feat: add LegacyBoolHelp to restore pre-v1.0.6 bool help formatting

flag.go

@@ -163,6 +163,10 @@ type FlagSet struct {
 	// help/usage messages.
 	SortFlags bool
 
+	// LegacyBoolHelp restores pre-v1.0.6 bool flag help formatting by omitting
+	// the [=true|false] syntax hint and default value from help output.
+	LegacyBoolHelp bool
+
 	// ParseErrorsAllowlist is used to configure an allowlist of errors
 	ParseErrorsAllowlist ParseErrorsAllowlist
 
@@ -731,7 +735,7 @@ func (f *FlagSet) FlagUsagesWrapped(cols int) string {
 		}
 
 		varname, usage := UnquoteUsage(flag)
-		if flag.Value.Type() == "bool" {
+		if flag.Value.Type() == "bool" && !f.LegacyBoolHelp {
 			line += "[=true|false]"
 		} else if varname != "" {
 			line += " " + varname
@@ -762,7 +766,13 @@ func (f *FlagSet) FlagUsagesWrapped(cols int) string {
 		}
 
 		line += usage
-		if !flag.defaultIsZeroValue() {
+		hideDefault := flag.defaultIsZeroValue()
+		if f.LegacyBoolHelp {
+			if _, ok := flag.Value.(boolFlag); ok {
+				hideDefault = true
+			}
+		}
+		if !hideDefault {
 			if flag.Value.Type() == "string" {
 				line += fmt.Sprintf(" (default %q)", flag.DefValue)
 			} else {

legacy_bool_help_test.go

@@ -0,0 +1,45 @@
+package pflag
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+func TestLegacyBoolHelp(t *testing.T) {
+	buf := bytes.Buffer{}
+	f := NewFlagSet("test", ContinueOnError)
+	f.LegacyBoolHelp = true
+	f.Bool("enabled", false, "Enable the feature")
+	f.Bool("verbose", true, "Verbose logging")
+	f.SetOutput(&buf)
+	f.PrintDefaults()
+
+	got := buf.String()
+	if strings.Contains(got, "[=true|false]") {
+		t.Fatalf("legacy bool help should omit [=true|false], got:\n%s", got)
+	}
+	if strings.Contains(got, "(default true)") || strings.Contains(got, "(default false)") {
+		t.Fatalf("legacy bool help should omit bool defaults, got:\n%s", got)
+	}
+	if !strings.Contains(got, "Enable the feature") || !strings.Contains(got, "Verbose logging") {
+		t.Fatalf("expected usage text in output, got:\n%s", got)
+	}
+}
+
+func TestLegacyBoolHelpBoolFunc(t *testing.T) {
+	buf := bytes.Buffer{}
+	f := NewFlagSet("test", ContinueOnError)
+	f.LegacyBoolHelp = true
+	f.BoolFunc("callback", "Run callback", func(string) error { return nil })
+	f.SetOutput(&buf)
+	f.PrintDefaults()
+
+	got := buf.String()
+	if strings.Contains(got, "(default ") {
+		t.Fatalf("legacy bool help should omit boolfunc defaults, got:\n%s", got)
+	}
+	if !strings.Contains(got, "Run callback") {
+		t.Fatalf("expected usage text in output, got:\n%s", got)
+	}
+}