<!DOCTYPE html> <style> #root { background-color: #ddd; font-size: 24pt; position: relative; width: 200px; } .flexbox { display: flex; } .flexbox * { width: 100px; } </style> This test verifies that a selection spanning nested flexbox boundaries is drawn correctly. <div id="root"> <div class="flexbox"> <span id="start">aaa</span> <div class="flexbox"><span>bbb</span></div> </div> <div class="flexbox"> <span>ccc</span> <div class="flexbox"><span id="end">ddd</span></div> </div> </div> <script> var start = document.querySelector('#start'), end = document.querySelector('#end'); getSelection().setBaseAndExtent(start.firstChild, 1, end.firstChild, 2); focus(); </script>