Have client.connect() return a Promise<RedisClient> (#2602)

* Connect returns the instance of the client

* Added a test

* No auto setup

* Added a bit of docs

* fix the return type, test, and the docs

* fix return type

* Update packages/client/lib/client/index.spec.ts

Co-authored-by: Francisco Presencia <franciscop@users.noreply.github.com>

---------

Co-authored-by: Leibale Eidelman <me@leibale.com>

packages/client/lib/client/index.spec.ts

@@ -107,6 +107,19 @@ describe('Client', () => {
         });
     });
 
+    describe('connect', () => {
+        testUtils.testWithClient('connect should return the client instance', async client => {
+            try {
+                assert.equal(await client.connect(), client);
+            } finally {
+                if (client.isOpen) await client.disconnect();
+            }
+        }, {
+            ...GLOBAL.SERVERS.PASSWORD,
+            disableClientSetup: true
+        });
+    });
+
     describe('authentication', () => {
         testUtils.testWithClient('Client should be authenticated', async client => {
             assert.equal(

packages/client/lib/client/index.ts

@@ -426,10 +426,11 @@ export default class RedisClient<
         });
     }
 
-    connect(): Promise<void> {
+    async connect() {
         // see comment in constructor
         this.#isolationPool ??= this.#initiateIsolationPool();
-        return this.#socket.connect();
+        await this.#socket.connect();
+        return this as unknown as RedisClientType<M, F, S>;
     }
 
     async commandsExecutor<C extends RedisCommand>(