Fix panic when error is not *exec.ExitError (Fixes #239)

exec.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"log"
 	"os"
 	"os/exec"
@@ -50,8 +51,16 @@ func runCmd(ctx context.Context, cancel context.CancelFunc, cmd string, args ...
 		log.Println("Command finished successfully.")
 	} else {
 		log.Printf("Command exited with error: %s\n", err)
-		// OPTIMIZE: This could be cleaner
-		os.Exit(err.(*exec.ExitError).Sys().(syscall.WaitStatus).ExitStatus())
+
+		var exitErr *exec.ExitError
+		if errors.As(err, &exitErr) {
+			if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
+				os.Exit(status.ExitStatus())
+			}
+		}
+
+		// Fallback for non-ExitError types (e.g., *os.SyscallError)
+		os.Exit(1)
 	}
 
 }

exec_error_test.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"errors"
+	"os/exec"
+	"syscall"
+	"testing"
+)
+
+// helper function mirroring the exit code extraction logic
+func extractExitCode(err error) int {
+	if err == nil {
+		return 0
+	}
+
+	var exitErr *exec.ExitError
+	if errors.As(err, &exitErr) {
+		if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
+			return status.ExitStatus()
+		}
+	}
+
+	return 1
+}
+
+func TestExtractExitCode_FromExitError(t *testing.T) {
+	cmd := exec.Command("sh", "-c", "exit 42")
+	err := cmd.Run()
+
+	if err == nil {
+		t.Fatalf("expected non-nil error")
+	}
+
+	code := extractExitCode(err)
+	if code != 42 {
+		t.Fatalf("expected exit code 42, got %d", code)
+	}
+}
+
+func TestExtractExitCode_FromGenericError(t *testing.T) {
+	err := errors.New("some generic error")
+
+	code := extractExitCode(err)
+	if code != 1 {
+		t.Fatalf("expected fallback exit code 1, got %d", code)
+	}
+}