dcrouter/test/suite/smtpclient_performance/test.cperf-06.caching-strategies.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('CPERF-06: should implement efficient caching strategies', async (tools) => {
  const testId = 'CPERF-06-caching-strategies';
  console.log(`\n${testId}: Testing caching strategies performance...`);

  let scenarioCount = 0;

  // Scenario 1: DNS resolution caching
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing DNS resolution caching`);
    
    let dnsLookupCount = 0;
    const dnsCache = new Map<string, { address: string; timestamp: number }>();
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        console.log('  [Server] Client connected');
        socket.write('220 dns-cache.example.com ESMTP\r\n');
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          
          if (command.startsWith('EHLO')) {
            socket.write('250-dns-cache.example.com\r\n');
            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 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();
          }
        });
      }
    });

    // Simulate DNS lookup caching
    const mockDnsLookup = (hostname: string) => {
      const cached = dnsCache.get(hostname);
      const now = Date.now();
      
      if (cached && (now - cached.timestamp) < 300000) { // 5 minute cache
        console.log(`  [DNS] Cache hit for ${hostname}`);
        return cached.address;
      }
      
      dnsLookupCount++;
      console.log(`  [DNS] Cache miss for ${hostname} (lookup #${dnsLookupCount})`);
      
      const address = testServer.hostname; // Mock resolution
      dnsCache.set(hostname, { address, timestamp: now });
      return address;
    };

    // Test multiple connections to same host
    const connectionCount = 10;
    console.log(`  Creating ${connectionCount} connections to test DNS caching...`);
    
    const clients: any[] = [];
    const startTime = Date.now();
    
    for (let i = 0; i < connectionCount; i++) {
      // Simulate DNS lookup
      const resolvedHost = mockDnsLookup(testServer.hostname);
      
      const client = createSmtpClient({
        host: resolvedHost,
        port: testServer.port,
        secure: false
      });
      clients.push(client);
    }
    
    // Send emails through cached connections
    const emails = clients.map((client, i) => 
      new plugins.smartmail.Email({
        from: 'sender@example.com',
        to: [`recipient${i + 1}@example.com`],
        subject: `DNS cache test ${i + 1}`,
        text: `Testing DNS resolution caching - connection ${i + 1}`
      })
    );
    
    await Promise.all(emails.map((email, i) => clients[i].sendMail(email)));
    
    const totalTime = Date.now() - startTime;
    const cacheHitRate = ((connectionCount - dnsLookupCount) / connectionCount) * 100;
    
    console.log(`  DNS lookups performed: ${dnsLookupCount}/${connectionCount}`);
    console.log(`  Cache hit rate: ${cacheHitRate.toFixed(1)}%`);
    console.log(`  Total time: ${totalTime}ms`);
    console.log(`  Time per connection: ${(totalTime / connectionCount).toFixed(1)}ms`);

    // Close clients
    await Promise.all(clients.map(client => {
      if (client.close) {
        return client.close();
      }
      return Promise.resolve();
    }));

    // DNS caching should reduce lookups
    expect(dnsLookupCount).toBeLessThan(connectionCount);
    expect(cacheHitRate).toBeGreaterThan(50); // At least 50% cache hit rate

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

  // Scenario 2: Connection pool caching
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing connection pool caching`);
    
    let connectionCount = 0;
    let connectionReuse = 0;
    const connectionPool = new Map<string, { connection: any; lastUsed: number; messageCount: number }>();
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        connectionCount++;
        const connId = connectionCount;
        console.log(`  [Server] New connection ${connId} created`);
        socket.write('220 pool-cache.example.com ESMTP\r\n');
        
        let messageCount = 0;
        
        socket.on('close', () => {
          console.log(`  [Server] Connection ${connId} closed after ${messageCount} messages`);
        });
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          
          if (command.startsWith('EHLO')) {
            socket.write('250-pool-cache.example.com\r\n');
            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 Start mail input\r\n');
          } else if (command === '.') {
            messageCount++;
            socket.write(`250 OK: Message ${messageCount} on connection ${connId}\r\n`);
          } else if (command === 'RSET') {
            socket.write('250 OK\r\n');
          } else if (command === 'QUIT') {
            socket.write('221 Bye\r\n');
            socket.end();
          }
        });
      }
    });

    // Mock connection pool management
    const getPooledConnection = (key: string) => {
      const cached = connectionPool.get(key);
      const now = Date.now();
      
      if (cached && (now - cached.lastUsed) < 60000) { // 1 minute idle timeout
        connectionReuse++;
        cached.lastUsed = now;
        cached.messageCount++;
        console.log(`  [Pool] Reusing connection for ${key} (reuse #${connectionReuse})`);
        return cached.connection;
      }
      
      console.log(`  [Pool] Creating new connection for ${key}`);
      const newConnection = createSmtpClient({
        host: testServer.hostname,
        port: testServer.port,
        secure: false,
        pool: true,
        maxConnections: 5,
        maxMessages: 10
      });
      
      connectionPool.set(key, {
        connection: newConnection,
        lastUsed: now,
        messageCount: 0
      });
      
      return newConnection;
    };

    // Test connection reuse with same destination
    const destinations = [
      'example.com',
      'example.com', // Same as first (should reuse)
      'example.com', // Same as first (should reuse)
      'another.com',
      'example.com', // Back to first (should reuse)
      'another.com'  // Same as fourth (should reuse)
    ];
    
    console.log(`  Sending emails to test connection pool caching...`);
    
    for (let i = 0; i < destinations.length; i++) {
      const destination = destinations[i];
      const poolKey = destination;
      
      const client = getPooledConnection(poolKey);
      
      const email = new plugins.smartmail.Email({
        from: 'sender@example.com',
        to: [`recipient${i + 1}@${destination}`],
        subject: `Pool cache test ${i + 1}`,
        text: `Testing connection pool caching - destination ${destination}`
      });
      
      await client.sendMail(email);
    }
    
    // Close all pooled connections
    for (const [key, pooled] of connectionPool) {
      if (pooled.connection.close) {
        await pooled.connection.close();
      }
    }
    
    const uniqueDestinations = new Set(destinations).size;
    const poolEfficiency = (connectionReuse / destinations.length) * 100;
    
    console.log(`  Total emails sent: ${destinations.length}`);
    console.log(`  Unique destinations: ${uniqueDestinations}`);
    console.log(`  New connections: ${connectionCount}`);
    console.log(`  Connection reuses: ${connectionReuse}`);
    console.log(`  Pool efficiency: ${poolEfficiency.toFixed(1)}%`);

    // Connection pool should reuse connections efficiently
    expect(connectionCount).toBeLessThanOrEqual(uniqueDestinations + 1);
    expect(connectionReuse).toBeGreaterThan(0);
    expect(poolEfficiency).toBeGreaterThan(30); // At least 30% reuse

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

  // Scenario 3: Template and content caching
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing template and content caching`);
    
    let templateCompilations = 0;
    let cacheHits = 0;
    const templateCache = new Map<string, { compiled: string; timestamp: number; uses: number }>();
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        socket.write('220 template-cache.example.com ESMTP\r\n');
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          
          if (command.startsWith('EHLO')) {
            socket.write('250-template-cache.example.com\r\n');
            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 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();
          }
        });
      }
    });

    // Mock template compilation and caching
    const compileTemplate = (template: string, data: any) => {
      const cacheKey = template;
      const cached = templateCache.get(cacheKey);
      const now = Date.now();
      
      if (cached && (now - cached.timestamp) < 3600000) { // 1 hour cache
        cacheHits++;
        cached.uses++;
        console.log(`  [Template] Cache hit for template (use #${cached.uses})`);
        return cached.compiled.replace(/\{\{(\w+)\}\}/g, (match, key) => data[key] || match);
      }
      
      templateCompilations++;
      console.log(`  [Template] Compiling template (compilation #${templateCompilations})`);
      
      // Simulate template compilation overhead
      const compiled = template.replace(/\{\{(\w+)\}\}/g, (match, key) => data[key] || match);
      
      templateCache.set(cacheKey, {
        compiled: template, // Store template for reuse
        timestamp: now,
        uses: 1
      });
      
      return compiled;
    };

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

    // Test template caching with repeated templates
    const templates = [
      {
        id: 'welcome',
        subject: 'Welcome {{name}}!',
        text: 'Hello {{name}}, welcome to our service!'
      },
      {
        id: 'notification',
        subject: 'Notification for {{name}}',
        text: 'Dear {{name}}, you have a new notification.'
      },
      {
        id: 'welcome', // Repeat of first template
        subject: 'Welcome {{name}}!',
        text: 'Hello {{name}}, welcome to our service!'
      }
    ];
    
    const users = [
      { name: 'Alice', email: 'alice@example.com' },
      { name: 'Bob', email: 'bob@example.com' },
      { name: 'Charlie', email: 'charlie@example.com' },
      { name: 'Diana', email: 'diana@example.com' }
    ];
    
    console.log('  Sending templated emails to test content caching...');
    const startTime = Date.now();
    
    for (const user of users) {
      for (const template of templates) {
        const compiledSubject = compileTemplate(template.subject, user);
        const compiledText = compileTemplate(template.text, user);
        
        const email = new plugins.smartmail.Email({
          from: 'sender@example.com',
          to: [user.email],
          subject: compiledSubject,
          text: compiledText
        });
        
        await smtpClient.sendMail(email);
      }
    }
    
    const totalTime = Date.now() - startTime;
    const totalTemplateUses = users.length * templates.length;
    const uniqueTemplates = new Set(templates.map(t => t.id)).size;
    const cacheEfficiency = (cacheHits / (templateCompilations + cacheHits)) * 100;
    
    console.log(`  Total template uses: ${totalTemplateUses}`);
    console.log(`  Unique templates: ${uniqueTemplates}`);
    console.log(`  Template compilations: ${templateCompilations}`);
    console.log(`  Cache hits: ${cacheHits}`);
    console.log(`  Cache efficiency: ${cacheEfficiency.toFixed(1)}%`);
    console.log(`  Average time per email: ${(totalTime / totalTemplateUses).toFixed(1)}ms`);

    // Template caching should reduce compilation overhead
    expect(templateCompilations).toBeLessThan(totalTemplateUses);
    expect(cacheHits).toBeGreaterThan(0);
    expect(cacheEfficiency).toBeGreaterThan(50); // At least 50% cache efficiency

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

  // Scenario 4: Message header caching
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing message header caching`);
    
    let headerGenerations = 0;
    let headerCacheHits = 0;
    const headerCache = new Map<string, { headers: any; timestamp: number }>();
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        socket.write('220 header-cache.example.com ESMTP\r\n');
        
        let messageCount = 0;
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          
          if (command.startsWith('EHLO')) {
            socket.write('250-header-cache.example.com\r\n');
            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 Start mail input\r\n');
          } else if (command === '.') {
            messageCount++;
            socket.write(`250 OK: Message ${messageCount} with cached headers\r\n`);
          } else if (command === 'QUIT') {
            socket.write('221 Bye\r\n');
            socket.end();
          }
        });
      }
    });

    // Mock header generation and caching
    const generateHeaders = (from: string, subject: string, messageType: string) => {
      const cacheKey = `${from}-${messageType}`;
      const cached = headerCache.get(cacheKey);
      const now = Date.now();
      
      if (cached && (now - cached.timestamp) < 1800000) { // 30 minute cache
        headerCacheHits++;
        console.log(`  [Headers] Cache hit for ${messageType} headers`);
        return {
          ...cached.headers,
          Subject: subject, // Subject is dynamic
          Date: new Date().toISOString(),
          'Message-ID': `<${Date.now()}-${Math.random()}@example.com>`
        };
      }
      
      headerGenerations++;
      console.log(`  [Headers] Generating ${messageType} headers (generation #${headerGenerations})`);
      
      // Simulate header generation overhead
      const headers = {
        From: from,
        Subject: subject,
        Date: new Date().toISOString(),
        'Message-ID': `<${Date.now()}-${Math.random()}@example.com>`,
        'X-Mailer': 'Test Mailer 1.0',
        'MIME-Version': '1.0',
        'Content-Type': messageType === 'html' ? 'text/html; charset=UTF-8' : 'text/plain; charset=UTF-8'
      };
      
      // Cache the static parts
      const cacheableHeaders = {
        From: from,
        'X-Mailer': 'Test Mailer 1.0',
        'MIME-Version': '1.0',
        'Content-Type': headers['Content-Type']
      };
      
      headerCache.set(cacheKey, {
        headers: cacheableHeaders,
        timestamp: now
      });
      
      return headers;
    };

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

    // Test header caching with similar message types
    const messageTypes = ['text', 'html', 'text', 'html', 'text']; // Repeated types
    const sender = 'sender@example.com';
    
    console.log('  Sending emails to test header caching...');
    
    for (let i = 0; i < messageTypes.length; i++) {
      const messageType = messageTypes[i];
      const headers = generateHeaders(sender, `Test ${i + 1}`, messageType);
      
      const email = new plugins.smartmail.Email({
        from: headers.From,
        to: [`recipient${i + 1}@example.com`],
        subject: headers.Subject,
        text: messageType === 'text' ? 'Plain text message' : undefined,
        html: messageType === 'html' ? '<p>HTML message</p>' : undefined,
        headers: {
          'X-Mailer': headers['X-Mailer'],
          'Message-ID': headers['Message-ID']
        }
      });
      
      await smtpClient.sendMail(email);
    }
    
    const uniqueMessageTypes = new Set(messageTypes).size;
    const headerCacheEfficiency = (headerCacheHits / (headerGenerations + headerCacheHits)) * 100;
    
    console.log(`  Messages sent: ${messageTypes.length}`);
    console.log(`  Unique message types: ${uniqueMessageTypes}`);
    console.log(`  Header generations: ${headerGenerations}`);
    console.log(`  Header cache hits: ${headerCacheHits}`);
    console.log(`  Header cache efficiency: ${headerCacheEfficiency.toFixed(1)}%`);

    // Header caching should reduce generation overhead
    expect(headerGenerations).toBeLessThan(messageTypes.length);
    expect(headerCacheHits).toBeGreaterThan(0);

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

  // Scenario 5: Attachment processing caching
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing attachment processing caching`);
    
    let attachmentProcessing = 0;
    let attachmentCacheHits = 0;
    const attachmentCache = new Map<string, { processed: string; timestamp: number; size: number }>();
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        socket.write('220 attachment-cache.example.com ESMTP\r\n');
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          
          if (command.startsWith('EHLO')) {
            socket.write('250-attachment-cache.example.com\r\n');
            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 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();
          }
        });
      }
    });

    // Mock attachment processing with caching
    const processAttachment = (filename: string, content: Buffer) => {
      const contentHash = require('crypto').createHash('md5').update(content).digest('hex');
      const cacheKey = `${filename}-${contentHash}`;
      const cached = attachmentCache.get(cacheKey);
      const now = Date.now();
      
      if (cached && (now - cached.timestamp) < 7200000) { // 2 hour cache
        attachmentCacheHits++;
        console.log(`  [Attachment] Cache hit for ${filename}`);
        return cached.processed;
      }
      
      attachmentProcessing++;
      console.log(`  [Attachment] Processing ${filename} (processing #${attachmentProcessing})`);
      
      // Simulate attachment processing (base64 encoding)
      const processed = content.toString('base64');
      
      attachmentCache.set(cacheKey, {
        processed,
        timestamp: now,
        size: content.length
      });
      
      return processed;
    };

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

    // Create reusable attachment content
    const commonAttachment = Buffer.from('This is a common attachment used in multiple emails.');
    const uniqueAttachment = Buffer.from('This is a unique attachment.');
    
    const emails = [
      {
        subject: 'Email 1 with common attachment',
        attachments: [{ filename: 'common.txt', content: commonAttachment }]
      },
      {
        subject: 'Email 2 with unique attachment',
        attachments: [{ filename: 'unique.txt', content: uniqueAttachment }]
      },
      {
        subject: 'Email 3 with common attachment again',
        attachments: [{ filename: 'common.txt', content: commonAttachment }] // Same as first
      },
      {
        subject: 'Email 4 with both attachments',
        attachments: [
          { filename: 'common.txt', content: commonAttachment },
          { filename: 'unique.txt', content: uniqueAttachment }
        ]
      }
    ];
    
    console.log('  Sending emails with attachments to test caching...');
    
    for (let i = 0; i < emails.length; i++) {
      const emailData = emails[i];
      
      // Process attachments (with caching)
      const processedAttachments = emailData.attachments.map(att => ({
        filename: att.filename,
        content: processAttachment(att.filename, att.content)
      }));
      
      const email = new plugins.smartmail.Email({
        from: 'sender@example.com',
        to: [`recipient${i + 1}@example.com`],
        subject: emailData.subject,
        text: 'Email with attachments for caching test',
        attachments: processedAttachments.map(att => ({
          filename: att.filename,
          content: att.content,
          encoding: 'base64' as const
        }))
      });
      
      await smtpClient.sendMail(email);
    }
    
    const totalAttachments = emails.reduce((sum, email) => sum + email.attachments.length, 0);
    const attachmentCacheEfficiency = (attachmentCacheHits / (attachmentProcessing + attachmentCacheHits)) * 100;
    
    console.log(`  Total attachments sent: ${totalAttachments}`);
    console.log(`  Attachment processing operations: ${attachmentProcessing}`);
    console.log(`  Attachment cache hits: ${attachmentCacheHits}`);
    console.log(`  Attachment cache efficiency: ${attachmentCacheEfficiency.toFixed(1)}%`);

    // Attachment caching should reduce processing overhead
    expect(attachmentProcessing).toBeLessThan(totalAttachments);
    expect(attachmentCacheHits).toBeGreaterThan(0);
    expect(attachmentCacheEfficiency).toBeGreaterThan(30); // At least 30% cache efficiency

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

  // Scenario 6: Overall caching performance impact
  await (async () => {
    scenarioCount++;
    console.log(`\nScenario ${scenarioCount}: Testing overall caching performance impact`);
    
    const testServer = await createTestServer({
      onConnection: async (socket) => {
        socket.write('220 performance-cache.example.com ESMTP\r\n');
        
        socket.on('data', (data) => {
          const command = data.toString().trim();
          
          if (command.startsWith('EHLO')) {
            socket.write('250-performance-cache.example.com\r\n');
            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 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 performance with caching enabled vs disabled
    const emailCount = 20;
    
    // Simulate no caching (always process)
    console.log('  Testing performance without caching...');
    const noCacheStart = Date.now();
    let noCacheOperations = 0;
    
    const noCacheClient = createSmtpClient({
      host: testServer.hostname,
      port: testServer.port,
      secure: false
    });
    
    for (let i = 0; i < emailCount; i++) {
      // Simulate processing overhead for each email
      noCacheOperations += 3; // DNS lookup, header generation, template processing
      
      const email = new plugins.smartmail.Email({
        from: 'sender@example.com',
        to: [`nocache${i + 1}@example.com`],
        subject: `No cache test ${i + 1}`,
        text: `Testing performance without caching - email ${i + 1}`
      });
      
      await noCacheClient.sendMail(email);
    }
    
    const noCacheTime = Date.now() - noCacheStart;
    
    // Simulate with caching (reduced processing)
    console.log('  Testing performance with caching...');
    const cacheStart = Date.now();
    let cacheOperations = 5; // Initial setup, then reuse
    
    const cacheClient = createSmtpClient({
      host: testServer.hostname,
      port: testServer.port,
      secure: false,
      pool: true,
      maxConnections: 2
    });
    
    for (let i = 0; i < emailCount; i++) {
      // Simulate reduced operations due to caching
      if (i < 5) {
        cacheOperations += 1; // Some cache misses initially
      }
      // Most operations are cache hits (no additional operations)
      
      const email = new plugins.smartmail.Email({
        from: 'sender@example.com',
        to: [`cache${i + 1}@example.com`],
        subject: `Cache test ${i + 1}`,
        text: `Testing performance with caching - email ${i + 1}`
      });
      
      await cacheClient.sendMail(email);
    }
    
    await cacheClient.close();
    const cacheTime = Date.now() - cacheStart;
    
    // Calculate performance improvements
    const timeImprovement = ((noCacheTime - cacheTime) / noCacheTime) * 100;
    const operationReduction = ((noCacheOperations - cacheOperations) / noCacheOperations) * 100;
    const throughputImprovement = (emailCount / cacheTime) / (emailCount / noCacheTime);
    
    console.log(`  Performance comparison (${emailCount} emails):`);
    console.log(`    Without caching: ${noCacheTime}ms, ${noCacheOperations} operations`);
    console.log(`    With caching: ${cacheTime}ms, ${cacheOperations} operations`);
    console.log(`    Time improvement: ${timeImprovement.toFixed(1)}%`);
    console.log(`    Operation reduction: ${operationReduction.toFixed(1)}%`);
    console.log(`    Throughput improvement: ${throughputImprovement.toFixed(2)}x`);

    // Caching should improve performance
    expect(cacheTime).toBeLessThan(noCacheTime);
    expect(cacheOperations).toBeLessThan(noCacheOperations);
    expect(timeImprovement).toBeGreaterThan(10); // At least 10% improvement
    expect(throughputImprovement).toBeGreaterThan(1.1); // At least 10% better throughput

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

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