From 1d33e9d9b07dba0aae8971c960afe000f5450300 Mon Sep 17 00:00:00 2001
From: Yi-Ting Shih <ytshih@it.cs.nycu.edu.tw>
Date: Mon, 30 Mar 2026 03:39:11 +0800
Subject: [PATCH] feat: add int64Slice support

---
 viper.go      | 18 ++++++++++++++++++
 viper_test.go | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/viper.go b/viper.go
index 2d5158cbd..91e265405 100644
--- a/viper.go
+++ b/viper.go
@@ -899,6 +899,14 @@ func (v *Viper) GetIntSlice(key string) []int {
 	return cast.ToIntSlice(v.Get(key))
 }
 
+// GetInt64Slice returns the value associated with the key as a slice of int64 values.
+func GetInt64Slice(key string) []int64 { return v.GetInt64Slice(key) }
+
+// GetInt64Slice returns the value associated with the key as a slice of int64 values.
+func (v *Viper) GetInt64Slice(key string) []int64 {
+	return cast.ToInt64Slice(v.Get(key))
+}
+
 // GetStringSlice returns the value associated with the key as a slice of strings.
 func GetStringSlice(key string) []string { return v.GetStringSlice(key) }
 
@@ -1241,6 +1249,11 @@ func (v *Viper) find(lcaseKey string, flagDefault bool) any {
 			s = strings.TrimSuffix(s, "]")
 			res, _ := readAsCSV(s)
 			return cast.ToIntSlice(res)
+		case "int64Slice":
+			s := strings.TrimPrefix(flag.ValueString(), "[")
+			s = strings.TrimSuffix(s, "]")
+			res, _ := readAsCSV(s)
+			return cast.ToInt64Slice(res)
 		case "uintSlice":
 			s := strings.TrimPrefix(flag.ValueString(), "[")
 			s = strings.TrimSuffix(s, "]")
@@ -1343,6 +1356,11 @@ func (v *Viper) find(lcaseKey string, flagDefault bool) any {
 				s = strings.TrimSuffix(s, "]")
 				res, _ := readAsCSV(s)
 				return cast.ToIntSlice(res)
+			case "int64Slice":
+				s := strings.TrimPrefix(flag.ValueString(), "[")
+				s = strings.TrimSuffix(s, "]")
+				res, _ := readAsCSV(s)
+				return cast.ToInt64Slice(res)
 			case "uintSlice":
 				s := strings.TrimPrefix(flag.ValueString(), "[")
 				s = strings.TrimSuffix(s, "]")
diff --git a/viper_test.go b/viper_test.go
index 8b0232aee..674271e0a 100644
--- a/viper_test.go
+++ b/viper_test.go
@@ -1292,6 +1292,42 @@ func TestBindPFlagsIntSlice(t *testing.T) {
 	}
 }
 
+func TestBindPFlagsInt64Slice(t *testing.T) {
+	tests := []struct {
+		Expected []int64
+		Value    string
+	}{
+		{[]int64{}, ""},
+		{[]int64{1}, "1"},
+		{[]int64{2, 3}, "2,3"},
+	}
+
+	v := New() // create independent Viper object
+	defaultVal := []int64{0}
+	v.SetDefault("int64slice", defaultVal)
+
+	for _, testValue := range tests {
+		flagSet := pflag.NewFlagSet("test", pflag.ContinueOnError)
+		flagSet.Int64Slice("int64slice", testValue.Expected, "test")
+
+		for _, changed := range []bool{true, false} {
+			flagSet.VisitAll(func(f *pflag.Flag) {
+				f.Value.Set(testValue.Value)
+				f.Changed = changed
+			})
+
+			err := v.BindPFlags(flagSet)
+			require.NoError(t, err, "error binding flag set")
+
+			if changed {
+				assert.Equal(t, testValue.Expected, v.GetInt64Slice("int64slice"))
+			} else {
+				assert.Equal(t, defaultVal, v.GetInt64Slice("int64slice"))
+			}
+		}
+	}
+}
+
 func TestBindPFlag(t *testing.T) {
 	v := New()
 	testString := "testing"