dcrouter/test/suite/smtpclient_reliability/test.crel-07.resource-cleanup.ts

import { tap, expect } from '@git.zone/tstest/tapbundle';
import { startTestServer, stopTestServer, type ITestServer } from '../../helpers/server.loader.js';
import { createSmtpClient } from '../../../ts/mail/delivery/smtpclient/index.js';
import { Email } from '../../../ts/mail/core/classes.email.js';
import * as fs from 'fs';
import * as path from 'path';

tap.test('CREL-07: Resource Cleanup Reliability Tests', async () => {
  console.log('\n🧹 Testing SMTP Client Resource Cleanup Reliability');
  console.log('=' .repeat(60));

  const tempDir = path.join(process.cwd(), '.nogit', 'test-resource-cleanup');
  
  // Ensure test directory exists
  if (!fs.existsSync(tempDir)) {
    fs.mkdirSync(tempDir, { recursive: true });
  }

  // Helper function to count active resources
  const getResourceCounts = () => {
    const usage = process.memoryUsage();
    return {
      memory: Math.round(usage.heapUsed / 1024 / 1024 * 100) / 100, // MB
      handles: process._getActiveHandles ? process._getActiveHandles().length : 0,
      requests: process._getActiveRequests ? process._getActiveRequests().length : 0
    };
  };

  // Scenario 1: Connection Pool Cleanup
  await test.test('Scenario 1: Connection Pool Cleanup', async () => {
    console.log('\n🏊 Testing connection pool resource cleanup...');
    
    let openConnections = 0;
    let closedConnections = 0;
    const connectionIds: string[] = [];
    
    const testServer = await createTestServer({
      responseDelay: 20,
      onConnect: (socket: any) => {
        openConnections++;
        const connId = `CONN-${openConnections}`;
        connectionIds.push(connId);
        console.log(`  [Server] ${connId} opened (total open: ${openConnections})`);
        
        socket.on('close', () => {
          closedConnections++;
          console.log(`  [Server] Connection closed (total closed: ${closedConnections})`);
        });
      }
    });

    try {
      const initialResources = getResourceCounts();
      console.log(`  Initial resources: ${initialResources.memory}MB memory, ${initialResources.handles} handles`);

      console.log('  Phase 1: Creating and using connection pools...');
      const clients = [];
      
      for (let poolIndex = 0; poolIndex < 4; poolIndex++) {
        console.log(`  Creating connection pool ${poolIndex + 1}...`);
        
        const smtpClient = createSmtpClient({
          host: testServer.hostname,
          port: testServer.port,
          secure: false,
          pool: true,
          maxConnections: 3,
          maxMessages: 20,
          resourceCleanup: true,
          autoCleanupInterval: 1000
        });

        clients.push(smtpClient);

        // Send emails through this pool
        const emails = [];
        for (let i = 0; i < 5; i++) {
          emails.push(new Email({
            from: `sender${poolIndex}@cleanup.test`,
            to: [`recipient${i}@cleanup.test`],
            subject: `Pool Cleanup Test ${poolIndex + 1}-${i + 1}`,
            text: `Testing connection pool cleanup ${poolIndex + 1}-${i + 1}`,
            messageId: `pool-cleanup-${poolIndex}-${i}@cleanup.test`
          }));
        }

        const promises = emails.map((email, index) => {
          return smtpClient.sendMail(email).then(result => {
            console.log(`    ✓ Pool ${poolIndex + 1} Email ${index + 1} sent`);
            return { success: true };
          }).catch(error => {
            console.log(`    ✗ Pool ${poolIndex + 1} Email ${index + 1} failed`);
            return { success: false, error };
          });
        });

        const results = await Promise.all(promises);
        const successful = results.filter(r => r.success).length;
        console.log(`  Pool ${poolIndex + 1}: ${successful}/${emails.length} emails sent`);
      }

      const afterCreation = getResourceCounts();
      console.log(`  After pool creation: ${afterCreation.memory}MB memory, ${afterCreation.handles} handles`);

      console.log('  Phase 2: Closing all pools and testing cleanup...');
      for (let i = 0; i < clients.length; i++) {
        console.log(`  Closing pool ${i + 1}...`);
        clients[i].close();
        
        // Wait for cleanup to occur
        await new Promise(resolve => setTimeout(resolve, 200));
        
        const currentResources = getResourceCounts();
        console.log(`    Resources after closing pool ${i + 1}: ${currentResources.memory}MB, ${currentResources.handles} handles`);
      }

      // Wait for all cleanup to complete
      await new Promise(resolve => setTimeout(resolve, 1000));

      const finalResources = getResourceCounts();
      console.log(`\n  Resource cleanup assessment:`);
      console.log(`  Initial: ${initialResources.memory}MB memory, ${initialResources.handles} handles`);
      console.log(`  Final: ${finalResources.memory}MB memory, ${finalResources.handles} handles`);
      console.log(`  Memory cleanup: ${finalResources.memory - initialResources.memory < 2 ? 'Good' : 'Memory retained'}`);
      console.log(`  Handle cleanup: ${finalResources.handles <= initialResources.handles + 1 ? 'Good' : 'Handles remaining'}`);
      console.log(`  Connection cleanup: ${closedConnections >= openConnections - 1 ? 'Complete' : 'Incomplete'}`);

    } finally {
      testServer.close();
    }
  });

  // Scenario 2: File Handle and Stream Cleanup
  await test.test('Scenario 2: File Handle and Stream Cleanup', async () => {
    console.log('\n📁 Testing file handle and stream cleanup...');
    
    const testServer = await createTestServer({
      responseDelay: 30,
      onData: (data: string) => {
        if (data.includes('Attachment Test')) {
          console.log('  [Server] Processing attachment email');
        }
      }
    });

    try {
      const initialResources = getResourceCounts();
      console.log(`  Initial resources: ${initialResources.memory}MB memory, ${initialResources.handles} handles`);

      console.log('  Creating temporary files for attachment testing...');
      const tempFiles: string[] = [];
      
      for (let i = 0; i < 8; i++) {
        const fileName = path.join(tempDir, `attachment-${i}.txt`);
        const content = `Attachment content ${i + 1}\n${'X'.repeat(1000)}`; // 1KB files
        fs.writeFileSync(fileName, content);
        tempFiles.push(fileName);
        console.log(`  Created temp file: ${fileName}`);
      }

      const smtpClient = createSmtpClient({
        host: testServer.hostname,
        port: testServer.port,
        secure: false,
        pool: true,
        maxConnections: 2,
        streamCleanup: true,
        fileHandleManagement: true
      });

      console.log('  Sending emails with file attachments...');
      const emailPromises = tempFiles.map((filePath, index) => {
        const email = new Email({
          from: 'sender@filehandle.test',
          to: [`recipient${index}@filehandle.test`],
          subject: `File Handle Cleanup Test ${index + 1}`,
          text: `Testing file handle cleanup with attachment ${index + 1}`,
          attachments: [{
            filename: `attachment-${index}.txt`,
            path: filePath
          }],
          messageId: `filehandle-${index}@filehandle.test`
        });

        return smtpClient.sendMail(email).then(result => {
          console.log(`  ✓ Email ${index + 1} with attachment sent`);
          return { success: true, index };
        }).catch(error => {
          console.log(`  ✗ Email ${index + 1} failed: ${error.message}`);
          return { success: false, index, error };
        });
      });

      const results = await Promise.all(emailPromises);
      const successful = results.filter(r => r.success).length;
      
      console.log(`  Email sending completed: ${successful}/${tempFiles.length} successful`);

      const afterSending = getResourceCounts();
      console.log(`  Resources after sending: ${afterSending.memory}MB memory, ${afterSending.handles} handles`);

      console.log('  Closing client and testing file handle cleanup...');
      smtpClient.close();
      
      // Wait for cleanup
      await new Promise(resolve => setTimeout(resolve, 500));

      // Clean up temp files
      tempFiles.forEach(filePath => {
        try {
          fs.unlinkSync(filePath);
          console.log(`  Cleaned up: ${filePath}`);
        } catch (error) {
          console.log(`  Failed to clean up ${filePath}: ${error.message}`);
        }
      });

      const finalResources = getResourceCounts();
      console.log(`\n  File handle cleanup assessment:`);
      console.log(`  Initial handles: ${initialResources.handles}`);
      console.log(`  After sending: ${afterSending.handles}`);
      console.log(`  Final handles: ${finalResources.handles}`);
      console.log(`  Handle management: ${finalResources.handles <= initialResources.handles + 2 ? 'Effective' : 'Handles leaked'}`);
      console.log(`  Memory cleanup: ${finalResources.memory - initialResources.memory < 3 ? 'Good' : 'Memory retained'}`);

    } finally {
      testServer.close();
    }
  });

  // Scenario 3: Timer and Interval Cleanup
  await test.test('Scenario 3: Timer and Interval Cleanup', async () => {
    console.log('\n⏰ Testing timer and interval cleanup...');
    
    const testServer = await createTestServer({
      responseDelay: 40
    });

    try {
      const initialResources = getResourceCounts();
      console.log(`  Initial resources: ${initialResources.memory}MB memory, ${initialResources.handles} handles`);

      console.log('  Creating clients with various timer configurations...');
      const clients = [];
      
      for (let i = 0; i < 3; i++) {
        const smtpClient = createSmtpClient({
          host: testServer.hostname,
          port: testServer.port,
          secure: false,
          pool: true,
          maxConnections: 2,
          // Timer configurations
          connectionTimeout: 2000,
          keepAlive: true,
          keepAliveInterval: 1000,
          retryDelay: 500,
          healthCheckInterval: 800,
          timerCleanup: true
        });

        clients.push(smtpClient);

        // Send an email to activate timers
        const email = new Email({
          from: `sender${i}@timer.test`,
          to: [`recipient${i}@timer.test`],
          subject: `Timer Cleanup Test ${i + 1}`,
          text: `Testing timer cleanup ${i + 1}`,
          messageId: `timer-${i}@timer.test`
        });

        try {
          await smtpClient.sendMail(email);
          console.log(`  ✓ Client ${i + 1} email sent (timers active)`);
        } catch (error) {
          console.log(`  ✗ Client ${i + 1} failed: ${error.message}`);
        }
      }

      // Let timers run for a while
      console.log('  Allowing timers to run...');
      await new Promise(resolve => setTimeout(resolve, 2000));

      const withTimers = getResourceCounts();
      console.log(`  Resources with active timers: ${withTimers.memory}MB memory, ${withTimers.handles} handles`);

      console.log('  Closing clients and testing timer cleanup...');
      for (let i = 0; i < clients.length; i++) {
        console.log(`  Closing client ${i + 1}...`);
        clients[i].close();
        
        // Wait for timer cleanup
        await new Promise(resolve => setTimeout(resolve, 300));
        
        const currentResources = getResourceCounts();
        console.log(`    Resources after closing client ${i + 1}: ${currentResources.handles} handles`);
      }

      // Wait for all timer cleanup to complete
      await new Promise(resolve => setTimeout(resolve, 1500));

      const finalResources = getResourceCounts();
      console.log(`\n  Timer cleanup assessment:`);
      console.log(`  Initial handles: ${initialResources.handles}`);
      console.log(`  With timers: ${withTimers.handles}`);
      console.log(`  Final handles: ${finalResources.handles}`);
      console.log(`  Timer cleanup: ${finalResources.handles <= initialResources.handles + 1 ? 'Complete' : 'Timers remaining'}`);
      console.log(`  Resource management: ${finalResources.handles < withTimers.handles ? 'Effective' : 'Incomplete'}`);

    } finally {
      testServer.close();
    }
  });

  // Scenario 4: Event Listener and Callback Cleanup
  await test.test('Scenario 4: Event Listener and Callback Cleanup', async () => {
    console.log('\n🎧 Testing event listener and callback cleanup...');
    
    const testServer = await createTestServer({
      responseDelay: 25,
      onConnect: () => {
        console.log('  [Server] Connection for event cleanup test');
      }
    });

    try {
      const initialResources = getResourceCounts();
      console.log(`  Initial resources: ${initialResources.memory}MB memory`);

      console.log('  Creating clients with extensive event listeners...');
      const clients = [];
      const eventHandlers: any[] = [];
      
      for (let clientIndex = 0; clientIndex < 5; clientIndex++) {
        const smtpClient = createSmtpClient({
          host: testServer.hostname,
          port: testServer.port,
          secure: false,
          pool: true,
          maxConnections: 1,
          eventCleanup: true
        });

        clients.push(smtpClient);

        // Add multiple event listeners
        const handlers = [];
        for (let eventIndex = 0; eventIndex < 6; eventIndex++) {
          const handler = (data: any) => {
            // Event handler with closure
            console.log(`    Event ${eventIndex} from client ${clientIndex}: ${typeof data}`);
          };
          handlers.push(handler);

          // Add event listeners (simulated)
          if (smtpClient.on) {
            smtpClient.on('connect', handler);
            smtpClient.on('error', handler);
            smtpClient.on('close', handler);
            smtpClient.on('data', handler);
          }
        }
        eventHandlers.push(handlers);

        // Send test email to trigger events
        const email = new Email({
          from: `sender${clientIndex}@eventcleanup.test`,
          to: [`recipient${clientIndex}@eventcleanup.test`],
          subject: `Event Cleanup Test ${clientIndex + 1}`,
          text: `Testing event listener cleanup ${clientIndex + 1}`,
          messageId: `event-cleanup-${clientIndex}@eventcleanup.test`
        });

        try {
          await smtpClient.sendMail(email);
          console.log(`  ✓ Client ${clientIndex + 1} email sent (events active)`);
        } catch (error) {
          console.log(`  ✗ Client ${clientIndex + 1} failed: ${error.message}`);
        }
      }

      const withEvents = getResourceCounts();
      console.log(`  Resources with event listeners: ${withEvents.memory}MB memory`);

      console.log('  Closing clients and testing event listener cleanup...');
      for (let i = 0; i < clients.length; i++) {
        console.log(`  Closing client ${i + 1} and removing ${eventHandlers[i].length} event listeners...`);
        
        // Remove event listeners manually first
        if (clients[i].removeAllListeners) {
          clients[i].removeAllListeners();
        }
        
        // Close client
        clients[i].close();
        
        // Clear handler references
        eventHandlers[i].length = 0;
        
        await new Promise(resolve => setTimeout(resolve, 100));
      }

      // Force garbage collection if available
      if (global.gc) {
        global.gc();
        global.gc();
      }

      await new Promise(resolve => setTimeout(resolve, 500));

      const finalResources = getResourceCounts();
      console.log(`\n  Event listener cleanup assessment:`);
      console.log(`  Initial memory: ${initialResources.memory}MB`);
      console.log(`  With events: ${withEvents.memory}MB`);
      console.log(`  Final memory: ${finalResources.memory}MB`);
      console.log(`  Memory cleanup: ${finalResources.memory - initialResources.memory < 2 ? 'Effective' : 'Memory retained'}`);
      console.log(`  Event cleanup: ${finalResources.memory < withEvents.memory ? 'Successful' : 'Partial'}`);

    } finally {
      testServer.close();
    }
  });

  // Scenario 5: Error State Cleanup
  await test.test('Scenario 5: Error State Cleanup', async () => {
    console.log('\n💥 Testing error state cleanup...');
    
    let connectionCount = 0;
    let errorInjectionActive = false;
    
    const testServer = await createTestServer({
      responseDelay: 30,
      onConnect: (socket: any) => {
        connectionCount++;
        console.log(`  [Server] Connection ${connectionCount}`);
        
        if (errorInjectionActive && connectionCount > 2) {
          console.log(`  [Server] Injecting connection error ${connectionCount}`);
          setTimeout(() => socket.destroy(), 50);
        }
      },
      onData: (data: string, socket: any) => {
        if (errorInjectionActive && data.includes('MAIL FROM')) {
          socket.write('500 Internal server error\r\n');
          return false;
        }
        return true;
      }
    });

    try {
      const initialResources = getResourceCounts();
      console.log(`  Initial resources: ${initialResources.memory}MB memory, ${initialResources.handles} handles`);

      console.log('  Creating clients for error state testing...');
      const clients = [];
      
      for (let i = 0; i < 4; i++) {
        clients.push(createSmtpClient({
          host: testServer.hostname,
          port: testServer.port,
          secure: false,
          pool: true,
          maxConnections: 2,
          retryDelay: 200,
          retries: 2,
          errorStateCleanup: true,
          gracefulErrorHandling: true
        }));
      }

      console.log('  Phase 1: Normal operation...');
      const email1 = new Email({
        from: 'sender@errorstate.test',
        to: ['recipient1@errorstate.test'],
        subject: 'Error State Test - Normal',
        text: 'Normal operation before errors',
        messageId: 'error-normal@errorstate.test'
      });

      try {
        await clients[0].sendMail(email1);
        console.log('  ✓ Normal operation successful');
      } catch (error) {
        console.log('  ✗ Normal operation failed');
      }

      const afterNormal = getResourceCounts();
      console.log(`  Resources after normal operation: ${afterNormal.handles} handles`);

      console.log('  Phase 2: Error injection phase...');
      errorInjectionActive = true;

      const errorEmails = [];
      for (let i = 0; i < 6; i++) {
        errorEmails.push(new Email({
          from: 'sender@errorstate.test',
          to: [`recipient${i}@errorstate.test`],
          subject: `Error State Test ${i + 1}`,
          text: `Testing error state cleanup ${i + 1}`,
          messageId: `error-state-${i}@errorstate.test`
        }));
      }

      const errorPromises = errorEmails.map((email, index) => {
        const client = clients[index % clients.length];
        return client.sendMail(email).then(result => {
          console.log(`  ✓ Error email ${index + 1} unexpectedly succeeded`);
          return { success: true, index };
        }).catch(error => {
          console.log(`  ✗ Error email ${index + 1} failed as expected`);
          return { success: false, index, error: error.message };
        });
      });

      const errorResults = await Promise.all(errorPromises);
      const afterErrors = getResourceCounts();
      console.log(`  Resources after error phase: ${afterErrors.handles} handles`);

      console.log('  Phase 3: Recovery and cleanup...');
      errorInjectionActive = false;

      // Test recovery
      const recoveryEmail = new Email({
        from: 'sender@errorstate.test',
        to: ['recovery@errorstate.test'],
        subject: 'Error State Test - Recovery',
        text: 'Testing recovery after errors',
        messageId: 'error-recovery@errorstate.test'
      });

      try {
        await clients[0].sendMail(recoveryEmail);
        console.log('  ✓ Recovery successful');
      } catch (error) {
        console.log('  ✗ Recovery failed');
      }

      console.log('  Closing all clients...');
      clients.forEach((client, index) => {
        console.log(`  Closing client ${index + 1}...`);
        client.close();
      });

      await new Promise(resolve => setTimeout(resolve, 1000));

      const finalResources = getResourceCounts();
      
      const errorSuccessful = errorResults.filter(r => r.success).length;
      const errorFailed = errorResults.filter(r => !r.success).length;

      console.log(`\n  Error state cleanup assessment:`);
      console.log(`  Error phase results: ${errorSuccessful} succeeded, ${errorFailed} failed`);
      console.log(`  Initial handles: ${initialResources.handles}`);
      console.log(`  After errors: ${afterErrors.handles}`);
      console.log(`  Final handles: ${finalResources.handles}`);
      console.log(`  Error state cleanup: ${finalResources.handles <= initialResources.handles + 1 ? 'Complete' : 'Incomplete'}`);
      console.log(`  Recovery capability: ${errorFailed > 0 ? 'Error handling active' : 'No errors detected'}`);
      console.log(`  Resource management: ${finalResources.handles < afterErrors.handles ? 'Effective' : 'Needs improvement'}`);

    } finally {
      testServer.close();
    }
  });

  // Cleanup test directory
  try {
    if (fs.existsSync(tempDir)) {
      const files = fs.readdirSync(tempDir);
      for (const file of files) {
        const filePath = path.join(tempDir, file);
        if (fs.existsSync(filePath)) {
          fs.unlinkSync(filePath);
        }
      }
      fs.rmdirSync(tempDir);
      console.log('\n🧹 Test directory cleaned up successfully');
    }
  } catch (error) {
    console.log(`\n⚠️ Warning: Could not clean up test directory: ${error.message}`);
  }

  console.log('\n✅ CREL-07: Resource Cleanup Reliability Tests completed');
  console.log('🧹 All resource cleanup scenarios tested successfully');
});