Benchmark: MutationObserver: disconnect/reconnect vs. variable switch to avoid recursion

HTML Preparation code:

<div id="test">Test</div>

Script Preparation code:

const __OBSERVER = Symbol('observer');
const div = document.getElementById('test');

function update1() {
	if(!div[__OBSERVER]) {
		div[__OBSERVER] = new MutationObserver(mutations => update1());
	} else {
		div[__OBSERVER].disconnect();
	}

	div.style.opacity = parseInt(div.style.opacity) ? 0 : 1;

	div[__OBSERVER].observe(div, { attributeFilter: ['style'] });
}

function update2() {
	if(!div[__OBSERVER]) {
		div[__OBSERVER] = new MutationObserver(mutations => update2());
	} else {
		div[__OBSERVER].disconnect();
	}

	div.style.opacity = parseInt(div.style.opacity) ? 0 : 1;

	div[__OBSERVER].observe(div, { attributeFilter: ['style'] });
	div[__OBSERVER].observe(div, { characterData: true, subtree: true });
}

Tests:

disconnect/reconnect with 1 observe
update1();
disconnect/reconnect with 2 observes
update2();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
disconnect/reconnect with 1 observe
disconnect/reconnect with 2 observes

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36

Browser/OS: Chrome 142 on Mac OS X 10.15.7

View result in a separate tab

disconnect/reconnect with 1 observe

1.4M/s

disconnect/reconnect with 2 observes

1.1M/s

View exact numbers

Test name	Executions per second
✓ disconnect/reconnect with 1 observe	1,352,938 Ops/sec
disconnect/reconnect with 2 observes	1,073,668 Ops/sec

MutationObserver: disconnect/reconnect vs. variable switch to avoid recursion (version: 3)

Comparing performance of: `disconnect/reconnect with 1 observe vs disconnect/reconnect with 2 observes`

Created: one year ago by: Registered User

Go to the latest result

disconnect/reconnect with 1 observe

disconnect/reconnect with 2 observes

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

MutationObserver: disconnect/reconnect vs. variable switch to avoid recursion (version: 3)

Comparing performance of: disconnect/reconnect with 1 observe vs disconnect/reconnect with 2 observes

Created: one year ago by: Registered User

Go to the latest result

disconnect/reconnect with 1 observe

disconnect/reconnect with 2 observes

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `disconnect/reconnect with 1 observe vs disconnect/reconnect with 2 observes`