added pong event

src/WAConnection/3.Connect.ts

@@ -264,6 +264,7 @@ export class WAConnection extends Base {
             // when the first character in the message is an '!', the server is updating the last seen
             const timestamp = message.slice(1, message.length).toString ('utf-8')
             this.lastSeen = new Date(parseInt(timestamp))
+            this.emit ('received-pong')
         } else {
             const decrypted = Utils.decryptWA (message, this.authInfo?.macKey, this.authInfo?.encKey, new Decoder())
             if (!decrypted) return

src/WAConnection/4.Events.ts

@@ -324,6 +324,9 @@ export class WAConnection extends Base {
     on (event: 'group-settings-update', listener: (update: {jid: string, restrict?: string, announce?: string, actor?: string}) => void): this
     /** when the group description is updated */
     on (event: 'group-description-update', listener: (update: {jid: string, description?: string, actor?: string}) => void): this
+    /** when WA sends back a pong */
+    on (event: 'received-pong', listener: () => void): this
+
 
     on (event: BaileysEvent, listener: (...args: any[]) => void) { return super.on (event, listener) }
     emit (event: BaileysEvent, ...args: any[]) { return super.emit (event, ...args) }

src/WAConnection/Constants.ts

@@ -368,4 +368,5 @@ export type BaileysEvent =
     'group-participants-promote' |
     'group-participants-demote' |
     'group-settings-update' |
-    'group-description-update'
+    'group-description-update' |
+    'received-pong'