dcrouter/test/suite/connection/test.plain-connection.ts

import { tap, expect } from '@git.zone/tstest/tapbundle';
import * as net from 'net';
import { startTestServer, stopTestServer, type ITestServer } from '../server.loader.js';

const TEST_PORT = 2525;
const TEST_TIMEOUT = 30000;

tap.test('Plain Connection - should establish basic TCP connection', async (tools) => {
  const done = tools.defer();
  
  // Start test server
  const testServer = await startTestServer();
  
  
  await new Promise(resolve => setTimeout(resolve, 1000));try {
    const socket = net.createConnection({
      host: 'localhost',
      port: TEST_PORT,
      timeout: TEST_TIMEOUT
    });
    
    const connected = await new Promise<boolean>((resolve) => {
      socket.once('connect', () => resolve(true));
      socket.once('error', () => resolve(false));
      setTimeout(() => resolve(false), 5000);
    });
    
    expect(connected).toBeTrue();
    
    if (connected) {
      console.log('Plain connection established:');
      console.log('- Local:', `${socket.localAddress}:${socket.localPort}`);
      console.log('- Remote:', `${socket.remoteAddress}:${socket.remotePort}`);
      
      // Close connection
      socket.destroy();
    }
    
  } finally {
    await stopTestServer();
    done.resolve();
  }
});

tap.test('Plain Connection - should receive SMTP banner on plain connection', async (tools) => {
  const done = tools.defer();
  
  // Start test server
  const testServer = await startTestServer();
  
  
  await new Promise(resolve => setTimeout(resolve, 1000));try {
    const socket = net.createConnection({
      host: 'localhost',
      port: TEST_PORT,
      timeout: TEST_TIMEOUT
    });
    
    await new Promise<void>((resolve, reject) => {
      socket.once('connect', () => resolve());
      socket.once('error', reject);
    });
    
    // Get banner
    const banner = await new Promise<string>((resolve) => {
      socket.once('data', (chunk) => resolve(chunk.toString()));
    });
    
    console.log('Received banner:', banner.trim());
    
    expect(banner).toInclude('220');
    expect(banner).toInclude('ESMTP');
    
    // Clean up
    socket.write('QUIT\r\n');
    socket.end();
    
  } finally {
    await stopTestServer();
    done.resolve();
  }
});

tap.test('Plain Connection - should complete full SMTP transaction on plain connection', async (tools) => {
  const done = tools.defer();
  
  // Start test server
  const testServer = await startTestServer();
  
  
  await new Promise(resolve => setTimeout(resolve, 1000));try {
    const socket = net.createConnection({
      host: 'localhost',
      port: TEST_PORT,
      timeout: TEST_TIMEOUT
    });
    
    await new Promise<void>((resolve, reject) => {
      socket.once('connect', () => resolve());
      socket.once('error', reject);
    });
    
    // Get banner
    await new Promise<string>((resolve) => {
      socket.once('data', (chunk) => resolve(chunk.toString()));
    });
    
    // Send EHLO
    socket.write('EHLO testhost\r\n');
    
    const ehloResponse = await new Promise<string>((resolve) => {
      let data = '';
      const handler = (chunk: Buffer) => {
        data += chunk.toString();
        if (data.includes('\r\n') && (data.match(/^250 /m) || data.match(/^250-.*\r\n250 /ms))) {
          socket.removeListener('data', handler);
          resolve(data);
        }
      };
      socket.on('data', handler);
    });
    
    expect(ehloResponse).toInclude('250');
    console.log('EHLO successful on plain connection');
    
    // Send MAIL FROM
    socket.write('MAIL FROM:<sender@example.com>\r\n');
    
    const mailResponse = await new Promise<string>((resolve) => {
      socket.once('data', (chunk) => resolve(chunk.toString()));
    });
    
    expect(mailResponse).toInclude('250');
    
    // Send RCPT TO
    socket.write('RCPT TO:<recipient@example.com>\r\n');
    
    const rcptResponse = await new Promise<string>((resolve) => {
      socket.once('data', (chunk) => resolve(chunk.toString()));
    });
    
    expect(rcptResponse).toInclude('250');
    
    // Send DATA
    socket.write('DATA\r\n');
    
    const dataResponse = await new Promise<string>((resolve) => {
      socket.once('data', (chunk) => resolve(chunk.toString()));
    });
    
    expect(dataResponse).toInclude('354');
    
    // Send email content
    const emailContent = 
      'From: sender@example.com\r\n' +
      'To: recipient@example.com\r\n' +
      'Subject: Plain Connection Test\r\n' +
      '\r\n' +
      'This email was sent over a plain connection.\r\n' +
      '.\r\n';
    
    socket.write(emailContent);
    
    const finalResponse = await new Promise<string>((resolve) => {
      socket.once('data', (chunk) => resolve(chunk.toString()));
    });
    
    expect(finalResponse).toInclude('250');
    console.log('Email sent successfully over plain connection');
    
    // Clean up
    socket.write('QUIT\r\n');
    
    const quitResponse = await new Promise<string>((resolve) => {
      socket.once('data', (chunk) => resolve(chunk.toString()));
    });
    
    expect(quitResponse).toInclude('221');
    socket.end();
    
  } finally {
    await stopTestServer();
    done.resolve();
  }
});

tap.test('Plain Connection - should handle multiple plain connections', async (tools) => {
  const done = tools.defer();
  
  // Start test server
  const testServer = await startTestServer();
  
  
  await new Promise(resolve => setTimeout(resolve, 1000));try {
    const connectionCount = 3;
    const connections: net.Socket[] = [];
    
    // Create multiple connections
    for (let i = 0; i < connectionCount; i++) {
      const socket = net.createConnection({
        host: 'localhost',
        port: TEST_PORT,
        timeout: TEST_TIMEOUT
      });
      
      await new Promise<void>((resolve, reject) => {
        socket.once('connect', () => {
          connections.push(socket);
          resolve();
        });
        socket.once('error', reject);
      });
      
      // Get banner
      const banner = await new Promise<string>((resolve) => {
        socket.once('data', (chunk) => resolve(chunk.toString()));
      });
      
      expect(banner).toInclude('220');
      console.log(`Connection ${i + 1} established`);
    }
    
    expect(connections.length).toBe(connectionCount);
    console.log(`All ${connectionCount} plain connections established successfully`);
    
    // Clean up all connections
    for (const socket of connections) {
      socket.write('QUIT\r\n');
      socket.end();
    }
    
  } finally {
    await stopTestServer();
    done.resolve();
  }
});

tap.test('Plain Connection - should work on standard SMTP port 25', async (tools) => {
  const done = tools.defer();
  
  // Test port 25 (standard SMTP port)
  const SMTP_PORT = 25;
  
  // Note: Port 25 might require special permissions or might be blocked
  // We'll test the connection but handle failures gracefully
  const socket = net.createConnection({
    host: 'localhost',
    port: SMTP_PORT,
    timeout: 5000
  });
  
  const result = await new Promise<{connected: boolean, error?: string}>((resolve) => {
    socket.once('connect', () => {
      socket.destroy();
      resolve({ connected: true });
    });
    
    socket.once('error', (err) => {
      resolve({ 
        connected: false, 
        error: err.message 
      });
    });
    
    setTimeout(() => {
      socket.destroy();
      resolve({ 
        connected: false, 
        error: 'Connection timeout' 
      });
    }, 5000);
  });
  
  if (result.connected) {
    console.log('Successfully connected to port 25 (standard SMTP)');
  } else {
    console.log(`Could not connect to port 25: ${result.error}`);
    console.log('This is expected if port 25 is blocked or requires privileges');
  }
  
  // Test passes regardless - port 25 connectivity is environment-dependent
  expect(true).toBeTrue();
  
  done.resolve();
});

tap.start();