Create node list from a single node in JavaScript

This is one of those it seems so simple, but I cannot come up with a good way to go about it.

I have a node, maybe nodelist = document.getElementById("mydiv"); - I need to normalize this to a node list. And not an array either: an actual, bona-fide nodeList object.

Not nodelist = [document.getElementById("mydiv")];

No libraries, please.

Reviving this because I recently remembered something about JavaScript. This depends on how the NodeList is being checked, but..

const singleNode = ((nodeList) => (node) => {
  const layer = { // define our specific case
    0: { value: node, enumerable: true },
    length: { value: 1 },
    item: {
      value(i) {
        return this[+i || 0];
      }, 
      enumerable: true,
    },
  };
  return Object.create(nodeList, layer); // put our case on top of true NodeList
})(document.createDocumentFragment().childNodes); // scope a true NodeList

Now, if you do

const list = singleNode(document.body); // for example

list instanceof NodeList; // true
list.constructor === NodeList; // true

and list has properties length 1 and 0 as your node, as well as anything inherited from NodeList.

If you can't use Object.create, you could do the same except as a constructor with prototype nodelist and set this['0'] = node;, this['length'] = 1; and create with new.

ES5 version

var singleNode = (function () {
    // make an empty node list to inherit from
    var nodelist = document.createDocumentFragment().childNodes;
    // return a function to create object formed as desired
    return function (node) {
        return Object.create(nodelist, {
            '0': {value: node, enumerable: true},
            'length': {value: 1},
            'item': {
                "value": function (i) {
                    return this[+i || 0];
                }, 
                enumerable: true
            }
        }); // return an object pretending to be a NodeList
    };
}());