text: 
  const highlightJs = require('highlight.js')
  
  const renderCode = defaultRenderer => (code, language, escaped) => {
  
      const isLanguageValid = !!(language && highlightJs.getLanguage(language))
  
      return isLanguageValid
          ? `<pre><code class="${language}">${highlightJs.highlight(code, { language }).value}</code></pre>`
          : defaultRenderer(code, language, escaped)
  }
  
  module.exports = renderCode
  