[#1103] node: Implement Get\Head requests for EC object

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

pkg/local_object_storage/util/ecinfo_test.go

@@ -0,0 +1,56 @@
+package util
+
+import (
+	"crypto/rand"
+	"testing"
+
+	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMergeECInfo(t *testing.T) {
+	id := generateV2ID()
+	target := objectSDK.NewECInfo()
+	var chunk objectSDK.ECChunk
+	chunk.Total = 2
+	chunk.Index = 0
+	chunk.SetID(id)
+	target.AddChunk(chunk)
+
+	t.Run("merge empty", func(t *testing.T) {
+		to := objectSDK.NewECInfo()
+
+		result := MergeECInfo(target, to)
+		require.Equal(t, result, target)
+	})
+
+	t.Run("merge existed", func(t *testing.T) {
+		to := objectSDK.NewECInfo()
+		to.AddChunk(chunk)
+
+		result := MergeECInfo(target, to)
+		require.Equal(t, result, target)
+	})
+	t.Run("merge extend", func(t *testing.T) {
+		to := objectSDK.NewECInfo()
+		var chunk objectSDK.ECChunk
+		chunk.Total = 2
+		chunk.Index = 1
+		chunk.SetID(generateV2ID())
+		to.AddChunk(chunk)
+
+		result := MergeECInfo(target, to)
+		require.Equal(t, len(result.Chunks), 2)
+	})
+}
+
+func generateV2ID() oid.ID {
+	var buf [32]byte
+	_, _ = rand.Read(buf[:])
+
+	var id oid.ID
+	_ = id.Decode(buf[:])
+
+	return id
+}