From 1b8e3287d07b70b09757a3d5e6645be9a61280c8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kamil=20My=C5=9Bliwiec?= <mail@kamilmysliwiec.com>
Date: Tue, 13 Aug 2024 10:07:03 +0200
Subject: [PATCH 1/2] fix(microservices): hold nats client connection promise
 ref #13880

---
 packages/microservices/client/client-nats.ts | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/packages/microservices/client/client-nats.ts b/packages/microservices/client/client-nats.ts
index 1c45437a56d..62b78ac1d70 100644
--- a/packages/microservices/client/client-nats.ts
+++ b/packages/microservices/client/client-nats.ts
@@ -18,6 +18,7 @@ let natsPackage = {} as any;
 export class ClientNats extends ClientProxy {
   protected readonly logger = new Logger(ClientNats.name);
   protected natsClient: Client;
+  protected clientConnectionPromise: Promise<Client>;
 
   constructor(protected readonly options: NatsOptions['options']) {
     super();
@@ -33,10 +34,11 @@ export class ClientNats extends ClientProxy {
   }
 
   public async connect(): Promise<any> {
-    if (this.natsClient) {
-      return this.natsClient;
+    if (this.clientConnectionPromise) {
+      return this.clientConnectionPromise;
     }
-    this.natsClient = await this.createClient();
+    this.clientConnectionPromise = this.createClient();
+    this.natsClient = await this.clientConnectionPromise;
     this.handleStatusUpdates(this.natsClient);
     return this.natsClient;
   }

From 0c84c7e1cc2d65d5dcc7fdfcabd9a0daa0d985df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kamil=20My=C5=9Bliwiec?= <mail@kamilmysliwiec.com>
Date: Tue, 13 Aug 2024 10:23:27 +0200
Subject: [PATCH 2/2] test: update client unit tests, add cleanup

---
 packages/microservices/client/client-nats.ts           | 1 +
 packages/microservices/test/client/client-nats.spec.ts | 1 +
 2 files changed, 2 insertions(+)

diff --git a/packages/microservices/client/client-nats.ts b/packages/microservices/client/client-nats.ts
index 62b78ac1d70..384fa4e8ed4 100644
--- a/packages/microservices/client/client-nats.ts
+++ b/packages/microservices/client/client-nats.ts
@@ -31,6 +31,7 @@ export class ClientNats extends ClientProxy {
   public async close() {
     await this.natsClient?.close();
     this.natsClient = null;
+    this.clientConnectionPromise = null;
   }
 
   public async connect(): Promise<any> {
diff --git a/packages/microservices/test/client/client-nats.spec.ts b/packages/microservices/test/client/client-nats.spec.ts
index 7bb0aa36fce..d9f93bc2170 100644
--- a/packages/microservices/test/client/client-nats.spec.ts
+++ b/packages/microservices/test/client/client-nats.spec.ts
@@ -253,6 +253,7 @@ describe('ClientNats', () => {
     describe('when is not connected', () => {
       beforeEach(async () => {
         client['natsClient'] = null;
+        client['clientConnectionPromise'] = null;
         await client.connect();
       });
       it('should call "handleStatusUpdatesSpy" once', async () => {