new BrowserWindow({ icon }) and app.dock.setIcon() decode the icon file
synchronously on the main process and throw on undecodable bytes. The
icon ladder was resolved with statSync().isFile(), which only proves a
file exists — a truncated or zero-byte PNG inside a packaged app.asar
(interrupted electron-builder run, partial copy) killed the main process
inside createWindow(): the window never appeared, running turns lost
their renderer, and the desktop log showed 'Uncaught exception: Error:
Failed to load image from path .../app.asar/public/apple-touch-icon.png
at createWindow'.
Resolution now runs through a decoding probe (nativeImage.createFromPath
must yield a non-empty image); a candidate that exists but does not
decode is skipped like a missing one, so the app falls through to the
next rung or starts with the platform default icon instead of dying.
The ladder and probe live in a pure module (electron/app-icon.ts) so
precedence is unit-testable without a running Electron app; window
factories re-resolve per call exactly as before.
Regression tests cover: skip-first-undecodable, all-fail -> undefined,
first-pass wins, missing/empty/directory rejection, and the unchanged
mac/Windows precedence ladder.
Co-authored-by: brooklyn! <brooklyn.bb.nicholson@gmail.com>
Leon Phull