<!DOCTYPE html>
<meta charset=utf-8>
<title>Selector: pseudo-classes (:required, :optional)</title>
<link rel="author" title="Denis Ah-Kang" href="mailto:denis@w3.org" id=link1>
<link rel=help href="https://html.spec.whatwg.org/multipage/#pseudo-classes" id=link2>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="utils.js"></script>
<div id="log"></div>
<input type=text id=text1 value="foobar" required>
<input type=text id=text2 required>
<input type=text id=text3>
<select id=select1 required>
 <optgroup label="options" id=optgroup1>
   <option value="option1" id=option1>option1
</select>
<select id=select2>
 <optgroup label="options" id=optgroup2>
   <option value="option2" id=option2>option2
</select>
<textarea required id=textarea1>textarea1</textarea>
<textarea id=textarea2>textarea2</textarea>

<script>
  testSelectorIdsMatch(":required", ["text1", "text2", "select1", "textarea1"], "':required' matches required <input>s, <select>s and <textarea>s");
  testSelectorIdsMatch(":optional", ["text3", "select2", "textarea2"], "':optional' matches elements <input>s, <select>s and <textarea>s that are not required");

  document.getElementById("text1").removeAttribute("required");
  testSelectorIdsMatch(":required", ["text2", "select1", "textarea1"], "':required' doesn't match elements whose required attribute has been removed");
  testSelectorIdsMatch(":optional", ["text1", "text3", "select2", "textarea2"], "':optional' matches elements whose required attribute has been removed");

  document.getElementById("select2").setAttribute("required", "required");
  testSelectorIdsMatch(":required", ["text2", "select1", "select2", "textarea1"], "':required' matches elements whose required attribute has been added");
  testSelectorIdsMatch(":optional", ["text1", "text3", "textarea2"], "':optional' doesn't match elements whose required attribute has been added");
</script>
