Advanced MCP Server

import { Request, Response, NextFunction } from 'express'; import { Logger } from '../utils/Logger'; export interface ValidationError { field: string; message: string; } export class RequestValidationMiddleware { private logger: Logger; constructor() { this.logger = new Logger('./logs/validation-middleware.log', 'DEBUG', 'RequestValidationMiddleware'); } /** * Validate that required fields are present in the request body * @param requiredFields List of required field names * @returns Express middleware function */ public validateRequiredFields(requiredFields: string[]) { return (req: Request, res: Response, next: NextFunction): void => { const requestId = Date.now().toString(36) + Math.random().toString(36).substr(2); this.logger.debug('Validating required fields', { requiredFields, body: req.body }, requestId); const errors: ValidationError[] = []; for (const field of requiredFields) { if (req.body[field] === undefined || req.body[field] === null) { errors.push({ field, message: `Field '${field}' is required` }); } } if (errors.length > 0) { this.logger.warn('Validation failed: Required fields missing', { errors }, requestId); res.status(400).json({ error: 'Validation failed', details: errors }); return; } this.logger.debug('Required fields validation passed', { requiredFields }, requestId); next(); }; } /** * Validate that fields match specified types * @param fieldTypes Object mapping field names to expected types * @returns Express middleware function */ public validateFieldTypes(fieldTypes: { [key: string]: string }) { return (req: Request, res: Response, next: NextFunction): void => { const requestId = Date.now().toString(36) + Math.random().toString(36).substr(2); this.logger.debug('Validating field types', { fieldTypes, body: req.body }, requestId); const errors: ValidationError[] = []; for (const [field, expectedType] of Object.entries(fieldTypes)) { if (req.body[field] !== undefined && req.body[field] !== null) { const actualType = typeof req.body[field]; if (actualType !== expectedType) { errors.push({ field, message: `Field '${field}' must be of type '${expectedType}', got '${actualType}'` }); } } } if (errors.length > 0) { this.logger.warn('Validation failed: Field type mismatch', { errors }, requestId); res.status(400).json({ error: 'Validation failed', details: errors }); return; } this.logger.debug('Field types validation passed', { fieldTypes }, requestId); next(); }; } /** * Validate string fields against regex patterns * @param fieldPatterns Object mapping field names to regex patterns * @returns Express middleware function */ public validateStringPatterns(fieldPatterns: { [key: string]: RegExp }) { return (req: Request, res: Response, next: NextFunction): void => { const requestId = Date.now().toString(36) + Math.random().toString(36).substr(2); this.logger.debug('Validating string patterns', { fieldPatterns, body: req.body }, requestId); const errors: ValidationError[] = []; for (const [field, pattern] of Object.entries(fieldPatterns)) { if (req.body[field] !== undefined && req.body[field] !== null) { const value = req.body[field]; if (typeof value !== 'string') { errors.push({ field, message: `Field '${field}' must be a string` }); } else if (!pattern.test(value)) { errors.push({ field, message: `Field '${field}' does not match required pattern` }); } } } if (errors.length > 0) { this.logger.warn('Validation failed: String pattern mismatch', { errors }, requestId); res.status(400).json({ error: 'Validation failed', details: errors }); return; } this.logger.debug('String patterns validation passed', { fieldPatterns }, requestId); next(); }; } }