LayoutTests/intersection-observer/intersection-observer-callback-leak.html - WebKit - Git at Google

 <!DOCTYPE html><!-- webkit-test-runner [ IntersectionObserverEnabled=true ] -->
 <html>

 <head>
     <script src="../resources/testharness.js"></script>
     <script src="../resources/testharnessreport.js"></script>
     <script src="../resources/gc.js"></script>
 </head>

 <body>
     <div id="container"></div>
     <script>
         function accessToObserverInCallback() {
             let test = async_test("test: Nodes inside callback should be garbage collected if no one refers to it");
             let initialNodesCount = internals.numberOfLiveNodes(document);
             const iterationCount = 50;
             let callbackCount = 0;
             for (let j = 0; j < iterationCount; ++j) {
                 const div = document.createElement('div');
                 container.appendChild(div);
                 let observer = new IntersectionObserver(() => {
                     callbackCount++;
                     observer.disconnect();
                     container.removeChild(div);
                     if (callbackCount == iterationCount) {
                         window.requestAnimationFrame(() => {
                             gc();
                             test.step(() => {
                                 let additionalNodesCount = internals.numberOfLiveNodes(document) - initialNodesCount;
                                 assert_true(additionalNodesCount < iterationCount, 'Nodes inside callback should be collected.');
                                 test.done();
                             });
                         });
                     }
                 });
                 observer.observe(div);
             }
         }

         window.onload = accessToObserverInCallback();
     </script>

 </body>

 </html>
	<!DOCTYPE html><!-- webkit-test-runner [ IntersectionObserverEnabled=true ] -->
	<html>

	<head>
	<script src="../resources/testharness.js"></script>
	<script src="../resources/testharnessreport.js"></script>
	<script src="../resources/gc.js"></script>
	</head>

	<body>
	<div id="container"></div>
	<script>
	function accessToObserverInCallback() {
	let test = async_test("test: Nodes inside callback should be garbage collected if no one refers to it");
	let initialNodesCount = internals.numberOfLiveNodes(document);
	const iterationCount = 50;
	let callbackCount = 0;
	for (let j = 0; j < iterationCount; ++j) {
	const div = document.createElement('div');
	container.appendChild(div);
	let observer = new IntersectionObserver(() => {
	callbackCount++;
	observer.disconnect();
	container.removeChild(div);
	if (callbackCount == iterationCount) {
	window.requestAnimationFrame(() => {
	gc();
	test.step(() => {
	let additionalNodesCount = internals.numberOfLiveNodes(document) - initialNodesCount;
	assert_true(additionalNodesCount < iterationCount, 'Nodes inside callback should be collected.');
	test.done();
	});
	});
	}
	});
	observer.observe(div);
	}
	}

	window.onload = accessToObserverInCallback();
	</script>

	</body>

	</html>