fixes

cmd/cli/main.go

@@ -1,9 +1,9 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"os"
-	"strings"
 
 	"github.com/Mond1c/judge/dsl"
 	"github.com/Mond1c/judge/reporter"
@@ -28,23 +28,25 @@ Example:
 `
 
 func main() {
-	args := os.Args[1:]
+	fs := flag.NewFlagSet("judge", flag.ContinueOnError)
+	fs.SetOutput(os.Stderr)
+	fs.Usage = func() { fmt.Fprint(os.Stderr, usage) }
 
-	if len(args) == 0 || contains(args, "--help") || contains(args, "-h") {
-		fmt.Print(usage)
-		os.Exit(0)
+	jsonOutput := fs.Bool("json", false, "output as JSON")
+	wrapper := fs.String("wrapper", "", "exec wrapper command")
+	binary := fs.String("binary", "", "binary name override")
+
+	if err := fs.Parse(os.Args[1:]); err != nil {
+		os.Exit(2)
 	}
 
-	if len(args) < 2 {
+	if fs.NArg() < 2 {
 		fmt.Fprintf(os.Stderr, "error: need <tests.jdg> and <solution-dir>\n\n%s", usage)
 		os.Exit(1)
 	}
 
-	testFile := args[0]
-	solutionDir := args[1]
-	jsonOutput := contains(args, "--json")
-	wrapper := flagValue(args, "--wrapper")
-	binary := flagValue(args, "--binary")
+	testFile := fs.Arg(0)
+	solutionDir := fs.Arg(1)
 
 	src, err := os.ReadFile(testFile)
 	if err != nil {
@@ -65,12 +67,12 @@ func main() {
 
 	r := runner.New(f, runner.Config{
 		WorkDir:    solutionDir,
-		BinaryName: binary,
-		Wrapper:    wrapper,
+		BinaryName: *binary,
+		Wrapper:    *wrapper,
 	})
 	result := r.Run()
 
-	if jsonOutput {
+	if *jsonOutput {
 		if err := reporter.JSON(os.Stdout, result); err != nil {
 			fatalf("json output error: %v", err)
 		}
@@ -87,26 +89,3 @@ func fatalf(msg string, args ...any) {
 	fmt.Fprintf(os.Stderr, "error: "+msg+"\n", args...)
 	os.Exit(1)
 }
-
-// flagValue returns the value of --name <value> or --name=value, else "".
-func flagValue(args []string, name string) string {
-	prefix := name + "="
-	for i, a := range args {
-		if a == name && i+1 < len(args) {
-			return args[i+1]
-		}
-		if strings.HasPrefix(a, prefix) {
-			return a[len(prefix):]
-		}
-	}
-	return ""
-}
-
-func contains(slice []string, s string) bool {
-	for _, v := range slice {
-		if v == s {
-			return true
-		}
-	}
-	return false
-}