code: function normalize(path) {
    var last = path.length - 1
    var lastC = path.charCodeAt(last)
  
    // If the uri ends with `#`, just return it without '#'
    if (lastC === 35 /* "#" */) {
      return path.substring(0, last)
    }
  
    return (path.substring(last - 2) === ".js" ||
        path.indexOf("?") > 0 ||
        lastC === 47 /* "/" */) ? path : path + ".js"
  }
docs: Normalize an id normalize("path/to/a") ==> "path/to/a.js" NOTICE: substring is faster than negative slice and RegExp