gistfile1.rbx

# Put in initializers
#
# Usage: 
# class Foo < ActiveRecord::Base
#   finds_by :bar
# end
# 
# foo = Foo.create(:bar => "omg")
# found = Foo.find "omg"
# assert_equal foo.id, found.id
#
class << ActiveRecord::Base
  def finds_by(field_name)
    eval %[
      class << self
        define_method :find_with_finds_by_#{field_name} do |*args|
          first = args.first
          if first.is_a?(String) && !(first =~ /^\d+$/)
            find_without_finds_by_#{field_name}(:first, :conditions => { "#{field_name}" => first} )
          else
            find_without_finds_by_#{field_name}(*args)
          end
        end
        alias_method_chain :find, :finds_by_#{field_name}
      end
    ]
  end
end