@tslock/fastify

TSLock middleware integration for Fastify.

The Fastify adapter acquires a lock in a route preHandler, returns a configurable lock-failure response when another request owns the lock, and releases the lock after the request completes.

Installation

pnpm add @tslock/core @tslock/fastify @tslock/in-memory fastify

Usage

import Fastify from 'fastify';
import { InMemoryLockProvider } from '@tslock/in-memory';
import { createFastifyLockPlugin } from '@tslock/fastify';

const app = Fastify();
await app.register(createFastifyLockPlugin({
  lockProvider: new InMemoryLockProvider(),
  lockAtMostFor: '30s',
}));

app.get('/reports', { preHandler: app.tslock() }, async () => ({ ok: true }));

The default lock name is derived from the HTTP method and route path. Configure lockNamePrefix, lockAtMostFor, lockAtLeastFor, or defaultLockedStatus through createFastifyLockPlugin.

Integration tests

The end-to-end suite uses Fastify's real request injector and covers acquisition, concurrent rejection, release and reacquisition, method-specific names, custom status codes, handler errors, LockAssert, and middleware reentrancy:

pnpm --filter @tslock/fastify test:integration

Requirements

• Node.js >= 22
• Peer: fastify

License

Apache 2.0 — see LICENSE for details.