handle eventAppeared callback returning Promise

index.d.ts

@@ -212,7 +212,7 @@ export interface PersistentSubscriptionDeleteResult {
 
 // Callbacks
 export interface EventAppearedCallback<TSubscription> {
-    (subscription: TSubscription, event: ResolvedEvent): void;
+    (subscription: TSubscription, event: ResolvedEvent): void | Promise<void>;
 }
 
 export interface LiveProcessingStartedCallback {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "node-eventstore-client",
-  "version": "0.1.5",
+  "version": "0.1.7",
   "description": "A port of the EventStore .Net ClientAPI to Node.js",
   "main": "index.js",
   "types": "index.d.ts",
@@ -49,8 +49,8 @@
     "uuid-parse": "^1.0.0"
   },
   "devDependencies": {
-    "jsdoc": "^3.4.2",
-    "nodeunit": "^0.11.0",
-    "webpack": "^2.4.1"
+    "jsdoc": "^3.5.3",
+    "nodeunit": "^0.11.1",
+    "webpack": "^3.3.0"
   }
 }

src/clientOperations/subscriptionOperation.js

@@ -232,7 +232,7 @@ SubscriptionOperation.prototype._onEventAppeared = function(e) {
         e.originalStreamId, e.originalEventNumber, e.originalEvent.eventType, e.originalPosition);
 
   var self = this;
-  this._executeAction(function() { self._eventAppeared(self._subscription, e); });
+  this._executeAction(function() { return self._eventAppeared(self._subscription, e); });
 };
 
 SubscriptionOperation.prototype._executeAction = function(action) {
@@ -249,15 +249,25 @@ SubscriptionOperation.prototype._executeActions = function() {
     this._actionExecuting = false;
     return;
   }
+  var promise;
   try
   {
-    action();
+    promise = action();
   }
   catch (err)
   {
     this._log.error(err, "Exception during executing user callback: %s.", err.message);
   }
-  setImmediate(this._executeActions.bind(this));
+  if (promise && promise.then) {
+    var self = this;
+    promise
+      .catch(function (err) {
+        self._log.error(err, "Exception during executing user callback: %s.", err.message);
+      })
+      .then(this._executeActions.bind(this));
+  } else {
+    setImmediate(this._executeActions.bind(this));
+  }
 };
 
 SubscriptionOperation.prototype.toString = function() {

src/eventStoreAllCatchUpSubscription.js

@@ -24,14 +24,10 @@ EventStoreAllCatchUpSubscription.prototype._readEventsTill = function(
   var self = this;
 
   function processEvents(events, index) {
-    index = index || 0;
     if (index >= events.length) return Promise.resolve();
     if (events[index].originalPosition === null) throw new Error("Subscription event came up with no OriginalPosition.");
 
-    return new Promise(function(resolve, reject) {
-          self._tryProcess(events[index]);
-          resolve();
-        })
+    return self._tryProcess(events[index])
         .then(function() {
           return processEvents(events, index + 1);
         });
@@ -40,13 +36,12 @@ EventStoreAllCatchUpSubscription.prototype._readEventsTill = function(
   function readNext() {
     return connection.readAllEventsForward(self._nextReadPosition, self.readBatchSize, resolveLinkTos, userCredentials)
         .then(function(slice) {
-          return processEvents(slice.events)
+          return processEvents(slice.events, 0)
               .then(function() {
                 self._nextReadPosition = slice.nextPosition;
-                var done = lastCommitPosition === null
+                return (lastCommitPosition === null)
                     ? slice.isEndOfStream
                     : slice.nextPosition.compareTo(new results.Position(lastCommitPosition, lastCommitPosition)) >= 0;
-                return Promise.resolve(done);
               });
         })
         .then(function(done) {
@@ -67,9 +62,10 @@ EventStoreAllCatchUpSubscription.prototype._readEventsTill = function(
 
 EventStoreAllCatchUpSubscription.prototype._tryProcess = function(e) {
   var processed = false;
+  var promise;
   if (e.originalPosition.compareTo(this._lastProcessedPosition) > 0)
   {
-    this._eventAppeared(this, e);
+    promise = this._eventAppeared(this, e);
     this._lastProcessedPosition = e.originalPosition;
     processed = true;
   }
@@ -77,6 +73,7 @@ EventStoreAllCatchUpSubscription.prototype._tryProcess = function(e) {
     this._log.debug("Catch-up Subscription to %s: %s event (%s, %d, %s @ %s).",
         this.streamId || '<all>', processed ? "processed" : "skipping",
         e.originalEvent.eventStreamId, e.originalEvent.eventNumber, e.originalEvent.eventType, e.originalPosition);
+  return (promise && promise.then) ? promise : Promise.resolve();
 };
 
 module.exports = EventStoreAllCatchUpSubscription;

src/eventStoreCatchUpSubscription.js

@@ -219,15 +219,25 @@ EventStoreCatchUpSubscription.prototype._processLiveQueue = function() {
     this._isProcessing = false;
     return;
   }
+  var promise;
   try {
-    this._tryProcess(ev);
+    promise = this._tryProcess(ev);
   }
   catch(err) {
     this._dropSubscription(SubscriptionDropReason.EventHandlerException, err);
     this._isProcessing = false;
     return;
   }
-  setImmediate(this._processLiveQueue.bind(this));
+  if (promise && promise.then) {
+    var self = this;
+    promise
+      .then(this._processLiveQueue.bind(this), function(err) {
+        self._dropSubscription(SubscriptionDropReason.EventHandlerException, err);
+        self._isProcessing = false;
+      });
+  } else {
+    setImmediate(this._processLiveQueue.bind(this));
+  }
 };
 
 EventStoreCatchUpSubscription.prototype._dropSubscription = function(reason, error) {

src/eventStorePersistentSubscriptionBase.js

@@ -112,6 +112,14 @@ EventStorePersistentSubscriptionBase.prototype._enqueue = function(resolvedEvent
   }
 };
 
+function runAsync(fn) {
+  try {
+    return Promise.resolve(fn());
+  } catch(e) {
+    return Promise.reject(e);
+  }
+}
+
 EventStorePersistentSubscriptionBase.prototype._processQueue = function() {
   var ev = this._queue.shift();
   if (!ev) {
@@ -132,24 +140,28 @@ EventStorePersistentSubscriptionBase.prototype._processQueue = function() {
     this._isProcessing = false;
     return;
   }
-  try
-  {
-    this._eventAppeared(this, ev);
-    if(this._autoAck)
-      this._subscription.notifyEventsProcessed([ev.originalEvent.eventId]);
-    if (this._verbose)
-      this._log.debug("Persistent Subscription to %s: processed event (%s, %d, %s @ %d).",
-          this._streamId, ev.originalEvent.eventStreamId, ev.originalEvent.eventNumber, ev.originalEvent.eventType,
+  var self = this;
+  runAsync(function() {
+    return self._eventAppeared(self, ev);
+  })
+    .then(function() {
+      if(self._autoAck)
+        self._subscription.notifyEventsProcessed([ev.originalEvent.eventId]);
+      if (self._verbose)
+        self._log.debug("Persistent Subscription to %s: processed event (%s, %d, %s @ %d).",
+          self._streamId, ev.originalEvent.eventStreamId, ev.originalEvent.eventNumber, ev.originalEvent.eventType,
           ev.originalEventNumber);
-  }
-  catch (err)
-  {
-    //TODO GFY should we autonak here?
-    this._dropSubscription(SubscriptionDropReason.EventHandlerException, err);
-    this._isProcessing = false;
-    return;
-  }
-  setImmediate(this._processQueue.bind(this));
+      return false;
+    }, function(err) {
+      //TODO GFY should we autonak here?
+      self._dropSubscription(SubscriptionDropReason.EventHandlerException, err);
+      self._isProcessing = false;
+      return true;
+    })
+    .then(function (faulted) {
+      if (faulted) return;
+      self._processQueue();
+    });
 };
 
 EventStorePersistentSubscriptionBase.prototype._dropSubscription = function(reason, error) {
@@ -162,8 +174,13 @@ EventStorePersistentSubscriptionBase.prototype._dropSubscription = function(reas
 
     if (this._subscription !== null)
       this._subscription.unsubscribe();
-    if (this._subscriptionDropped !== null)
-      this._subscriptionDropped(this, reason, error);
+    if (this._subscriptionDropped !== null) {
+      try {
+        this._subscriptionDropped(this, reason, error);
+      } catch (e) {
+        this._log.error(e, "Persistent Subscription to %s: subscriptionDropped callback failed.", this._streamId);
+      }
+    }
     this._stopped = true;
   }
 };

src/eventStoreStreamCatchUpSubscription.js

@@ -19,19 +19,21 @@ function EventStoreStreamCatchUpSubscription(
 }
 util.inherits(EventStoreStreamCatchUpSubscription, EventStoreCatchUpSubscription);
 
+function delay(ms, result) {
+  return new Promise(function (resolve, reject) {
+    setTimeout(resolve, ms, result);
+  })
+}
+
 EventStoreStreamCatchUpSubscription.prototype._readEventsTill = function(
     connection, resolveLinkTos, userCredentials, lastCommitPosition, lastEventNumber
 ) {
   var self = this;
 
   function processEvents(events, index) {
-    index = index || 0;
     if (index >= events.length) return Promise.resolve();
 
-    return new Promise(function(resolve, reject) {
-          self._tryProcess(events[index]);
-          resolve();
-        })
+    return self._tryProcess(events[index])
         .then(function() {
           return processEvents(events, index + 1);
         });
@@ -42,12 +44,12 @@ EventStoreStreamCatchUpSubscription.prototype._readEventsTill = function(
         .then(function(slice) {
           switch(slice.status) {
             case SliceReadStatus.Success:
-              return processEvents(slice.events)
+              return processEvents(slice.events, 0)
                   .then(function() {
                     self._nextReadEventNumber = slice.nextEventNumber;
                     var done = Promise.resolve(lastEventNumber === null ? slice.isEndOfStream : slice.nextEventNumber > lastEventNumber);
                     if (!done && slice.isEndOfStream)
-                        return done.delay(10);
+                        return delay(100, false);
                     return done;
                   });
               break;
@@ -77,8 +79,9 @@ EventStoreStreamCatchUpSubscription.prototype._readEventsTill = function(
 
 EventStoreStreamCatchUpSubscription.prototype._tryProcess = function(e) {
   var processed = false;
+  var promise;
   if (e.originalEventNumber > this._lastProcessedEventNumber) {
-    this._eventAppeared(this, e);
+    promise = this._eventAppeared(this, e);
     this._lastProcessedEventNumber = e.originalEventNumber;
     processed = true;
   }
@@ -86,6 +89,7 @@ EventStoreStreamCatchUpSubscription.prototype._tryProcess = function(e) {
     this._log.debug("Catch-up Subscription to %s: %s event (%s, %d, %s @ %d).",
         this.isSubscribedToAll ? '<all>' : this.streamId, processed ? "processed" : "skipping",
         e.originalEvent.eventStreamId, e.originalEvent.eventNumber, e.originalEvent.eventType, e.originalEventNumber)
+  return (promise && promise.then) ? promise : Promise.resolve();
 };
 
 

test/persistentSubscription_test.js

@@ -9,6 +9,20 @@ function createRandomEvent() {
 
 var testStreamName = 'test-' + uuid.v4();
 
+function delay(ms) {
+  return new Promise(function (resolve, reject) {
+    setTimeout(resolve, ms);
+  })
+}
+
+function delayOnlyFirst(count, action) {
+  if (count === 0) return action();
+  return delay(200)
+    .then(function () {
+      action();
+    })
+}
+
 module.exports = {
   'Test Create Persistent Subscription': function(test) {
     var settings = client.PersistentSubscriptionSettings.create();
@@ -22,7 +36,8 @@ module.exports = {
   },
   //TODO: Update Persistent Subscription
   'Test ConnectTo Persistent Subscription': function(test) {
-    test.expect(3);
+    test.expect(4);
+    var receivedEvents = [];
     var _doneCount = 0;
     function done(err) {
       test.ok(!err, err ? err.stack : '');
@@ -31,16 +46,21 @@ module.exports = {
       test.done();
     }
     function eventAppeared(s, e) {
-      s.stop();
+      return delayOnlyFirst(receivedEvents.length, function () {
+        receivedEvents.push(e);
+        if (receivedEvents.length === 2) s.stop();
+      });
     }
     function subscriptionDropped(connection, reason, error) {
-      done(error);
+      if (error) return done(error);
+      test.ok(receivedEvents[1].originalEventNumber > receivedEvents[0].originalEventNumber, "Received events are out of order.");
+      done();
     }
     var self = this;
     this.conn.connectToPersistentSubscription(testStreamName, 'consumer-1', eventAppeared, subscriptionDropped)
       .then(function(subscription) {
         test.ok(subscription, "Subscription is null.");
-        return self.conn.appendToStream(testStreamName, client.expectedVersion.any, [createRandomEvent()]);
+        return self.conn.appendToStream(testStreamName, client.expectedVersion.any, [createRandomEvent(), createRandomEvent()]);
       })
       .then(function () {
         done();

test/subscribeToAllFrom_test.js

@@ -7,9 +7,23 @@ function createRandomEvent() {
   return client.createJsonEventData(uuid.v4(), {a: uuid.v4(), b: Math.random()}, {createdAt: Date.now()}, 'testEvent');
 }
 
+function delay(ms) {
+  return new Promise(function (resolve, reject) {
+    setTimeout(resolve, ms);
+  })
+}
+
+function delayOnlyFirst(count, action) {
+  if (count === 0) return action();
+  return delay(200)
+    .then(function () {
+      action();
+    })
+}
+
 module.exports = {
   'Test Subscribe to All From (Start)': function(test) {
-    test.expect(4);
+    test.expect(6);
     var self = this;
     var liveProcessing = false;
     var catchUpEvents = [];
@@ -19,19 +33,33 @@ module.exports = {
       test.ok(!err, err ? err.stack : '');
       _doneCount++;
       if (_doneCount < 2) return;
+
+      var catchUpInOrder = true;
+      for(var i = 1; i < catchUpEvents.length; i++)
+        catchUpInOrder = catchUpInOrder && (catchUpEvents[i].originalPosition.compareTo(catchUpEvents[i-1].originalPosition) > 0);
+      test.ok(catchUpInOrder, "Catch-up events are out of order.");
+
+      var liveInOrder = true;
+      for(var j = 1; j < liveEvents.length; j++)
+        liveInOrder = liveInOrder && (liveEvents[j].originalPosition.compareTo(liveEvents[j-1].originalPosition) > 0);
+      test.ok(liveInOrder, "Live events are out of order.");
+
       test.done();
     }
     function eventAppeared(s, e) {
-      if (liveProcessing) {
-        liveEvents.push(e);
-        s.stop();
-      } else {
-        catchUpEvents.push(e);
-      }
+      var isLive = liveProcessing;
+      delayOnlyFirst(isLive ? liveEvents.length : catchUpEvents.length, function() {
+        if (isLive) {
+          liveEvents.push(e);
+        } else {
+          catchUpEvents.push(e);
+        }
+        if (isLive && liveEvents.length === 2) s.stop();
+      });
     }
     function liveProcessingStarted() {
       liveProcessing = true;
-      var events = [createRandomEvent()];
+      var events = [createRandomEvent(), createRandomEvent()];
       self.conn.appendToStream(self.testStreamName, client.expectedVersion.any, events)
           .then(function () {
             done();
@@ -39,14 +67,14 @@ module.exports = {
           .catch(done);
     }
     function subscriptionDropped(connection, reason, error) {
-      test.ok(liveEvents.length === 1, "Expecting 1 live event, got " + liveEvents.length);
+      test.ok(liveEvents.length === 2, "Expecting 2 live event, got " + liveEvents.length);
       test.ok(catchUpEvents.length > 1, "Expecting at least 1 catchUp event, got " + catchUpEvents.length);
       done(error);
     }
     var subscription = this.conn.subscribeToAllFrom(null, false, eventAppeared, liveProcessingStarted, subscriptionDropped, allCredentials);
   },
   'Test Subscribe to All From (Position)': function(test) {
-    test.expect(5);
+    test.expect(7);
     var self = this;
     var liveProcessing = false;
     var catchUpEvents = [];
@@ -56,19 +84,33 @@ module.exports = {
       test.ok(!err, err ? err.stack : '');
       _doneCount++;
       if (_doneCount < 2) return;
+
+      var catchUpInOrder = true;
+      for(var i = 1; i < catchUpEvents.length; i++)
+        catchUpInOrder = catchUpInOrder && (catchUpEvents[i].originalPosition.compareTo(catchUpEvents[i-1].originalPosition) > 0);
+      test.ok(catchUpInOrder, "Catch-up events are out of order.");
+
+      var liveInOrder = true;
+      for(var j = 1; j < liveEvents.length; j++)
+        liveInOrder = liveInOrder && (liveEvents[j].originalPosition.compareTo(liveEvents[j-1].originalPosition) > 0);
+      test.ok(liveInOrder, "Live events are out of order.");
+
       test.done();
     }
     function eventAppeared(s, e) {
-      if (liveProcessing) {
-        liveEvents.push(e);
-        s.stop();
-      } else {
-        catchUpEvents.push(e);
-      }
+      var isLive = liveProcessing;
+      delayOnlyFirst(isLive ? liveEvents.length : catchUpEvents.length, function() {
+        if (isLive) {
+          liveEvents.push(e);
+        } else {
+          catchUpEvents.push(e);
+        }
+        if (isLive && liveEvents.length === 2) s.stop();
+      });
     }
     function liveProcessingStarted() {
       liveProcessing = true;
-      var events = [createRandomEvent()];
+      var events = [createRandomEvent(), createRandomEvent()];
       self.conn.appendToStream(self.testStreamName, client.expectedVersion.any, events)
         .then(function () {
           done();
@@ -76,7 +118,7 @@ module.exports = {
         .catch(done);
     }
     function subscriptionDropped(connection, reason, error) {
-      test.ok(liveEvents.length === 1, "Expecting 1 live event, got " + liveEvents.length);
+      test.ok(liveEvents.length === 2, "Expecting 2 live event, got " + liveEvents.length);
       test.ok(catchUpEvents.length > 1, "Expecting at least 1 catchUp event, got " + catchUpEvents.length);
       done(error);
     }
@@ -87,7 +129,7 @@ module.exports = {
       });
   },
   'Test Subscribe to All From (End)': function(test) {
-    test.expect(5);
+    test.expect(6);
     var self = this;
     var liveProcessing = false;
     var catchUpEvents = [];
@@ -97,19 +139,28 @@ module.exports = {
       test.ok(!err, err ? err.stack : '');
       _doneCount++;
       if (_doneCount < 2) return;
+
+      var liveInOrder = true;
+      for(var j = 1; j < liveEvents.length; j++)
+        liveInOrder = liveInOrder && (liveEvents[j].originalPosition.compareTo(liveEvents[j-1].originalPosition) > 0);
+      test.ok(liveInOrder, "Live events are out of order.");
+
       test.done();
     }
     function eventAppeared(s, e) {
-      if (liveProcessing) {
-        liveEvents.push(e);
-        s.stop();
-      } else {
-        catchUpEvents.push(e);
-      }
+      var isLive = liveProcessing;
+      delayOnlyFirst(isLive ? liveEvents.length : catchUpEvents.length, function() {
+        if (isLive) {
+          liveEvents.push(e);
+        } else {
+          catchUpEvents.push(e);
+        }
+        if (isLive && liveEvents.length === 2) s.stop();
+      });
     }
     function liveProcessingStarted() {
       liveProcessing = true;
-      var events = [createRandomEvent()];
+      var events = [createRandomEvent(), createRandomEvent()];
       self.conn.appendToStream(self.testStreamName, client.expectedVersion.any, events)
         .then(function () {
           done();
@@ -117,7 +168,7 @@ module.exports = {
         .catch(done);
     }
     function subscriptionDropped(connection, reason, error) {
-      test.ok(liveEvents.length === 1, "Expecting 1 live event, got " + liveEvents.length);
+      test.ok(liveEvents.length === 2, "Expecting 2 live event, got " + liveEvents.length);
       test.ok(catchUpEvents.length === 0, "Expecting 0 catchUp event, got " + catchUpEvents.length);
       done(error);
     }

test/subscribeToAll_test.js

@@ -2,6 +2,20 @@ const uuid = require('uuid');
 const client = require('../src/client');
 const allCredentials = new client.UserCredentials("admin", "changeit");
 
+function delay(ms) {
+  return new Promise(function (resolve, reject) {
+    setTimeout(resolve, ms);
+  })
+}
+
+function delayOnlyFirst(count, action) {
+  if (count === 0) return action();
+  return delay(200)
+    .then(function () {
+      action();
+    })
+}
+
 module.exports = {
   'Test Subscribe To All Happy Path': function(test) {
     const resolveLinkTos = false;
@@ -30,8 +44,10 @@ module.exports = {
 
     var receivedEvents = [];
     function eventAppeared(subscription, event) {
-      receivedEvents.push(event);
-      if (receivedEvents.length === numberOfPublishedEvents) subscription.close();
+      delayOnlyFirst(receivedEvents.length, function() {
+        receivedEvents.push(event);
+        if (receivedEvents.length === numberOfPublishedEvents) subscription.close();
+      });
     }
     function subscriptionDropped(subscription, reason, error) {
       if (error) return done(error);

test/subscribeToStreamFrom_test.js

@@ -6,9 +6,23 @@ function createRandomEvent() {
   return client.createJsonEventData(uuid.v4(), {a: uuid.v4(), b: Math.random()}, {createdAt: Date.now()}, 'testEvent');
 }
 
+function delay(ms) {
+  return new Promise(function (resolve, reject) {
+    setTimeout(resolve, ms);
+  })
+}
+
+function delayOnlyFirst(count, action) {
+  if (count === 0) return action();
+  return delay(200)
+    .then(function () {
+      action();
+    })
+}
+
 module.exports = {
   'Test Subscribe to Stream From Beginning (null)': function(test) {
-    test.expect(22);
+    test.expect(36);
     var self = this;
     var liveProcessing = false;
     var catchUpEvents = [];
@@ -22,16 +36,19 @@ module.exports = {
     }
 
     function eventAppeared(s, e) {
-      if (liveProcessing) {
-        liveEvents.push(e);
-        s.stop();
-      } else {
-        catchUpEvents.push(e);
-      }
+      var isLive = liveProcessing;
+      delayOnlyFirst(isLive ? liveEvents.length : catchUpEvents.length, function() {
+        if (isLive) {
+          liveEvents.push(e);
+        } else {
+          catchUpEvents.push(e);
+        }
+        if (isLive && liveEvents.length === 2) s.stop();
+      });
     }
     function liveProcessingStarted() {
       liveProcessing = true;
-      var events = [createRandomEvent()];
+      var events = [createRandomEvent(), createRandomEvent()];
       self.conn.appendToStream(self.testStreamName, client.expectedVersion.any, events)
           .then(function () {
             done();
@@ -39,16 +56,20 @@ module.exports = {
           .catch(done);
     }
     function subscriptionDropped(connection, reason, error) {
-      test.ok(liveEvents.length === 1, "Expecting 1 live event, got " + liveEvents.length);
+      test.ok(liveEvents.length === 2, "Expecting 2 live event, got " + liveEvents.length);
       test.testLiveEvent('liveEvents[0]', liveEvents[0]);
-      test.ok(liveEvents[0].originalEventNumber, 1);
-      test.ok(catchUpEvents.length === 1, "Expecting 1 catchUp event, got " + catchUpEvents.length);
+      test.testLiveEvent('liveEvents[1]', liveEvents[1]);
+      test.ok(liveEvents[0].originalEventNumber, 2);
+      test.ok(liveEvents[1].originalEventNumber, 3);
+      test.ok(catchUpEvents.length === 2, "Expecting 2 catchUp event, got " + catchUpEvents.length);
       test.testReadEvent('catchUpEvents[0]', catchUpEvents[0]);
+      test.testReadEvent('catchUpEvents[1]', catchUpEvents[1]);
       test.ok(liveEvents[0].originalEventNumber, 0);
+      test.ok(liveEvents[1].originalEventNumber, 1);
       done(error);
     }
 
-    var events = [createRandomEvent()];
+    var events = [createRandomEvent(), createRandomEvent()];
     this.conn.appendToStream(self.testStreamName, client.expectedVersion.noStream, events)
       .then(function() {
         var subscription = self.conn.subscribeToStreamFrom(self.testStreamName, null, false, eventAppeared, liveProcessingStarted, subscriptionDropped);
@@ -61,7 +82,7 @@ module.exports = {
       .catch(test.done);
   },
   'Test Subscribe to Stream From 0': function(test) {
-    test.expect(22);
+    test.expect(29);
     var self = this;
     var liveProcessing = false;
     var catchUpEvents = [];
@@ -75,16 +96,19 @@ module.exports = {
     }
 
     function eventAppeared(s, e) {
-      if (liveProcessing) {
-        liveEvents.push(e);
-        s.stop();
-      } else {
-        catchUpEvents.push(e);
-      }
+      var isLive = liveProcessing;
+      delayOnlyFirst(isLive ? liveEvents.length : catchUpEvents.length, function() {
+        if (isLive) {
+          liveEvents.push(e);
+        } else {
+          catchUpEvents.push(e);
+        }
+        if (isLive && liveEvents.length === 2) s.stop();
+      });
     }
     function liveProcessingStarted() {
       liveProcessing = true;
-      var events = [createRandomEvent()];
+      var events = [createRandomEvent(), createRandomEvent()];
       self.conn.appendToStream(self.testStreamName, client.expectedVersion.any, events)
         .then(function () {
           done();
@@ -92,9 +116,11 @@ module.exports = {
         .catch(done);
     }
     function subscriptionDropped(connection, reason, error) {
-      test.ok(liveEvents.length === 1, "Expecting 1 live event, got " + liveEvents.length);
+      test.ok(liveEvents.length === 2, "Expecting 2 live event, got " + liveEvents.length);
       test.testLiveEvent('liveEvents[0]', liveEvents[0]);
+      test.testLiveEvent('liveEvents[1]', liveEvents[1]);
       test.ok(liveEvents[0].originalEventNumber, 2);
+      test.ok(liveEvents[1].originalEventNumber, 3);
       test.ok(catchUpEvents.length === 1, "Expecting 1 catchUp event, got " + catchUpEvents.length);
       test.testReadEvent('catchUpEvents[0]', catchUpEvents[0]);
       test.ok(liveEvents[0].originalEventNumber, 1);

test/subscribeToStream_test.js

@@ -1,6 +1,20 @@
 const uuid = require('uuid');
 const client = require('../src/client');
 
+function delay(ms) {
+  return new Promise(function (resolve, reject) {
+    setTimeout(resolve, ms);
+  })
+}
+
+function delayOnlyFirst(count, action) {
+  if (count === 0) return action();
+  return delay(200)
+    .then(function () {
+      action();
+    })
+}
+
 module.exports = {
   'Test Subscribe To Stream Happy Path': function(test) {
     const resolveLinkTos = false;
@@ -28,8 +42,10 @@ module.exports = {
 
     var receivedEvents = [];
     function eventAppeared(subscription, event) {
-      receivedEvents.push(event);
-      if (receivedEvents.length === numberOfPublishedEvents) subscription.close();
+      delayOnlyFirst(receivedEvents.length, function () {
+        receivedEvents.push(event);
+        if (receivedEvents.length === numberOfPublishedEvents) subscription.close();
+      });
     }
     function subscriptionDropped(subscription, reason, error) {
       if (error) return done(error);