[fix] updated.check() is promise<boolean> (#8400)

Author: chrskerr

.changeset/dry-poets-crash.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+`updated.check()` type changed to Promise<boolean>

packages/kit/src/runtime/client/utils.js

@@ -211,6 +211,7 @@ export function create_updated_store() {
 	/** @type {NodeJS.Timeout} */
 	let timeout;
 
+	/** @type {() => Promise<boolean>} */
 	async function check() {
 		if (DEV || !BROWSER) return false;
 

packages/kit/types/ambient.d.ts

@@ -320,7 +320,7 @@ declare module '$app/stores' {
 	/**
 	 *  A readable store whose initial value is `false`. If [`version.pollInterval`](https://kit.svelte.dev/docs/configuration#version) is a non-zero value, SvelteKit will poll for new versions of the app and update the store value to `true` when it detects one. `updated.check()` will force an immediate check, regardless of polling.
 	 */
-	export const updated: Readable<boolean> & { check(): boolean };
+	export const updated: Readable<boolean> & { check(): Promise<boolean> };
 
 	/**
 	 * A function that returns all of the contextual stores. On the server, this must be called during component initialization.