Demo of `document.currentScript` polyfill

HTML

<script src="https://rawgit.com/JamesMGreene/fb4a71e060da6e26511d/raw/76893c67ea3a88ef2eeefc5daecbff64c2d9aa63/document.currentScript.js"></script>
<script src="https://rawgit.com/JamesMGreene/79c0cbb29addd5eefd14/raw/2e2e5382097f2ca65bfde4f1c2738206408831dc/test.js"></script>
<!doctype html>
<html>
  <head>
    <title>currentScript Example</title>
    <script type="text/javascript" id="mainscript" async>
    debugger
			console.log(document.currentScript);
      if (document.currentScript.async) {
        console.log("Executing asynchronously");
      } else {
        console.log("Executing synchronously");
      }

    </script>
  </head>
  
  <body>
    <p>Demonstration of <code>beforescriptexecute</code> and
    <code>afterscriptexecute</code>.</p>
    <h3>Output</h3>
    <ul id="output">
    </ul>
  </body>
  
</html>

JavaScript

/*
Polyfill script:

https://github.com/JamesMGreene/document.currentScript

*/