[bug] const update = await check(); update return undefined

[555chy]

Describe the bug

import { check } from '@tauri-apps/plugin-updater';
import { relaunch } from '@tauri-apps/plugin-process';

const update = await check();
if (update) {
console.log(
found update ${update.version} from ${update.date} with notes ${update.body}
);
let downloaded = 0;
let contentLength = 0;
// alternatively we could also call update.download() and update.install() separately
await update.downloadAndInstall((event) => {
switch (event.event) {
case 'Started':
contentLength = event.data.contentLength;
console.log(started downloading ${event.data.contentLength} bytes);
break;
case 'Progress':
downloaded += event.data.chunkLength;
console.log(downloaded ${downloaded} from ${contentLength});
break;
case 'Finished':
console.log('download finished');
break;
}
});

console.log('update installed');
await relaunch();
}

const update = await check(); why return is undefined，and how can i get current app version?

Reproduction

No response

Expected behavior

No response

Full tauri info output

[✔] Environment
    - OS: Windows 10.0.22631 x86_64 (X64)
    ✔ WebView2: 133.0.3065.92
    ✔ MSVC:
        - Visual Studio Community 2022
        - Visual Studio 生成工具 2019
    ✔ rustc: 1.85.0 (4d91de4e4 2025-02-17)
    ✔ cargo: 1.85.0 (d73d2caf9 2024-12-31)
    ✔ rustup: 1.28.1 (f9edccde0 2025-03-05)
    ✔ Rust toolchain: stable-x86_64-pc-windows-msvc (default)
    - node: 21.6.0
    - yarn: 1.22.19
    - npm: 10.2.4

[-] Packages
    - tauri 🦀: 2.3.1
    - tauri-build 🦀: 2.0.6
    - wry 🦀: 0.50.4
    - tao 🦀: 0.32.8
    - @tauri-apps/api : 2.3.0
    - @tauri-apps/cli : 2.3.1

[-] Plugins
    - tauri-plugin-updater 🦀: 2.6.0
    - @tauri-apps/plugin-updater : 2.6.0
    - tauri-plugin-opener 🦀: 2.2.6
    - @tauri-apps/plugin-opener : 2.2.6

[-] App
    - build-type: bundle
    - CSP: unset
    - frontendDist: ../dist
    - devUrl: http://localhost:1420/
    - framework: React
    - bundler: Vite

Stack trace

Additional context

No response

[FabianLars]

null/undefined should mean that there's no new update but the requests themselves should have worked (otherwise there should be an error).

and how can i get current app version?

For the currently running app: https://v2.tauri.app/reference/javascript/api/namespaceapp/#getversion
For the server side version it'll be the response (which you don't see here if check() returns null so you have to check what your server responds with yourself)