[建议] 为 async engine 和 smart_scheduler 添加单元测试

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现状

test_crawler.py 有 294 个测试，覆盖了工具函数、parser、storage 等模块。但以下核心组件完全没有测试：

组件	文件	重要性
异步爬取引擎	crawler/engine.py	核心，负责所有网络请求
智能调度器	crawler/smart_scheduler.py	决定哪些站点需要爬取
GitHub Actions 告警	alerter.py	故障通知
Gist 存储	gist_store.py	数据持久化
Playwright 渲染	crawler/network.py (Playwright path)	JS 渲染站点

改进建议

优先级 1：smart_scheduler

def test_should_crawl_high_tier_within_interval():
    """High-tier sites should always be crawled when interval elapsed."""

def test_should_skip_recently_crawched():
    """Sites crawled 5 min ago with 30-min interval should be skipped."""

def test_night_mode_triples_interval():
    """Between 23:00-07:00, interval should be multiplied by 3."""

优先级 2：alerter

def test_alert_triggered_after_consecutive_failures():
    """Alert should fire after N consecutive failures for a site."""

def test_no_duplicate_alerts():
    """Same failure should not trigger multiple alerts."""

优先级 3：engine（使用 mock）

@patch('aiohttp.ClientSession')
async def test_ssrf_blocks_private_ip():
    """Redirect to 192.168.x.x should be blocked."""

预期效果

• 核心逻辑变更时有回归保护
• 新贡献者更容易理解各组件的预期行为
• CI 测试覆盖率从 ~60% 提升到 ~85%

复杂度

高。需要 mock 网络请求和 asyncio 事件循环。