dcrouter/test/suite/smtpclient_edge-cases/test.cedge-02.malformed-commands.ts

import { expect, tap } from '@git.zone/tstest/tapbundle';
import * as plugins from './plugins.js';
import { createTestServer } from '../../helpers/server.loader.js';
import { createSmtpClient } from '../../helpers/smtp.client.js';

tap.test('CEDGE-02: should handle malformed commands gracefully', async (tools) => {
  const testId = 'CEDGE-02-malformed-commands';
  console.log(`\n${testId}: Testing malformed command handling...`);

  let scenarioCount = 0;

  // Scenario 1: Commands with extra spaces
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing commands with extra spaces`);
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        console.log('  [Server] Client connected');
        socket.write('220 mail.example.com ESMTP\r\n');
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          console.log(`  [Server] Received: ${command}`);
          
          // Accept commands with extra spaces
          if (command.match(/^EHLO\s+/i)) {
            socket.write('250-mail.example.com\r\n');
            socket.write('250 STARTTLS\r\n');
          } else if (command.match(/^MAIL\s+FROM:/i)) {
            // Even with multiple spaces
            socket.write('250 OK\r\n');
          } else if (command.match(/^RCPT\s+TO:/i)) {
            socket.write('250 OK\r\n');
          } else if (command === 'DATA') {
            socket.write('354 Start mail input\r\n');
          } else if (command === '.') {
            socket.write('250 OK\r\n');
          } else if (command === 'QUIT') {
            socket.write('221 Bye\r\n');
            socket.end();
          }
        });
      }
    });

    const smtpClient = createSmtpClient({
      host: testServer.hostname,
      port: testServer.port,
      secure: false
    });

    // Test sending with commands that might have extra spaces
    const email = new plugins.smartmail.Email({
      from: 'sender@example.com',
      to: ['recipient@example.com'],
      subject: 'Test with extra spaces',
      text: 'Testing command formatting'
    });

    const result = await smtpClient.sendMail(email);
    console.log(`  Result: ${result.messageId ? 'Success' : 'Failed'}`);
    expect(result).toBeDefined();
    expect(result.messageId).toBeDefined();

    await testServer.server.close();
  })();

  // Scenario 2: Commands with incorrect case mixing
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing mixed case commands`);
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        console.log('  [Server] Client connected');
        socket.write('220 mail.example.com ESMTP\r\n');
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          console.log(`  [Server] Received: ${command}`);
          
          // RFC says commands should be case-insensitive
          const upperCommand = command.toUpperCase();
          
          if (upperCommand.startsWith('EHLO')) {
            socket.write('250-mail.example.com\r\n');
            socket.write('250 8BITMIME\r\n');
          } else if (upperCommand.startsWith('MAIL FROM:')) {
            socket.write('250 OK\r\n');
          } else if (upperCommand.startsWith('RCPT TO:')) {
            socket.write('250 OK\r\n');
          } else if (upperCommand === 'DATA') {
            socket.write('354 Start mail input\r\n');
          } else if (command === '.') {
            socket.write('250 OK\r\n');
          } else if (upperCommand === 'QUIT') {
            socket.write('221 Bye\r\n');
            socket.end();
          }
        });
      }
    });

    const smtpClient = createSmtpClient({
      host: testServer.hostname,
      port: testServer.port,
      secure: false
    });

    const email = new plugins.smartmail.Email({
      from: 'sender@example.com',
      to: ['recipient@example.com'],
      subject: 'Mixed case test',
      text: 'Testing case sensitivity'
    });

    const result = await smtpClient.sendMail(email);
    console.log(`  Result: ${result.messageId ? 'Success' : 'Failed'}`);
    expect(result).toBeDefined();
    expect(result.messageId).toBeDefined();

    await testServer.server.close();
  })();

  // Scenario 3: Commands with missing parameters
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing commands with missing parameters`);
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        console.log('  [Server] Client connected');
        socket.write('220 mail.example.com ESMTP\r\n');
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          console.log(`  [Server] Received: ${command}`);
          
          if (command.startsWith('EHLO')) {
            if (command === 'EHLO' || command === 'EHLO ') {
              // Missing hostname
              socket.write('501 Syntax error in parameters or arguments\r\n');
            } else {
              socket.write('250-mail.example.com\r\n');
              socket.write('250 OK\r\n');
            }
          } else if (command === 'MAIL FROM:' || command === 'MAIL') {
            // Missing address
            socket.write('501 Syntax error in parameters or arguments\r\n');
          } else if (command.startsWith('MAIL FROM:')) {
            socket.write('250 OK\r\n');
          } else if (command === 'RCPT TO:' || command === 'RCPT') {
            // Missing address
            socket.write('501 Syntax error in parameters or arguments\r\n');
          } else if (command.startsWith('RCPT TO:')) {
            socket.write('250 OK\r\n');
          } else if (command === 'DATA') {
            socket.write('354 Start mail input\r\n');
          } else if (command === '.') {
            socket.write('250 OK\r\n');
          } else if (command === 'QUIT') {
            socket.write('221 Bye\r\n');
            socket.end();
          }
        });
      }
    });

    // Test with a forgiving client that handles syntax errors
    const smtpClient = createSmtpClient({
      host: testServer.hostname,
      port: testServer.port,
      secure: false
    });

    const email = new plugins.smartmail.Email({
      from: 'sender@example.com',
      to: ['recipient@example.com'],
      subject: 'Syntax error recovery test',
      text: 'Testing error recovery'
    });

    const result = await smtpClient.sendMail(email);
    console.log(`  Result: ${result.messageId ? 'Success' : 'Failed'}`);
    expect(result).toBeDefined();

    await testServer.server.close();
  })();

  // Scenario 4: Commands with invalid syntax
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing invalid command syntax`);
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        console.log('  [Server] Client connected');
        socket.write('220 mail.example.com ESMTP\r\n');
        
        let state = 'connected';
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          console.log(`  [Server] Received: ${command}`);
          
          if (command.startsWith('EHLO')) {
            socket.write('250-mail.example.com\r\n');
            socket.write('250 OK\r\n');
            state = 'ready';
          } else if (command.includes('FROM') && !command.startsWith('MAIL FROM:')) {
            // Invalid MAIL command format
            socket.write('500 Syntax error, command unrecognized\r\n');
          } else if (command.startsWith('MAIL FROM:')) {
            socket.write('250 OK\r\n');
            state = 'mail';
          } else if (command.includes('TO') && !command.startsWith('RCPT TO:')) {
            // Invalid RCPT command format
            socket.write('500 Syntax error, command unrecognized\r\n');
          } else if (command.startsWith('RCPT TO:')) {
            socket.write('250 OK\r\n');
            state = 'rcpt';
          } else if (command === 'DATA') {
            socket.write('354 Start mail input\r\n');
            state = 'data';
          } else if (command === '.' && state === 'data') {
            socket.write('250 OK\r\n');
            state = 'done';
          } else if (command === 'QUIT') {
            socket.write('221 Bye\r\n');
            socket.end();
          } else if (state !== 'data') {
            // Unknown command
            socket.write('502 Command not implemented\r\n');
          }
        });
      }
    });

    const smtpClient = createSmtpClient({
      host: testServer.hostname,
      port: testServer.port,
      secure: false
    });

    const email = new plugins.smartmail.Email({
      from: 'sender@example.com',
      to: ['recipient@example.com'],
      subject: 'Invalid syntax test',
      text: 'Testing invalid command handling'
    });

    const result = await smtpClient.sendMail(email);
    console.log(`  Result: ${result.messageId ? 'Success' : 'Failed'}`);
    expect(result).toBeDefined();

    await testServer.server.close();
  })();

  // Scenario 5: Commands sent out of order
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing out-of-order commands`);
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        console.log('  [Server] Client connected');
        socket.write('220 mail.example.com ESMTP\r\n');
        
        let state = 'connected';
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          console.log(`  [Server] Received: ${command} (state: ${state})`);
          
          if (command.startsWith('EHLO')) {
            socket.write('250-mail.example.com\r\n');
            socket.write('250 OK\r\n');
            state = 'ready';
          } else if (command.startsWith('RCPT TO:') && state !== 'mail' && state !== 'rcpt') {
            // RCPT before MAIL
            socket.write('503 Bad sequence of commands\r\n');
          } else if (command.startsWith('DATA') && state !== 'rcpt') {
            // DATA before RCPT
            socket.write('503 Bad sequence of commands\r\n');
          } else if (command.startsWith('MAIL FROM:')) {
            if (state === 'ready' || state === 'done') {
              socket.write('250 OK\r\n');
              state = 'mail';
            } else {
              socket.write('503 Bad sequence of commands\r\n');
            }
          } else if (command.startsWith('RCPT TO:')) {
            socket.write('250 OK\r\n');
            state = 'rcpt';
          } else if (command === 'DATA') {
            socket.write('354 Start mail input\r\n');
            state = 'data';
          } else if (command === '.' && state === 'data') {
            socket.write('250 OK\r\n');
            state = 'done';
          } else if (command === 'QUIT') {
            socket.write('221 Bye\r\n');
            socket.end();
          }
        });
      }
    });

    const smtpClient = createSmtpClient({
      host: testServer.hostname,
      port: testServer.port,
      secure: false
    });

    const email = new plugins.smartmail.Email({
      from: 'sender@example.com',
      to: ['recipient@example.com'],
      subject: 'Command sequence test',
      text: 'Testing command ordering'
    });

    const result = await smtpClient.sendMail(email);
    console.log(`  Result: ${result.messageId ? 'Success' : 'Failed'}`);
    expect(result).toBeDefined();

    await testServer.server.close();
  })();

  // Scenario 6: Commands with invalid characters
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing commands with invalid characters`);
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        console.log('  [Server] Client connected');
        socket.write('220 mail.example.com ESMTP\r\n');
        
        socket.on('data', (data) => {
          const command = data.toString();
          const printable = command.replace(/[\r\n]/g, '\\r\\n').replace(/[^\x20-\x7E]/g, '?');
          console.log(`  [Server] Received: ${printable}`);
          
          // Check for non-ASCII characters
          if (/[^\x00-\x7F]/.test(command)) {
            socket.write('500 Syntax error, non-ASCII characters not allowed\r\n');
            return;
          }
          
          const cleanCommand = command.trim();
          
          if (cleanCommand.startsWith('EHLO')) {
            socket.write('250-mail.example.com\r\n');
            socket.write('250 OK\r\n');
          } else if (cleanCommand.startsWith('MAIL FROM:')) {
            socket.write('250 OK\r\n');
          } else if (cleanCommand.startsWith('RCPT TO:')) {
            socket.write('250 OK\r\n');
          } else if (cleanCommand === 'DATA') {
            socket.write('354 Start mail input\r\n');
          } else if (cleanCommand === '.') {
            socket.write('250 OK\r\n');
          } else if (cleanCommand === 'QUIT') {
            socket.write('221 Bye\r\n');
            socket.end();
          }
        });
      }
    });

    const smtpClient = createSmtpClient({
      host: testServer.hostname,
      port: testServer.port,
      secure: false
    });

    const email = new plugins.smartmail.Email({
      from: 'sender@example.com',
      to: ['recipient@example.com'],
      subject: 'Character encoding test',
      text: 'Testing character validation'
    });

    const result = await smtpClient.sendMail(email);
    console.log(`  Result: ${result.messageId ? 'Success' : 'Failed'}`);
    expect(result).toBeDefined();

    await testServer.server.close();
  })();

  console.log(`\n${testId}: All ${scenarioCount} malformed command scenarios tested ✓`);
});