From 7b4acd5a7fbc5e387c6f4e81f04441b6718b4787 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Wed, 29 Jul 2020 12:59:19 +0300
Subject: [PATCH] vm: allow to convert stack to a slice

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
---
 pkg/vm/stack.go      |  9 +++++++++
 pkg/vm/stack_test.go | 16 ++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/pkg/vm/stack.go b/pkg/vm/stack.go
index 44e9d6d94..f5f93287d 100644
--- a/pkg/vm/stack.go
+++ b/pkg/vm/stack.go
@@ -396,6 +396,15 @@ func (s *Stack) PopSigElements() ([][]byte, error) {
 	return elems, nil
 }
 
+// ToArray converts stack to an array of stackitems with top item being the last.
+func (s *Stack) ToArray() []stackitem.Item {
+	items := make([]stackitem.Item, 0, s.len)
+	s.IterBack(func(e *Element) {
+		items = append(items, e.Item())
+	})
+	return items
+}
+
 // ToContractParameters converts Stack to slice of smartcontract.Parameter.
 func (s *Stack) ToContractParameters() []smartcontract.Parameter {
 	items := make([]smartcontract.Parameter, 0, s.Len())
diff --git a/pkg/vm/stack_test.go b/pkg/vm/stack_test.go
index 82c15e962..885ccbf08 100644
--- a/pkg/vm/stack_test.go
+++ b/pkg/vm/stack_test.go
@@ -237,6 +237,22 @@ func TestPushVal(t *testing.T) {
 	assert.IsType(t, elem.value, &stackitem.Array{})
 }
 
+func TestStack_ToArray(t *testing.T) {
+	t.Run("Empty", func(t *testing.T) {
+		s := NewStack("test")
+		items := s.ToArray()
+		require.Equal(t, 0, len(items))
+	})
+	t.Run("NonEmpty", func(t *testing.T) {
+		s := NewStack("test")
+		expected := []stackitem.Item{stackitem.Make(1), stackitem.Make(true)}
+		for i := range expected {
+			s.PushVal(expected[i])
+		}
+		require.Equal(t, expected, s.ToArray())
+	})
+}
+
 func TestSwapElemValues(t *testing.T) {
 	s := NewStack("test")