class Guard::PluginUtil

def add_to_guardfile
  klass = plugin_class # call here to avoid failing later
  require_relative "guardfile/evaluator"
  # TODO: move this to Generator?
  options = Guard.state.session.evaluator_options
  evaluator = Guardfile::Evaluator.new(options)
  begin
    evaluator.evaluate
  rescue Guard::Guardfile::Evaluator::NoPluginsError
  end
  if evaluator.guardfile_include?(name)
    UI.info "Guardfile already includes #{ name } guard"
  else
    content = File.read("Guardfile")
    File.open("Guardfile", "wb") do |f|
      f.puts(content)
      f.puts("")
      f.puts(klass.template(plugin_location))
    end
    UI.info INFO_ADDED_GUARD_TO_GUARDFILE % name
  end
end