Node: add AZ Affinity ReadFrom strategy Support (valkey-io#2686)

* Added AZAffinity strategy to Node.js

---------

Signed-off-by: Muhammad Awawdi <mawawdi@amazon.com>

node/src/BaseClient.ts

@@ -574,6 +574,18 @@ export interface BaseClientConfiguration {
      * used.
      */
     inflightRequestsLimit?: number;
+    /**
+     * Availability Zone of the client.
+     * If ReadFrom strategy is AZAffinity, this setting ensures that readonly commands are directed to replicas within the specified AZ if exits.
+     *
+     * @example
+     * ```typescript
+     * // Example configuration for setting client availability zone and read strategy
+     * configuration.clientAz = 'us-east-1a'; // Sets the client's availability zone
+     * configuration.readFrom = 'AZAffinity'; // Directs read operations to nodes within the same AZ
+     * ```
+     */
+    clientAz?: string;
 }
 
 /**
@@ -719,6 +731,7 @@ export class BaseClient {
     private readonly pubsubFutures: [PromiseFunction, ErrorFunction][] = [];
     private pendingPushNotification: response.Response[] = [];
     private readonly inflightRequestsLimit: number;
+    private readonly clientAz: string | undefined;
     private config: BaseClientConfiguration | undefined;
 
     protected configurePubsub(
@@ -7578,6 +7591,7 @@ export class BaseClient {
             readFrom,
             authenticationInfo,
             inflightRequestsLimit: options.inflightRequestsLimit,
+            clientAz: options.clientAz ?? null,
         };
     }
 

node/tests/GlideClient.test.ts

@@ -51,7 +51,9 @@ const TIMEOUT = 50000;
 describe("GlideClient", () => {
     let testsFailed = 0;
     let cluster: ValkeyCluster;
+    let azCluster: ValkeyCluster;
     let client: GlideClient;
+    let azClient: GlideClient;
     beforeAll(async () => {
         const standaloneAddresses = global.STAND_ALONE_ENDPOINT;
         cluster = standaloneAddresses
@@ -61,17 +63,28 @@ describe("GlideClient", () => {
                   getServerVersion,
               )
             : await ValkeyCluster.createCluster(false, 1, 1, getServerVersion);
+
+        azCluster = standaloneAddresses
+            ? await ValkeyCluster.initFromExistingCluster(
+                  false,
+                  parseEndpoints(standaloneAddresses),
+                  getServerVersion,
+              )
+            : await ValkeyCluster.createCluster(false, 1, 1, getServerVersion);
     }, 20000);
 
     afterEach(async () => {
         await flushAndCloseClient(false, cluster.getAddresses(), client);
+        await flushAndCloseClient(false, azCluster.getAddresses(), azClient);
     });
 
     afterAll(async () => {
         if (testsFailed === 0) {
             await cluster.close();
+            await azCluster.close();
         } else {
             await cluster.close(true);
+            await azCluster.close();
         }
     }, TIMEOUT);
 
@@ -1500,18 +1513,25 @@ describe("GlideClient", () => {
             }
         },
     );
-
     runBaseTests({
         init: async (protocol, configOverrides) => {
             const config = getClientConfigurationOption(
                 cluster.getAddresses(),
                 protocol,
                 configOverrides,
             );
+            client = await GlideClient.createClient(config);
+
+            const configNew = getClientConfigurationOption(
+                azCluster.getAddresses(),
+                protocol,
+                configOverrides,
+            );
 
             testsFailed += 1;
+            azClient = await GlideClient.createClient(configNew);
             client = await GlideClient.createClient(config);
-            return { client, cluster };
+            return { client, cluster, azClient, azCluster };
         },
         close: (testSucceeded: boolean) => {
             if (testSucceeded) {