[#168] object: Implement binary/JSON encoders/decoders on Object

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

v2/object/json.go

@@ -104,3 +104,23 @@ func (h *HeaderWithSignature) UnmarshalJSON(data []byte) error {
 
 	return nil
 }
+
+func (o *Object) MarshalJSON() ([]byte, error) {
+	return protojson.MarshalOptions{
+		EmitUnpopulated: true,
+	}.Marshal(
+		ObjectToGRPCMessage(o),
+	)
+}
+
+func (o *Object) UnmarshalJSON(data []byte) error {
+	msg := new(object.Object)
+
+	if err := protojson.Unmarshal(data, msg); err != nil {
+		return err
+	}
+
+	*o = *ObjectFromGRPCMessage(msg)
+
+	return nil
+}

v2/object/json_test.go

@@ -66,3 +66,15 @@ func TestHeaderWithSignatureJSON(t *testing.T) {
 
 	require.Equal(t, h, h2)
 }
+
+func TestObjectJSON(t *testing.T) {
+	o := generateObject("data")
+
+	data, err := o.MarshalJSON()
+	require.NoError(t, err)
+
+	o2 := new(object.Object)
+	require.NoError(t, o2.UnmarshalJSON(data))
+
+	require.Equal(t, o, o2)
+}

v2/object/marshal.go

@@ -557,6 +557,17 @@ func (o *Object) StableUnmarshal(data []byte) error {
 	return nil
 }
 
+func (o *Object) Unmarshal(data []byte) error {
+	m := new(object.Object)
+	if err := goproto.Unmarshal(data, m); err != nil {
+		return err
+	}
+
+	*o = *ObjectFromGRPCMessage(m)
+
+	return nil
+}
+
 func (r *GetRequestBody) StableMarshal(buf []byte) ([]byte, error) {
 	if r == nil {
 		return []byte{}, nil

v2/object/marshal_test.go

@@ -78,16 +78,14 @@ func TestHeader_StableMarshal(t *testing.T) {
 
 func TestObject_StableMarshal(t *testing.T) {
 	from := generateObject("Payload")
-	transport := new(grpc.Object)
 
 	t.Run("non empty", func(t *testing.T) {
 		wire, err := from.StableMarshal(nil)
 		require.NoError(t, err)
 
-		err = goproto.Unmarshal(wire, transport)
-		require.NoError(t, err)
+		to := new(object.Object)
+		require.NoError(t, to.Unmarshal(wire))
 
-		to := object.ObjectFromGRPCMessage(transport)
 		require.Equal(t, from, to)
 	})
 }