Merge pull request #15190 from nestjs/feat/nats-v3-migration

feat(microservices): nats v3 upgrade

integration/microservices/src/disconnected.controller.ts

@@ -26,7 +26,8 @@ export class DisconnectedClientController {
           code === 'CONN_ERR' ||
           code === 'ENOTFOUND' ||
           code === 'CONNECTION_REFUSED' ||
-          error.message.includes('Connection is closed.')
+          error.message.includes('Connection is closed.') ||
+          error.message.includes('connection refused')
             ? new RequestTimeoutException('ECONNREFUSED')
             : new InternalServerErrorException(),
         );

integration/microservices/src/nats/nats.controller.ts

@@ -1,3 +1,4 @@
+import * as nats from '@nats-io/nats-core';
 import { Body, Controller, Get, HttpCode, Post, Query } from '@nestjs/common';
 import {
   ClientProxy,
@@ -11,7 +12,6 @@ import {
   RpcException,
   Transport,
 } from '@nestjs/microservices';
-import * as nats from 'nats';
 import { from, lastValueFrom, Observable, of, throwError } from 'rxjs';
 import { catchError, scan } from 'rxjs/operators';
 import { NatsService } from './nats.service.js';

package.json

@@ -97,6 +97,7 @@
     "@fastify/view": "11.1.1",
     "@grpc/grpc-js": "1.14.3",
     "@grpc/proto-loader": "0.8.0",
+    "@nats-io/transport-node": "^3.0.2",
     "@nestjs/apollo": "13.2.4",
     "@nestjs/graphql": "13.2.4",
     "@nestjs/mongoose": "11.0.4",
@@ -153,8 +154,7 @@
     "mqtt": "5.15.0",
     "multer": "2.0.2",
     "mysql2": "3.17.1",
-    "nats": "2.29.3",
-    "prettier": "^3.7.4",
+    "prettier": "3.7.4",
     "redis": "5.10.0",
     "reusify": "1.1.0",
     "rxjs-compat": "6.6.7",
@@ -165,9 +165,9 @@
     "tsx": "4.19.2",
     "typeorm": "0.3.28",
     "typescript": "5.9.3",
-    "typescript-eslint": "^8.55.1-alpha.4",
-    "unplugin-swc": "^1.5.9",
-    "vitest": "^4.0.18",
+    "typescript-eslint": "8.55.1-alpha.4",
+    "unplugin-swc": "1.5.9",
+    "vitest": "4.0.18",
     "ws": "8.19.0"
   },
   "engines": {

packages/core/test/nest-application.spec.ts

@@ -1,5 +1,6 @@
 import { RequestMethod } from '@nestjs/common';
 import { loadPackage } from '@nestjs/common/utils/load-package.util.js';
+import * as microservicesPackage from '@nestjs/microservices';
 import { MicroserviceOptions } from '@nestjs/microservices';
 import { ApplicationConfig } from '../application-config.js';
 import { NestContainer } from '../injector/container.js';
@@ -12,12 +13,13 @@ describe('NestApplication', () => {
   beforeAll(async () => {
     // Pre-populate the package cache so that connectMicroservice()
     // can synchronously retrieve @nestjs/microservices via loadPackageCached.
+    // Use the already-imported module to avoid a slow dynamic import() on CI.
     await loadPackage(
       '@nestjs/microservices',
       'NestApplication tests',
-      () => import('@nestjs/microservices'),
+      () => microservicesPackage,
     );
-  }, 30_000);
+  });
 
   describe('Hybrid Application', () => {
     class Interceptor {

packages/microservices/client/client-nats.ts

@@ -1,5 +1,7 @@
-import { createRequire } from 'module';
+import { Logger } from '@nestjs/common';
+import { isObject, loadPackageSync } from '@nestjs/common/internal';
 import { EventEmitter } from 'events';
+import { createRequire } from 'module';
 import { NATS_DEFAULT_URL } from '../constants.js';
 import { NatsResponseJSONDeserializer } from '../deserializers/nats-response-json.deserializer.js';
 import { EmptyResponseException } from '../errors/empty-response.exception.js';
@@ -17,8 +19,6 @@ import {
 import { NatsRecord } from '../record-builders/index.js';
 import { NatsRecordSerializer } from '../serializers/nats-record.serializer.js';
 import { ClientProxy } from './client-proxy.js';
-import { Logger } from '@nestjs/common';
-import { loadPackageSync, isObject } from '@nestjs/common/internal';
 
 let natsPackage = {} as any;
 
@@ -26,8 +26,8 @@ let natsPackage = {} as any;
 // because it would require the user to install the nats package even if they dont use Nats
 // Otherwise, TypeScript would fail to compile the code.
 //
-// type Client = import('nats').NatsConnection;
-// type NatsMsg = import('nats').Msg;
+// type Client = import('@nats-io/transport-node').NatsConnection;
+// type NatsMsg = import('@nats-io/transport-node').Msg;
 
 type Client = Record<string, any>;
 type NatsMsg = Record<string, any>;
@@ -46,8 +46,10 @@ export class ClientNats extends ClientProxy<NatsEvents, NatsStatus> {
 
   constructor(protected readonly options: Required<NatsOptions>['options']) {
     super();
-    natsPackage = loadPackageSync('nats', ClientNats.name, () =>
-      createRequire(import.meta.url)('nats'),
+    natsPackage = loadPackageSync(
+      '@nats-io/transport-node',
+      ClientNats.name,
+      () => createRequire(import.meta.url)('@nats-io/transport-node'),
     );
 
     this.initializeSerializer(options);
@@ -101,15 +103,10 @@ export class ClientNats extends ClientProxy<NatsEvents, NatsStatus> {
 
   public async handleStatusUpdates(client: Client) {
     for await (const status of client.status()) {
-      const data =
-        status.data && isObject(status.data)
-          ? JSON.stringify(status.data)
-          : status.data;
-
       switch (status.type) {
         case 'error':
           this.logger.error(
-            `NatsError: type: "${status.type}", data: "${data}".`,
+            `NatsError: type: "${status.type}", error: "${status.error}".`,
           );
           break;
 
@@ -120,14 +117,12 @@ export class ClientNats extends ClientProxy<NatsEvents, NatsStatus> {
           // Prevent unhandled promise rejection
           this.connectionPromise.catch(() => {});
 
-          this.logger.error(
-            `NatsError: type: "${status.type}", data: "${data}".`,
-          );
+          this.logger.error(`NatsError: type: "${status.type}".`);
 
           this._status$.next(NatsStatus.DISCONNECTED);
           this.statusEventEmitter.emit(
             NatsEventsMap.DISCONNECT,
-            status.data as string,
+            status.server as string,
           );
           break;
 
@@ -137,37 +132,42 @@ export class ClientNats extends ClientProxy<NatsEvents, NatsStatus> {
 
         case 'reconnect':
           this.connectionPromise = Promise.resolve(client);
-          this.logger.log(
-            `NatsStatus: type: "${status.type}", data: "${data}".`,
-          );
+          this.logger.log(`NatsStatus: type: "${status.type}".`);
 
           this._status$.next(NatsStatus.CONNECTED);
           this.statusEventEmitter.emit(
             NatsEventsMap.RECONNECT,
-            status.data as string,
+            status.server as string,
           );
           break;
 
-        case 'pingTimer':
+        case 'ping':
           if (this.options.debug) {
             this.logger.debug(
-              `NatsStatus: type: "${status.type}", data: "${data}".`,
+              `NatsStatus: type: "${status.type}", pending pings: "${status.pendingPings}".`,
             );
           }
           break;
 
         case 'update':
           this.logger.log(
-            `NatsStatus: type: "${status.type}", data: "${data}".`,
+            `NatsStatus: type: "${status.type}", added: "${status.added}", deleted: "${status.deleted}".`,
           );
-          this.statusEventEmitter.emit(NatsEventsMap.UPDATE, status.data);
+          this.statusEventEmitter.emit(NatsEventsMap.UPDATE, undefined);
           break;
 
-        default:
+        default: {
+          const data =
+            'data' in status && isObject(status.data)
+              ? JSON.stringify(status.data)
+              : 'data' in status
+                ? status.data
+                : '';
           this.logger.log(
             `NatsStatus: type: "${status.type}", data: "${data}".`,
           );
           break;
+        }
       }
     }
   }
@@ -192,7 +192,7 @@ export class ClientNats extends ClientProxy<NatsEvents, NatsStatus> {
     packet: ReadPacket & PacketId,
     callback: (packet: WritePacket) => any,
   ) {
-    return async (error: string | Error | undefined, natsMsg: NatsMsg) => {
+    return async (error: Error | null, natsMsg: NatsMsg) => {
       if (error) {
         return callback({
           err: error,
@@ -207,7 +207,7 @@ export class ClientNats extends ClientProxy<NatsEvents, NatsStatus> {
           isDisposed: true,
         });
       }
-      const message = await this.deserializer.deserialize(rawPacket);
+      const message = await this.deserializer.deserialize(natsMsg);
       if (message.id && message.id !== packet.id) {
         return undefined;
       }
@@ -244,7 +244,10 @@ export class ClientNats extends ClientProxy<NatsEvents, NatsStatus> {
       );
 
       const subscription = this.natsClient!.subscribe(inbox, {
-        callback: subscriptionHandler,
+        callback: subscriptionHandler as (
+          err: Error | null,
+          msg: NatsMsg,
+        ) => Promise<never>,
       });
 
       const headers = this.mergeHeaders(serializedPacket.headers);

packages/microservices/deserializers/nats-request-json.deserializer.ts

@@ -1,36 +1,27 @@
-import { createRequire } from 'module';
-import { NatsCodec } from '../external/nats-codec.interface.js';
 import { IncomingEvent, IncomingRequest } from '../interfaces/index.js';
 import { IncomingRequestDeserializer } from './incoming-request.deserializer.js';
-import { loadPackageSync } from '@nestjs/common/internal';
 
-let natsPackage = {} as any;
+// To enable type safety for Nats. This cant be uncommented by default
+// because it would require the user to install the nats package even if they dont use Nats
+// Otherwise, TypeScript would fail to compile the code.
+//
+// type NatsMsg = import('@nats-io/transport-node').Msg;
+
+type NatsMsg = any;
 
 /**
  * @publicApi
  */
 export class NatsRequestJSONDeserializer extends IncomingRequestDeserializer {
-  private readonly jsonCodec: NatsCodec<unknown>;
-
-  constructor() {
-    super();
-
-    natsPackage = loadPackageSync(
-      'nats',
-      NatsRequestJSONDeserializer.name,
-      () => createRequire(import.meta.url)('nats'),
-    );
-    this.jsonCodec = natsPackage.JSONCodec();
-  }
-
   deserialize(
-    value: Uint8Array,
+    value: NatsMsg,
     options?: Record<string, any>,
   ):
     | IncomingRequest
     | IncomingEvent
-    | Promise<IncomingRequest | IncomingEvent> {
-    const decodedRequest = this.jsonCodec.decode(value);
+    | Promise<IncomingRequest>
+    | Promise<IncomingEvent> {
+    const decodedRequest = value.json();
     return super.deserialize(decodedRequest, options);
   }
 }

packages/microservices/deserializers/nats-response-json.deserializer.ts

@@ -1,33 +1,23 @@
-import { createRequire } from 'module';
-import { NatsCodec } from '../external/nats-codec.interface.js';
 import { IncomingResponse } from '../interfaces/index.js';
 import { IncomingResponseDeserializer } from './incoming-response.deserializer.js';
-import { loadPackageSync } from '@nestjs/common/internal';
 
-let natsPackage = {} as any;
+// To enable type safety for Nats. This cant be uncommented by default
+// because it would require the user to install the nats package even if they dont use Nats
+// Otherwise, TypeScript would fail to compile the code.
+//
+// type NatsMsg = import('@nats-io/transport-node').Msg;
+
+type NatsMsg = any;
 
 /**
  * @publicApi
  */
 export class NatsResponseJSONDeserializer extends IncomingResponseDeserializer {
-  private readonly jsonCodec: NatsCodec<unknown>;
-
-  constructor() {
-    super();
-
-    natsPackage = loadPackageSync(
-      'nats',
-      NatsResponseJSONDeserializer.name,
-      () => createRequire(import.meta.url)('nats'),
-    );
-    this.jsonCodec = natsPackage.JSONCodec();
-  }
-
   deserialize(
-    value: Uint8Array,
+    value: NatsMsg,
     options?: Record<string, any>,
   ): IncomingResponse | Promise<IncomingResponse> {
-    const decodedRequest = this.jsonCodec.decode(value);
+    const decodedRequest = value.json();
     return super.deserialize(decodedRequest, options);
   }
 }

packages/microservices/package.json

@@ -49,6 +49,7 @@
   },
   "peerDependencies": {
     "@grpc/grpc-js": "*",
+    "@nats-io/transport-node": "*",
     "@nestjs/common": "^11.0.0",
     "@nestjs/core": "^11.0.0",
     "@nestjs/websockets": "^11.0.0",
@@ -58,7 +59,6 @@
     "ioredis": "*",
     "kafkajs": "*",
     "mqtt": "*",
-    "nats": "*",
     "reflect-metadata": "^0.1.12 || ^0.2.0",
     "rxjs": "^7.1.0"
   },
@@ -66,6 +66,9 @@
     "@grpc/grpc-js": {
       "optional": true
     },
+    "@nats-io/transport-node": {
+      "optional": true
+    },
     "@nestjs/websockets": {
       "optional": true
     },
@@ -78,9 +81,6 @@
     "mqtt": {
       "optional": true
     },
-    "nats": {
-      "optional": true
-    },
     "ioredis": {
       "optional": true
     },

packages/microservices/serializers/nats-record.serializer.ts

@@ -1,25 +1,12 @@
-import { createRequire } from 'module';
-import { NatsCodec } from '../external/nats-codec.interface.js';
+import { isObject } from '@nestjs/common/internal';
 import { ReadPacket } from '../interfaces/index.js';
 import { Serializer } from '../interfaces/serializer.interface.js';
 import { NatsRecord, NatsRecordBuilder } from '../record-builders/index.js';
-import { loadPackageSync, isObject } from '@nestjs/common/internal';
-
-let natsPackage = {} as any;
 
 export class NatsRecordSerializer implements Serializer<
   ReadPacket,
   NatsRecord
 > {
-  private readonly jsonCodec: NatsCodec<unknown>;
-
-  constructor() {
-    natsPackage = loadPackageSync('nats', NatsRecordSerializer.name, () =>
-      createRequire(import.meta.url)('nats'),
-    );
-    this.jsonCodec = natsPackage.JSONCodec();
-  }
-
   serialize(packet: any): NatsRecord {
     const natsMessage =
       packet?.data && isObject(packet.data) && packet.data instanceof NatsRecord
@@ -27,7 +14,7 @@ export class NatsRecordSerializer implements Serializer<
         : new NatsRecordBuilder(packet?.data).build();
 
     return {
-      data: this.jsonCodec.encode({ ...packet, data: natsMessage.data }),
+      data: JSON.stringify({ ...packet, data: natsMessage.data }),
       headers: natsMessage.headers,
     };
   }

packages/microservices/server/server-nats.ts

@@ -1,3 +1,4 @@
+import { isObject, isUndefined } from '@nestjs/common/internal';
 import { EventEmitter } from 'events';
 import {
   NATS_DEFAULT_GRACE_PERIOD,
@@ -20,15 +21,14 @@ import { IncomingRequest } from '../interfaces/packet.interface.js';
 import { NatsRecord } from '../record-builders/index.js';
 import { NatsRecordSerializer } from '../serializers/nats-record.serializer.js';
 import { Server } from './server.js';
-import { isObject, isUndefined } from '@nestjs/common/internal';
 
 // To enable type safety for Nats. This cant be uncommented by default
 // because it would require the user to install the nats package even if they dont use Nats
 // Otherwise, TypeScript would fail to compile the code.
 //
-// type Client = import('nats').NatsConnection;
-// type NatsMsg = import('nats').Msg;
-// type Subscription = import('nats').Subscription;
+// type Client = import('@nats-io/transport-node').NatsConnection;
+// type NatsMsg = import('@nats-io/transport-node').Msg;
+// type Subscription = import('@nats-io/transport-node').Subscription;
 
 type Client = any;
 type NatsMsg = any;
@@ -123,25 +123,11 @@ export class ServerNats<
 
   public async createNatsClient(): Promise<Client> {
     const natsPackage = await this.loadPackage(
-      'nats',
+      '@nats-io/transport-node',
       ServerNats.name,
-      () => import('nats'),
+      () => import('@nats-io/transport-node'),
     );
 
-    // Eagerly initialize serializer/deserializer so they can be used synchronously
-    if (
-      this.serializer &&
-      typeof (this.serializer as any).init === 'function'
-    ) {
-      await (this.serializer as any).init();
-    }
-    if (
-      this.deserializer &&
-      typeof (this.deserializer as any).init === 'function'
-    ) {
-      await (this.deserializer as any).init();
-    }
-
     const options = this.options || ({} as NatsOptions);
     return natsPackage.connect({
       servers: NATS_DEFAULT_URL,
@@ -164,7 +150,7 @@ export class ServerNats<
     const replyTo = natsMsg.reply;
 
     const natsCtx = new NatsContext([callerSubject, natsMsg.headers]);
-    const message = await this.deserializer.deserialize(rawMessage, {
+    const message = await this.deserializer.deserialize(natsMsg, {
       channel,
       replyTo,
     });
@@ -216,34 +202,24 @@ export class ServerNats<
 
   public async handleStatusUpdates(client: Client) {
     for await (const status of client.status()) {
-      const data =
-        status.data && isObject(status.data)
-          ? JSON.stringify(status.data)
-          : status.data;
-
       switch (status.type) {
         case 'error':
           this.logger.error(
-            `NatsError: type: "${status.type}", data: "${data}".`,
+            `NatsError: type: "${status.type}", error: "${status.error}".`,
           );
           break;
 
         case 'disconnect':
-          this.logger.error(
-            `NatsError: type: "${status.type}", data: "${data}".`,
-          );
+          this.logger.error(`NatsError: type: "${status.type}".`);
 
           this._status$.next(NatsStatus.DISCONNECTED as S);
-          this.statusEventEmitter.emit(
-            NatsEventsMap.DISCONNECT,
-            status.data as string,
-          );
+          this.statusEventEmitter.emit(NatsEventsMap.DISCONNECT, status.server);
           break;
 
-        case 'pingTimer':
+        case 'ping':
           if (this.options.debug) {
             this.logger.debug!(
-              `NatsStatus: type: "${status.type}", data: "${data}".`,
+              `NatsStatus: type: "${status.type}", pending pings: "${status.pendingPings}".`,
             );
           }
           break;
@@ -253,29 +229,31 @@ export class ServerNats<
           break;
 
         case 'reconnect':
-          this.logger.log(
-            `NatsStatus: type: "${status.type}", data: "${data}".`,
-          );
+          this.logger.log(`NatsStatus: type: "${status.type}".`);
 
           this._status$.next(NatsStatus.CONNECTED as S);
-          this.statusEventEmitter.emit(
-            NatsEventsMap.RECONNECT,
-            status.data as string,
-          );
+          this.statusEventEmitter.emit(NatsEventsMap.RECONNECT, status.server);
           break;
 
         case 'update':
           this.logger.log(
-            `NatsStatus: type: "${status.type}", data: "${data}".`,
+            `NatsStatus: type: "${status.type}", added: "${status.added}", deleted: "${status.deleted}".`,
           );
-          this.statusEventEmitter.emit(NatsEventsMap.UPDATE, status.data);
+          this.statusEventEmitter.emit(NatsEventsMap.UPDATE, undefined);
           break;
 
-        default:
+        default: {
+          const data =
+            'data' in status && isObject(status.data)
+              ? JSON.stringify(status.data)
+              : 'data' in status
+                ? status.data
+                : '';
           this.logger.log(
             `NatsStatus: type: "${status.type}", data: "${data}".`,
           );
           break;
+        }
       }
     }
   }

packages/microservices/test/client/client-nats.spec.ts

@@ -1,6 +1,6 @@
-import { headers as createHeaders, JSONCodec } from 'nats';
+import { headers as createHeaders } from '@nats-io/transport-node';
 import { ClientNats } from '../../client/client-nats.js';
-import { ReadPacket } from '../../interfaces/index.js';
+import { ReadPacket, WritePacket } from '../../interfaces/index.js';
 import { NatsRecord } from '../../record-builders/index.js';
 
 describe('ClientNats', () => {
@@ -93,7 +93,10 @@ describe('ClientNats', () => {
             Object.assign(packet as object, { id }),
           );
 
-        subscription = client['publish'](msg, callback);
+        subscription = client['publish'](
+          msg,
+          callback as (packet: WritePacket) => any,
+        );
         subscription();
       });
       afterEach(() => {
@@ -160,7 +163,8 @@ describe('ClientNats', () => {
       id: '1',
     };
     const natsMessage = {
-      data: JSONCodec().encode(responseMessage),
+      data: JSON.stringify(responseMessage),
+      json: () => responseMessage,
     };
 
     let callback: ReturnType<typeof vi.fn>, subscription;
@@ -169,7 +173,10 @@ describe('ClientNats', () => {
       beforeEach(async () => {
         callback = vi.fn();
 
-        subscription = client.createSubscriptionHandler(msg, callback);
+        subscription = client.createSubscriptionHandler(
+          msg,
+          callback as (packet: WritePacket) => any,
+        );
         await subscription(undefined, natsMessage);
       });
       it('should call callback with expected arguments', () => {
@@ -182,12 +189,18 @@ describe('ClientNats', () => {
     describe('disposed and "id" is correct', () => {
       beforeEach(async () => {
         callback = vi.fn();
-        subscription = client.createSubscriptionHandler(msg, callback);
-        await subscription(undefined, {
-          data: JSONCodec().encode({
+        subscription = client.createSubscriptionHandler(
+          msg,
+          callback as (packet: WritePacket) => any,
+        );
+        subscription(undefined, {
+          data: JSON.stringify({
             ...responseMessage,
             isDisposed: true,
           }),
+          json: function () {
+            return JSON.parse(this.data);
+          },
         });
       });
 
@@ -207,13 +220,16 @@ describe('ClientNats', () => {
             ...msg,
             id: '2',
           },
-          callback,
+          callback as (packet: WritePacket) => any,
         );
         subscription(undefined, {
-          data: JSONCodec().encode({
+          data: JSON.stringify({
             ...responseMessage,
             isDisposed: true,
           }),
+          json: function () {
+            return JSON.parse(this.data);
+          },
         });
       });
 
@@ -296,18 +312,20 @@ describe('ClientNats', () => {
       const clientMock = {
         status: vi.fn().mockReturnValue({
           async *[Symbol.asyncIterator]() {
-            yield { type: 'disconnect', data: 'localhost' };
-            yield { type: 'error', data: {} };
+            yield { type: 'disconnect' };
+            yield { type: 'error', error: 'Test error' };
           },
         }),
       };
       await client.handleStatusUpdates(clientMock as any);
       expect(logErrorSpy).toHaveBeenCalledTimes(2);
-      expect(logErrorSpy).toHaveBeenCalledWith(
-        'NatsError: type: "disconnect", data: "localhost".',
+      expect(logErrorSpy).toHaveBeenNthCalledWith(
+        1,
+        'NatsError: type: "disconnect".',
       );
-      expect(logErrorSpy).toHaveBeenCalledWith(
-        'NatsError: type: "error", data: "{}".',
+      expect(logErrorSpy).toHaveBeenNthCalledWith(
+        2,
+        'NatsError: type: "error", error: "Test error".',
       );
     });
     it('should log other statuses as "logs"', async () => {

packages/microservices/test/serializers/nats-record.serializer.spec.ts

@@ -1,9 +1,7 @@
-import * as nats from 'nats';
+import * as nats from '@nats-io/nats-core';
 import { NatsRecordBuilder } from '../../record-builders/index.js';
 import { NatsRecordSerializer } from '../../serializers/nats-record.serializer.js';
 
-const jsonCodec = nats.JSONCodec();
-
 describe('NatsRecordSerializer', () => {
   let instance: NatsRecordSerializer;
   beforeEach(() => {
@@ -13,42 +11,42 @@ describe('NatsRecordSerializer', () => {
     it('undefined', () => {
       expect(instance.serialize({ data: undefined })).toEqual({
         headers: undefined,
-        data: jsonCodec.encode({ data: undefined }),
+        data: JSON.stringify({ data: undefined }),
       });
     });
 
     it('null', () => {
       expect(instance.serialize({ data: null })).toEqual({
         headers: undefined,
-        data: jsonCodec.encode({ data: null }),
+        data: JSON.stringify({ data: null }),
       });
     });
 
     it('string', () => {
       expect(instance.serialize({ data: 'string' })).toEqual({
         headers: undefined,
-        data: jsonCodec.encode({ data: 'string' }),
+        data: JSON.stringify({ data: 'string' }),
       });
     });
 
     it('number', () => {
       expect(instance.serialize({ data: 12345 })).toEqual({
         headers: undefined,
-        data: jsonCodec.encode({ data: 12345 }),
+        data: JSON.stringify({ data: 12345 }),
       });
     });
 
     it('buffer', () => {
       expect(instance.serialize({ data: Buffer.from('buffer') })).toEqual({
         headers: undefined,
-        data: jsonCodec.encode({ data: Buffer.from('buffer') }),
+        data: JSON.stringify({ data: Buffer.from('buffer') }),
       });
     });
 
     it('array', () => {
       expect(instance.serialize({ data: [1, 2, 3, 4, 5] })).toEqual({
         headers: undefined,
-        data: jsonCodec.encode({ data: [1, 2, 3, 4, 5] }),
+        data: JSON.stringify({ data: [1, 2, 3, 4, 5] }),
       });
     });
 
@@ -56,7 +54,7 @@ describe('NatsRecordSerializer', () => {
       const serObject = { prop: 'value' };
       expect(instance.serialize({ data: serObject })).toEqual({
         headers: undefined,
-        data: jsonCodec.encode({ data: serObject }),
+        data: JSON.stringify({ data: serObject }),
       });
     });
 
@@ -73,7 +71,7 @@ describe('NatsRecordSerializer', () => {
         }),
       ).toEqual({
         headers: natsHeaders,
-        data: jsonCodec.encode({
+        data: JSON.stringify({
           data: {
             value: 'string',
           },

packages/microservices/test/server/server-nats.spec.ts

@@ -1,11 +1,10 @@
-import { JSONCodec } from 'nats';
 import { NO_MESSAGE_HANDLER } from '../../constants.js';
 import { BaseRpcContext } from '../../ctx-host/base-rpc.context.js';
 import { NatsContext } from '../../ctx-host/index.js';
 import { ServerNats } from '../../server/server-nats.js';
 import { objectToMap } from './utils/object-to-map.js';
 
-// type NatsMsg = import('nats').Msg;
+// type NatsMsg = import('@nats-io/nats-core').Msg;
 type NatsMsg = any;
 
 describe('ServerNats', () => {
@@ -44,7 +43,7 @@ describe('ServerNats', () => {
         vi.spyOn(server, 'start').mockImplementation(() => {
           throw error;
         });
-        await server.listen(callbackSpy);
+        await server.listen(callbackSpy as any);
         expect(callbackSpy).toHaveBeenCalledWith(error);
       });
     });
@@ -178,23 +177,24 @@ describe('ServerNats', () => {
     beforeEach(() => {
       getPublisherSpy = vi.fn();
       vi.spyOn(server, 'getPublisher').mockImplementation(
-        () => getPublisherSpy,
+        () => getPublisherSpy as any,
       );
     });
     it('should call "handleEvent" if identifier is not present', async () => {
       const handleEventSpy = vi.spyOn(server, 'handleEvent');
-      const data = JSONCodec().encode({ id: 10 });
+      const data = JSON.stringify({ id: 10 });
       const natsMsg: NatsMsg = {
         data,
         subject: channel,
         sid: +id,
         respond: vi.fn(),
+        json: () => JSON.parse(data),
       };
       await server.handleMessage(channel, natsMsg);
       expect(handleEventSpy).toHaveBeenCalled();
     });
     it(`should publish NO_MESSAGE_HANDLER if pattern does not exist in messageHandlers object`, async () => {
-      const data = JSONCodec().encode({
+      const data = JSON.stringify({
         id,
         pattern: 'test',
         data: 'test',
@@ -204,6 +204,7 @@ describe('ServerNats', () => {
         subject: channel,
         sid: +id,
         respond: vi.fn(),
+        json: () => JSON.parse(data),
       };
 
       await server.handleMessage(channel, natsMsg);
@@ -222,7 +223,7 @@ describe('ServerNats', () => {
       const headers = {};
       const natsContext = new NatsContext([channel, headers]);
 
-      const data = JSONCodec().encode({
+      const data = JSON.stringify({
         pattern: channel,
         data: 'test',
         id,
@@ -233,6 +234,7 @@ describe('ServerNats', () => {
         sid: +id,
         respond: vi.fn(),
         headers,
+        json: () => JSON.parse(data),
       };
       await server.handleMessage(channel, natsMsg);
       expect(handler).toHaveBeenCalledWith('test', natsContext);
@@ -261,13 +263,13 @@ describe('ServerNats', () => {
         sid: +id,
         respond: vi.fn(),
         reply: replyTo,
-      };
+      } as NatsMsg;
       const publisher = server.getPublisher(natsMsg, id, context);
 
       const respond = 'test';
       publisher({ respond, id });
       expect(natsMsg.respond).toHaveBeenCalledWith(
-        JSONCodec().encode({ respond, id }),
+        JSON.stringify({ respond, id }),
         expect.objectContaining({}),
       );
     });
@@ -279,7 +281,7 @@ describe('ServerNats', () => {
         reply: replyTo,
         sid: +id,
         respond: vi.fn(),
-      };
+      } as NatsMsg;
       const publisher = server.getPublisher(natsMsg, id, context);
 
       const respond = 'test';
@@ -321,18 +323,18 @@ describe('ServerNats', () => {
       const serverMock = {
         status: vi.fn().mockReturnValue({
           async *[Symbol.asyncIterator]() {
-            yield { type: 'disconnect', data: 'localhost' };
-            yield { type: 'error', data: {} };
+            yield { type: 'disconnect' };
+            yield { type: 'error', error: 'Test error' };
           },
         }),
       };
       await server.handleStatusUpdates(serverMock as any);
       expect(logErrorSpy).toHaveBeenCalledTimes(2);
       expect(logErrorSpy).toHaveBeenCalledWith(
-        `NatsError: type: "disconnect", data: "localhost".`,
+        `NatsError: type: "disconnect".`,
       );
       expect(logErrorSpy).toHaveBeenCalledWith(
-        `NatsError: type: "error", data: "{}".`,
+        `NatsError: type: "error", error: "Test error".`,
       );
     });
     it('should log other statuses as "logs"', async () => {