add tests, one failing

packages/svelte/tests/runtime-runes/samples/async-block-destroy-during-init/_config.js

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+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	async test({ assert, target }) {
+		const [increment, shift] = target.querySelectorAll('button');
+
+		increment.click();
+		await tick();
+
+		shift.click();
+		await tick();
+
+		shift.click();
+		await tick();
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>increment</button>
+				<button>shift</button>
+				<p>false</p>
+				<p>1</p>
+			`
+		);
+	}
+});

packages/svelte/tests/runtime-runes/samples/async-block-destroy-during-init/main.svelte

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+<script>
+	let count = $state(0);
+
+	let deferreds = [];
+
+	function push() {
+		const deferred = Promise.withResolvers();
+		deferreds.push(deferred);
+		return deferred.promise;
+	}
+</script>
+
+<button onclick={() => count += 1}>increment</button>
+<button onclick={() => deferreds.shift()?.resolve(count)}>shift</button>
+
+<svelte:boundary>
+	{#if count % 2 === 0}
+		<p>true</p>
+		<p>{await push()}</p>
+	{:else}
+		<p>false</p>
+		<p>{await push()}</p>
+	{/if}
+
+	{#snippet pending()}
+		<p>loading...</p>
+	{/snippet}
+</svelte:boundary>

packages/svelte/tests/runtime-runes/samples/async-block-reject-each-during-init/_config.js

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+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	async test({ assert, target }) {
+		const [increment, shift] = target.querySelectorAll('button');
+
+		increment.click();
+		await tick();
+
+		shift.click();
+		await tick();
+
+		shift.click();
+		await tick();
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>increment</button>
+				<button>shift</button>
+				<p>false</p>
+				<p>1</p>
+			`
+		);
+	}
+});

packages/svelte/tests/runtime-runes/samples/async-block-reject-each-during-init/main.svelte

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+<script>
+	let count = $state(0);
+
+	let deferreds = [];
+
+	function push() {
+		const deferred = Promise.withResolvers();
+		deferreds.push(deferred);
+		return deferred.promise;
+	}
+</script>
+
+<button onclick={() => count += 1}>increment</button>
+<button onclick={() => deferreds.shift()?.resolve([count])}>resolve</button>
+<button onclick={() => deferreds.shift()?.reject(new Error('oops'))}>reject</button>
+
+<svelte:boundary>
+	{#if count % 2 === 0}
+		<p>true</p>
+		{#each await push() as count}<p>{count}</p>{/each}
+	{:else}
+		<p>false</p>
+		{#each await push() as count}<p>{count}</p>{/each}
+	{/if}
+
+	{#snippet pending()}
+		<p>loading...</p>
+	{/snippet}
+</svelte:boundary>