test: Enhance Coverage + CI (#1055)

Reviewed-on: https://gitea.com/gitea/runner/pulls/1055
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: bircni <bircni@icloud.com>

internal/pkg/process/treekill_test.go

@@ -0,0 +1,36 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package process
+
+import (
+	"context"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewTreeKillConfiguresCommand(t *testing.T) {
+	cmd := exec.CommandContext(context.Background(), "sleep", "1")
+	tk := NewTreeKill(cmd)
+
+	require.NotNil(t, tk)
+	require.NotNil(t, cmd.Cancel)
+	require.Equal(t, treeKillWaitDelay, cmd.WaitDelay)
+	require.NoError(t, cmd.Cancel())
+}
+
+func TestTreeKillCaptureStoresKiller(t *testing.T) {
+	cmd := exec.CommandContext(context.Background(), "sleep", "10")
+	cmd.SysProcAttr = SysProcAttr("", false)
+	tk := NewTreeKill(cmd)
+	require.NoError(t, cmd.Start())
+	defer func() { _ = cmd.Wait() }()
+
+	killer, err := tk.Capture(cmd.Process)
+	require.NoError(t, err)
+	require.NotNil(t, killer)
+	require.NoError(t, cmd.Cancel())
+	require.NoError(t, killer.Close())
+}