feat: use --version instead of version subcommand

cmd/go-cli-github/main.go

@@ -12,19 +12,26 @@ import (
 
 // CLI represents the command-line interface.
 type CLI struct {
-	Version VersionCmd `kong:"cmd,help='Print version information'"`
-	Serve   ServeCmd   `kong:"cmd,default=1,help='(default) Example serve command'"`
+	Version kong.VersionFlag `kong:"help='Print version information'"`
+	Serve   ServeCmd         `kong:"cmd,default=1,help='(default) Example serve command'"`
 }
 
 func main() {
 	ctx, stop := signal.NotifyContext(
 		context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer stop()
+	verJSON, err := formatVersionJSON()
+	if err != nil {
+		panic(err)
+	}
 	// parse CLI config
 	cli := CLI{}
 	kctx := kong.Parse(&cli,
 		kong.UsageOnError(),
 		kong.BindFor(ctx),
+		kong.Vars{
+			"version": verJSON,
+		},
 	)
 	// execute CLI
 	kctx.FatalIfErrorf(kctx.Run())

cmd/go-cli-github/version.go

@@ -1,9 +1,7 @@
 package main
 
 import (
-	"context"
-	"encoding/json"
-	"fmt"
+	"encoding/json/v2"
 	"runtime"
 )
 
@@ -15,11 +13,8 @@ var (
 	version     string
 )
 
-// VersionCmd represents the `version` command.
-type VersionCmd struct{}
-
-// Run the Version command.
-func (*VersionCmd) Run(ctx context.Context) error {
+// formatVersionJSON formats version information as a JSON string.
+func formatVersionJSON() (string, error) {
 	v, err := json.Marshal(
 		struct {
 			ProjectName string
@@ -35,8 +30,7 @@ func (*VersionCmd) Run(ctx context.Context) error {
 			runtime.Version(),
 		})
 	if err != nil {
-		return err
+		return "", err
 	}
-	_, err = fmt.Println(string(v))
-	return err
+	return string(v), nil
 }

go.mod

@@ -1,6 +1,6 @@
 module github.com/smlx/go-cli-github
 
-go 1.22.2
+go 1.27
 
 require (
 	github.com/alecthomas/assert/v2 v2.11.0