Support OBJECT [...] commands (#2014)

* Support OBJECT [...] commands

* move commands to cluster/commands.ts

Co-authored-by: leibale <leibale1998@gmail.com>

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

@@ -0,0 +1,19 @@
+import { strict as assert } from 'assert';
+import testUtils, { GLOBAL } from '../test-utils';
+import { transformArguments } from './OBJECT_ENCODING';
+
+describe('OBJECT ENCODING', () => {
+    it('transformArguments', () => {
+        assert.deepEqual(
+            transformArguments('key'),
+            ['OBJECT', 'ENCODING', 'key']
+        );
+    });
+
+    testUtils.testWithClient('client.objectEncoding', async client => {
+        assert.equal(
+            await client.objectEncoding('key'),
+            null
+        );
+    }, GLOBAL.SERVERS.OPEN);
+});