Node.js wrapper around NSWorkspace.setIcon(_:forFile:options:) with a prebuilt binary. You can use this to change icons for .apps.
yarn add set-icon
# or
npm install set-icon
set-icon <file_path> <icon_path> # to change
set-icon <file_path> # to reset
import setIcon from 'set-icon'
// to change
await setIcon('/Applications/Foo.app', 'icon.png')
// to reset
await setIcon('/Applications/Foo.app', null)