var
  ol = document.getElementById('test-list'),
  sortedLis = [],
  lisIndex = [];
for(var i=0;i<ol.children.length;i++){
  lisIndex.push(i);
}

lisIndex.sort(function(x,y){
  return ol.children[x].innerText > ol.children[y].innerText ? 1 : -1;
});

for(var i=0;i<lisIndex.length;i++){
  sortedLis.push(ol.children[lisIndex[i]]);
}
for(var i=0;i<lisIndex.length;i++){
  ol.appendChild(sortedLis[i]);
}