Override ActionView::Renderer to inject view template/partial names into the HTML.

renderer.rb

module ActionView
  class Renderer
    def render(context, options)
      Rails.logger.info options.inspect

      result = if options.key?(:partial)
        render_partial(context, options)
      else
        render_template(context, options)
      end

      result + "#{options}"
    end
  end
end

You'll probably need to add some logic here to ignore things like the layout, but this will output the options hash at the end of each template that is rendered.

It also prints out the hash in the console so you can see what it's like.