<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <script>
      var sendMessage = `require('electron').ipcRenderer.send('answer', 'extension loaded')`
      window.chrome.devtools.inspectedWindow.eval(sendMessage, function () {})
    </script>
  </head>
  <body>
    a custom devtools extension
  </body>
</html>