feat: add health check route

Implement handleHealth endpoint for Bun.serve to verify DB connection.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/routes/health.js

@@ -0,0 +1,13 @@
+import logger from '../utils/logger.js';
+import { db } from '../db/index.js';
+import { sql } from 'drizzle-orm';
+
+export const handleHealth = async (req) => {
+  try {
+    await db.execute(sql`SELECT 1`);
+    return Response.json({ status: 'ok' }, { status: 200 });
+  } catch (error) {
+    logger.error('Health check failed', { error: error.message });
+    return Response.json({ status: 'error', error: error.message }, { status: 500 });
+  }
+};

test/health.test.js

@@ -0,0 +1,41 @@
+import { describe, it, expect, mock, beforeEach } from "bun:test";
+
+// Mock database layer
+const mockExecute = mock(() => Promise.resolve());
+
+mock.module("../src/db/index.js", () => ({
+  db: {
+    execute: mockExecute
+  }
+}));
+
+describe("Health Route Handler", () => {
+  let handleHealth;
+
+  beforeEach(async () => {
+    mockExecute.mockClear();
+    const healthRoute = await import("../src/routes/health.js");
+    handleHealth = healthRoute.handleHealth;
+  });
+
+  it("should return status 200 and ok when DB is healthy", async () => {
+    const req = new Request("http://localhost:3000/health");
+    const res = await handleHealth(req);
+
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body).toEqual({ status: "ok" });
+    expect(mockExecute).toHaveBeenCalled();
+  });
+
+  it("should return status 500 and error details when DB health check fails", async () => {
+    mockExecute.mockImplementationOnce(() => Promise.reject(new Error("DB Connection Failed")));
+    const req = new Request("http://localhost:3000/health");
+    const res = await handleHealth(req);
+
+    expect(res.status).toBe(500);
+    const body = await res.json();
+    expect(body.status).toBe("error");
+    expect(body.error).toBe("DB Connection Failed");
+  });
+});