Add optional group name to DeathLinkService

Archipelago.MultiClient.Net.Tests/DeathLinkFixture.cs

@@ -201,5 +201,104 @@ public void Should_disable_death_link_if_its_already_enabled()
             Assert.That(connectionInfo.Tags.Length, Is.EqualTo(1));
             Assert.That(connectionInfo.Tags[0], Is.EqualTo("SomeTag"));
         }
+
+        [Test]
+        public void Should_enable_death_link_with_group_tag()
+        {
+            var socket = Substitute.For<IArchipelagoSocketHelper>();
+            var connectionInfo = new ConnectionInfoHelper(socket) { Tags = Array.Empty<string>() };
+
+            var sut = new DeathLinkService(socket, connectionInfo, "MyGroup");
+
+            sut.EnableDeathLink();
+
+            socket.Received().SendPacket(Arg.Is<ConnectUpdatePacket>(p => p.Tags.Length == 1 && p.Tags[0] == "DeathLinkMyGroup"));
+
+            Assert.That(connectionInfo.Tags.Length, Is.EqualTo(1));
+            Assert.That(connectionInfo.Tags[0], Is.EqualTo("DeathLinkMyGroup"));
+        }
+
+        [Test]
+        public void Should_send_death_link_with_group_tag()
+        {
+            var socket = Substitute.For<IArchipelagoSocketHelper>();
+            var connectionInfo = Substitute.For<IConnectionInfoProvider>();
+
+            var sut = new DeathLinkService(socket, connectionInfo, "MyGroup");
+
+            sut.SendDeathLink(new DeathLink("TestPlayer", "Died"));
+
+            socket.Received().SendPacketAsync(Arg.Is<BouncePacket>(p => p.Tags.Count == 1 && p.Tags[0] == "DeathLinkMyGroup"));
+        }
+
+        [Test]
+        public void Should_receive_death_link_with_matching_group_tag()
+        {
+            var socket = Substitute.For<IArchipelagoSocketHelper>();
+            var connectionInfo = Substitute.For<IConnectionInfoProvider>();
+
+            var sut = new DeathLinkService(socket, connectionInfo, "MyGroup");
+
+            DeathLink receivedDeathLink = null;
+            sut.OnDeathLinkReceived += dl => receivedDeathLink = dl;
+
+            var death = new DeathLink("SomeoneElse", "Died");
+            var bouncePacket = new BouncedPacket {
+                Tags = new List<string> { "DeathLinkMyGroup" },
+                Data = new Dictionary<string, JToken> {
+                    { "source", death.Source },
+                    { "time", death.Timestamp.ToUnixTimeStamp() },
+                    { "cause", death.Cause }
+                }
+            };
+
+            socket.PacketReceived += Raise.Event<ArchipelagoSocketHelperDelagates.PacketReceivedHandler>(bouncePacket);
+
+            Assert.That(receivedDeathLink, Is.Not.Null);
+        }
+
+        [Test]
+        public void Should_not_receive_death_link_from_a_different_group()
+        {
+            var socket = Substitute.For<IArchipelagoSocketHelper>();
+            var connectionInfo = Substitute.For<IConnectionInfoProvider>();
+
+            var sut = new DeathLinkService(socket, connectionInfo, "MyGroup");
+
+            DeathLink receivedDeathLink = null;
+            sut.OnDeathLinkReceived += dl => receivedDeathLink = dl;
+
+            // A fully-valid death in the default pool ("DeathLink") must not reach a grouped client.
+            var death = new DeathLink("SomeoneElse", "Died");
+            var bouncePacket = new BouncedPacket {
+                Tags = new List<string> { "DeathLink" },
+                Data = new Dictionary<string, JToken> {
+                    { "source", death.Source },
+                    { "time", death.Timestamp.ToUnixTimeStamp() },
+                    { "cause", death.Cause }
+                }
+            };
+
+            socket.PacketReceived += Raise.Event<ArchipelagoSocketHelperDelagates.PacketReceivedHandler>(bouncePacket);
+
+            Assert.That(receivedDeathLink, Is.Null);
+        }
+
+        [Test]
+        public void Should_use_default_tag_for_blank_group()
+        {
+            var socket = Substitute.For<IArchipelagoSocketHelper>();
+            var connectionInfo = new ConnectionInfoHelper(socket) { Tags = Array.Empty<string>() };
+
+            // Blank group is wire-identical to standard DeathLink (default pool).
+            var sut = new DeathLinkService(socket, connectionInfo, "");
+
+            sut.EnableDeathLink();
+
+            socket.Received().SendPacket(Arg.Is<ConnectUpdatePacket>(p => p.Tags.Length == 1 && p.Tags[0] == "DeathLink"));
+
+            Assert.That(connectionInfo.Tags.Length, Is.EqualTo(1));
+            Assert.That(connectionInfo.Tags[0], Is.EqualTo("DeathLink"));
+        }
     }
 }

Archipelago.MultiClient.Net/BounceFeatures/DeathLink/DeathLinkProvider.cs

@@ -9,5 +9,14 @@ public static class DeathLinkProvider
         /// </summary>
         public static DeathLinkService CreateDeathLinkService(this ArchipelagoSession session) => 
 	        new DeathLinkService(session.Socket, session.ConnectionInfo);
+
+        // ReSharper disable once UnusedMember.Global
+        /// <summary>
+        ///     creates and returns a <see cref="DeathLinkService"/> for this <paramref name="session"/>,
+        ///     scoped to the DeathLink <paramref name="group"/>. Only players sharing the same group name
+        ///     send and receive deaths to one another; a null or empty group joins the default DeathLink pool.
+        /// </summary>
+        public static DeathLinkService CreateDeathLinkService(this ArchipelagoSession session, string group) =>
+	        new DeathLinkService(session.Socket, session.ConnectionInfo, group);
     }
 }

Archipelago.MultiClient.Net/BounceFeatures/DeathLink/DeathLinkService.cs

@@ -12,6 +12,7 @@ public class DeathLinkService
     {
         readonly IArchipelagoSocketHelper socket;
         readonly IConnectionInfoProvider connectionInfoProvider;
+        readonly string tag;
 
         DeathLink lastSendDeathLink;
 
@@ -26,10 +27,12 @@ public class DeathLinkService
         /// </summary>
         public event DeathLinkReceivedHandler OnDeathLinkReceived;
 
-        internal DeathLinkService(IArchipelagoSocketHelper socket, IConnectionInfoProvider connectionInfoProvider)
+        internal DeathLinkService(IArchipelagoSocketHelper socket, IConnectionInfoProvider connectionInfoProvider,
+            string group = null)
         {
             this.socket = socket;
             this.connectionInfoProvider = connectionInfoProvider;
+            this.tag = "DeathLink" + (group ?? "");
 
             socket.PacketReceived += OnPacketReceived;
         }
@@ -38,7 +41,7 @@ void OnPacketReceived(ArchipelagoPacketBase packet)
         {
             switch (packet)
             {
-                case BouncedPacket bouncedPacket when bouncedPacket.Tags.Contains("DeathLink"):
+                case BouncedPacket bouncedPacket when bouncedPacket.Tags.Contains(tag):
                     if (DeathLink.TryParse(bouncedPacket.Data, out var deathLink))
                     {
                         if (lastSendDeathLink != null && lastSendDeathLink == deathLink)
@@ -66,7 +69,7 @@ public void SendDeathLink(DeathLink deathLink)
         {
             var bouncePacket = new BouncePacket
             {
-                Tags = new List<string> { "DeathLink" },
+                Tags = new List<string> { tag },
                 Data = new Dictionary<string, JToken> {
                     {"time", deathLink.Timestamp.ToUnixTimeStamp()},
                     {"source", deathLink.Source},
@@ -82,27 +85,29 @@ public void SendDeathLink(DeathLink deathLink)
         }
 
         /// <summary>
-        /// Adds "DeathLink" to your <see cref="ArchipelagoSession"/>'s tags and opts you in to receiving
+        /// Adds the DeathLink tag (suffixed with the group name, if any) to your
+        /// <see cref="ArchipelagoSession"/>'s tags and opts you in to receiving
         /// <see cref="OnDeathLinkReceived"/> events
         /// </summary>
         public void EnableDeathLink()
         {
-            if (Array.IndexOf(connectionInfoProvider.Tags, "DeathLink") == -1)
+            if (Array.IndexOf(connectionInfoProvider.Tags, tag) == -1)
                 connectionInfoProvider.UpdateConnectionOptions(
-                    connectionInfoProvider.Tags.Concat(new[] { "DeathLink" }).ToArray());
+                    connectionInfoProvider.Tags.Concat(new[] { tag }).ToArray());
         }
 
         /// <summary>
-        /// Removes the "DeathLink" tag from your <see cref="ArchipelagoSession"/> and opts out of further
+        /// Removes the DeathLink tag (suffixed with the group name, if any) from your
+        /// <see cref="ArchipelagoSession"/> and opts out of further
         /// <see cref="OnDeathLinkReceived"/> events
         /// </summary>
         public void DisableDeathLink()
         {
-            if (Array.IndexOf(connectionInfoProvider.Tags, "DeathLink") == -1)
+            if (Array.IndexOf(connectionInfoProvider.Tags, tag) == -1)
                 return;
 
             connectionInfoProvider.UpdateConnectionOptions(
-                connectionInfoProvider.Tags.Where(t => t != "DeathLink").ToArray());
+                connectionInfoProvider.Tags.Where(t => t != tag).ToArray());
         }
     }
 }