feat: enrich health-check response

Author: gusanthiago

src/transports/monitoringServer.ts

@@ -1,5 +1,6 @@
 import type express from "express";
 import { LogId } from "../common/logging/loggingDefinitions.js";
+import { packageInfo } from "../common/packageInfo.js";
 import type {
     DefaultMetrics,
     MonitoringServerFeature,
@@ -53,7 +54,14 @@ export class MonitoringServer<TMetrics extends DefaultMetrics = DefaultMetrics>
     protected override setupRoutes(): Promise<void> {
         if (this.features.includes("health-check")) {
             this.app.get("/health", (_req: express.Request, res: express.Response) => {
-                res.json({ status: "ok" });
+                // Health responses should never be cached by proxies or load balancers.
+                res.set("Cache-Control", "no-store");
+                res.json({
+                    status: "ok",
+                    version: packageInfo.version,
+                    uptimeSeconds: Math.floor(process.uptime()),
+                    timestamp: new Date().toISOString(),
+                });
             });
         }
 

tests/unit/transports/monitoringServer.test.ts

@@ -47,9 +47,20 @@ describe("MonitoringServer", () => {
 
             const response = await fetch(`${server.serverAddress}/health`);
             expect(response.status).toBe(200);
-            // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-            const body = await response.json();
-            expect(body).toEqual({ status: "ok" });
+            expect(response.headers.get("cache-control")).toBe("no-store");
+            const body = (await response.json()) as {
+                status: string;
+                version: string;
+                uptimeSeconds: number;
+                timestamp: string;
+            };
+            // status remains "ok" for backward compatibility with existing probes
+            expect(body.status).toBe("ok");
+            expect(typeof body.version).toBe("string");
+            expect(typeof body.uptimeSeconds).toBe("number");
+            expect(body.uptimeSeconds).toBeGreaterThanOrEqual(0);
+            // timestamp is a valid ISO date string
+            expect(Number.isNaN(Date.parse(body.timestamp))).toBe(false);
         });
 
         it("does not expose health endpoint when health-check feature is disabled", async () => {