currentScript.js

// document.currentScript polyfill by Adam Miller

// MIT license

(function(document){
  var currentScript = "currentScript",
      scripts = document.getElementsByTagName('script'); // Live NodeList collection

  // If browser needs currentScript polyfill, add get currentScript() to the document object
  if (!(currentScript in document)) {
    Object.defineProperty(document, currentScript, {
      get: function(){

        // IE 6-10 supports script readyState
        // IE 10+ support stack trace
        try { throw new Error(); }
        catch (err) {

          // Find the second match for the "at" string to get file src url from stack.
          // Specifically works with the format of stack traces in IE.
          var i, res = ((/.*at [^\(]*\((.*):.+:.+\)$/ig).exec(err.stack) || [false])[1];

          // For all scripts on the page, if src matches or if ready state is interactive, return the script tag
          for(i in scripts){
            if(scripts[i].src == res || scripts[i].readyState == "interactive"){
              return scripts[i];
            }
          }

          // If no match, return null
          return null;
        }
      }
    });
  }
})(document);