use the latest testscript to drop func() int

And don't fail when requesting help, which is what Go's flag package
has been moving towards.

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/bluekeyes/go-gitdiff v0.8.0
 	github.com/go-quicktest/qt v1.101.0
 	github.com/google/go-cmp v0.6.0
-	github.com/rogpeppe/go-internal v1.13.1
+	github.com/rogpeppe/go-internal v1.13.2-0.20241226121412-a5dc8ff20d0a
 	golang.org/x/mod v0.22.0
 	golang.org/x/tools v0.27.0
 )

go.sum

@@ -11,8 +11,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
-github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
-github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
+github.com/rogpeppe/go-internal v1.13.2-0.20241226121412-a5dc8ff20d0a h1:w3tdWGKbLGBPtR/8/oO74W6hmz0qE5q0z9aqSAewaaM=
+github.com/rogpeppe/go-internal v1.13.2-0.20241226121412-a5dc8ff20d0a/go.mod h1:S8kfXMp+yh77OxPD4fdM6YUknrZpQxLhvxzS4gDHENY=
 golang.org/x/mod v0.22.0 h1:D4nJWe9zXqHOmWqj4VMOJhvzj7bEZg4wEYa759z1pH4=
 golang.org/x/mod v0.22.0/go.mod h1:6SkKJ3Xj0I0BrPOZoBy3bdMptDDU9oJrpohJ3eWZ1fY=
 golang.org/x/sync v0.9.0 h1:fEo0HyrW1GIgZdpbhCRO0PkJajUS5H9IFUztCgEo2jQ=

main.go

@@ -51,7 +51,7 @@ import (
 	"mvdan.cc/garble/internal/literals"
 )
 
-var flagSet = flag.NewFlagSet("garble", flag.ContinueOnError)
+var flagSet = flag.NewFlagSet("garble", flag.ExitOnError)
 
 var (
 	flagLiterals bool
@@ -146,8 +146,6 @@ For more information, see https://github.com/burrowers/garble.
 `[1:])
 }
 
-func main() { os.Exit(main1()) }
-
 var (
 	// Presumably OK to share fset across packages.
 	fset = token.NewFileSet()
@@ -220,7 +218,7 @@ func debugSince(start time.Time) time.Duration {
 	return time.Since(start).Truncate(10 * time.Microsecond)
 }
 
-func main1() int {
+func main() {
 	if dir := os.Getenv("GARBLE_WRITE_CPUPROFILES"); dir != "" {
 		f, err := os.CreateTemp(dir, "garble-cpu-*.pprof")
 		if err != nil {
@@ -256,9 +254,7 @@ func main1() int {
 			fmt.Fprintf(os.Stderr, "garble allocs: %d\n", memStats.Mallocs)
 		}
 	}()
-	if err := flagSet.Parse(os.Args[1:]); err != nil {
-		return 2
-	}
+	flagSet.Parse(os.Args[1:])
 	log.SetPrefix("[garble] ")
 	log.SetFlags(0) // no timestamps, as they aren't very useful
 	if flagDebug {
@@ -270,7 +266,7 @@ func main1() int {
 	args := flagSet.Args()
 	if len(args) < 1 {
 		usage()
-		return 2
+		os.Exit(2)
 	}
 
 	// If a random seed was used, the user won't be able to reproduce the
@@ -283,12 +279,11 @@ func main1() int {
 	}
 	if err := mainErr(args); err != nil {
 		if code, ok := err.(errJustExit); ok {
-			return int(code)
+			os.Exit(int(code))
 		}
 		fmt.Fprintln(os.Stderr, err)
-		return 1
+		os.Exit(1)
 	}
-	return 0
 }
 
 type errJustExit int
@@ -358,13 +353,13 @@ func mainErr(args []string) error {
 	case "help":
 		if hasHelpFlag(args) || len(args) > 1 {
 			fmt.Fprintf(os.Stderr, "usage: garble help [command]\n")
-			return errJustExit(2)
+			return errJustExit(0)
 		}
 		if len(args) == 1 {
 			return mainErr([]string{args[0], "-h"})
 		}
 		usage()
-		return errJustExit(2)
+		return errJustExit(0)
 	case "version":
 		if hasHelpFlag(args) || len(args) > 0 {
 			fmt.Fprintf(os.Stderr, "usage: garble version\n")

main_test.go

@@ -41,11 +41,11 @@ func TestMain(m *testing.M) {
 		os.Setenv("GORACE", "atexit_sleep_ms=10")
 	}
 	if os.Getenv("RUN_GARBLE_MAIN") == "true" {
-		os.Exit(main1())
+		main()
 	}
-	os.Exit(testscript.RunMain(garbleMain{m}, map[string]func() int{
-		"garble": main1,
-	}))
+	testscript.Main(garbleMain{m}, map[string]func(){
+		"garble": main,
+	})
 }
 
 type garbleMain struct {

testdata/script/help.txtar

@@ -4,22 +4,22 @@ stderr 'garble \[garble flags\] command'
 ! stderr 'usage: go build'
 ! stdout .
 
-! exec garble -h
+exec garble -h
 stderr 'Garble obfuscates Go code'
 stderr 'garble \[garble flags\] command'
 ! stdout .
 
-! exec garble help
+exec garble help
 stderr 'Garble obfuscates Go code'
 stderr 'garble \[garble flags\] command'
 ! stdout .
 
-! exec garble help foo bar
+exec garble help foo bar
 stderr 'usage: garble help'
 ! stderr 'Garble obfuscates Go code'
 ! stdout .
 
-! exec garble help -h
+exec garble help -h
 stderr 'usage: garble help'
 ! stdout .