feat: NATS 连接与 JetStream 流引导（BPOS_EVT/CMD/DLQ）＋touch 发布

src/app/app.ts

@@ -1,7 +1,9 @@
 import { Hono } from 'hono';
-import { healthRoute } from './health';
+import { healthRoute, registerHealthCheck } from './health';
+import { checkNats } from '../shared/bus/nats';
 
 export function buildApp(): Hono {
+  registerHealthCheck('nats', checkNats);
   const app = new Hono();
   app.route('/health', healthRoute());
   return app;

src/shared/bus/nats.ts

@@ -0,0 +1,28 @@
+import { connect } from 'nats';
+import type { NatsConnection } from 'nats';
+import { config } from '../config';
+
+let nc: NatsConnection | null = null;
+
+export async function getNats(): Promise<NatsConnection> {
+  if (nc && !nc.isClosed()) return nc;
+  nc = await connect({ servers: config.natsUrl, name: config.serviceName, timeout: 5000 });
+  return nc;
+}
+
+export async function checkNats(): Promise<'ok' | 'fail'> {
+  try {
+    const c = await getNats();
+    await c.flush();
+    return 'ok';
+  } catch {
+    return 'fail';
+  }
+}
+
+export async function closeNats(): Promise<void> {
+  if (nc) {
+    await nc.drain().catch(() => {});
+    nc = null;
+  }
+}

test/unit/health.test.ts

@@ -1,12 +1,23 @@
-import { describe, expect, it } from 'vitest';
+import { describe, expect, it, vi } from 'vitest';
+
+// 单测不碰真实总线：mock 掉 bus/nats，真实模块（及其 NATS 连接）永不求值
+vi.mock('../../src/shared/bus/nats', () => ({
+  checkNats: async () => 'ok' as const,
+}));
+
 import { buildApp } from '../../src/app/app';
 
 describe('health', () => {
-  it('无探活项时返回 200 ok', async () => {
+  it('nats 探活 ok（mock）时返回 200', async () => {
     const res = await buildApp().request('/health');
     expect(res.status).toBe(200);
-    const body = (await res.json()) as { ok: boolean; service: string };
+    const body = (await res.json()) as {
+      ok: boolean;
+      service: string;
+      checks: Record<string, string>;
+    };
     expect(body.ok).toBe(true);
     expect(body.service).toMatch(/^bpos-service-/);
+    expect(body.checks['nats']).toBe('ok');
   });
 });