Brummer MCP Server

import express, { Request, Response, NextFunction } from 'express'; const app = express(); const port = process.env.PORT || 3000; app.use(express.json()); // Middleware with intentional errors app.use((req: Request, res: Response, next: NextFunction) => { // Error: Accessing undefined property console.log((req as any).undefinedProperty.length); next(); }); // Route with TypeScript errors app.get('/typescript-error', (req: Request, res: Response) => { // Error: Type 'string' is not assignable to type 'number' const numberVar: number = "invalid" as any; // Error: Property 'nonExistent' does not exist on type 'Request' console.log((req as any).nonExistent); res.json({ error: 'TypeScript error endpoint' }); }); // Route with runtime errors app.get('/runtime-error', (req: Request, res: Response) => { try { // Error: Cannot read properties of null const nullVar = null; console.log((nullVar as any).someProperty); // Error: Cannot read properties of undefined const undefinedVar = undefined; console.log((undefinedVar as any).someMethod()); // Error: ReferenceError console.log((global as any).undefinedGlobal); } catch (error) { console.error('Runtime error in /runtime-error:', error); res.status(500).json({ error: 'Internal server error' }); } }); // Route with async errors app.get('/async-error', async (req: Request, res: Response) => { try { // Error: Network request to invalid URL const response = await fetch('https://invalid-api-endpoint.nonexistent'); const data = await response.json(); res.json(data); } catch (error) { console.error('Async error in /async-error:', error); res.status(500).json({ error: 'Failed to fetch external data' }); } }); // Route with database simulation errors app.get('/database-error', async (req: Request, res: Response) => { try { // Simulate MongoDB connection error throw new Error('MongoError: getaddrinfo ENOTFOUND cluster0.mongodb.net'); } catch (error) { console.error('Database error:', error); res.status(500).json({ error: 'Database connection failed' }); } }); // Route with validation errors app.post('/validation-error', (req: Request, res: Response) => { const { email, password } = req.body; // Error: Missing required fields if (!email) { const error = new Error('ValidationError: email is required'); console.error('Validation error:', error); return res.status(400).json({ error: error.message }); } // Error: Invalid email format if (!email.includes('@')) { const error = new Error('ValidationError: invalid email format'); console.error('Validation error:', error); return res.status(400).json({ error: error.message }); } res.json({ message: 'Validation passed' }); }); // Route that throws unhandled errors app.get('/unhandled-error', (req: Request, res: Response) => { // Error: Unhandled exception throw new Error('Unhandled server error'); }); // Route with promise rejection app.get('/promise-rejection', (req: Request, res: Response) => { // Error: Unhandled promise rejection Promise.reject(new Error('Unhandled promise rejection in Express route')); res.json({ message: 'Response sent before promise rejection' }); }); // Route with file system errors app.get('/file-error', (req: Request, res: Response) => { const fs = require('fs'); try { // Error: ENOENT: no such file or directory const data = fs.readFileSync('/nonexistent/file.txt', 'utf8'); res.json({ data }); } catch (error) { console.error('File system error:', error); res.status(500).json({ error: 'File not found' }); } }); // Route with parsing errors app.post('/parse-error', (req: Request, res: Response) => { try { // Error: Unexpected token in JSON const invalidJson = '{"invalid": json}'; const parsed = JSON.parse(invalidJson); res.json(parsed); } catch (error) { console.error('JSON parse error:', error); res.status(400).json({ error: 'Invalid JSON format' }); } }); // Global error handler app.use((error: Error, req: Request, res: Response, next: NextFunction) => { console.error('Global error handler caught:', error); console.error('Stack trace:', error.stack); if (!res.headersSent) { res.status(500).json({ error: 'Internal Server Error', message: error.message, stack: process.env.NODE_ENV === 'development' ? error.stack : undefined }); } }); // Handle 404 errors app.use('*', (req: Request, res: Response) => { const error = new Error(`Route ${req.originalUrl} not found`); console.error('404 error:', error); res.status(404).json({ error: 'Route not found' }); }); // Process error handlers process.on('uncaughtException', (error: Error) => { console.error('Uncaught Exception:', error); console.error('Stack:', error.stack); process.exit(1); }); process.on('unhandledRejection', (reason: any, promise: Promise<any>) => { console.error('Unhandled Rejection at:', promise); console.error('Reason:', reason); }); app.listen(port, () => { console.log(`Express server running on port ${port}`); // Trigger some initial errors triggerStartupErrors(); }); function triggerStartupErrors() { // Error: Startup configuration error try { const config = JSON.parse('{"invalid": json}'); } catch (error) { console.error('Startup configuration error:', error); } // Error: Environment variable access const requiredEnvVar = process.env.REQUIRED_VAR; if (!requiredEnvVar) { console.error('Environment Error: REQUIRED_VAR is not set'); } } export default app;