[#86] node: Move testing utils to one package

Move testing utils from tests in local_object_storage package to
unified testutil package

Signed-off-by: Airat Arifullin <aarifullin@yadro.com>

pkg/local_object_storage/internal/testutil/object.go

@@ -0,0 +1,68 @@
+package testutil
+
+import (
+	"crypto/sha256"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/checksum"
+	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
+	cidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id/test"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	oidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id/test"
+	usertest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user/test"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/version"
+	"git.frostfs.info/TrueCloudLab/tzhash/tz"
+	"golang.org/x/exp/rand"
+)
+
+const defaultDataSize = 32
+
+func GenerateObject() *object.Object {
+	return GenerateObjectWithCID(cidtest.ID())
+}
+
+func GenerateObjectWithCID(cnr cid.ID) *object.Object {
+	data := make([]byte, defaultDataSize)
+	rand.Read(data)
+	return GenerateObjectWithCIDWithPayload(cnr, data)
+}
+
+func GenerateObjectWithCIDWithPayload(cnr cid.ID, data []byte) *object.Object {
+	var ver version.Version
+	ver.SetMajor(2)
+	ver.SetMinor(1)
+
+	var csum checksum.Checksum
+	csum.SetSHA256(sha256.Sum256(data))
+
+	var csumTZ checksum.Checksum
+	csumTZ.SetTillichZemor(tz.Sum(csum.Value()))
+
+	obj := object.New()
+	obj.SetID(oidtest.ID())
+	obj.SetOwnerID(usertest.ID())
+	obj.SetContainerID(cnr)
+	obj.SetVersion(&ver)
+	obj.SetPayload(data)
+	obj.SetPayloadChecksum(csum)
+	obj.SetPayloadHomomorphicHash(csumTZ)
+
+	return obj
+}
+
+func AddAttribute(obj *object.Object, key, val string) {
+	var attr object.Attribute
+	attr.SetKey(key)
+	attr.SetValue(val)
+
+	attrs := obj.Attributes()
+	attrs = append(attrs, attr)
+	obj.SetAttributes(attrs...)
+}
+
+func AddPayload(obj *object.Object, size int) {
+	buf := make([]byte, size)
+	_, _ = rand.Read(buf)
+
+	obj.SetPayload(buf)
+	obj.SetPayloadSize(uint64(size))
+}