Merge branch 'master' into treewip

* master: (113 commits)
  remove useless method
  Updated file documentation [ci skip]
  changes caching guide to add note on weak etags
  Don't put config.action_mailer.perform_caching entry twice in development.rb
  Fix wording and wrong reference
  Add Ruby formatting to CHANGELOG entry
  Fix ActionView's cache section reference
  Do not define methods in the included block
  Add caching guide in ActionMailer basics
  Add ActionMailer configuration options
  Preparing for 5.0.0.beta3 release
  Update 5.0 release notes
  Enable tmp_restart plugin for puma
  Prep release for Rails 5 beta3
  [ci skip] Move collection caching changelog entry.
  Ensure `drop_table` even if tests failure or interrupted
  :bomb: run the test @rafaelfranca :angry:
  Remove changelog entry for reverted commit
  Add CHANGELOG for https://github.com/rails/rails/pull/23734 [ci skip]
  No need CHANGELOG entry for #23849.
  ...

3 files changed, 42 insertions, 5 deletions

diff --git a/actioncable/app/assets/javascripts/action_cable.coffee.erb b/actioncable/app/assets/javascripts/action_cable.coffee.erb
index 18a48c0610..d95fe78ac5 100644
--- a/actioncable/app/assets/javascripts/action_cable.coffee.erb
+++ b/actioncable/app/assets/javascripts/action_cable.coffee.erb
@@ -21,3 +21,14 @@
       a.href
     else
       url
+
+  startDebugging: ->
+    @debugging = true
+
+  stopDebugging: ->
+    @debugging = null
+
+  log: (messages...) ->
+    if @debugging
+      messages.push(Date.now())
+      console.log("[ActionCable]", messages...)
diff --git a/actioncable/app/assets/javascripts/action_cable/connection.coffee b/actioncable/app/assets/javascripts/action_cable/connection.coffee
index fbd7dbd35b..ee888f567b 100644
--- a/actioncable/app/assets/javascripts/action_cable/connection.coffee
+++ b/actioncable/app/assets/javascripts/action_cable/connection.coffee
@@ -16,9 +16,12 @@ class ActionCable.Connection
       false
 
   open: =>
-    if @webSocket and not @isState("closed")
+    if @isAlive()
+      ActionCable.log("Attemped to open WebSocket, but existing socket is #{@getState()}")
       throw new Error("Existing connection must be closed before opening")
     else
+      ActionCable.log("Opening WebSocket, current state is #{@getState()}")
+      @uninstallEventHandlers() if @webSocket?
       @webSocket = new WebSocket(@consumer.url)
       @installEventHandlers()
       true
@@ -27,19 +30,26 @@ class ActionCable.Connection
     @webSocket?.close()
 
   reopen: ->
-    if @isState("closed")
-      @open()
-    else
+    ActionCable.log("Reopening WebSocket, current state is #{@getState()}")
+    if @isAlive()
       try
         @close()
+      catch error
+        ActionCable.log("Failed to reopen WebSocket", error)
       finally
+        ActionCable.log("Reopening WebSocket in #{@constructor.reopenDelay}ms")
         setTimeout(@open, @constructor.reopenDelay)
+    else
+      @open()
 
   isOpen: ->
     @isState("open")
 
   # Private
 
+  isAlive: ->
+    @webSocket? and not @isState("closing", "closed")
+
   isState: (states...) ->
     @getState() in states
 
@@ -53,6 +63,11 @@ class ActionCable.Connection
       @webSocket["on#{eventName}"] = handler
     return
 
+  uninstallEventHandlers: ->
+    for eventName of @events
+      @webSocket["on#{eventName}"] = ->
+    return
+
   events:
     message: (event) ->
       {identifier, message, type} = JSON.parse(event.data)
@@ -66,13 +81,16 @@ class ActionCable.Connection
           @consumer.subscriptions.notify(identifier, "received", message)
 
     open: ->
+      ActionCable.log("WebSocket onopen event")
       @disconnected = false
       @consumer.subscriptions.reload()
 
     close: ->
+      ActionCable.log("WebSocket onclose event")
       @disconnect()
 
     error: ->
+      ActionCable.log("WebSocket onerror event")
       @disconnect()
 
   disconnect: ->
diff --git a/actioncable/app/assets/javascripts/action_cable/connection_monitor.coffee b/actioncable/app/assets/javascripts/action_cable/connection_monitor.coffee
index 99b9a1c6d5..75a6f1fb07 100644
--- a/actioncable/app/assets/javascripts/action_cable/connection_monitor.coffee
+++ b/actioncable/app/assets/javascripts/action_cable/connection_monitor.coffee
@@ -17,6 +17,7 @@ class ActionCable.ConnectionMonitor
     @reset()
     @pingedAt = now()
     delete @disconnectedAt
+    ActionCable.log("ConnectionMonitor connected")
 
   disconnected: ->
     @disconnectedAt = now()
@@ -33,10 +34,12 @@ class ActionCable.ConnectionMonitor
     @startedAt = now()
     @poll()
     document.addEventListener("visibilitychange", @visibilityDidChange)
+    ActionCable.log("ConnectionMonitor started, pollInterval is #{@getInterval()}ms")
 
   stop: ->
     @stoppedAt = now()
     document.removeEventListener("visibilitychange", @visibilityDidChange)
+    ActionCable.log("ConnectionMonitor stopped")
 
   poll: ->
     setTimeout =>
@@ -52,8 +55,12 @@ class ActionCable.ConnectionMonitor
 
   reconnectIfStale: ->
     if @connectionIsStale()
+      ActionCable.log("ConnectionMonitor detected stale connection, reconnectAttempts = #{@reconnectAttempts}")
       @reconnectAttempts++
-      unless @disconnectedRecently()
+      if @disconnectedRecently()
+        ActionCable.log("ConnectionMonitor skipping reopen because recently disconnected at #{@disconnectedAt}")
+      else
+        ActionCable.log("ConnectionMonitor reopening")
         @consumer.connection.reopen()
 
   connectionIsStale: ->
@@ -66,6 +73,7 @@ class ActionCable.ConnectionMonitor
     if document.visibilityState is "visible"
       setTimeout =>
         if @connectionIsStale() or not @consumer.connection.isOpen()
+          ActionCable.log("ConnectionMonitor reopening stale connection after visibilitychange to #{document.visibilityState}")
           @consumer.connection.reopen()
       , 200