Fix utxoindex deserialization (#1566)

* Fix broken deserialization in utxoindex

* Add Tests for hashes serialization in utxo index

domain/utxoindex/serialization.go

@@ -45,8 +45,7 @@ func serializeHashes(hashes []*externalapi.DomainHash) []byte {
 	for i, hash := range hashes {
 		start := hashesLengthSize + externalapi.DomainHashSize*i
 		end := start + externalapi.DomainHashSize
-		copy(serializedHashes[start:end],
+		copy(serializedHashes[start:end], hash.ByteSlice())
-			hash.ByteSlice())
 	}
 	return serializedHashes
 }
@@ -63,12 +62,11 @@ func deserializeHashes(serializedHashes []byte) ([]*externalapi.DomainHash, erro
 		}
 
 		var err error
-		hashes[i], err = externalapi.
+		hashes[i], err = externalapi.NewDomainHashFromByteSlice(serializedHashes[start:end])
-			NewDomainHashFromByteSlice(serializedHashes[start:end])
 		if err != nil {
 			return nil, err
 		}
 	}
 
-	return nil, nil
+	return hashes, nil
 }

domain/utxoindex/serialization_test.go

@@ -0,0 +1,44 @@
+package utxoindex
+
+import (
+	"encoding/binary"
+	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
+	"github.com/pkg/errors"
+	"io"
+	"math/rand"
+	"testing"
+)
+
+func Test_serializeHashes(t *testing.T) {
+	r := rand.New(rand.NewSource(0))
+
+	for length := 0; length < 32; length++ {
+		hashes := make([]*externalapi.DomainHash, length)
+		for i := range hashes {
+			var hashBytes [32]byte
+			r.Read(hashBytes[:])
+			hashes[i] = externalapi.NewDomainHashFromByteArray(&hashBytes)
+		}
+		result, err := deserializeHashes(serializeHashes(hashes))
+		if err != nil {
+			t.Fatalf("Failed deserializing hashes: %v", err)
+		}
+		if !externalapi.HashesEqual(hashes, result) {
+			t.Fatalf("Expected \n %s \n==\n %s\n", hashes, result)
+		}
+	}
+}
+
+func Test_deserializeHashesFailure(t *testing.T) {
+	hashes := []*externalapi.DomainHash{
+		externalapi.NewDomainHashFromByteArray(&[externalapi.DomainHashSize]byte{1}),
+		externalapi.NewDomainHashFromByteArray(&[externalapi.DomainHashSize]byte{2}),
+		externalapi.NewDomainHashFromByteArray(&[externalapi.DomainHashSize]byte{3}),
+	}
+	serialized := serializeHashes(hashes)
+	binary.LittleEndian.PutUint64(serialized[:8], uint64(len(hashes)+1))
+	_, err := deserializeHashes(serialized)
+	if !errors.Is(err, io.ErrUnexpectedEOF) {
+		t.Fatalf("Expected error to be EOF, instead got: %v", err)
+	}
+}