From 76ac53feaa09f309428e9f0ddbfc8adaa4aa83a8 Mon Sep 17 00:00:00 2001
From: Joseph Gu <aceralon@outlook.com>
Date: Fri, 24 Dec 2021 17:19:21 +0800
Subject: [PATCH] fix: potential error in combine (#525)

add ut for combine and split
---
 engine/virt/helper.go      |  6 ++++++
 engine/virt/helper_test.go | 40 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 engine/virt/helper_test.go

diff --git a/engine/virt/helper.go b/engine/virt/helper.go
index e93cc6a99..617a94e14 100644
--- a/engine/virt/helper.go
+++ b/engine/virt/helper.go
@@ -61,5 +61,11 @@ func splitUserImage(combined string) (user, imageName string, err error) {
 }
 
 func combineUserImage(user, imageName string) string {
+	if len(imageName) < 1 {
+		return ""
+	}
+	if len(user) < 1 {
+		return imageName
+	}
 	return fmt.Sprintf("%s%s%s", user, sep, imageName)
 }
diff --git a/engine/virt/helper_test.go b/engine/virt/helper_test.go
new file mode 100644
index 000000000..727b27c1f
--- /dev/null
+++ b/engine/virt/helper_test.go
@@ -0,0 +1,40 @@
+package virt
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCombineUserImage(t *testing.T) {
+	user := "user"
+	image := "image"
+
+	combine := combineUserImage(user, image)
+	require.Equal(t, "user@image", combine)
+	u, i, err := splitUserImage(combine)
+	require.NoError(t, err)
+	require.Equal(t, user, u)
+	require.Equal(t, image, i)
+
+	combine = combineUserImage("", image)
+	require.Equal(t, image, combine)
+	u, i, err = splitUserImage(combine)
+	require.NoError(t, err)
+	require.Equal(t, "", u)
+	require.Equal(t, image, i)
+
+	combine = combineUserImage(user, "")
+	require.Equal(t, "", combine)
+	u, i, err = splitUserImage(combine)
+	require.Error(t, err)
+
+	combine = combineUserImage("", "")
+	require.Equal(t, "", combine)
+
+	u, i, err = splitUserImage("@")
+	require.Error(t, err)
+
+	u, i, err = splitUserImage("hello@")
+	require.Error(t, err)
+}