check if socket is still disconnecting and allow connect (#6110)

* check if socket is still disconnecting and allow connect

Fixes #6103.

* check connectClock in teardown

Author: SteffenDE

assets/js/phoenix/socket.js

@@ -126,6 +126,7 @@ export default class Socket {
     this.defaultEncoder = Serializer.encode.bind(Serializer)
     this.defaultDecoder = Serializer.decode.bind(Serializer)
     this.closeWasClean = false
+    this.disconnecting = false
     this.binaryType = opts.binaryType || "arraybuffer"
     this.connectClock = 1
     if(this.transport !== LongPoll){
@@ -237,10 +238,14 @@ export default class Socket {
    */
   disconnect(callback, code, reason){
     this.connectClock++
+    this.disconnecting = true
     this.closeWasClean = true
     clearTimeout(this.fallbackTimer)
     this.reconnectTimer.reset()
-    this.teardown(callback, code, reason)
+    this.teardown(() => {
+      this.disconnecting = false
+      callback && callback()
+    }, code, reason)
   }
 
   /**
@@ -255,7 +260,7 @@ export default class Socket {
       console && console.log("passing params to connect is deprecated. Instead pass :params to the Socket constructor")
       this.params = closure(params)
     }
-    if(this.conn){ return }
+    if(this.conn && !this.disconnecting){ return }
     if(this.longPollFallbackMs && this.transport !== LongPoll){
       this.connectWithFallback(LongPoll, this.longPollFallbackMs)
     } else {
@@ -418,6 +423,7 @@ export default class Socket {
   onConnOpen(){
     if(this.hasLogger()) this.log("transport", `${this.transport.name} connected to ${this.endPointURL()}`)
     this.closeWasClean = false
+    this.disconnecting = false
     this.establishedConnections++
     this.flushSendBuffer()
     this.reconnectTimer.reset()
@@ -450,13 +456,16 @@ export default class Socket {
     if(!this.conn){
       return callback && callback()
     }
+    let connectClock = this.connectClock
 
     this.waitForBufferDone(() => {
+      if(connectClock !== this.connectClock){ return }
       if(this.conn){
         if(code){ this.conn.close(code, reason || "") } else { this.conn.close() }
       }
 
       this.waitForSocketClosed(() => {
+        if(connectClock !== this.connectClock){ return }
         if(this.conn){
           this.conn.onopen = function (){ } // noop
           this.conn.onerror = function (){ } // noop