LayoutTests/intersection-observer/intersection-observer-keeps-js-wrapper-of-target-alive.html - WebKit - Git at Google

 <!DOCTYPE html>
 <html>
 <body>
 <p>This tests that JS wrappers of targets enqueued to be delivered to an intersection observer do not get collected.</p>
 <pre id="log"></pre>
 <script src="../resources/gc.js"></script>
 <script>

 if (window.testRunner)
     testRunner.dumpAsText();

 const targetCount = 5;
 const iterationCount = 5;
 var deadCount = 0;

 async function runAll() {
     if (window.testRunner)
         testRunner.waitUntilDone();

     for (let i = 0; i < iterationCount; ++i) {
         runTest();
         gc();
         await new Promise((resolve) => requestAnimationFrame(resolve))
     }

     document.getElementById('log').textContent = (deadCount ? `FAIL - ${deadCount} targets lost JS wrappers` : 'PASS') + '\n';

     if (window.testRunner)
         testRunner.notifyDone();
 }

 function runTest() {
     document.querySelectorAll('div').forEach(target => { target.remove(); });

     for (let i = 0; i < targetCount; ++i) {
         let target = document.createElement('div');
         target.myState = 'live';
         document.body.appendChild(target);
     }

     document.querySelectorAll('div').forEach(target => { observer.observe(target); });
 }

 const observer = new IntersectionObserver(entries => {
     for (const entry of entries) {
         if (entry.target.myState != 'live')
             deadCount++;
     }
 });

 runAll();

 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<body>
	<p>This tests that JS wrappers of targets enqueued to be delivered to an intersection observer do not get collected.</p>
	<pre id="log"></pre>
	<script src="../resources/gc.js"></script>
	<script>

	if (window.testRunner)
	testRunner.dumpAsText();

	const targetCount = 5;
	const iterationCount = 5;
	var deadCount = 0;

	async function runAll() {
	if (window.testRunner)
	testRunner.waitUntilDone();

	for (let i = 0; i < iterationCount; ++i) {
	runTest();
	gc();
	await new Promise((resolve) => requestAnimationFrame(resolve))
	}

	document.getElementById('log').textContent = (deadCount ? `FAIL - ${deadCount} targets lost JS wrappers` : 'PASS') + '\n';

	if (window.testRunner)
	testRunner.notifyDone();
	}

	function runTest() {
	document.querySelectorAll('div').forEach(target => { target.remove(); });

	for (let i = 0; i < targetCount; ++i) {
	let target = document.createElement('div');
	target.myState = 'live';
	document.body.appendChild(target);
	}

	document.querySelectorAll('div').forEach(target => { observer.observe(target); });
	}

	const observer = new IntersectionObserver(entries => {
	for (const entry of entries) {
	if (entry.target.myState != 'live')
	deadCount++;
	}
	});

	runAll();

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