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

 <!DOCTYPE html><!-- webkit-test-runner [ experimental:ResizeObserverEnabled=true ] -->
 <html>
 <body>
 <p>This tests that JS wrappers of targets in an ResizeObserverEntry 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 = 10;

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

     return new Promise((resolve) => {
         const observer = new ResizeObserver(entries => {
             resolve(entries);
             observer.disconnect();
         });
         document.querySelectorAll('div').forEach(target => observer.observe(target));
     });
 }

 function check(entries) {
     let deadCount = 0;
     for (const entry of entries) {
         if (entry.target.myState != 'live')
             deadCount++;
     }
     document.getElementById('log').textContent += (deadCount ? `FAIL - ${deadCount} targets lost JS wrappers` : 'PASS') + '\n';
 }

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

     for (let j = 0; j < iterationCount; ++j) {
         const entries = await observe();
         document.querySelectorAll('div').forEach(target => target.remove());
         await Promise.resolve();
         gc();
         check(entries);
     }

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

 runAll();

 </script>
 </body>
 </html>
	<!DOCTYPE html><!-- webkit-test-runner [ experimental:ResizeObserverEnabled=true ] -->
	<html>
	<body>
	<p>This tests that JS wrappers of targets in an ResizeObserverEntry 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 = 10;

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

	return new Promise((resolve) => {
	const observer = new ResizeObserver(entries => {
	resolve(entries);
	observer.disconnect();
	});
	document.querySelectorAll('div').forEach(target => observer.observe(target));
	});
	}

	function check(entries) {
	let deadCount = 0;
	for (const entry of entries) {
	if (entry.target.myState != 'live')
	deadCount++;
	}
	document.getElementById('log').textContent += (deadCount ? `FAIL - ${deadCount} targets lost JS wrappers` : 'PASS') + '\n';
	}

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

	for (let j = 0; j < iterationCount; ++j) {
	const entries = await observe();
	document.querySelectorAll('div').forEach(target => target.remove());
	await Promise.resolve();
	gc();
	check(entries);
	}

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

	runAll();

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