# File lib/brakeman/scanner.rb, line 159
  def guess_rails_version
    unless tracker.options[:rails3] or tracker.options[:rails4]
      if @app_tree.exists?("script/rails")
        tracker.options[:rails3] = true
        Brakeman.notify "[Notice] Detected Rails 3 application"
      elsif @app_tree.exists?("app/channels")
        tracker.options[:rails3] = true
        tracker.options[:rails4] = true
        tracker.options[:rails5] = true
        Brakeman.notify "[Notice] Detected Rails 5 application"
      elsif not @app_tree.exists?("script")
        tracker.options[:rails3] = true
        tracker.options[:rails4] = true
        Brakeman.notify "[Notice] Detected Rails 4 application"
      end
    end
  end