nef: support JSON serialization

pkg/smartcontract/nef/nef.go

@@ -36,16 +36,16 @@ const (
 
 // File represents compiled contract file structure according to the NEF3 standard.
 type File struct {
-	Header   Header
-	Script   []byte
-	Checksum uint32
+	Header
+	Script   []byte `json:"script"`
+	Checksum uint32 `json:"checksum"`
 }
 
 // Header represents File header.
 type Header struct {
-	Magic    uint32
-	Compiler string
-	Version  string
+	Magic    uint32 `json:"magic"`
+	Compiler string `json:"compiler"`
+	Version  string `json:"version"`
 }
 
 // NewFile returns new NEF3 file with script specified.

pkg/smartcontract/nef/nef_test.go

@@ -1,6 +1,9 @@
 package nef
 
 import (
+	"encoding/base64"
+	"encoding/json"
+	"strconv"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/testserdes"
@@ -74,3 +77,28 @@ func TestBytesFromBytes(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, expected, actual)
 }
+
+func TestMarshalUnmarshalJSON(t *testing.T) {
+	expected := &File{
+		Header: Header{
+			Magic:    Magic,
+			Compiler: "test.compiler",
+			Version:  "test.ver",
+		},
+		Script: []byte{1, 2, 3, 4},
+	}
+	expected.Checksum = expected.CalculateChecksum()
+
+	data, err := json.Marshal(expected)
+	require.NoError(t, err)
+	require.JSONEq(t, `{
+		"magic":`+strconv.FormatUint(uint64(Magic), 10)+`,
+		"compiler": "test.compiler",
+		"version": "test.ver",
+		"script": "`+base64.StdEncoding.EncodeToString(expected.Script)+`",
+		"checksum":`+strconv.FormatUint(uint64(expected.Checksum), 10)+`}`, string(data))
+
+	actual := new(File)
+	require.NoError(t, json.Unmarshal(data, actual))
+	require.Equal(t, expected, actual)
+}