f.rb

module FunctionsHelper
  def render_code(ruby)
    CodeRender.new.render(ruby)
  end

  class CustomRender < Redcarpet::Render::HTML
      def codespan(code)
        CodeRender.new.render(code)
      end
  end

  def markdown(content)
    renderer = CustomRender.new({
      filter_html: true,
      escape_html: true,
      no_images: true,
      no_styles: true,
      safe_links_only: true,
      hard_wrap: true,
      prettify: true,
      fenced_code_blocks: false,
      disable_indented_code_blocks: false,
      link_attributes: { target: '_blank', rel: 'nofollow noopener' },
    })
    Redcarpet::Markdown.new(renderer).render(content).html_safe
  end
end