(async () => {
  const randomName = Math.random().toString().substr(2);
  try {
    // Create a file, but keep no reference to it.
    await storageFoundation.open(randomName);
    console.log('Created', randomName);
    // Delete all files.
    storageFoundation.getAll().then((names) => names.forEach(async (name) => { 
      console.log('Deleting', name);
      // This fails, since the just created file is open.
      await storageFoundation.delete(name);
      // Throws a `DOMException: File is open` error.
      // At the same time there is no way to close the file, since all I have
      // at this stage is the file's `name`, and I can't call `NativeIOFile.close()`
      // without a file reference.
    }));
  } catch (err) {
    console.error(err.name, err.message);
  }
})();

const file = await storageFoundation.getFileReference(name);
if (await file.isOpen()) {
  await file.close();
}
// Deleting would now succeed.