fix(connection): filter zombie connections part 2

test/test.stuck-connection-cleanup.node.ts

@@ -0,0 +1,144 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as net from 'net';
+import { SmartProxy } from '../ts/index.js';
+import * as plugins from '../ts/plugins.js';
+
+tap.test('stuck connection cleanup - verify connections to hanging backends are cleaned up', async (tools) => {
+  console.log('\n=== Stuck Connection Cleanup Test ===');
+  console.log('Purpose: Verify that connections to backends that accept but never respond are cleaned up');
+  
+  // Create a hanging backend that accepts connections but never responds
+  let backendConnections = 0;
+  const hangingBackend = net.createServer((socket) => {
+    backendConnections++;
+    console.log(`Hanging backend: Connection ${backendConnections} received`);
+    // Accept the connection but never send any data back
+    // This simulates a hung backend service
+  });
+  
+  await new Promise<void>((resolve) => {
+    hangingBackend.listen(9997, () => {
+      console.log('✓ Hanging backend started on port 9997');
+      resolve();
+    });
+  });
+  
+  // Create proxy that forwards to hanging backend
+  const proxy = new SmartProxy({
+    routes: [{
+      name: 'to-hanging-backend',
+      match: { ports: 8589 },
+      action: {
+        type: 'forward',
+        target: { host: 'localhost', port: 9997 }
+      }
+    }],
+    keepAlive: true,
+    enableDetailedLogging: false,
+    inactivityTimeout: 5000, // 5 second inactivity check interval for faster testing
+  });
+  
+  await proxy.start();
+  console.log('✓ Proxy started on port 8589');
+  
+  // Create connections that will get stuck
+  console.log('\n--- Creating connections to hanging backend ---');
+  const clients: net.Socket[] = [];
+  
+  for (let i = 0; i < 5; i++) {
+    const client = net.connect(8589, 'localhost');
+    clients.push(client);
+    
+    await new Promise<void>((resolve) => {
+      client.on('connect', () => {
+        console.log(`Client ${i} connected`);
+        // Send data that will never get a response
+        client.write(`GET / HTTP/1.1\r\nHost: localhost\r\n\r\n`);
+        resolve();
+      });
+      
+      client.on('error', (err) => {
+        console.log(`Client ${i} error: ${err.message}`);
+        resolve();
+      });
+    });
+  }
+  
+  // Wait a moment for connections to establish
+  await plugins.smartdelay.delayFor(1000);
+  
+  // Check initial connection count
+  const initialCount = (proxy as any).connectionManager.getConnectionCount();
+  console.log(`\nInitial connection count: ${initialCount}`);
+  expect(initialCount).toEqual(5);
+  
+  // Get connection details
+  const connections = (proxy as any).connectionManager.getConnections();
+  let stuckCount = 0;
+  
+  for (const [id, record] of connections) {
+    if (record.bytesReceived > 0 && record.bytesSent === 0) {
+      stuckCount++;
+      console.log(`Stuck connection ${id}: received=${record.bytesReceived}, sent=${record.bytesSent}`);
+    }
+  }
+  
+  console.log(`Stuck connections found: ${stuckCount}`);
+  expect(stuckCount).toEqual(5);
+  
+  // Wait for inactivity check to run (it checks every 30s by default, but we set it to 5s)
+  console.log('\n--- Waiting for stuck connection detection (65 seconds) ---');
+  console.log('Note: Stuck connections are cleaned up after 60 seconds with no response');
+  
+  // Speed up time by manually triggering inactivity check after simulating time passage
+  // First, age the connections by updating their timestamps
+  const now = Date.now();
+  for (const [id, record] of connections) {
+    // Simulate that these connections are 61 seconds old
+    record.incomingStartTime = now - 61000;
+    record.lastActivity = now - 61000;
+  }
+  
+  // Manually trigger inactivity check
+  console.log('Manually triggering inactivity check...');
+  (proxy as any).connectionManager.performOptimizedInactivityCheck();
+  
+  // Wait for cleanup to complete
+  await plugins.smartdelay.delayFor(1000);
+  
+  // Check connection count after cleanup
+  const afterCleanupCount = (proxy as any).connectionManager.getConnectionCount();
+  console.log(`\nConnection count after cleanup: ${afterCleanupCount}`);
+  
+  // Verify termination stats
+  const stats = (proxy as any).connectionManager.getTerminationStats();
+  console.log('\nTermination stats:', stats);
+  
+  // All connections should be cleaned up as "stuck_no_response"
+  expect(afterCleanupCount).toEqual(0);
+  
+  // The termination reason might be under incoming or general stats
+  const stuckCleanups = (stats.incoming.stuck_no_response || 0) + 
+                       (stats.outgoing?.stuck_no_response || 0);
+  console.log(`Stuck cleanups detected: ${stuckCleanups}`);
+  expect(stuckCleanups).toBeGreaterThan(0);
+  
+  // Verify clients were disconnected
+  let closedClients = 0;
+  for (const client of clients) {
+    if (client.destroyed) {
+      closedClients++;
+    }
+  }
+  console.log(`Closed clients: ${closedClients}/5`);
+  expect(closedClients).toEqual(5);
+  
+  // Cleanup
+  console.log('\n--- Cleanup ---');
+  await proxy.stop();
+  hangingBackend.close();
+  
+  console.log('✓ Test complete: Stuck connections are properly detected and cleaned up');
+});
+
+tap.start();