RTL6d

Source/ARTRealtime.m

@@ -526,9 +526,11 @@ - (void)send:(ARTProtocolMessage *)msg callback:(void (^)(ARTStatus *))cb {
         [self sendImpl:msg callback:cb];
     } else if ([self shouldQueueEvents]) {
         BOOL merged = NO;
-        if ([self.queuedMessages count]) {
-            ARTQueuedMessage *lastQueued = [self.queuedMessages objectAtIndex:(self.queuedMessages.count) - 1];
-            merged = [lastQueued mergeFrom:msg callback:cb];
+        for (ARTQueuedMessage *queuedMsg in self.queuedMessages) {
+            merged = [queuedMsg mergeFrom:msg callback:cb];
+            if (merged) {
+                break;
+            }
         }
         if (!merged) {
             ARTQueuedMessage *qm = [[ARTQueuedMessage alloc] initWithProtocolMessage:msg callback:cb];

Source/ARTRealtimeChannel.m

@@ -142,8 +142,7 @@ - (void)publishProtocolMessage:(ARTProtocolMessage *)pm callback:(void (^)(ARTSt
             // intentional fall-through
         case ARTRealtimeChannelAttaching:
         {
-            ARTQueuedMessage *qm = [[ARTQueuedMessage alloc] initWithProtocolMessage:pm callback:cb];
-            [self.queuedMessages addObject:qm];
+            [self addToQueue:pm callback:cb];
             break;
         }
         case ARTRealtimeChannelDetaching:
@@ -161,8 +160,7 @@ - (void)publishProtocolMessage:(ARTProtocolMessage *)pm callback:(void (^)(ARTSt
             if (_realtime.connection.state == ARTRealtimeConnected) {
                 [self sendMessage:pm callback:cb];
             } else {
-                ARTQueuedMessage *qm = [[ARTQueuedMessage alloc] initWithProtocolMessage:pm callback:cb];
-                [self.queuedMessages addObject:qm];
+                [self addToQueue:pm callback:cb];
 
                 [_realtime.connection once:ARTRealtimeConnected callback:^(ARTConnectionStateChange *__art_nullable change) {
                     [self sendQueuedMessages];
@@ -175,6 +173,20 @@ - (void)publishProtocolMessage:(ARTProtocolMessage *)pm callback:(void (^)(ARTSt
     }
 }
 
+- (void)addToQueue:(ARTProtocolMessage *)msg callback:(void (^)(ARTStatus *))cb {
+    BOOL merged = NO;
+    for (ARTQueuedMessage *queuedMsg in self.queuedMessages) {
+        merged = [queuedMsg mergeFrom:msg callback:cb];
+        if (merged) {
+            break;
+        }
+    }
+    if (!merged) {
+        ARTQueuedMessage *qm = [[ARTQueuedMessage alloc] initWithProtocolMessage:msg callback:cb];
+        [self.queuedMessages addObject:qm];
+    }
+}
+
 - (void)sendMessage:(ARTProtocolMessage *)pm callback:(void (^)(ARTStatus *))cb {
     __block BOOL gotFailure = false;
     NSString *oldConnectionId = self.realtime.connection.id;

Spec/RealtimeClientChannel.swift

@@ -1110,6 +1110,60 @@ class RealtimeClientChannel: QuickSpec {
 
                 }
 
+                // RTL6d
+                it("Messages are delivered using a single ProtocolMessage where possible by bundling in all messages for that channel") {
+                    let options = AblyTests.commonAppSetup()
+                    options.autoConnect = false
+                    let client = AblyTests.newRealtime(options)
+                    defer { client.close() }
+                    let channel = client.channels.get("test")
+
+                    // Test that the initially queued messages are sent together.
+
+                    let messagesSent = 3
+                    waitUntil(timeout: testTimeout) { done in
+                        let partialDone = AblyTests.splitDone(messagesSent, done: done)
+                        for i in 1...messagesSent {
+                            channel.publish("initial", data: "message\(i)") { error in
+                                expect(error).to(beNil())
+                                partialDone()
+                            }
+                        }
+                        client.connect()
+                    }
+
+                    let transport = client.transport as! TestProxyTransport
+                    let protocolMessages = transport.protocolMessagesSent.filter{ $0.action == .Message }
+                    expect(protocolMessages).to(haveCount(1))
+                    if protocolMessages.count != 1 {
+                        return
+                    }
+                    expect(protocolMessages[0].messages).to(haveCount(messagesSent))
+
+                    // Test that publishing an array of messages sends them together. 
+
+                    // TODO: limit the total number of messages bundled per ProtocolMessage
+                    let maxMessages = 50
+
+                    var messages = [ARTMessage]()
+                    for i in 1...maxMessages {
+                        messages.append(ARTMessage(name: "total number of messages", data: "message\(i)"))
+                    }
+                    waitUntil(timeout: testTimeout) { done in
+                        channel.publish(messages) { error in
+                            expect(error).to(beNil())
+                            let transport = client.transport as! TestProxyTransport
+                            let protocolMessages = transport.protocolMessagesSent.filter{ $0.action == .Message }
+                            expect(protocolMessages).to(haveCount(2))
+                            if protocolMessages.count != 2 {
+                                done(); return
+                            }
+                            expect(protocolMessages[1].messages).to(haveCount(maxMessages))
+                            done()
+                        }
+                    }
+                }
+
                 // RTL6e
                 context("Unidentified clients using Basic Auth") {