Fix for #2456 (#2457)

* - Updated tests in ClusterClientConfigSpec
- Changed range check in ClusterClientSettings

* - Added ClusterClientStartSpec

* Disabled new spec

src/contrib/cluster/Akka.Cluster.Tools.Tests.MultiNode/Akka.Cluster.Tools.Tests.MultiNode.csproj

@@ -76,6 +76,7 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="ClusterClient\ClusterClientStartSpecConfig.cs" />
     <Compile Include="ClusterClient\ClusterClientStopSpec.cs" />
     <Compile Include="ClusterClient\ClusterClientSpec.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />

src/contrib/cluster/Akka.Cluster.Tools.Tests.MultiNode/ClusterClient/ClusterClientStartSpecConfig.cs

@@ -0,0 +1,135 @@
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using Akka.Actor;
+using Akka.Cluster.TestKit;
+using Akka.Cluster.Tools.Client;
+using Akka.Cluster.Tools.PublishSubscribe;
+using Akka.Cluster.Tools.PublishSubscribe.Internal;
+using Akka.Configuration;
+using Akka.Remote.TestKit;
+using FluentAssertions;
+
+namespace Akka.Cluster.Tools.Tests.MultiNode.Client
+{
+
+    public class ClusterClientStartSpecConfig : MultiNodeConfig
+    {
+        public RoleName Client { get; }
+        public RoleName First { get; }
+        public RoleName Second { get; }
+
+        public ClusterClientStartSpecConfig()
+        {
+            Client = Role("client");
+            First = Role("first");
+            Second = Role("second");
+
+            CommonConfig = ConfigurationFactory.ParseString(@"
+                akka.loglevel = INFO
+                akka.actor.provider = ""Akka.Cluster.ClusterActorRefProvider, Akka.Cluster""
+                akka.remote.log-remote-lifecycle-events = off
+                akka.cluster.client {
+                  heartbeat-interval = 1s
+                  acceptable-heartbeat-pause = 1s
+                  reconnect-timeout = 60s
+                  receptionist.number-of-contacts = 1
+                }
+                akka.test.filter-leeway = 10s
+            ")
+                .WithFallback(ClusterClientReceptionist.DefaultConfig())
+                .WithFallback(DistributedPubSub.DefaultConfig());
+        }
+
+        public class Service : ReceiveActor
+        {
+            public Service()
+            {
+                ReceiveAny(msg => Sender.Tell(msg));
+            }
+        }
+
+        public class ClusterClientStartMultiNode1 : ClusterClientStartSpec { }
+        public class ClusterClientStartMultiNode2 : ClusterClientStartSpec { }
+        public class ClusterClientStartMultiNode3 : ClusterClientStartSpec { }
+
+        public abstract class ClusterClientStartSpec : MultiNodeClusterSpec
+        {
+            private readonly ClusterClientStartSpecConfig _config;
+
+            protected ClusterClientStartSpec() : this(new ClusterClientStartSpecConfig())
+            {
+            }
+
+            protected ClusterClientStartSpec(ClusterClientStartSpecConfig config) : base(config)
+            {
+                _config = config;
+            }
+
+            protected override int InitialParticipantsValueFactory => 3;
+
+            private ImmutableHashSet<ActorPath> InitialContacts
+            {
+                get
+                {
+                    //return new List<ActorPath>().ToImmutableHashSet();
+                    return ImmutableHashSet
+                        .Create(_config.First, _config.Second)
+                        .Select(r => Node(r) / "system" / "receptionist")
+                        .ToImmutableHashSet();
+                }
+            }
+
+            [MultiNodeFact(Skip = "Disable due to known issues with this spec which are currently under investigation by ArjenSmitss")]
+            public void ClusterClientStartSpecs()
+            {
+                Start_Cluster();
+                ClusterClient_can_start_with_zero_buffer();
+            }
+
+            public void Start_Cluster()
+            {
+                Within(30.Seconds(), () =>
+                {
+                    AwaitClusterUp(_config.First, _config.Second);
+
+                    //start our test service
+                    RunOn(() =>
+                    {
+                        var service = Sys.ActorOf(Props.Create(() => new ClusterClientStopSpecConfig.Service()), "testService");
+
+                        //here we explicitly do _not_ register the service with the cluster receptionist to force the clusterclient in buffer mode
+                        //ClusterClientReceptionist.Get(Sys).RegisterService(service);
+                    }, _config.First, _config.Second);
+
+                    EnterBarrier("receptionist-started");
+                });
+            }
+
+            public void ClusterClient_can_start_with_zero_buffer()
+            {
+                Within(30.Seconds(), () =>
+                {
+                    //start the cluster client 
+                    RunOn(() =>
+                    {
+                        var c = Sys.ActorOf(ClusterClient.Props(ClusterClientSettings.Create(Sys).WithBufferSize(0).WithInitialContacts(InitialContacts)), "client1");
+                        //check for the debug log message that the cluster client will output in case of an 0 buffersize
+                        EventFilter.Debug(start: "Receptionist not available and buffering is disabled, dropping message").ExpectOne(
+                            () =>
+                            {
+                                c.Tell(new ClusterClient.Send("/user/testService", "hello"));
+                            });
+
+                        //ExpectMsg<string>(3.Seconds()).Should().Be("hello");
+
+
+                        ExpectTerminated(c, 10.Seconds());
+                    }, _config.Client);
+
+                    EnterBarrier("end-of-test");
+                });
+            }
+        }
+    }
+}

src/contrib/cluster/Akka.Cluster.Tools.Tests/ClusterClient/ClusterClientConfigSpec.cs

@@ -42,7 +42,7 @@ public void ClusterClientSettings_must_have_default_config()
         }
 
         [Theory]
-        [InlineData(0)]
+        [InlineData(-1)]
         [InlineData(10001)]
         public void ClusterClientSettings_must_throw_exception_on_wrong_buffer(int bufferSize)
         {

src/contrib/cluster/Akka.Cluster.Tools/Client/ClusterClientSettings.cs

@@ -102,7 +102,7 @@ public ClusterClientSettings(
             int bufferSize,
             TimeSpan? reconnectTimeout = null)
         {
-            if (bufferSize == 0 || bufferSize > 10000)
+            if (bufferSize < 0 || bufferSize > 10000)
             {
                 throw new ArgumentException("BufferSize must be >= 0 and <= 10000");
             }