Wrapping around Snappy error

SnappyError.go

// SnappyJSON type implements json.Marshaler and represents a snappy compressed []byte
type SnappyJSON []byte

// SnappyError wrapper around the error returned from snappy
type SnappyError struct {
	json SnappyJSON
	err  error
}

func (s *SnappyError) Error() string {
	return fmt.Sprintf("SnappyJSON: Error compressing %v", s)
}

// UnmarshalJSON from json -> SnappyJSON
func (s *SnappyJSON) UnmarshalJSON(b []byte) error {
	compressed, err := snappyCompress(b)
	if err != nil {
		return &SnappyError{b, err}
		// return err
	}
	//Assign compressed to `s`
	*s = compressed
	return nil
}

inspired by https://blog.golang.org/error-handling-and-go