SvelteSet infinite loop

[megashrieks]

Hi, I'm a newbie to svelte and I was trying out this piece of code.

Whenever there is an update to a SvelteSet inside an effect block it triggers an infinite update, any idea if this is the expected behavior or any explanation on this behavior would be helpful

<script>
	import { SvelteSet } from 'svelte/reactivity';
	let x = new SvelteSet();
	$effect(() => {
		let y = new SvelteSet();
		y.add(1); // seems to trigger the update
		if (y.symmetricDifference(x).size != 0) {
			console.log("diff found");
			// x = y;
		}
	})
</script>

[brunnerh]

I suspect that this is expected, you read and write to a reactive object in the same $effect, causing it to trigger again.

Here would be a minimal example causing the same:

<script>
	$effect(() => {
		let v = $state(0);
		v = v + 1;
	})
</script>

Would recommend not unnecessarily creating stateful objects in the $effect and/or untracking the read operations.