class Chef::Knife::RoleRunListReplace

def replace_in_env_run_list(role, environment, old_entry, new_entry)
  nlist = []
  role.run_list_for(environment).each do |entry|
    if entry == old_entry
      nlist << new_entry
    else
      nlist << entry
    end
  end
  role.env_run_lists_add(environment => nlist)
end

def run
  role = Chef::Role.load(@name_args[0])
  role.name(@name_args[0])
  environment = "_default"
  old_entry = @name_args[1]
  new_entry = @name_args[2]
  replace_in_env_run_list(role, environment, old_entry, new_entry)
  role.save
  config[:env_run_list] = true
  output(format_for_display(role))
end