Documented disconnect reason

src/WAConnection/0.Base.ts

@@ -76,10 +76,10 @@ export class WAConnection extends EventEmitter {
     async unexpectedDisconnect (error: DisconnectReason) {
         const willReconnect = 
             (this.autoReconnect === ReconnectMode.onAllErrors || 
-            (this.autoReconnect === ReconnectMode.onConnectionLost && (error !== 'replaced'))) &&
+            (this.autoReconnect === ReconnectMode.onConnectionLost && (error !== DisconnectReason.replaced))) &&
-            error !== 'invalid_session'      
+            error !== DisconnectReason.invalidSession // do not reconnect if credentials have been invalidated
+        
         this.closeInternal(error, willReconnect)
-
         willReconnect && !this.cancelReconnect && this.reconnectLoop ()
     }
     /**
@@ -215,7 +215,7 @@ export class WAConnection extends EventEmitter {
         const response = await this.waitForMessage(tag, json, timeoutMs)
         if (expect200 && response.status && Math.floor(+response.status / 100) !== 2) {
             if (response.status >= 500) {
-                this.unexpectedDisconnect ('bad_session')
+                this.unexpectedDisconnect (DisconnectReason.badSession)
                 const response = await this.query ({json, binaryTags, tag, timeoutMs, expect200, waitForOpen})
                 return response
             }
@@ -286,7 +286,7 @@ export class WAConnection extends EventEmitter {
     }
     /** Close the connection to WhatsApp Web */
     close () {
-        this.closeInternal ('intentional')
+        this.closeInternal (DisconnectReason.intentional)
         this.cancelReconnect && this.cancelReconnect ()
     }
     protected closeInternal (reason?: DisconnectReason, isReconnecting: boolean=false) {

src/WAConnection/3.Connect.ts

@@ -1,5 +1,5 @@
 import * as Utils from './Utils'
-import { WAMessage, WAChat, WAContact, MessageLogLevel, WANode, KEEP_ALIVE_INTERVAL_MS, BaileysError, WAConnectOptions } from './Constants'
+import { WAMessage, WAChat, WAContact, MessageLogLevel, WANode, KEEP_ALIVE_INTERVAL_MS, BaileysError, WAConnectOptions, DisconnectReason } from './Constants'
 import {WAConnection as Base} from './1.Validation'
 import Decoder from '../Binary/Decoder'
 
@@ -26,7 +26,7 @@ export class WAConnection extends Base {
                 this.startKeepAliveRequest()
                 this.conn.removeAllListeners ('error')
                 this.conn.removeAllListeners ('close')
-                this.conn.on ('close', () => this.unexpectedDisconnect ('close'))
+                this.conn.on ('close', () => this.unexpectedDisconnect (DisconnectReason.close))
             })
             .then (resolve)
             .catch (reject)
@@ -249,7 +249,7 @@ export class WAConnection extends Base {
 				check if it's been a suspicious amount of time since the server responded with our last seen
 				it could be that the network is down
 			*/
-            if (diff > KEEP_ALIVE_INTERVAL_MS+5000) this.unexpectedDisconnect ('lost')
+            if (diff > KEEP_ALIVE_INTERVAL_MS+5000) this.unexpectedDisconnect (DisconnectReason.lost)
             else this.send ('?,,') // if its all good, send a keep alive request
         }, KEEP_ALIVE_INTERVAL_MS)
     }
@@ -266,7 +266,9 @@ export class WAConnection extends Base {
                 
                 await delay
                 try {
-                    const reconnectID = this.lastDisconnectReason !== 'replaced' && this.lastDisconnectReason !== 'unknown' && this.user ? this.user.id.replace ('@s.whatsapp.net', '@c.us') : null
+                    const shouldUseReconnect = this.lastDisconnectReason !== DisconnectReason.replaced && this.lastDisconnectReason !== DisconnectReason.unknown && this.user
+                    const reconnectID = shouldUseReconnect ? this.user.id.replace ('@s.whatsapp.net', '@c.us') : null
+                    
                     await this.connect ({ timeoutMs: 30000, retryOnNetworkErrors: true, reconnectID })
                     this.cancelReconnect = null
                     break

src/WAConnection/4.Events.ts

@@ -1,6 +1,6 @@
 import * as QR from 'qrcode-terminal'
 import { WAConnection as Base } from './3.Connect'
-import { MessageStatusUpdate, WAMessage, WAContact, WAChat, WAMessageProto, WA_MESSAGE_STUB_TYPE, WA_MESSAGE_STATUS_TYPE, MessageLogLevel, PresenceUpdate, BaileysEvent } from './Constants'
+import { MessageStatusUpdate, WAMessage, WAContact, WAChat, WAMessageProto, WA_MESSAGE_STUB_TYPE, WA_MESSAGE_STATUS_TYPE, MessageLogLevel, PresenceUpdate, BaileysEvent, DisconnectReason } from './Constants'
 import { whatsappID, unixTimestampSeconds, isGroupID } from './Utils'
 
 export class WAConnection extends Base {
@@ -273,7 +273,7 @@ export class WAConnection extends Base {
     /** when the connection is opening */
     on (event: 'connecting', listener: () => void): this
     /** when the connection has closed */
-    on (event: 'close', listener: (err: {reason?: string, isReconnecting: boolean}) => void): this
+    on (event: 'close', listener: (err: {reason?: DisconnectReason | string, isReconnecting: boolean}) => void): this
     /** when a new QR is generated, ready for scanning */
     on (event: 'qr', listener: (qr: string) => void): this
     /** when the connection to the phone changes */

src/WAConnection/Constants.ts

@@ -67,7 +67,25 @@ export type WAConnectOptions = {
 }
 
 export type WAConnectionState = 'open' | 'connecting' | 'close'
-export type DisconnectReason = 'close' | 'lost' | 'replaced' | 'intentional' | 'invalid_session' | 'unknown' | 'bad_session'
+/** Types of Disconnect Reasons */
+export enum DisconnectReason {
+  /** The connection was closed intentionally */
+  intentional = 'intentional',
+  /** The connection was terminated either by the client or server */
+  close = 'close',
+  /** The connection was lost, called when the server stops responding to requests */
+  lost = 'lost',
+  /** When WA Web is opened elsewhere & this session is disconnected */
+  replaced = 'intentional',
+  /** The credentials for the session have been invalidated, i.e. logged out either from the phone or WA Web */
+  invalidSession = 'invalid_session',
+  /** Received a 500 result in a query -- something has gone very wrong */
+  badSession = 'bad_session',
+  /** No idea, can be a sign of log out too */
+  unknown = 'unknown',
+  /** Well, the connection timed out */
+  timedOut = 'timed out'
+}
 export enum MessageLogLevel {
     none=0,
     info=1,