}
		}

		if got := bb.String(); got != wantStr {
			t.Fatalf("test %d, String() = %q, want %q", i, got, wantStr)
		}
	}
}

func TestWriterAddFS(t *testing.T) {
	fsys := fstest.MapFS{
		"emptyfolder":          {Mode: 0o755 | os.ModeDir},
		"file.go":              {Data: []byte("hello")},
		"subfolder/another.go": {Data: []byte("world")},