tests: cover agent sequencing, tick watchdog, presence fingerprint

src/gateway/client.test.ts

@@ -0,0 +1,67 @@
+import { createServer } from "node:net";
+import { afterEach, describe, expect, test } from "vitest";
+import { WebSocketServer } from "ws";
+import { GatewayClient } from "./client.js";
+
+// Find a free localhost port for ad-hoc WS servers.
+async function getFreePort(): Promise<number> {
+  return await new Promise((resolve, reject) => {
+    const server = createServer();
+    server.listen(0, "127.0.0.1", () => {
+      const port = (server.address() as { port: number }).port;
+      server.close((err) => (err ? reject(err) : resolve(port)));
+    });
+  });
+}
+
+describe("GatewayClient", () => {
+  let wss: WebSocketServer | null = null;
+
+  afterEach(async () => {
+    if (wss) {
+      await new Promise<void>((resolve) => wss?.close(() => resolve()));
+      wss = null;
+    }
+  });
+
+  test("closes on missing ticks", async () => {
+    const port = await getFreePort();
+    wss = new WebSocketServer({ port, host: "127.0.0.1" });
+
+    wss.on("connection", (socket) => {
+      socket.once("message", () => {
+        // Respond with tiny tick interval to trigger watchdog quickly.
+        const helloOk = {
+          type: "hello-ok",
+          protocol: 1,
+          server: { version: "dev", connId: "c1" },
+          features: { methods: [], events: [] },
+          snapshot: {
+            presence: [],
+            health: {},
+            stateVersion: { presence: 1, health: 1 },
+            uptimeMs: 1,
+          },
+          policy: {
+            maxPayload: 512 * 1024,
+            maxBufferedBytes: 1024 * 1024,
+            tickIntervalMs: 5,
+          },
+        };
+        socket.send(JSON.stringify(helloOk));
+      });
+    });
+
+    const closed = new Promise<{ code: number; reason: string }>((resolve) => {
+      const client = new GatewayClient({
+        url: `ws://127.0.0.1:${port}`,
+        onClose: (code, reason) => resolve({ code, reason }),
+      });
+      client.start();
+    });
+
+    const res = await closed;
+    expect(res.code).toBe(4000);
+    expect(res.reason).toContain("tick timeout");
+  }, 4000);
+});