Ensure events are delivered in order

src/packages/collaboration/lib/bootstrap.coffee

@@ -1,6 +1,5 @@
 require 'atom'
 require 'window'
-_ = require 'underscore'
 {createPeer, connectDocument} = require './session-utils'
 {createSite, Document} = require 'telepath'
 

src/packages/collaboration/lib/session-utils.coffee

@@ -7,14 +7,39 @@ module.exports =
     new Peer(id, host: 'ec2-54-218-51-127.us-west-2.compute.amazonaws.com', port: 8080)
 
   connectDocument: (doc, connection) ->
+    nextOutputEventId = 1
     outputListener = (event) ->
-      console.log 'sending event', event
+      event.id = nextOutputEventId++
+      console.log 'sending event', event.id, event
       connection.send(event)
     doc.outputEvents.on('changed', outputListener)
 
-    connection.on 'data', (event) ->
-      console.log 'receiving event', event
+    queuedEvents = []
+    nextInputEventId = 1
+    handleInputEvent = (event) ->
+      console.log 'received event', event.id, event
       doc.handleInputEvent(event)
+      nextInputEventId = event.id + 1
+    flushQueuedEvents = ->
+      loop
+        eventHandled = false
+        for event, index in queuedEvents when event.id is nextInputEventId
+          handleInputEvent(event)
+          queuedEvents.splice(index, 1)
+          eventHandled = true
+          break
+        break unless eventHandled
+
+    connection.on 'data', (event) ->
+      if event.id is nextInputEventId
+        handleInputEvent(event)
+        flushQueuedEvents()
+      else
+        console.log 'enqueing event', event.id, event
+        queuedEvents.push(event)
 
     connection.on 'close', ->
       doc.outputEvents.removeListener('changed', outputListener)
+
+    connection.on 'error', (error) ->
+      console.error 'connection error', error.stack ? error