LayoutTests/fast/forms/elements-invalidate-on-form-attribute-invalidation.html - WebKit - Git at Google

 <!DOCTYPE html>
 <html>
 <body>
 <div id="container">
 <form id="someForm"></form>
 <input type="text" name="someName" form="someForm">
 </div>
 <script src="../../resources/js-test-pre.js"></script>
 <script>

 description("Tests form.elements is invalidated when input element's form attribute is changed.");

 var input = document.querySelector('input');
 var collection;
 evalAndLog("collection = document.getElementById('someForm').elements;");
 shouldBe("collection.length", "1");
 shouldBe("collection.length; input.setAttribute('form', 'otherForm'); collection.length", "0");
 shouldBe("collection.length; input.setAttribute('form', 'someForm'); collection.length", "1");

 container.style.display = 'none';

 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<body>
	<div id="container">
	<form id="someForm"></form>
	<input type="text" name="someName" form="someForm">
	</div>
	<script src="../../resources/js-test-pre.js"></script>
	<script>

	description("Tests form.elements is invalidated when input element's form attribute is changed.");

	var input = document.querySelector('input');
	var collection;
	evalAndLog("collection = document.getElementById('someForm').elements;");
	shouldBe("collection.length", "1");
	shouldBe("collection.length; input.setAttribute('form', 'otherForm'); collection.length", "0");
	shouldBe("collection.length; input.setAttribute('form', 'someForm'); collection.length", "1");

	container.style.display = 'none';

	</script>
	</body>
	</html>