[#255] v2/object: Implement json.Marshaler/Unmarshaler on SearchFilter

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

v2/object/json.go

@@ -124,3 +124,23 @@ func (o *Object) UnmarshalJSON(data []byte) error {
 
 	return nil
 }
+
+func (f *SearchFilter) MarshalJSON() ([]byte, error) {
+	return protojson.MarshalOptions{
+		EmitUnpopulated: true,
+	}.Marshal(
+		SearchFilterToGRPCMessage(f),
+	)
+}
+
+func (f *SearchFilter) UnmarshalJSON(data []byte) error {
+	msg := new(object.SearchRequest_Body_Filter)
+
+	if err := protojson.Unmarshal(data, msg); err != nil {
+		return err
+	}
+
+	*f = *SearchFilterFromGRPCMessage(msg)
+
+	return nil
+}

v2/object/json_test.go

@@ -78,3 +78,15 @@ func TestObjectJSON(t *testing.T) {
 
 	require.Equal(t, o, o2)
 }
+
+func TestSearchFilterJSON(t *testing.T) {
+	f := generateFilter("key", "value")
+
+	data, err := f.MarshalJSON()
+	require.NoError(t, err)
+
+	f2 := new(object.SearchFilter)
+	require.NoError(t, f2.UnmarshalJSON(data))
+
+	require.Equal(t, f, f2)
+}