Add support for PUBSUB SHARDNUMSUB (#2541)

* Add support for command 'PUBSUB SHARDNUMSUB'

* Use import from PUBSUB_SHARDNUMSUB

* Add test case for non-empty reply

* clean tests

* run tests in redis >= 7, fix integration test

---------

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

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

@@ -0,0 +1,48 @@
+import { strict as assert } from 'assert';
+import testUtils, { GLOBAL } from '../test-utils';
+import { transformArguments } from './PUBSUB_SHARDNUMSUB';
+
+describe('PUBSUB SHARDNUMSUB', () => {
+    testUtils.isVersionGreaterThanHook([7]);
+
+    describe('transformArguments', () => {
+        it('simple', () => {
+            assert.deepEqual(
+                transformArguments(),
+                ['PUBSUB', 'SHARDNUMSUB']
+            );
+        });
+
+        it('string', () => {
+            assert.deepEqual(
+                transformArguments('channel'),
+                ['PUBSUB', 'SHARDNUMSUB', 'channel']
+            );
+        });
+
+        it('array', () => {
+            assert.deepEqual(
+                transformArguments(['1', '2']),
+                ['PUBSUB', 'SHARDNUMSUB', '1', '2']
+            );
+        });
+    });
+
+    testUtils.testWithClient('client.pubSubShardNumSub', async client => {
+        assert.deepEqual(
+            await client.pubSubShardNumSub(['foo', 'bar']),
+            Object.create(null, {
+                foo: {
+                    value: 0,
+                    configurable: true,
+                    enumerable: true
+                },
+                bar: {
+                    value: 0,
+                    configurable: true,
+                    enumerable: true
+                }
+            })
+        );
+    }, GLOBAL.SERVERS.OPEN);
+});

packages/client/lib/commands/PUBSUB_SHARDNUMSUB.ts

@@ -0,0 +1,24 @@
+import { pushVerdictArguments } from './generic-transformers';
+import { RedisCommandArgument, RedisCommandArguments } from '.';
+
+export const IS_READ_ONLY = true;
+
+export function transformArguments(
+    channels?: Array<RedisCommandArgument> | RedisCommandArgument
+): RedisCommandArguments {
+    const args = ['PUBSUB', 'SHARDNUMSUB'];
+
+    if (channels) return pushVerdictArguments(args, channels);
+
+    return args;
+}
+
+export function transformReply(rawReply: Array<string | number>): Record<string, number> {
+    const transformedReply = Object.create(null);
+
+    for (let i = 0; i < rawReply.length; i += 2) {
+        transformedReply[rawReply[i]] = rawReply[i + 1];
+    }
+
+    return transformedReply;
+}