return filepath.Join(t.dir, t.goFile)
}

func (t test) goDirName() string {
	return filepath.Join(t.dir, strings.Replace(t.goFile, ".go", ".dir", -1))
}

// goDirFiles returns .go files in dir.
func goDirFiles(dir string) (filter []fs.DirEntry, _ error) {
	files, err := os.ReadDir(dir)
	if err != nil {
		return nil, err
	}
	for _, goFile := range files {
		if filepath.Ext(goFile.Name()) == ".go" {