inject_alias_method_chain.rb

class Module
  # Use this to replace a method in an alias_method_chain
  def inject_alias_method_chain(target, method_to_replace, method_to_use)
    method_instance_to_replace = instance_method(method_to_replace)
    meths = (private_instance_methods | instance_methods).sort.grep(/^#{target}/)
    found = meths.detect do |m|
      m != method_to_replace.to_s && instance_method(m) == method_instance_to_replace
    end
    if found
      alias_method found, method_to_use
    end
  end
end