[bug] Main window onCloseRequested is not triggered when the window is closed via APIs

[CrendKing]

Describe the bug

It seems the main window's onCloseRequested is correctly triggered when user closes the app with top right X button or Alt+F4, but not triggered via APIs such as appWindow.close() or exit().

Reproduction

1. Create a Svelte component or anything equivalent:

<script lang="ts">
    appWindow.onCloseRequested(async () => {
        await invoke('test')
    })
</script>

<button on:click={() => appWindow.close()}>Test</button>

2. Click the test button
3. Confirm that the "test" command is not triggered.
4. However, close the app with Alt+F4. Observe "test" command is triggered.

Expected behavior

Closing the app or main window via API should also trigger onCloseRequested.

Platform and versions

Environment
  › OS: Windows 10.0.22621 X64
  › Webview2: 105.0.1343.42
  › MSVC: 
      - Visual Studio Community 2022
  › Node.js: 16.17.1
  › npm: 8.15.0
  › pnpm: 7.12.2
  › yarn: Not installed!
  › rustup: 1.25.1
  › rustc: 1.64.0
  › cargo: 1.64.0
  › Rust toolchain: stable-x86_64-pc-windows-msvc 

Packages
  › @tauri-apps/cli [NPM]: 1.1.1
  › @tauri-apps/api [NPM]: 1.1.0
  › tauri [RUST]: 1.1.1,
  › tauri-build [RUST]: 1.1.1,
  › tao [RUST]: 0.14.0,
  › wry [RUST]: 0.21.1,

App
  › build-type: build
  › CSP: unset
  › distDir: ../dist
  › devPath: http://localhost:5173/
  › framework: Svelte

App directory structure
  ├─ .git
  ├─ dist
  ├─ node_modules
  ├─ src
  └─ src-tauri

Stack trace

No response

Additional context

This is needed so that the app can do necessary clean up and save data to file regardless of how user initiates the app termination. Otherwise, we have to duplicate the clean-up logic to all the possible routes.

[amrbashir]

For exit(), it is a desired behavior since it is meant to close the process as soon as possible. If you want to run code before that, you can just run the code before calling it.

For window.close() This is a known behavior for v1 but is planned to be changed in v2 where there will be window.close() that triggers the event and window.destroy() that will bypass it.

[CrendKing]

Thanks for clarification. If we can explain this (especially exit() at the moment) in doc that will help clear up the confusion.