t.Errorf("Error opening %q with fs.FS API: %v", "test.txt", err)
	}
	dirEntries, err := fs.ReadDir(r, ".")
	if err != nil {
		t.Fatalf("Error reading the root directory: %v", err)
	}
	if len(dirEntries) != 1 || dirEntries[0].Name() != "test.txt" {
		t.Errorf("Unexpected directory entries")
		for _, dirEntry := range dirEntries {
			_, err := r.Open(dirEntry.Name())