Svelte 5: Logging a proxy in an `$effect` causes it to fire on any mutation

[brunnerh]

Describe the bug

In #13142 logic was added that snapshots state proxies for logging.
The state is deeply evaluated without untrack which can lead to different $effect behavior in dev.

(Promoted my comment to an issue so it's not lost)

Reproduction

<script>
	let count = $state({ value: 0 });

	function increment() {
		count.value += 1;
	}

	$effect(() => {
		console.log('triggered on mutation', count);
	});
	
	$effect(() => {
		count;
		console.log('not triggered on mutation');
	});
</script>

<button onclick={increment}>
	clicks: {count.value}
</button>
<button onclick={() => count = { value: 0 }}>
	Reset via object assignment
</button>

REPL

Logs

No response

System Info

REPL

Severity

annoyance

[brunnerh]

Looks like Simon did see my comment after all 😅
31481e0