Add test to ensure that database packing produces sorted values

database/helpers_test.go

@@ -0,0 +1,43 @@
+// Copyright (C) 2019-2023, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package database
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"golang.org/x/exp/slices"
+
+	"github.com/ava-labs/avalanchego/utils"
+)
+
+func TestSortednessUint64(t *testing.T) {
+	ints := make([]uint64, 1024)
+	for i := range ints {
+		ints[i] = rand.Uint64() //#nosec G404
+	}
+	slices.Sort(ints)
+
+	intBytes := make([][]byte, 1024)
+	for i, val := range ints {
+		intBytes[i] = PackUInt64(val)
+	}
+	require.True(t, utils.IsSortedBytes(intBytes))
+}
+
+func TestSortednessUint32(t *testing.T) {
+	ints := make([]uint32, 1024)
+	for i := range ints {
+		ints[i] = rand.Uint32() //#nosec G404
+	}
+	slices.Sort(ints)
+
+	intBytes := make([][]byte, 1024)
+	for i, val := range ints {
+		intBytes[i] = PackUInt32(val)
+	}
+	require.True(t, utils.IsSortedBytes(intBytes))
+}

utils/sorting.go

@@ -44,6 +44,16 @@ func SortBytes[T ~[]byte](arr []T) {
 	})
 }
 
+// Returns true iff the elements in [arr] are sorted.
+func IsSortedBytes[T ~[]byte](arr []T) bool {
+	for i := 0; i < len(arr)-1; i++ {
+		if bytes.Compare(arr[i], arr[i+1]) == 1 {
+			return false
+		}
+	}
+	return true
+}
+
 // Returns true iff the elements in [s] are unique and sorted.
 func IsSortedAndUniqueSortable[T Sortable[T]](s []T) bool {
 	for i := 0; i < len(s)-1; i++ {