feat(platform-fastify): add fastify custom log level feature

packages/platform-fastify/adapters/fastify-adapter.ts

@@ -53,6 +53,7 @@ import { parse as querystringParse } from 'querystring';
 import {
   FASTIFY_ROUTE_CONFIG_METADATA,
   FASTIFY_ROUTE_CONSTRAINTS_METADATA,
+  FASTIFY_ROUTE_LOG_METADATA,
 } from '../constants';
 import { NestFastifyBodyParserOptions } from '../interfaces';
 import {
@@ -750,8 +751,15 @@ export class FastifyAdapter<
       handlerRef,
     );
 
+    const routeLog = Reflect.getMetadata(
+      FASTIFY_ROUTE_LOG_METADATA,
+      handlerRef,
+    );
+
+
     const hasConfig = !isUndefined(routeConfig);
     const hasConstraints = !isUndefined(routeConstraints);
+    const hasLog = !isUndefined(routeLog);
 
     const routeToInject: RouteOptions<TServer, TRawRequest, TRawResponse> &
       RouteShorthandOptions = {
@@ -760,7 +768,7 @@ export class FastifyAdapter<
       handler: handlerRef,
     };
 
-    if (isVersioned || hasConstraints || hasConfig) {
+    if (isVersioned || hasConstraints || hasConfig || hasLog) {
       const isPathAndRouteTuple = args.length === 2;
       if (isPathAndRouteTuple) {
         const constraints = {
@@ -777,6 +785,9 @@ export class FastifyAdapter<
               ...routeConfig,
             },
           }),
+          ...(hasLog && {
+            ...routeLog,
+          }),
         };
 
         const routeToInjectWithOptions = { ...routeToInject, ...options };

packages/platform-fastify/constants.ts

@@ -1,3 +1,4 @@
 export const FASTIFY_ROUTE_CONFIG_METADATA = '__fastify_route_config__';
 export const FASTIFY_ROUTE_CONSTRAINTS_METADATA =
   '__fastify_route_constraints__';
+export const FASTIFY_ROUTE_LOG_METADATA = '__fastify_route_log__';

packages/platform-fastify/decorators/index.ts

@@ -1,2 +1,4 @@
 export * from './route-config.decorator';
 export * from './route-constraints.decorator';
+export * from './route-log.decorator';
+

packages/platform-fastify/decorators/route-log.decorator.ts

@@ -0,0 +1,11 @@
+import { SetMetadata } from '@nestjs/common';
+import { FASTIFY_ROUTE_LOG_METADATA } from '../constants';
+import { LogLevel } from 'fastify';
+
+/**
+ * @publicApi
+ *
+ * @param config See {@link https://fastify.dev/docs/latest/Reference/Routes/#custom-log-level}
+ */
+export const RouteLog = (config: { logLevel: LogLevel }) =>
+  SetMetadata(FASTIFY_ROUTE_LOG_METADATA, config);

packages/platform-fastify/test/decorators/router-log.decorator.spec.ts

@@ -0,0 +1,17 @@
+import { expect } from 'chai';
+import { FASTIFY_ROUTE_LOG_METADATA } from '../../constants';
+import { RouteLog } from '../../decorators/route-log.decorator';
+
+describe('@RouteConfig', () => {
+  const routeConfig = { logLevel: 'debug' };
+  class Test {
+    config;
+    @RouteLog(routeConfig)
+    public static test() {}
+  }
+
+  it('should enhance method with expected fastify route config', () => {
+    const path = Reflect.getMetadata(FASTIFY_ROUTE_LOG_METADATA, Test.test);
+    expect(path).to.be.eql(routeConfig);
+  });
+});