getPackageFileUri function
Utility function to get the URI of a file in the package.
The filePath should be relative to the lib directory of the package.
Implementation
Future<Uri?> getPackageFileUri(String filePath) async {
final uri = Uri.tryParse('package:flutter_release/$filePath');
if (uri == null) return null;
return await Isolate.resolvePackageUri(uri);
}