MCP Server Template

/** * Timeout utilities with AbortSignal support * * Prevents long-running operations from blocking the MCP connection. */ import { TimeoutError } from './errors.js'; /** * Execute a function with a timeout * * @example * ```typescript * const result = await withTimeout( * () => longRunningOperation(), * 5000, * 'data-fetch' * ); * ``` */ export async function withTimeout<T>( fn: (signal: AbortSignal) => Promise<T>, timeoutMs: number, operationName: string = 'operation' ): Promise<T> { const controller = new AbortController(); const timeoutId = setTimeout(() => controller.abort(), timeoutMs); try { const result = await fn(controller.signal); clearTimeout(timeoutId); return result; } catch (error) { clearTimeout(timeoutId); if (error instanceof Error && error.name === 'AbortError') { throw new TimeoutError(operationName, timeoutMs); } throw error; } } /** * Create a promise that rejects after a timeout */ export function timeoutPromise(ms: number, message?: string): Promise<never> { return new Promise((_, reject) => { setTimeout(() => { reject(new TimeoutError(message ?? 'operation', ms)); }, ms); }); } /** * Race a promise against a timeout * * @example * ```typescript * const result = await raceTimeout(fetchData(), 5000, 'fetch'); * ``` */ export async function raceTimeout<T>( promise: Promise<T>, timeoutMs: number, operationName: string = 'operation' ): Promise<T> { return Promise.race([promise, timeoutPromise(timeoutMs, operationName)]); } /** * Create an AbortSignal that times out after specified duration */ export function createTimeoutSignal(timeoutMs: number): AbortSignal { const controller = new AbortController(); setTimeout(() => controller.abort(), timeoutMs); return controller.signal; } /** * Combine multiple AbortSignals into one */ export function combineSignals(...signals: AbortSignal[]): AbortSignal { const controller = new AbortController(); for (const signal of signals) { if (signal.aborted) { controller.abort(signal.reason); return controller.signal; } signal.addEventListener('abort', () => controller.abort(signal.reason), { once: true }); } return controller.signal; }