Update doctest client with latest v4 release (#2844)

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

@@ -0,0 +1,27 @@
+import {strict as assert} from 'assert';
+import testUtils, {GLOBAL} from '../test-utils';
+import { transformArguments } from './LATENCY_LATEST';
+
+describe('LATENCY LATEST', () => {
+    it('transformArguments', () => {
+        assert.deepEqual(
+            transformArguments(),
+            ['LATENCY', 'LATEST']
+        );
+    });
+
+    testUtils.testWithClient('client.latencyLatest', async client => {
+        await Promise.all([
+            client.configSet('latency-monitor-threshold', '100'),
+            client.sendCommand(['DEBUG', 'SLEEP', '1'])
+        ]);
+        const latency = await client.latencyLatest();
+        assert.ok(Array.isArray(latency));
+        for (const [name, timestamp, latestLatency, allTimeLatency] of latency) {
+            assert.equal(typeof name, 'string');
+            assert.equal(typeof timestamp, 'number');
+            assert.equal(typeof latestLatency, 'number');
+            assert.equal(typeof allTimeLatency, 'number');
+        }
+    }, GLOBAL.SERVERS.OPEN);
+});