fix(exec): terminate process tree on timeout

pkg/tools/shell_timeout_unix_test.go

@@ -0,0 +1,61 @@
+//go:build !windows
+
+package tools
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func processExists(pid int) bool {
+	if pid <= 0 {
+		return false
+	}
+	err := syscall.Kill(pid, 0)
+	return err == nil || err == syscall.EPERM
+}
+
+func TestShellTool_TimeoutKillsChildProcess(t *testing.T) {
+	tool := NewExecTool(t.TempDir(), false)
+	tool.SetTimeout(500 * time.Millisecond)
+
+	args := map[string]interface{}{
+		// Spawn a child process that would outlive the shell unless process-group kill is used.
+		"command": "sleep 60 & echo $! > child.pid; wait",
+	}
+
+	result := tool.Execute(context.Background(), args)
+	if !result.IsError {
+		t.Fatalf("expected timeout error, got success: %s", result.ForLLM)
+	}
+	if !strings.Contains(result.ForLLM, "timed out") {
+		t.Fatalf("expected timeout message, got: %s", result.ForLLM)
+	}
+
+	childPIDPath := filepath.Join(tool.workingDir, "child.pid")
+	data, err := os.ReadFile(childPIDPath)
+	if err != nil {
+		t.Fatalf("failed to read child pid file: %v", err)
+	}
+
+	childPID, err := strconv.Atoi(strings.TrimSpace(string(data)))
+	if err != nil {
+		t.Fatalf("failed to parse child pid: %v", err)
+	}
+
+	deadline := time.Now().Add(2 * time.Second)
+	for time.Now().Before(deadline) {
+		if !processExists(childPID) {
+			return
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+
+	t.Fatalf("child process %d is still running after timeout", childPID)
+}