JSFiddle - React, Tailwind, and code Playground

HTML

<input id="test" type="text" value="some text" />

JavaScript

function setSelectionRange(input, selectionStart, selectionEnd) {
  if (input.setSelectionRange) {
    input.focus();
    input.setSelectionRange(selectionStart, selectionEnd);
  }
  else if (input.createTextRange) {
    var range = input.createTextRange();
    range.collapse(true);
    range.moveEnd('character', selectionEnd);
    range.moveStart('character', selectionStart);
    range.select();
  }
}

function setCaretToPos (input, pos) {
  setSelectionRange(input, pos, pos);
}

function getCaretPos(input) {
    // Internet Explorer Caret Position (TextArea)
    if (document.selection && document.selection.createRange) {
        var range = document.selection.createRange();
        var bookmark = range.getBookmark();
        var caret_pos = bookmark.charCodeAt(2) - 2;
    } else {
        // Firefox Caret Position (TextArea)
        if (input.setSelectionRange)
            var caret_pos = input.selectionStart;
    }

    return caret_pos;
}

setCaretToPos(document.getElementById("test"), 2);
alert(getCaretPos(test));