From 23dc250098b233f3e84ca8a20c672d06de56c09f Mon Sep 17 00:00:00 2001
From: Ben Moore <ben@madcatconsulting.co.uk>
Date: Wed, 20 Jul 2016 12:18:34 +0100
Subject: [PATCH] Fix - large numbers of undispatched events This resolves an
 issue where the maximum call stack size could be hit when processing 1000s of
 undispatched events on startup

---
 lib/eventDispatcher.js      |  5 +++++
 test/eventDispatcherTest.js | 40 +++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/lib/eventDispatcher.js b/lib/eventDispatcher.js
index 53acb9aa..46ba435c 100644
--- a/lib/eventDispatcher.js
+++ b/lib/eventDispatcher.js
@@ -112,8 +112,13 @@ EventDispatcher.prototype = {
       }
 
       if (events) {
+        
         for (var i = 0, len = events.length; i < len; i++) {
           self.undispatchedEventsQueue.push(events[i]);
+          // If there are a lot of events then we can hit issues with the call stack size when processing in one go
+          if(i % 1000 === 0){
+            trigger(self);
+          }
         }
       }
 
diff --git a/test/eventDispatcherTest.js b/test/eventDispatcherTest.js
index 9bba76bb..129da510 100644
--- a/test/eventDispatcherTest.js
+++ b/test/eventDispatcherTest.js
@@ -92,6 +92,46 @@ describe('EventDispatcher', function () {
 
       });
 
+      it('should not crash when there are lots of pending events', function (done) {
+        
+        var eventsInStore = [];
+
+        for(var i = 0; i < 10000; i++){
+          eventsInStore.push({
+            payload: {
+              index: i
+            }
+          });
+        }
+
+        function getUndispatchedEvents (callback) {
+          callback(null, eventsInStore);
+        }
+        
+        var publishedEvents = [];
+        
+        function publisher (evt) {
+          publishedEvents.push(evt);
+          check();
+        }
+        
+        function check () {
+          if (publishedEvents.length === eventsInStore.length) {
+            done();
+          }
+        }
+
+        var eventDispatcher = new EventDispatcher(publisher, {
+                                    getUndispatchedEvents: getUndispatchedEvents,
+                                    setEventToDispatched: function (evt, callback) { callback(null); }});
+        expect(eventDispatcher.undispatchedEventsQueue.length).to.eql(0);
+        
+        eventDispatcher.start(function(err) {
+          expect(err).not.to.be.ok();
+        });
+
+      });
+
     });
 
     describe('and calling addUndispatchedEvents', function () {