From 6c12b4dfb6e8396e5fb79c7fc3c88869fe31aaaf Mon Sep 17 00:00:00 2001
From: Pavel Karpy <carpawell@nspcc.ru>
Date: Tue, 8 Jun 2021 19:01:00 +0300
Subject: [PATCH] [#302] pkg/object: Document default values set in `NewID`

Document field values of instance constructed via `NewID`.
Assert the values in corresponding unit test.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
---
 pkg/object/id.go      |  3 +++
 pkg/object/id_test.go | 16 ++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/pkg/object/id.go b/pkg/object/id.go
index e4871a9..26e70f7 100644
--- a/pkg/object/id.go
+++ b/pkg/object/id.go
@@ -25,6 +25,9 @@ func NewIDFromV2(idV2 *refs.ObjectID) *ID {
 // NewID creates and initializes blank ID.
 //
 // Works similar as NewIDFromV2(new(ObjectID)).
+//
+// Defaults:
+// 	- value: nil.
 func NewID() *ID {
 	return NewIDFromV2(new(refs.ObjectID))
 }
diff --git a/pkg/object/id_test.go b/pkg/object/id_test.go
index e5e80db..e4086d8 100644
--- a/pkg/object/id_test.go
+++ b/pkg/object/id_test.go
@@ -71,6 +71,11 @@ func TestID_Parse(t *testing.T) {
 }
 
 func TestID_String(t *testing.T) {
+	t.Run("nil", func(t *testing.T) {
+		id := NewID()
+		require.Empty(t, id.String())
+	})
+
 	t.Run("should be equal", func(t *testing.T) {
 		for i := 0; i < 10; i++ {
 			t.Run(strconv.Itoa(i), func(t *testing.T) {
@@ -124,3 +129,14 @@ func TestID_ToV2(t *testing.T) {
 		require.Nil(t, x.ToV2())
 	})
 }
+
+func TestNewID(t *testing.T) {
+	t.Run("default values", func(t *testing.T) {
+		id := NewID()
+
+		// convert to v2 message
+		idV2 := id.ToV2()
+
+		require.Nil(t, idV2.GetValue())
+	})
+}