[Feature Request] Support Liquid Glass Icons for macOS 26

[0xlau]

Pre-flight checklist

• I have read the contribution documentation for this project.
• I agree to follow the code of conduct that this project uses.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Problem description

To add an icon to a macOS app, all you have to do is to create an .icns file and stuff it in the app's Resources folder.

You can provide the .icns file to electron-forge, and it will automatically bundle and make it work with the app.

Apple introduced a new way to create icons using Icon Composer. This is not a standard image format and has assets & layers bundled inside it.

However, this app creates .icon files which does not currently work with electron-forge.

Reference electron-userland/electron-builder#9254

Proposed solution

Support Liquid Glass Icons for macOS 26

Alternatives considered

None

Additional information

No response

[erickzhao]

Hey @0xlau, I think this should be already available via packagerOptions as long as your version of Packager within Forge is above 18.4.0: electron/packager#1806

Could be better documented though for sure 🤞

[0xlau]

I think this document should also include instructions on how to use an Icon Compose file as the macOS .icon icon in Electron Forge.

https://www.electronforge.io/guides/create-and-add-icons

[erickzhao]

Makes sense! I haven't personally gotten around to playing around with the new format yet. When I get the chance, I'll look to add some docs as well (if no one else has opened a PR for it yet).

[0xlau]

@erickzhao could you take a look?

I added documentation and a minimal example for using macOS Icon Composer (.icon) files with Electron Forge.

Example:
https://github.com/0xlau/macos26-icon-compose-example

Relates to electron-forge/electron-forge-docs#254

[erickzhao]

Thank you!