add test

packages/svelte/tests/runtime-runes/samples/async-derived-destructured/Child.svelte

@@ -0,0 +1,13 @@
+<script>
+	let count = $state(1);
+
+	let { squared, cubed } = $derived(await {
+		squared: count ** 2,
+		cubed: count ** 3
+	});
+</script>
+
+<button onclick={() => count++}>increment</button>
+
+<p>{count} ** 2 = {squared}</p>
+<p>{count} ** 3 = {cubed}</p>

packages/svelte/tests/runtime-runes/samples/async-derived-destructured/_config.js

@@ -0,0 +1,31 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	async test({ assert, target }) {
+		await tick();
+
+		const [increment] = target.querySelectorAll('button');
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>increment</button>
+				<p>1 ** 2 = 1</p>
+				<p>1 ** 3 = 1</p>
+			`
+		);
+
+		increment.click();
+		await tick();
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>increment</button>
+				<p>2 ** 2 = 4</p>
+				<p>2 ** 3 = 8</p>
+			`
+		);
+	}
+});

packages/svelte/tests/runtime-runes/samples/async-derived-destructured/main.svelte

@@ -0,0 +1,11 @@
+<script>
+	import Child from './Child.svelte';
+</script>
+
+<svelte:boundary>
+	<Child />
+
+	{#snippet pending()}
+		<p>pending</p>
+	{/snippet}
+</svelte:boundary>