From 0206bd9a5d9eba68a227eb8265479c41d45558b2 Mon Sep 17 00:00:00 2001
From: Pavel Karpy <carpawell@nspcc.ru>
Date: Tue, 8 Jun 2021 16:29:20 +0300
Subject: [PATCH] [#302] pkg/container: Convert nil `Attributes` to nil message

Make `Attributes.ToV2` method to return `nil`
when called on `nil`. Make `NewAttributesFromV2`
function to return `nil` when called on `nil`.
Write corresponding unit tests.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
---
 pkg/container/attribute.go      | 8 ++++++++
 pkg/container/attribute_test.go | 8 ++++++++
 pkg/container/opts.go           | 4 ++--
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/pkg/container/attribute.go b/pkg/container/attribute.go
index 2e4492f..ec633e8 100644
--- a/pkg/container/attribute.go
+++ b/pkg/container/attribute.go
@@ -50,6 +50,10 @@ func (a *Attribute) ToV2() *container.Attribute {
 }
 
 func NewAttributesFromV2(v []*container.Attribute) Attributes {
+	if v == nil {
+		return nil
+	}
+
 	attrs := make(Attributes, 0, len(v))
 	for i := range v {
 		attrs = append(attrs, NewAttributeFromV2(v[i]))
@@ -59,6 +63,10 @@ func NewAttributesFromV2(v []*container.Attribute) Attributes {
 }
 
 func (a Attributes) ToV2() []*container.Attribute {
+	if a == nil {
+		return nil
+	}
+
 	attrs := make([]*container.Attribute, 0, len(a))
 	for i := range a {
 		attrs = append(attrs, a[i].ToV2())
diff --git a/pkg/container/attribute_test.go b/pkg/container/attribute_test.go
index e32dfda..acd7bbd 100644
--- a/pkg/container/attribute_test.go
+++ b/pkg/container/attribute_test.go
@@ -61,6 +61,14 @@ func TestAttribute(t *testing.T) {
 }
 
 func TestAttributes(t *testing.T) {
+	t.Run("nil", func(t *testing.T) {
+		var x container.Attributes
+
+		require.Nil(t, x.ToV2())
+
+		require.Nil(t, container.NewAttributesFromV2(nil))
+	})
+
 	var (
 		keys = []string{"key1", "key2", "key3"}
 		vals = []string{"val1", "val2", "val3"}
diff --git a/pkg/container/opts.go b/pkg/container/opts.go
index d07b684..8c15ed1 100644
--- a/pkg/container/opts.go
+++ b/pkg/container/opts.go
@@ -28,8 +28,8 @@ func defaultContainerOptions() containerOptions {
 	}
 
 	return containerOptions{
-		acl:        acl.PrivateBasicRule,
-		nonce:      rand,
+		acl:   acl.PrivateBasicRule,
+		nonce: rand,
 	}
 }