module FlashHelper
  DEFAULT_MAPPING = {
    :notice => :info,
    :alert => :danger,
    :error => :danger,
  }

  def flash_messages
    messages =
      flash.map do |type, message|
        content_tag(:div, message, class: "alert alert-#{DEFAULT_MAPPING[type.to_sym] || type}", role: "alert")
      end
     safe_join(messages, "\n")
  end
end