JSFiddle - React, Tailwind, and code Playground

HTML

<div contentEditable="true" id="div"></div>

JavaScript

/* 
* Normal behaviour: Only "2" should be selected
* Bug in Opera: Space before "2" selects too
*/
$(function() {
    var el = $("#div");
   var _document =  el.parents("body").parent().parent()[0];
    var _window = _document.defaultView || _document.parentWindow;
    
    //Clear all content
    var contents = el.contents();
    for ( var i = 0; i < contents.length; i++ ) {
        $(contents[i]).remove();    
    }
      
    //Append to text nodes
    el.append($(_document.createTextNode("1 ")));
    el.append($(_document.createTextNode("2")));
    
    var rng = _document.createRange();
    //After space of first text node
    rng.setStart(el.contents()[0],2);
    //After 2 of second text node
    rng.setEnd(el.contents()[1],1);
    
    var sel = _window.getSelection();
    sel.removeAllRanges();
    sel.addRange(rng);
});