[#378] version: Add JSON encoding for Version type

Define `MarshalJSON` / `UnmarshalJSON` methods of the `Version` type.

Signed-off-by: Leonard Lyubich <ctulhurider@gmail.com>

version/version.go

@@ -84,3 +84,29 @@ func (v Version) Equal(v2 Version) bool {
 	return v.Major() == v2.Major() &&
 		v.Minor() == v2.Minor()
 }
+
+// MarshalJSON encodes Version into a JSON format of the NeoFS API
+// protocol (Protocol Buffers JSON).
+//
+// See also UnmarshalJSON.
+func (v Version) MarshalJSON() ([]byte, error) {
+	var m refs.Version
+	v.WriteToV2(&m)
+
+	return m.MarshalJSON()
+}
+
+// UnmarshalJSON decodes NeoFS API protocol JSON format into the Version
+// (Protocol Buffers JSON). Returns an error describing a format violation.
+//
+// See also MarshalJSON.
+func (v *Version) UnmarshalJSON(data []byte) error {
+	var m refs.Version
+
+	err := m.UnmarshalJSON(data)
+	if err != nil {
+		return err
+	}
+
+	return v.ReadFromV2(m)
+}

version/version_test.go

@@ -1,6 +1,7 @@
 package version
 
 import (
+	"math/rand"
 	"testing"
 
 	"github.com/nspcc-dev/neofs-api-go/v2/refs"
@@ -48,3 +49,17 @@ func TestSDKVersion(t *testing.T) {
 	require.Equal(t, uint32(sdkMjr), v.Major())
 	require.Equal(t, uint32(sdkMnr), v.Minor())
 }
+
+func TestVersion_MarshalJSON(t *testing.T) {
+	var v Version
+	v.SetMajor(rand.Uint32())
+	v.SetMinor(rand.Uint32())
+
+	data, err := v.MarshalJSON()
+	require.NoError(t, err)
+
+	var v2 Version
+	require.NoError(t, v2.UnmarshalJSON(data))
+
+	require.Equal(t, v, v2)
+}