feat(tests,client): add flow control and load test coverage and honor configured keepalive intervals

changelog.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 2026-03-17 - 1.3.0 - feat(tests,client)
+add flow control and load test coverage and honor configured keepalive intervals
+
+- Adds end-to-end node tests for client/server flow control, keepalive exchange, connection quality telemetry, rate limiting, concurrent clients, and disconnect tracking.
+- Adds load testing with throttled proxy scenarios to validate behavior under constrained bandwidth and repeated client churn.
+- Updates the Rust client to pass configured keepaliveIntervalSecs into the adaptive keepalive monitor instead of always using defaults.
+
 ## 2026-03-15 - 1.2.0 - feat(readme)
 document QoS, telemetry, MTU, and rate limiting capabilities in the README
 

rust/src/client.rs

@@ -167,8 +167,15 @@ impl VpnClient {
 
         info!("Connected to VPN, assigned IP: {}", assigned_ip);
 
-        // Create adaptive keepalive monitor
-        let (monitor, handle) = keepalive::create_keepalive(None);
+        // Create adaptive keepalive monitor (use custom interval if configured)
+        let ka_config = config.keepalive_interval_secs.map(|secs| {
+            let mut cfg = keepalive::AdaptiveKeepaliveConfig::default();
+            cfg.degraded_interval = std::time::Duration::from_secs(secs);
+            cfg.healthy_interval = std::time::Duration::from_secs(secs * 2);
+            cfg.critical_interval = std::time::Duration::from_secs((secs / 3).max(1));
+            cfg
+        });
+        let (monitor, handle) = keepalive::create_keepalive(ka_config);
         self.quality_rx = Some(handle.quality_rx);
 
         // Spawn the keepalive monitor

test/test.flowcontrol.node.ts

@@ -0,0 +1,271 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as net from 'net';
+import { VpnClient, VpnServer } from '../ts/index.js';
+import type { IVpnClientOptions, IVpnServerOptions, IVpnKeypair, IVpnServerConfig } from '../ts/index.js';
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+async function findFreePort(): Promise<number> {
+  const server = net.createServer();
+  await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve));
+  const port = (server.address() as net.AddressInfo).port;
+  await new Promise<void>((resolve) => server.close(() => resolve()));
+  return port;
+}
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function waitFor(
+  fn: () => Promise<boolean>,
+  timeoutMs: number = 10000,
+  pollMs: number = 500,
+): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    if (await fn()) return;
+    await delay(pollMs);
+  }
+  throw new Error(`waitFor timed out after ${timeoutMs}ms`);
+}
+
+// ---------------------------------------------------------------------------
+// Test state
+// ---------------------------------------------------------------------------
+
+let server: VpnServer;
+let serverPort: number;
+let keypair: IVpnKeypair;
+let client: VpnClient;
+const extraClients: VpnClient[] = [];
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+tap.test('setup: start VPN server', async () => {
+  serverPort = await findFreePort();
+
+  const options: IVpnServerOptions = {
+    transport: { transport: 'stdio' },
+  };
+  server = new VpnServer(options);
+
+  // Phase 1: start the daemon bridge
+  const started = await server['bridge'].start();
+  expect(started).toBeTrue();
+  expect(server.running).toBeTrue();
+
+  // Phase 2: generate a keypair
+  keypair = await server.generateKeypair();
+  expect(keypair.publicKey).toBeTypeofString();
+  expect(keypair.privateKey).toBeTypeofString();
+
+  // Phase 3: start the VPN listener
+  const serverConfig: IVpnServerConfig = {
+    listenAddr: `127.0.0.1:${serverPort}`,
+    privateKey: keypair.privateKey,
+    publicKey: keypair.publicKey,
+    subnet: '10.8.0.0/24',
+  };
+  await server['bridge'].sendCommand('start', { config: serverConfig });
+
+  // Verify server is now running
+  const status = await server.getStatus();
+  expect(status.state).toEqual('connected');
+});
+
+tap.test('single client connects and gets IP', async () => {
+  const options: IVpnClientOptions = {
+    transport: { transport: 'stdio' },
+  };
+  client = new VpnClient(options);
+  const started = await client.start();
+  expect(started).toBeTrue();
+
+  const result = await client.connect({
+    serverUrl: `ws://127.0.0.1:${serverPort}`,
+    serverPublicKey: keypair.publicKey,
+    keepaliveIntervalSecs: 3,
+  });
+
+  expect(result.assignedIp).toBeTypeofString();
+  expect(result.assignedIp).toStartWith('10.8.0.');
+
+  // Verify client status
+  const clientStatus = await client.getStatus();
+  expect(clientStatus.state).toEqual('connected');
+
+  // Verify server sees the client
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 1;
+  });
+  const clients = await server.listClients();
+  expect(clients.length).toEqual(1);
+  expect(clients[0].assignedIp).toEqual(result.assignedIp);
+});
+
+tap.test('keepalive exchange', async () => {
+  // Wait for at least 2 keepalive cycles (interval=3s, so 8s should be enough)
+  await delay(8000);
+
+  const clientStats = await client.getStatistics();
+  expect(clientStats.keepalivesSent).toBeGreaterThanOrEqual(1);
+  expect(clientStats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+
+  const serverStats = await server.getStatistics();
+  expect(serverStats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+  expect(serverStats.keepalivesSent).toBeGreaterThanOrEqual(1);
+
+  // Verify per-client keepalive tracking
+  const clients = await server.listClients();
+  expect(clients[0].keepalivesReceived).toBeGreaterThanOrEqual(1);
+});
+
+tap.test('connection quality telemetry', async () => {
+  const quality = await client.getConnectionQuality();
+
+  expect(quality.srttMs).toBeGreaterThanOrEqual(0);
+  expect(quality.jitterMs).toBeTypeofNumber();
+  expect(quality.minRttMs).toBeGreaterThanOrEqual(0);
+  expect(quality.maxRttMs).toBeGreaterThanOrEqual(0);
+  expect(quality.lossRatio).toBeTypeofNumber();
+  expect(['healthy', 'degraded', 'critical']).toContain(quality.linkHealth);
+});
+
+tap.test('rate limiting: set and verify', async () => {
+  const clients = await server.listClients();
+  const clientId = clients[0].clientId;
+
+  // Set a tight rate limit
+  await server.setClientRateLimit(clientId, 100, 100);
+
+  // Verify via telemetry
+  const telemetry = await server.getClientTelemetry(clientId);
+  expect(telemetry.rateLimitBytesPerSec).toEqual(100);
+  expect(telemetry.burstBytes).toEqual(100);
+  expect(telemetry.clientId).toEqual(clientId);
+});
+
+tap.test('rate limiting: removal', async () => {
+  const clients = await server.listClients();
+  const clientId = clients[0].clientId;
+
+  await server.removeClientRateLimit(clientId);
+
+  // Verify telemetry no longer shows rate limit
+  const telemetry = await server.getClientTelemetry(clientId);
+  expect(telemetry.rateLimitBytesPerSec).toBeNullOrUndefined();
+  expect(telemetry.burstBytes).toBeNullOrUndefined();
+
+  // Connection still healthy
+  const status = await client.getStatus();
+  expect(status.state).toEqual('connected');
+});
+
+tap.test('5 concurrent clients', async () => {
+  const assignedIps = new Set<string>();
+
+  // Get the first client's IP
+  const existingClients = await server.listClients();
+  assignedIps.add(existingClients[0].assignedIp);
+
+  for (let i = 0; i < 5; i++) {
+    const c = new VpnClient({ transport: { transport: 'stdio' } });
+    await c.start();
+    const result = await c.connect({
+      serverUrl: `ws://127.0.0.1:${serverPort}`,
+      serverPublicKey: keypair.publicKey,
+      keepaliveIntervalSecs: 3,
+    });
+    expect(result.assignedIp).toStartWith('10.8.0.');
+    assignedIps.add(result.assignedIp);
+    extraClients.push(c);
+  }
+
+  // All IPs should be unique (6 total: original + 5 new)
+  expect(assignedIps.size).toEqual(6);
+
+  // Server should see 6 clients
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 6;
+  });
+  const allClients = await server.listClients();
+  expect(allClients.length).toEqual(6);
+});
+
+tap.test('client disconnect tracking', async () => {
+  // Disconnect 3 of the 5 extra clients
+  for (let i = 0; i < 3; i++) {
+    const c = extraClients[i];
+    await c.disconnect();
+    c.stop();
+  }
+
+  // Wait for server to detect disconnections
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 3;
+  }, 15000);
+
+  const clients = await server.listClients();
+  expect(clients.length).toEqual(3);
+
+  const stats = await server.getStatistics();
+  expect(stats.totalConnections).toBeGreaterThanOrEqual(6);
+});
+
+tap.test('server-side client disconnection', async () => {
+  const clients = await server.listClients();
+  // Pick one of the remaining extra clients (not the original)
+  const targetClient = clients.find((c) => {
+    // Find a client that belongs to extraClients[3] or extraClients[4]
+    return c.clientId !== clients[0].clientId;
+  });
+  expect(targetClient).toBeTruthy();
+
+  await server.disconnectClient(targetClient!.clientId);
+
+  // Wait for server to update
+  await waitFor(async () => {
+    const remaining = await server.listClients();
+    return remaining.length === 2;
+  });
+
+  const remaining = await server.listClients();
+  expect(remaining.length).toEqual(2);
+});
+
+tap.test('teardown: stop all', async () => {
+  // Stop the original client
+  await client.disconnect();
+  client.stop();
+
+  // Stop remaining extra clients
+  for (const c of extraClients) {
+    if (c.running) {
+      try {
+        await c.disconnect();
+      } catch {
+        // May already be disconnected
+      }
+      c.stop();
+    }
+  }
+
+  await delay(500);
+
+  // Stop the server
+  await server.stopServer();
+  server.stop();
+  await delay(500);
+
+  expect(server.running).toBeFalse();
+});
+
+export default tap.start();

test/test.loadtest.node.ts

@@ -0,0 +1,357 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as net from 'net';
+import * as stream from 'stream';
+import { VpnClient, VpnServer } from '../ts/index.js';
+import type { IVpnKeypair, IVpnServerConfig } from '../ts/index.js';
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+async function findFreePort(): Promise<number> {
+  const server = net.createServer();
+  await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve));
+  const port = (server.address() as net.AddressInfo).port;
+  await new Promise<void>((resolve) => server.close(() => resolve()));
+  return port;
+}
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function waitFor(
+  fn: () => Promise<boolean>,
+  timeoutMs: number = 10000,
+  pollMs: number = 500,
+): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    if (await fn()) return;
+    await delay(pollMs);
+  }
+  throw new Error(`waitFor timed out after ${timeoutMs}ms`);
+}
+
+// ---------------------------------------------------------------------------
+// ThrottleProxy (adapted from remoteingress)
+// ---------------------------------------------------------------------------
+
+class ThrottleTransform extends stream.Transform {
+  private bytesPerSec: number;
+  private bucket: number;
+  private lastRefill: number;
+  private destroyed_: boolean = false;
+
+  constructor(bytesPerSecond: number) {
+    super();
+    this.bytesPerSec = bytesPerSecond;
+    this.bucket = bytesPerSecond;
+    this.lastRefill = Date.now();
+  }
+
+  _transform(chunk: Buffer, _encoding: BufferEncoding, callback: stream.TransformCallback) {
+    if (this.destroyed_) return;
+
+    const now = Date.now();
+    const elapsed = (now - this.lastRefill) / 1000;
+    this.bucket = Math.min(this.bytesPerSec, this.bucket + elapsed * this.bytesPerSec);
+    this.lastRefill = now;
+
+    if (chunk.length <= this.bucket) {
+      this.bucket -= chunk.length;
+      callback(null, chunk);
+    } else {
+      const deficit = chunk.length - this.bucket;
+      this.bucket = 0;
+      const delayMs = Math.min((deficit / this.bytesPerSec) * 1000, 1000);
+      setTimeout(() => {
+        if (this.destroyed_) { callback(); return; }
+        this.lastRefill = Date.now();
+        this.bucket = 0;
+        callback(null, chunk);
+      }, delayMs);
+    }
+  }
+
+  _destroy(err: Error | null, callback: (error: Error | null) => void) {
+    this.destroyed_ = true;
+    callback(err);
+  }
+}
+
+interface ThrottleProxy {
+  server: net.Server;
+  close: () => Promise<void>;
+}
+
+async function startThrottleProxy(
+  listenPort: number,
+  targetHost: string,
+  targetPort: number,
+  bytesPerSecond: number,
+): Promise<ThrottleProxy> {
+  const connections = new Set<net.Socket>();
+  const server = net.createServer((clientSock) => {
+    connections.add(clientSock);
+    const upstream = net.createConnection({ host: targetHost, port: targetPort });
+    connections.add(upstream);
+
+    const throttleUp = new ThrottleTransform(bytesPerSecond);
+    const throttleDown = new ThrottleTransform(bytesPerSecond);
+
+    clientSock.pipe(throttleUp).pipe(upstream);
+    upstream.pipe(throttleDown).pipe(clientSock);
+
+    let cleaned = false;
+    const cleanup = () => {
+      if (cleaned) return;
+      cleaned = true;
+      throttleUp.destroy();
+      throttleDown.destroy();
+      clientSock.destroy();
+      upstream.destroy();
+      connections.delete(clientSock);
+      connections.delete(upstream);
+    };
+    clientSock.on('error', () => cleanup());
+    upstream.on('error', () => cleanup());
+    throttleUp.on('error', () => cleanup());
+    throttleDown.on('error', () => cleanup());
+    clientSock.on('close', () => cleanup());
+    upstream.on('close', () => cleanup());
+  });
+
+  await new Promise<void>((resolve) => server.listen(listenPort, '127.0.0.1', resolve));
+  return {
+    server,
+    close: async () => {
+      for (const c of connections) c.destroy();
+      connections.clear();
+      await new Promise<void>((resolve) => server.close(() => resolve()));
+    },
+  };
+}
+
+// ---------------------------------------------------------------------------
+// Test state
+// ---------------------------------------------------------------------------
+
+let server: VpnServer;
+let serverPort: number;
+let proxyPort: number;
+let keypair: IVpnKeypair;
+let throttle: ThrottleProxy;
+const allClients: VpnClient[] = [];
+
+async function createConnectedClient(port: number): Promise<VpnClient> {
+  const c = new VpnClient({ transport: { transport: 'stdio' } });
+  await c.start();
+  await c.connect({
+    serverUrl: `ws://127.0.0.1:${port}`,
+    serverPublicKey: keypair.publicKey,
+    keepaliveIntervalSecs: 3,
+  });
+  allClients.push(c);
+  return c;
+}
+
+async function stopClient(c: VpnClient): Promise<void> {
+  if (c.running) {
+    try { await c.disconnect(); } catch { /* already disconnected */ }
+    c.stop();
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+tap.test('setup: start throttled VPN tunnel (1 MB/s)', async () => {
+  serverPort = await findFreePort();
+  proxyPort = await findFreePort();
+
+  // Start VPN server
+  server = new VpnServer({ transport: { transport: 'stdio' } });
+  const started = await server['bridge'].start();
+  expect(started).toBeTrue();
+
+  keypair = await server.generateKeypair();
+  const serverConfig: IVpnServerConfig = {
+    listenAddr: `127.0.0.1:${serverPort}`,
+    privateKey: keypair.privateKey,
+    publicKey: keypair.publicKey,
+    subnet: '10.8.0.0/24',
+  };
+  await server['bridge'].sendCommand('start', { config: serverConfig });
+
+  const status = await server.getStatus();
+  expect(status.state).toEqual('connected');
+
+  // Start throttle proxy: 1 MB/s
+  throttle = await startThrottleProxy(proxyPort, '127.0.0.1', serverPort, 1024 * 1024);
+});
+
+tap.test('throttled connection: handshake succeeds through throttle', async () => {
+  const client = await createConnectedClient(proxyPort);
+
+  const status = await client.getStatus();
+  expect(status.state).toEqual('connected');
+  expect(status.assignedIp).toStartWith('10.8.0.');
+
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 1;
+  });
+});
+
+tap.test('sustained keepalive under throttle', async () => {
+  // Wait for at least 2 keepalive cycles (3s interval)
+  await delay(8000);
+
+  const client = allClients[0];
+  const stats = await client.getStatistics();
+  expect(stats.keepalivesSent).toBeGreaterThanOrEqual(1);
+  expect(stats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+
+  // Throttle adds latency — RTT should be measurable
+  const quality = await client.getConnectionQuality();
+  expect(quality.srttMs).toBeGreaterThanOrEqual(0);
+  expect(quality.jitterMs).toBeTypeofNumber();
+});
+
+tap.test('3 concurrent throttled clients', async () => {
+  for (let i = 0; i < 3; i++) {
+    await createConnectedClient(proxyPort);
+  }
+
+  // All 4 clients should be visible
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 4;
+  });
+
+  const clients = await server.listClients();
+  expect(clients.length).toEqual(4);
+
+  // Verify all IPs are unique
+  const ips = new Set(clients.map((c) => c.assignedIp));
+  expect(ips.size).toEqual(4);
+});
+
+tap.test('rate limiting combined with network throttle', async () => {
+  const clients = await server.listClients();
+  const targetId = clients[0].clientId;
+
+  // Set rate limit on first client
+  await server.setClientRateLimit(targetId, 500, 500);
+  const telemetry = await server.getClientTelemetry(targetId);
+  expect(telemetry.rateLimitBytesPerSec).toEqual(500);
+  expect(telemetry.burstBytes).toEqual(500);
+
+  // Verify another client has no rate limit
+  const otherTelemetry = await server.getClientTelemetry(clients[1].clientId);
+  expect(otherTelemetry.rateLimitBytesPerSec).toBeNullOrUndefined();
+
+  // Clean up the rate limit
+  await server.removeClientRateLimit(targetId);
+});
+
+tap.test('burst waves: 3 waves of 3 clients', async () => {
+  const initialCount = (await server.listClients()).length;
+
+  for (let wave = 0; wave < 3; wave++) {
+    const waveClients: VpnClient[] = [];
+
+    // Connect 3 clients
+    for (let i = 0; i < 3; i++) {
+      const c = await createConnectedClient(proxyPort);
+      waveClients.push(c);
+    }
+
+    // Verify all connected
+    await waitFor(async () => {
+      const all = await server.listClients();
+      return all.length === initialCount + 3;
+    });
+
+    // Disconnect all wave clients
+    for (const c of waveClients) {
+      await stopClient(c);
+    }
+
+    // Wait for server to detect disconnections
+    await waitFor(async () => {
+      const all = await server.listClients();
+      return all.length === initialCount;
+    }, 15000);
+
+    await delay(500);
+  }
+
+  // Verify total connections accumulated
+  const stats = await server.getStatistics();
+  expect(stats.totalConnections).toBeGreaterThanOrEqual(9 + initialCount);
+
+  // Original clients still connected
+  const remaining = await server.listClients();
+  expect(remaining.length).toEqual(initialCount);
+});
+
+tap.test('aggressive throttle: 10 KB/s', async () => {
+  // Close current throttle proxy and start an aggressive one
+  await throttle.close();
+  const aggressivePort = await findFreePort();
+  throttle = await startThrottleProxy(aggressivePort, '127.0.0.1', serverPort, 10 * 1024);
+
+  // Connect a client through the aggressive throttle
+  const client = await createConnectedClient(aggressivePort);
+  const status = await client.getStatus();
+  expect(status.state).toEqual('connected');
+
+  // Wait for keepalive exchange (might take longer due to throttle)
+  await delay(10000);
+
+  const stats = await client.getStatistics();
+  expect(stats.keepalivesSent).toBeGreaterThanOrEqual(1);
+  expect(stats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+});
+
+tap.test('post-load health: direct connection still works', async () => {
+  // Server should still be healthy after all load tests
+  const serverStatus = await server.getStatus();
+  expect(serverStatus.state).toEqual('connected');
+
+  // Connect one more client directly (no throttle)
+  const directClient = await createConnectedClient(serverPort);
+  const status = await directClient.getStatus();
+  expect(status.state).toEqual('connected');
+
+  await delay(5000);
+
+  const stats = await directClient.getStatistics();
+  expect(stats.keepalivesSent).toBeGreaterThanOrEqual(1);
+});
+
+tap.test('teardown: stop all', async () => {
+  // Stop all clients
+  for (const c of allClients) {
+    await stopClient(c);
+  }
+
+  await delay(500);
+
+  // Close throttle proxy
+  if (throttle) {
+    await throttle.close();
+  }
+
+  // Stop server
+  await server.stopServer();
+  server.stop();
+  await delay(500);
+
+  expect(server.running).toBeFalse();
+});
+
+export default tap.start();

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartvpn',
-  version: '1.2.0',
+  version: '1.3.0',
   description: 'A VPN solution with TypeScript control plane and Rust data plane daemon'
 }