From 9a3258719aa5848a1a1cc065e3754066c5c802d9 Mon Sep 17 00:00:00 2001
From: Vincent Bernat <vincent@bernat.ch>
Date: Fri, 9 Sep 2022 13:57:25 +0200
Subject: [PATCH] common/helpers: remove global side-effect from DiffFormatter
 option

---
 common/helpers/tests_diff.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/common/helpers/tests_diff.go b/common/helpers/tests_diff.go
index 3213c804..11ff5093 100644
--- a/common/helpers/tests_diff.go
+++ b/common/helpers/tests_diff.go
@@ -20,12 +20,15 @@ var prettyC = pretty.Config{
 	PrintStringers:    false,
 	SkipZeroFields:    true,
 	IncludeUnexported: false,
-	Formatter: map[reflect.Type]interface{}{
+}
+
+func defaultPrettyFormatters() map[reflect.Type]interface{} {
+	return map[reflect.Type]interface{}{
 		reflect.TypeOf(net.IP{}):            fmt.Sprint,
 		reflect.TypeOf(netip.Addr{}):        fmt.Sprint,
 		reflect.TypeOf(time.Time{}):         fmt.Sprint,
 		reflect.TypeOf(SubnetMap[string]{}): fmt.Sprint,
-	},
+	}
 }
 
 // DiffOption changes the behavior of the Diff function.
@@ -40,6 +43,7 @@ type DiffOption struct {
 // returned.
 func Diff(a, b interface{}, options ...DiffOption) string {
 	prettyC = prettyC
+	prettyC.Formatter = defaultPrettyFormatters()
 	for _, option := range options {
 		switch option.kind {
 		case DiffUnexported.kind: