Add persistence for slice flags

app_test.go

@@ -3083,13 +3083,20 @@ func TestPersistentFlag(t *testing.T) {
 	var topInt, topPersistentInt, subCommandInt int
 	var appFlag string
 
+	appSliceInt := NewInt64Slice()
+
 	a := &App{
 		Flags: []Flag{
 			&StringFlag{
 				Name:        "persistentAppFlag",
 				Persistent:  true,
 				Destination: &appFlag,
 			},
+			&Int64SliceFlag{
+				Name:        "persistentAppSliceFlag",
+				Persistent:  true,
+				Destination: appSliceInt,
+			},
 		},
 		Commands: []*Command{
 			{
@@ -3133,9 +3140,11 @@ func TestPersistentFlag(t *testing.T) {
 		t.Errorf("Expected 'hello' got %s", appFlag)
 	}
 
-	err = a.Run([]string{"app", "--persistentAppFlag", "hello",
-		"cmd", "--cmdFlag", "12",
-		"subcmd", "--cmdPersistentFlag", "20", "--cmdFlag", "11", "--persistentAppFlag", "bar"})
+	err = a.Run([]string{"app",
+		"--persistentAppFlag", "hello",
+		"--persistentAppSliceFlag", "100",
+		"cmd", "--cmdFlag", "12", "--persistentAppSliceFlag", "102",
+		"subcmd", "--cmdPersistentFlag", "20", "--cmdFlag", "11", "--persistentAppFlag", "bar", "--persistentAppSliceFlag", "130"})
 
 	if err != nil {
 		t.Fatal(err)
@@ -3156,4 +3165,9 @@ func TestPersistentFlag(t *testing.T) {
 	if subCommandInt != 11 {
 		t.Errorf("Expected 11 got %d", subCommandInt)
 	}
+
+	expectedInt := []int64{100, 102, 130}
+	if !reflect.DeepEqual(appSliceInt.slice, expectedInt) {
+		t.Errorf("Expected %v got %d", expectedInt, appSliceInt.slice)
+	}
 }

command.go

@@ -347,11 +347,11 @@ func (c *Command) parseFlags(args Args, ctx *Context) (*flag.FlagSet, error) {
 		}
 	}
 
-	if err = parseIter(set, c, args.Tail(), ctx.shellComplete); err != nil {
+	if err := parseIter(set, c, args.Tail(), ctx.shellComplete); err != nil {
 		return nil, err
 	}
 
-	if err = normalizeFlags(c.Flags, set); err != nil {
+	if err := normalizeFlags(c.Flags, set); err != nil {
 		return nil, err
 	}
 

godoc-current.txt

@@ -1714,6 +1714,8 @@ func (x *SliceFlag[T, S, E]) GetUsage() string
 
 func (x *SliceFlag[T, S, E]) GetValue() string
 
+func (x *SliceFlag[T, S, E]) IsPersistent() bool
+
 func (x *SliceFlag[T, S, E]) IsRequired() bool
 
 func (x *SliceFlag[T, S, E]) IsSet() bool
@@ -1736,6 +1738,7 @@ type SliceFlagTarget[E any] interface {
 	DocGenerationFlag
 	VisibleFlag
 	CategorizableFlag
+	PersistentFlag
 
 	// SetValue should propagate the given slice to the target, ideally as a new value.
 	// Note that a nil slice should nil/clear any existing value (modelled as ~[]E).

sliceflag.go

@@ -28,6 +28,7 @@ type (
 		DocGenerationFlag
 		VisibleFlag
 		CategorizableFlag
+		PersistentFlag
 
 		// SetValue should propagate the given slice to the target, ideally as a new value.
 		// Note that a nil slice should nil/clear any existing value (modelled as ~[]E).
@@ -128,6 +129,7 @@ func (x *SliceFlag[T, S, E]) GetDefaultText() string { return x.Target.GetDefaul
 func (x *SliceFlag[T, S, E]) GetEnvVars() []string   { return x.Target.GetEnvVars() }
 func (x *SliceFlag[T, S, E]) IsVisible() bool        { return x.Target.IsVisible() }
 func (x *SliceFlag[T, S, E]) GetCategory() string    { return x.Target.GetCategory() }
+func (x *SliceFlag[T, S, E]) IsPersistent() bool     { return x.Target.IsPersistent() }
 
 func (x *flagValueHook) Set(value string) error {
 	if err := x.value.Set(value); err != nil {

testdata/godoc-v2.x.txt

@@ -1714,6 +1714,8 @@ func (x *SliceFlag[T, S, E]) GetUsage() string
 
 func (x *SliceFlag[T, S, E]) GetValue() string
 
+func (x *SliceFlag[T, S, E]) IsPersistent() bool
+
 func (x *SliceFlag[T, S, E]) IsRequired() bool
 
 func (x *SliceFlag[T, S, E]) IsSet() bool
@@ -1736,6 +1738,7 @@ type SliceFlagTarget[E any] interface {
 	DocGenerationFlag
 	VisibleFlag
 	CategorizableFlag
+	PersistentFlag
 
 	// SetValue should propagate the given slice to the target, ideally as a new value.
 	// Note that a nil slice should nil/clear any existing value (modelled as ~[]E).