VS Code auto save on window change doesn't work with AltTab on Mac

[QumiQumi]

Does this issue occur when all extensions are disabled?: Yes

With a standard window change, autosave works correctly, but when using AltTab the file is not saved on Window change or on Focus change. I've created an issue in AltTab repo lwouis/alt-tab-macos#3367, but nothing they could do with this. Could you please check this out?

• VS Code Version: 1.89.1
• OS Version: macOS Sonoma 14.4.1
• AltTab version: 6.69.0

Steps to Reproduce:

1. Go to 'Preferences -> Files: Auto Save -> On Window Change'
2. Add changes to any file
3. Alt tab to other window and back
4. File is still unsaved

[bpasero]

So this does not reproduce when you disable Alt-Tab and use macOS built-in window switching?

[QumiQumi]

Yes, with native window switching works just fine.
Pls, check last comments lwouis/alt-tab-macos#3367 in this issue. AltTab developer said nothing they could do with this problem and advised me to ask VS code developers..

[bpasero]

We rely on this Electron event being fired: https://github.com/electron/electron/blob/main/docs/api/app.md#event-browser-window-focus to figure out that window focus changed.

The comment in lwouis/alt-tab-macos#1663 (comment) indicates that AltTab might be using a private API for focusing a window and probably we do not get the focus event from Electron then.

I suggest you change auto save to use onFocusChange.

I do not feel this is something VS Code can address, rather AltTab should fix.