__FILE__ in JavaScript

__FILE__.js

/***  
 * This gist provides a __FILE__ variable, which holds the path to the file
 * from which the currently running source is being executed.
 *
 * Usage example: alert(__FILE__);
 *
 * Thanks to http://ejohn.org/blog/__file__-in-javascript/ on which this gist
 * is based on.
 *
 * Tested in Mozilla Firefox 9, Mozilla Firefox 16, Opera 12, Chromium 18
 */

(function(){
  this.__defineGetter__("__FILE__", function() {
    var stack=((new Error).stack).split("\n");

    if(stack[0]=="Error") { // Chromium
      var m;
      if(m=stack[2].match(/\((.*):[0-9]+:[0-9]+\)/))
	return m[1];
    }
    else { // Firefox, Opera
      return stack[1].split("@")[1].split(":").slice(0,-1).join(":");
    }
  });
})();

Simplified and shortened code: https://gist.github.com/BR0kEN-/8620537

One more version for nodejs, that will also not fail in REPL:

(function(){
  Object.defineProperty(globalThis, '__FILE__', { get() {
    return (new Error).stack.split('at file://')?.at(1)?.split(':')?.at(0)
  }})
})()