fix: reschedule pings problem (#1904)

* reschedulePingForcely

* reset KeepalivTimer if client receives pingresp

* test for pingresp

* reschedulePing with force arg

* call reschedulePing with true

* npm run lint-fix

---------

Co-authored-by: kksuke <kajigaya.keisuke@gmail.com>

Author: k-keisuke

src/lib/client.ts

@@ -2109,11 +2109,11 @@ export default class MqttClient extends TypedEventEmitter<MqttClientEventCallbac
 	/**
 	 * Reschedule the ping interval
 	 */
-	public reschedulePing() {
+	public reschedulePing(force = false) {
 		if (
 			this.keepaliveManager &&
 			this.options.keepalive &&
-			this.options.reschedulePings
+			(force || this.options.reschedulePings)
 		) {
 			this._reschedulePing()
 		}

src/lib/handlers/index.ts

@@ -56,7 +56,7 @@ const handle: PacketHandler = (client, packet, done) => {
 			break
 		case 'pingresp':
 			client.log('_handlePacket :: received pingresp')
-			client.reschedulePing()
+			client.reschedulePing(true)
 			done()
 			break
 		case 'disconnect':

test/abstract_client.ts

@@ -2120,6 +2120,41 @@ export default function abstractTest(server, config, ports) {
 
 		reschedulePing(true)
 		reschedulePing(false)
+
+		const pingresp = (reschedulePings: boolean) => {
+			it(`should shift ping on pingresp when reschedulePings===${reschedulePings}`, function _test(t, done) {
+				const intervalMs = 3000
+
+				let client = connect({
+					keepalive: intervalMs / 1000,
+					reschedulePings,
+				})
+
+				const spy = sinon.spy(client, '_reschedulePing' as any)
+
+				client.on('packetreceive', (packet) => {
+					if (packet.cmd === 'pingresp') {
+						process.nextTick(() => {
+							assert.strictEqual(spy.callCount, 1)
+							client.end(true, done)
+							client = null
+						})
+					}
+				})
+
+				client.on('error', (err) => {
+					client.end(true, () => {
+						done(err)
+					})
+				})
+
+				client.once('connect', () => {
+					clock.tick(intervalMs)
+				})
+			})
+		}
+		pingresp(true)
+		pingresp(false)
 	})
 
 	describe('pinging', () => {