[#15] Use extended error response

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

internal/util/transformers_test.go

@@ -0,0 +1,27 @@
+package util
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"testing"
+
+	apistatus "github.com/nspcc-dev/neofs-sdk-go/client/status"
+	"github.com/stretchr/testify/require"
+)
+
+func TestErrors(t *testing.T) {
+	apiErr := fmt.Errorf("some context: %w", apistatus.ContainerNotFound{})
+
+	resp := NewErrorResponse(apiErr)
+	data, err := json.Marshal(resp)
+	require.NoError(t, err)
+	require.Equal(t, `{"code":3072,"message":"some context: status: code = 3072","type":"API"}`, string(data))
+
+	gwErr := fmt.Errorf("some context: %w", errors.New("sanity check error"))
+
+	resp = NewErrorResponse(gwErr)
+	data, err = json.Marshal(resp)
+	require.NoError(t, err)
+	require.Equal(t, `{"message":"some context: sanity check error","type":"GW"}`, string(data))
+}