoreExtensionsTest < ActiveSupport::TestCase
    
  context "or called on an object" do
    
    should "should return the object if not nil" do   
      assert_equal "something", "something".or("nothing")
      
      assert_equal [1,2], [1,2].or([3,4])
    end
    
    should "should return the alternative if nil or empty" do   
      assert_equal "nothing", nil.or("nothing")
      assert_equal "nothing", "".or("nothing")
      assert_equal [1,2], [].or([1,2])
    end

  end
  
end