Add support for CLUSTER MYSHARDID (#2528)

* Add support for CLUSTER.MYSHARDID command

* Update CLUSTER_MYSHARDID.ts

* Update CLUSTER_MYSHARDID.spec.ts

* add test and clean code

---------

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

packages/client/lib/commands/CLUSTER_MYSHARDID.spec.ts

@@ -0,0 +1,22 @@
+import { strict as assert } from 'assert';
+import testUtils, { GLOBAL } from '../test-utils';
+import { transformArguments } from './CLUSTER_MYSHARDID';
+
+describe('CLUSTER MYSHARDID', () => {
+    testUtils.isVersionGreaterThanHook([7, 2]);
+
+    it('transformArguments', () => {
+        assert.deepEqual(
+            transformArguments(),
+            ['CLUSTER', 'MYSHARDID']
+        );
+    });
+
+    testUtils.testWithCluster('clusterNode.clusterMyShardId', async cluster => {
+        const client = await cluster.nodeClient(cluster.masters[0]);
+        assert.equal(
+            typeof await client.clusterMyShardId(),
+            'string'
+        );
+    }, GLOBAL.CLUSTERS.OPEN);
+});

packages/client/lib/commands/CLUSTER_MYSHARDID.ts

@@ -0,0 +1,7 @@
+export const IS_READ_ONLY = true;
+
+export function transformArguments() {
+    return ['CLUSTER', 'MYSHARDID'];
+}
+
+export declare function transformReply(): string | Buffer;