From 6eac19951443cc6dc29984fa3a355a4823c0c5d3 Mon Sep 17 00:00:00 2001
From: Rich Harris <rich.harris@vercel.com>
Date: Sun, 20 Apr 2025 13:48:17 -0400
Subject: [PATCH] failing test

---
 .../samples/async-child-effect/_config.js     | 74 +++++++++++++++++++
 .../samples/async-child-effect/main.svelte    | 26 +++++++
 2 files changed, 100 insertions(+)
 create mode 100644 packages/svelte/tests/runtime-runes/samples/async-child-effect/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/async-child-effect/main.svelte

diff --git a/packages/svelte/tests/runtime-runes/samples/async-child-effect/_config.js b/packages/svelte/tests/runtime-runes/samples/async-child-effect/_config.js
new file mode 100644
index 0000000000..41d4130470
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-child-effect/_config.js
@@ -0,0 +1,74 @@
+import { flushSync, tick } from 'svelte';
+import { ok, test } from '../../test';
+
+export default test({
+	html: `
+		<button>shift</button>
+		<p>loading</p>
+	`,
+
+	async test({ assert, target, variant }) {
+		if (variant === 'hydrate') {
+			await Promise.resolve();
+		}
+
+		flushSync(() => {
+			target.querySelector('button')?.click();
+		});
+
+		await Promise.resolve();
+		await Promise.resolve();
+		await Promise.resolve();
+		await tick();
+		flushSync();
+
+		const [button1, button2] = target.querySelectorAll('button');
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>shift</button>
+				<button>+</button>
+				<p>A</p>
+				<p>a</p>
+			`
+		);
+
+		flushSync(() => button2.click());
+		flushSync(() => button2.click());
+
+		flushSync(() => button1.click());
+		await Promise.resolve();
+		await Promise.resolve();
+		await Promise.resolve();
+		await tick();
+		flushSync();
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>shift</button>
+				<button>+</button>
+				<p>AA</p>
+				<p>aa</p>
+			`
+		);
+
+		flushSync(() => button1.click());
+		await Promise.resolve();
+		await Promise.resolve();
+		await Promise.resolve();
+		await tick();
+		flushSync();
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>shift</button>
+				<button>+</button>
+				<p>AAA</p>
+				<p>aaa</p>
+			`
+		);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/async-child-effect/main.svelte b/packages/svelte/tests/runtime-runes/samples/async-child-effect/main.svelte
new file mode 100644
index 0000000000..edb0eaea44
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-child-effect/main.svelte
@@ -0,0 +1,26 @@
+<script>
+	let input = $state('a');
+
+	let queue = [];
+
+	function push(value) {
+		const deferred = Promise.withResolvers();
+		queue.push(() => deferred.resolve(value));
+		return deferred.promise;
+	}
+</script>
+
+<button onclick={() => queue.shift()()}>shift</button>
+
+<svelte:boundary>
+	<button onclick={() => input += 'a'}>+</button>
+	<p>{await push(input.toUpperCase())}</p>
+
+	{#if true}
+		<p>{input}</p>
+	{/if}
+
+	{#snippet pending()}
+		<p>loading</p>
+	{/snippet}
+</svelte:boundary>