golang json encode

mashal_json.go

package marshal

import (
	"bytes"
	"encoding/json"
	"testing"
)

type MarshalInterface interface {
	Example() string
}

type MarshalObject struct {
	key string
	val string
}

func (m *MarshalObject) Example() string {
	return m.key
}

func (m *MarshalObject) MarshalJSON() ([]byte, error) {
	data := make(map[string]string)
	data["key"] = m.key
	data["val"] = m.val
	buf := &bytes.Buffer{}
	enc := json.NewEncoder(buf)
	err := enc.Encode(data)
	return buf.Bytes(), err
}

func (m *MarshalObject) UnmarshalJSON(data []byte) error {
	marshalData := make(map[string]string)
	buf := bytes.NewBuffer(data)
	dec := json.NewDecoder(buf)
	if err := dec.Decode(&marshalData); err != nil {
		return err
	}
	m.key = marshalData["key"]
	m.val = marshalData["val"]
	return nil
}

func TestMarshal(t *testing.T) {
	var im MarshalInterface
	var m MarshalObject
	im = &MarshalObject{
		key: "Example",
		val: "Test",
	}

	buf := &bytes.Buffer{}
	enc := json.NewEncoder(buf)
	err := enc.Encode(im)
	if err != nil {
		t.Fatal(err)
	}

	dec := json.NewDecoder(buf)

	if err = dec.Decode(&m); err != nil {
		t.Fatal(err)
	}

	if m.key != "Example" {
		t.Fatal("key error")
	}

	if m.val != "Test" {
		t.Fatal("key error")
	}

}