Here is how to accept files dropped on an @electronjs app's icon in osx. For this to work you need to properly package the app into a `.app`, and to place the CFBundleDocumentTypes spec into it's Info.plist. Here we're using electron-packager.

extend.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <dict>
    <key>CFBundleDocumentTypes</key>
    <array>
      <dict>
        <key>CFBundleTypeName</key>
        <string>All Files</string>
        <key>LSHandlerRank</key>
        <string>Alternate</string>
        <key>LSItemContentTypes</key>
        <array>
          <string>public.data</string>
          <string>public.content</string>
        </array>
      </dict>
    </array>
  </dict>
</plist>

index.js

// ...

app.on('will-finish-launching', () => {
  app.on('open-file', (ev, path) => {
    ev.preventDefault();
    // send the path to the renderer process via rpc
  });
});

// ...

package.json

{
  "scripts": {
    "package": "electron-packager . --all --extend-info extend.plist"
  }
}