func (fs *DefaultFs) ReadDir(dirname string) ([]os.DirEntry, error) {
	return os.ReadDir(fs.prefix(dirname))
}

// Walk via filepath.Walk
func (fs *DefaultFs) Walk(root string, walkFn filepath.WalkFunc) error {
	return filepath.Walk(fs.prefix(root), walkFn)
}

// defaultFile implements File using same-named functions from "os"
type defaultFile struct {
	file *os.File
}

// Name via os.File.Name

	// from "os"
	ReadFile(filename string) ([]byte, error)
	TempDir(dir, prefix string) (string, error)
	TempFile(dir, prefix string) (File, error)
	ReadDir(dirname string) ([]os.DirEntry, error)
	Walk(root string, walkFn filepath.WalkFunc) error
}

// File is an interface that we can use to mock various filesystem operations typically
// accessed through the File object from the "os" package
type File interface {