Method deprecation helper

gistfile1.rb

module MethodDeprecator
  def self.included(base)
    base.extend(ClassMethods)
  end
  
  module ClassMethods
    def deprecate_method(method, replacement)
      class_eval <<-DEPRECATE_METHOD_END
        def #{method.to_s}_with_deprecation
          puts "WARNING: Deprecated method #{self.class}##{method.to_s} called, use #{replacement} instead.  Called from #{Kernel.caller[0]}"
          #{method.to_s}_without_deprecation
        end
        alias_method_chain :#{method.to_s}, :deprecation
      DEPRECATE_METHOD_END
    end
  end
end

The _with_deprecation method also needs to take in (*args, &block) and pass them through to the _without_deprecation version. Other than that, it looks fine to me.

Hmm... one other idea: should we instead make this into a core extension for Module? This way you won't need to explicitly include MethodDeprecator into the class (which is extra clutter).

I like the idea of making it a core extension. The original question was (not sure why it was deleted):

Because this method uses alias_method_chain the results from Kernerl.caller[0] are always the original method. For example, if you have a method foo and you deprecate it with this helper, and you call foo then foo ends up calling foo_with_deprecation, so Kernel.caller[0] returns foo which doesn't help you pinpoint the deprecation. Ideas?

Kernel.caller is the whole execution stack, isn't it? So you can use Kernel.caller[1] instead to get one level up.