Script-injected "async scripts" considered harmful
What if you stick this as the first thing in your body:<p><pre><code>  <iframe src="/file.js" style="display:none">
</code></pre>
And then at the very end of the body tag:<p><pre><code>  <script src="/file.js"></script>
</code></pre>
Wont that allow us to start a non-blocking fetch of the script early, but then execute it later? I assume it wont be fetched twice. Especially if you send future Expires headers.