Fixes destructuring signal with await bug

packages/svelte/src/compiler/phases/3-transform/client/utils.js

@@ -142,15 +142,16 @@ export function serialize_set_binding(node, context, fallback) {
 		}
 
 		return b.call(
-			b.thunk(
+			b.arrow(
+				[b.id(tmp_id)],
 				b.block([
-					b.const(tmp_id, /** @type {import('estree').Expression} */ (visit(node.right))),
 					b.stmt(b.sequence(assignments)),
 					// return because it could be used in a nested expression where the value is needed.
 					// example: { foo: ({ bar } = { bar: 1 })}
 					b.return(b.id(tmp_id))
 				])
-			)
+			),
+			/** @type {import('estree').Expression} */ (visit(node.right)),
 		);
 	}
 

packages/svelte/tests/runtime-runes/samples/async-state-assignment/_config.js

@@ -0,0 +1,28 @@
+import { test } from '../../test';
+import { setTimeout } from 'node:timers/promises';
+
+export default test({
+	html: `
+		<p>Name: tom</p>
+		<p>Email: tom@mail.com</p>
+		<p>Number: 555</p>
+		<button>Update me</button>
+	`,
+	async test({ assert, target }) {
+		const [button] = target.querySelectorAll('button');
+		const event = new window.MouseEvent('click', { bubbles: true });
+
+		await button.dispatchEvent(event);
+		await setTimeout(100);
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+			<p>Name: jerry</p>
+			<p>Email: jerry@mail.com</p>
+			<p>Number: 777</p>
+			<button>Update me</button>
+			`
+		);
+	}
+});

packages/svelte/tests/runtime-runes/samples/async-state-assignment/main.svelte

@@ -0,0 +1,22 @@
+<script>
+	let name = $state("tom");
+	let email = $state("tom@mail.com");
+	let number = $state(555);
+
+	export const fetch_user = () => {
+		return new Promise((resolve) => {
+			setTimeout(() => {
+				resolve([{name: "jerry", email: "jerry@mail.com"}, 777])
+			}, 100)
+		})
+	}
+
+	const update = async () => {
+		[{ name, email }, number] = await fetch_user();
+	}
+</script>
+
+<p>Name: {name}</p>
+<p>Email: {email}</p>
+<p>Number: {number}</p>
+<button on:click={update}>Update me</button>