Hex byte array JSON encoding

hexbytes.go

package main

import (
	"encoding/hex"
	"encoding/json"
	"fmt"
)

type HexEncodedByteArray []byte

type Message struct {
	Text string
	ID   HexEncodedByteArray
}

func (b HexEncodedByteArray) MarshalJSON() ([]byte, error) {
	hexString := hex.EncodeToString(b)

	return json.Marshal(hexString)
}

func (b *HexEncodedByteArray) UnmarshalJSON(data []byte) (err error) {
	var hexString string

	if err = json.Unmarshal(data, &hexString); err != nil {
		return
	}

	*b, err = hex.DecodeString(hexString)
	return
}

func testMarshal() {
	var (
		data []byte
		err  error
	)

	message := Message{
		Text: "Marshal this message",
		ID:   HexEncodedByteArray{0x86, 0xCE, 0xC5, 0x88, 0x22, 0x4B, 0x04, 0x7F},
	}

	if data, err = json.Marshal(message); err != nil {
		panic(err)
	}

	fmt.Println("Marshaled message:", string(data))
}

func testUnmarshal() {
	data := `{
		"Text": "Unmarshal this message",
		"ID": "86CEC588224B047F"
	}`

	message := &Message{}

	if err := json.Unmarshal([]byte(data), message); err != nil {
		panic(err)
	}

	fmt.Println("Unmarshaled message:", message)
}

func main() {
	testMarshal()
	testUnmarshal()
}