[backport 9.x] fix: return type of rateLimit

types/index.d.ts

@@ -1,15 +1,31 @@
 /// <reference types='node' />
 
 import {
+  ContextConfigDefault,
   FastifyPluginCallback,
   FastifyRequest,
+  FastifySchema,
   preHandlerAsyncHookHandler,
+  RouteGenericInterface,
   RouteOptions
 } from 'fastify';
 
 declare module 'fastify' {
-  interface FastifyInstance {
-    rateLimit: (options?: fastifyRateLimit.RateLimitOptions) => preHandlerAsyncHookHandler;
+  interface FastifyInstance<RawServer, RawRequest, RawReply, Logger, TypeProvider> {
+    rateLimit<
+      RouteGeneric extends RouteGenericInterface = RouteGenericInterface,
+      ContextConfig = ContextConfigDefault,
+      SchemaCompiler extends FastifySchema = FastifySchema,
+    >(options?: fastifyRateLimit.RateLimitOptions): preHandlerAsyncHookHandler<
+      RawServer,
+      RawRequest,
+      RawReply,
+      RouteGeneric,
+      ContextConfig,
+      SchemaCompiler,
+      TypeProvider,
+      Logger
+    >;
   }
   interface FastifyContextConfig {
     rateLimit?: fastifyRateLimit.RateLimitOptions | false;

types/index.test-d.ts

@@ -7,6 +7,7 @@ import fastify, {
 } from 'fastify'
 import * as http2 from 'http2'
 import { default as ioredis } from 'ioredis'
+import pino from 'pino';
 import fastifyRateLimit, {
   errorResponseBuilderContext,
   FastifyRateLimitOptions,
@@ -160,3 +161,15 @@ const errorResponseContext: errorResponseBuilderContext = {
   max: 1000,
   ttl: 123
 }
+const appWithCustomLogger = fastify({
+  logger: pino(),
+}).withTypeProvider()
+
+appWithCustomLogger.register(fastifyRateLimit, options1)
+
+appWithCustomLogger.route({
+  method: 'GET',
+  url: '/',
+  preHandler: appWithCustomLogger.rateLimit({}),
+  handler: () => {},
+})