From 1bee20875a466b369fadb3733e642340db36da3d Mon Sep 17 00:00:00 2001
From: Naveen Gogineni <dear.chap@gmail.com>
Date: Sun, 16 Aug 2026 08:36:31 -0400
Subject: [PATCH] test: fix ineffective mutex error-string assertion and add
 mirror cases

The assertion checking the mutually exclusive error string used t.Logf
instead of t.Errorf, so a wrong error message never failed the test.
This masked that the message reports the flag's primary name (Names()[0])
rather than the alias typed on the command line. Align the expectation
with the actual (and codebase-consistent) behavior.

Also add coverage for cross-group combinations where the conflicting flag
is not the first member of its group: --i --q and --s --q.
---
 flag_mutex_test.go | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/flag_mutex_test.go b/flag_mutex_test.go
index b6c9a161c5..114ab57c44 100644
--- a/flag_mutex_test.go
+++ b/flag_mutex_test.go
@@ -1,7 +1,6 @@
 package cli
 
 import (
-	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -58,7 +57,12 @@ func TestFlagMutuallyExclusiveFlags(t *testing.T) {
 		{
 			name:   "set both flags",
 			args:   []string{"--i", "11", "--ai", "12"},
-			errStr: "option i cannot be set along with option ai",
+			errStr: "option i cannot be set along with option t",
+		},
+		{
+			name:   "set both flags second member",
+			args:   []string{"--i", "11", "--q"},
+			errStr: "option i cannot be set along with option q",
 		},
 		{
 			name:     "required none set",
@@ -73,7 +77,7 @@ func TestFlagMutuallyExclusiveFlags(t *testing.T) {
 		{
 			name:     "required both set",
 			args:     []string{"--i", "11", "--ai", "12"},
-			errStr:   "option i cannot be set along with option ai",
+			errStr:   "option i cannot be set along with option t",
 			required: true,
 		},
 		{
@@ -82,6 +86,12 @@ func TestFlagMutuallyExclusiveFlags(t *testing.T) {
 			errStr:   "option i cannot be set along with option q",
 			required: true,
 		},
+		{
+			name:     "required both set second member both groups",
+			args:     []string{"--s", "value", "--q"},
+			errStr:   "option s cannot be set along with option q",
+			required: true,
+		},
 		{
 			name:     "set env var",
 			required: true,
@@ -113,9 +123,7 @@ func TestFlagMutuallyExclusiveFlags(t *testing.T) {
 
 			switch err.(type) {
 			case (*mutuallyExclusiveGroup), (*mutuallyExclusiveGroupRequiredFlag):
-				if !strings.Contains(err.Error(), test.errStr) {
-					t.Logf("Invalid error string %v", err)
-				}
+				assert.Contains(t, err.Error(), test.errStr)
 			default:
 				t.Errorf("got invalid error type %T", err)
 			}