feat(storage): add comprehensive tests for StorageManager with memory, filesystem, and custom function backends

feat(email): implement EmailSendJob class for robust email delivery with retry logic and MX record resolution

feat(mail): restructure mail module exports for simplified access to core and delivery functionalities

test/suite/smtpclient_error-handling/test.cerr-07.message-size-limits.ts

@@ -0,0 +1,320 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import { startTestServer, stopTestServer, type ITestServer } from '../../helpers/server.loader.ts';
+import { createSmtpClient } from '../../../ts/mail/delivery/smtpclient/index.ts';
+import { Email } from '../../../ts/mail/core/classes.email.ts';
+import * as net from 'net';
+
+let testServer: ITestServer;
+
+tap.test('setup - start SMTP server for size limit tests', async () => {
+  testServer = await startTestServer({
+    port: 2573,
+    tlsEnabled: false,
+    authRequired: false
+  });
+  
+  expect(testServer.port).toEqual(2573);
+});
+
+tap.test('CERR-07: Server with SIZE extension', async () => {
+  // Create server that advertises SIZE extension
+  const sizeServer = net.createServer((socket) => {
+    socket.write('220 Size Test Server\r\n');
+    
+    let buffer = '';
+    let inData = false;
+
+    socket.on('data', (data) => {
+      buffer += data.toString();
+      
+      let lines = buffer.split('\r\n');
+      buffer = lines.pop() || '';
+      
+      for (const line of lines) {
+        const command = line.trim();
+        if (!command) continue;
+        
+        if (inData) {
+          if (command === '.') {
+            inData = false;
+            socket.write('250 OK\r\n');
+          }
+          continue;
+        }
+        
+        if (command.startsWith('EHLO')) {
+          socket.write('250-SIZE 1048576\r\n'); // 1MB limit
+          socket.write('250 OK\r\n');
+        } else if (command.startsWith('MAIL FROM')) {
+          socket.write('250 OK\r\n');
+        } else if (command.startsWith('RCPT TO')) {
+          socket.write('250 OK\r\n');
+        } else if (command === 'DATA') {
+          socket.write('354 Send data\r\n');
+          inData = true;
+        } else if (command === 'QUIT') {
+          socket.write('221 Bye\r\n');
+          socket.end();
+        }
+      }
+    });
+  });
+
+  await new Promise<void>((resolve) => {
+    sizeServer.listen(2574, () => resolve());
+  });
+
+  const smtpClient = await createSmtpClient({
+    host: '127.0.0.1',
+    port: 2574,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'recipient@example.com',
+    subject: 'Size Test',
+    text: 'Testing SIZE extension'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeTrue();
+  console.log('✅ Email sent with SIZE extension support');
+
+  await smtpClient.close();
+  await new Promise<void>((resolve) => {
+    sizeServer.close(() => resolve());
+  });
+});
+
+tap.test('CERR-07: Message too large at MAIL FROM', async () => {
+  // Create server that rejects based on SIZE parameter
+  const strictSizeServer = net.createServer((socket) => {
+    socket.write('220 Strict Size Server\r\n');
+
+    socket.on('data', (data) => {
+      const command = data.toString().trim();
+      
+      if (command.startsWith('EHLO')) {
+        socket.write('250-SIZE 1000\r\n'); // Very small limit
+        socket.write('250 OK\r\n');
+      } else if (command.startsWith('MAIL FROM')) {
+        // Always reject with size error
+        socket.write('552 5.3.4 Message size exceeds fixed maximum message size\r\n');
+      } else if (command === 'QUIT') {
+        socket.write('221 Bye\r\n');
+        socket.end();
+      }
+    });
+  });
+
+  await new Promise<void>((resolve) => {
+    strictSizeServer.listen(2575, () => resolve());
+  });
+
+  const smtpClient = await createSmtpClient({
+    host: '127.0.0.1',
+    port: 2575,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'recipient@example.com',
+    subject: 'Large Message',
+    text: 'This message will be rejected due to size'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeFalse();
+  console.log('Actual error:', result.error?.message);
+  expect(result.error?.message).toMatch(/552|size|exceeds|maximum/i);
+  console.log('✅ Message size rejection at MAIL FROM handled');
+
+  await smtpClient.close();
+  await new Promise<void>((resolve) => {
+    strictSizeServer.close(() => resolve());
+  });
+});
+
+tap.test('CERR-07: Message too large at DATA', async () => {
+  // Create server that rejects after receiving data
+  const dataRejectServer = net.createServer((socket) => {
+    socket.write('220 Data Reject Server\r\n');
+    
+    let buffer = '';
+    let inData = false;
+
+    socket.on('data', (data) => {
+      buffer += data.toString();
+      
+      let lines = buffer.split('\r\n');
+      buffer = lines.pop() || '';
+      
+      for (const line of lines) {
+        const command = line.trim();
+        if (!command) continue;
+        
+        if (inData) {
+          if (command === '.') {
+            inData = false;
+            socket.write('552 5.3.4 Message too big for system\r\n');
+          }
+          continue;
+        }
+        
+        if (command.startsWith('EHLO')) {
+          socket.write('250 OK\r\n');
+        } else if (command.startsWith('MAIL FROM')) {
+          socket.write('250 OK\r\n');
+        } else if (command.startsWith('RCPT TO')) {
+          socket.write('250 OK\r\n');
+        } else if (command === 'DATA') {
+          socket.write('354 Send data\r\n');
+          inData = true;
+        } else if (command === 'QUIT') {
+          socket.write('221 Bye\r\n');
+          socket.end();
+        }
+      }
+    });
+  });
+
+  await new Promise<void>((resolve) => {
+    dataRejectServer.listen(2576, () => resolve());
+  });
+
+  const smtpClient = await createSmtpClient({
+    host: '127.0.0.1',
+    port: 2576,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'recipient@example.com',
+    subject: 'Large Message Test',
+    text: 'x'.repeat(10000) // Simulate large content
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeFalse();
+  console.log('Actual error:', result.error?.message);
+  expect(result.error?.message).toMatch(/552|big|size|data/i);
+  console.log('✅ Message size rejection at DATA handled');
+
+  await smtpClient.close();
+  await new Promise<void>((resolve) => {
+    dataRejectServer.close(() => resolve());
+  });
+});
+
+tap.test('CERR-07: Temporary size error - 452', async () => {
+  // Create server that returns temporary size error
+  const tempSizeServer = net.createServer((socket) => {
+    socket.write('220 Temp Size Server\r\n');
+    
+    let buffer = '';
+    let inData = false;
+
+    socket.on('data', (data) => {
+      buffer += data.toString();
+      
+      let lines = buffer.split('\r\n');
+      buffer = lines.pop() || '';
+      
+      for (const line of lines) {
+        const command = line.trim();
+        if (!command) continue;
+        
+        if (inData) {
+          if (command === '.') {
+            inData = false;
+            socket.write('452 4.3.1 Insufficient system storage\r\n');
+          }
+          continue;
+        }
+        
+        if (command.startsWith('EHLO')) {
+          socket.write('250 OK\r\n');
+        } else if (command.startsWith('MAIL FROM')) {
+          socket.write('250 OK\r\n');
+        } else if (command.startsWith('RCPT TO')) {
+          socket.write('250 OK\r\n');
+        } else if (command === 'DATA') {
+          socket.write('354 Send data\r\n');
+          inData = true;
+        } else if (command === 'QUIT') {
+          socket.write('221 Bye\r\n');
+          socket.end();
+        }
+      }
+    });
+  });
+
+  await new Promise<void>((resolve) => {
+    tempSizeServer.listen(2577, () => resolve());
+  });
+
+  const smtpClient = await createSmtpClient({
+    host: '127.0.0.1',
+    port: 2577,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'recipient@example.com',
+    subject: 'Temporary Size Error Test',
+    text: 'Testing temporary size error'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeFalse();
+  console.log('Actual error:', result.error?.message);
+  expect(result.error?.message).toMatch(/452|storage|data/i);
+  console.log('✅ Temporary size error handled');
+
+  await smtpClient.close();
+  await new Promise<void>((resolve) => {
+    tempSizeServer.close(() => resolve());
+  });
+});
+
+tap.test('CERR-07: Normal email within size limits', async () => {
+  // Test successful email send with working server
+  const smtpClient = await createSmtpClient({
+    host: testServer.hostname,
+    port: testServer.port,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'recipient@example.com',
+    subject: 'Normal Size Test',
+    text: 'Testing normal size email that should succeed'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeTrue();
+  console.log('✅ Normal size email sent successfully');
+
+  await smtpClient.close();
+});
+
+tap.test('cleanup - stop SMTP server', async () => {
+  await stopTestServer(testServer);
+});
+
+export default tap.start();