MCP Boilerplate

/** * Validation Utilities * * This module provides utility functions for validating * tool inputs and handling validation errors. */ import { z } from 'zod'; import { handleZodError } from './errors.js'; /** * Validate tool input using a Zod schema * * @template T - The expected input type * @param schema - Zod schema to validate against * @param input - Input to validate * @returns Validated and typed input * @throws McpError if validation fails */ export function validateToolInput<T>(schema: z.ZodSchema<T>, input: unknown): T { try { return schema.parse(input); } catch (error) { if (error instanceof z.ZodError) { throw handleZodError(error); } throw error; } } /** * Safe validation that returns a result object instead of throwing * * @template T - The expected input type * @param schema - Zod schema to validate against * @param input - Input to validate * @returns Validation result with success flag and data/error */ export function safeValidateToolInput<T>( schema: z.ZodSchema<T>, input: unknown ): { success: true; data: T } | { success: false; error: string } { try { const data = schema.parse(input); return { success: true, data }; } catch (error) { if (error instanceof z.ZodError) { const firstIssue = error.issues[0]; if (!firstIssue) { return { success: false, error: 'Unknown validation error' }; } const path = firstIssue.path.length > 0 ? ` at '${firstIssue.path.join('.')}'` : ''; return { success: false, error: `${firstIssue.message}${path}` }; } return { success: false, error: 'Unknown validation error' }; } } /** * Check if a value is a safe number (finite, not NaN, within bounds) * * @param value - Value to check * @param min - Minimum allowed value (default: -1e10) * @param max - Maximum allowed value (default: 1e10) * @returns True if the value is a safe number */ export function isSafeNumber( value: unknown, min: number = -1e10, max: number = 1e10 ): value is number { return ( typeof value === 'number' && Number.isFinite(value) && !Number.isNaN(value) && value >= min && value <= max ); }