christopherread · Oct 25, 2026 · Oct 25, 2026 · Oct 25, 2026 · Oct 25, 2026 · Oct 25, 2026
diff --git a/.github/workflows/dotnet.yml b/.github/workflows/dotnet.yml
@@ -41,7 +41,9 @@ jobs:
     - name: Build
       run: dotnet build --no-restore --configuration Release -p:Version=${{ steps.gitversion.outputs.semVer }} -p:ContinuousIntegrationBuild=true -p:Deterministic=true
     - name: Test
-      run: dotnet test --no-build --configuration Release --verbosity normal --filter Category!=Explicit 
+      # xUnit v3 runs on Microsoft.Testing.Platform (global.json). Exit code 8 means a project ran no tests,
+      # as the transport test projects only contain Explicit tests.
+      run: dotnet test --solution Obvs.sln --no-build --configuration Release -- --filter-not-trait "Category=Explicit" --ignore-exit-code 8
     - name: Pack
       if: github.event_name == 'push'
       run: |

diff --git a/Directory.Packages.props b/Directory.Packages.props
@@ -28,7 +28,7 @@
         <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.11.0"/>
         <!-- Keep in step with System.Reactive -->
         <PackageVersion Include="Microsoft.Reactive.Testing" Version="7.0.0"/>
-        <PackageVersion Include="xunit" Version="2.9.3"/>
+        <PackageVersion Include="xunit.v3" Version="4.0.2"/>
         <PackageVersion Include="xunit.runner.visualstudio" Version="4.0.1"/>
     </ItemGroup>
 </Project>
diff --git a/Obvs.ActiveMQ.Tests/Obvs.ActiveMQ.Tests.csproj b/Obvs.ActiveMQ.Tests/Obvs.ActiveMQ.Tests.csproj
@@ -1,5 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
     <Company>Christopher Read</Company>
     <Copyright>Copyright © Christopher Read 2014</Copyright>
@@ -10,7 +11,7 @@
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

diff --git a/Obvs.Kafka.Tests/Obvs.Kafka.Tests.csproj b/Obvs.Kafka.Tests/Obvs.Kafka.Tests.csproj
@@ -1,12 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>

diff --git a/Obvs.Kafka.Tests/TestMessageSendAndReceive.cs b/Obvs.Kafka.Tests/TestMessageSendAndReceive.cs
@@ -82,15 +82,15 @@ public async Task TestSendAndReceiveMessage()
 
             var delay1 = TimeSpan.FromSeconds(2);
             Console.WriteLine($"Waiting {delay1}...");
-            await Task.Delay(delay1);
+            await Task.Delay(delay1, TestContext.Current.CancellationToken);
 
             await _publisher.PublishAsync(new TestMessage($"hello world {DateTime.Now}"));
             await _publisher.PublishAsync(new TestMessage($"hello world {DateTime.Now}"));
             await _publisher.PublishAsync(new TestMessage($"hello world {DateTime.Now}"));
 
             var delay2 = TimeSpan.FromSeconds(2);
             Console.WriteLine($"Waiting {delay2}...");
-            await Task.Delay(delay2);
+            await Task.Delay(delay2, TestContext.Current.CancellationToken);
 
             Assert.NotEmpty(messages);
             Assert.Equal(3, messages.Count);

diff --git a/Obvs.Logging.Tests/Obvs.Logging.Tests.csproj b/Obvs.Logging.Tests/Obvs.Logging.Tests.csproj
@@ -1,11 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

diff --git a/Obvs.Monitoring.Tests/Obvs.Monitoring.Tests.csproj b/Obvs.Monitoring.Tests/Obvs.Monitoring.Tests.csproj
@@ -1,5 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
     <Company>Christopher Read</Company>
     <Copyright>Copyright © Christopher Read 2014</Copyright>
@@ -10,7 +11,7 @@
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>

diff --git a/Obvs.NATS.Tests/Obvs.NATS.Tests.csproj b/Obvs.NATS.Tests/Obvs.NATS.Tests.csproj
@@ -1,12 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>

diff --git a/Obvs.NATS.Tests/TestServiceBus.cs b/Obvs.NATS.Tests/TestServiceBus.cs
@@ -49,7 +49,7 @@ public async Task TestBasicSendReceiveOfAllMessageTypes()
             var response = await bus.GetResponse<TestResponse>(new TestRequest());
             Console.WriteLine(response);
 
-            await Task.Delay(TimeSpan.FromSeconds(1));
+            await Task.Delay(TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
 
             ((IDisposable)bus).Dispose();
         }

diff --git a/Obvs.NATS.Tests/TestSourceAndPublisher.cs b/Obvs.NATS.Tests/TestSourceAndPublisher.cs
@@ -39,7 +39,7 @@ public async Task TestSendAndReceiveMessage()
                 await publisher.PublishAsync(new TestMessage {Id = i});
             }
 
-            await Task.Delay(TimeSpan.FromSeconds(1));
+            await Task.Delay(TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
             subscription.Dispose();
         }
     }

diff --git a/Obvs.NetMQ.Tests/Obvs.NetMQ.Tests.csproj b/Obvs.NetMQ.Tests/Obvs.NetMQ.Tests.csproj
@@ -1,12 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>

diff --git a/Obvs.NetMQ.Tests/TestPublishSubscribe.cs b/Obvs.NetMQ.Tests/TestPublishSubscribe.cs
@@ -13,6 +13,8 @@
 
 namespace Obvs.NetMQ.Tests
 {
+    // Each test uses its own port, clear of the ranges TestServiceBusWithNetMq binds,
+    // because xUnit runs test classes in parallel
     public class TestPublishSubscribe
     {
         [Fact, Trait("Category", "Explicit")]
@@ -29,7 +31,7 @@ public async Task TestSendingAndReceivingStringsOverLocalHost()
 
             }, err => Console.WriteLine("Error: " + err));
 
-            IMessageSource<IMessage> source = new MessageSource<IMessage>("tcp://localhost:5556",
+            IMessageSource<IMessage> source = new MessageSource<IMessage>("tcp://localhost:5560",
                 new IMessageDeserializer<IMessage>[]
                 {
                     new JsonMessageDeserializer<TestMessage1>(), 
@@ -39,7 +41,7 @@ public async Task TestSendingAndReceivingStringsOverLocalHost()
 
             var sub = source.Messages.Subscribe(observer);
 
-            IMessagePublisher<IMessage> publisher = new MessagePublisher<IMessage>("tcp://localhost:5556",
+            IMessagePublisher<IMessage> publisher = new MessagePublisher<IMessage>("tcp://localhost:5560",
                 new JsonMessageSerializer(), topic);
 
             await publisher.PublishAsync(new TestMessage1 { Id = 1 });
@@ -48,7 +50,11 @@ public async Task TestSendingAndReceivingStringsOverLocalHost()
             await publisher.PublishAsync(new TestMessage2 { Id = 2 });
             await publisher.PublishAsync(new TestMessage1 { Id = 3 });
             await publisher.PublishAsync(new TestMessage2 { Id = 3 });
-            await Task.Delay(TimeSpan.FromSeconds(2));
+            await Task.Delay(TimeSpan.FromSeconds(2), TestContext.Current.CancellationToken);
+
+            sub.Dispose();
+            source.Dispose();
+            publisher.Dispose();
 
             Assert.True(messages.OfType<TestMessage1>().Any(msg => msg.Id == 1), "TestMessage1 1 not received");
             Assert.True(messages.OfType<TestMessage1>().Any(msg => msg.Id == 2), "TestMessage1 2 not received");
@@ -57,9 +63,6 @@ public async Task TestSendingAndReceivingStringsOverLocalHost()
             Assert.True(messages.OfType<TestMessage2>().Any(msg => msg.Id == 1), "TestMessage2 1 not received");
             Assert.True(messages.OfType<TestMessage2>().Any(msg => msg.Id == 2), "TestMessage2 2 not received");
             Assert.True(messages.OfType<TestMessage2>().Any(msg => msg.Id == 3), "TestMessage2 3 not received");
-
-            sub.Dispose();
-            source.Dispose();
         }
 
         [Fact, Trait("Category", "Explicit")]
@@ -76,7 +79,7 @@ public async Task TestSendingAndReceivingBytesOverLocalHost()
 
             }, err => Console.WriteLine("Error: " + err));
 
-            IMessageSource<IMessage> source = new MessageSource<IMessage>("tcp://localhost:5556",
+            IMessageSource<IMessage> source = new MessageSource<IMessage>("tcp://localhost:5561",
                 new IMessageDeserializer<IMessage>[]
                 {
                     new ProtoBufMessageDeserializer<TestMessage1>(), 
@@ -86,7 +89,7 @@ public async Task TestSendingAndReceivingBytesOverLocalHost()
 
             var sub = source.Messages.Subscribe(observer);
 
-            IMessagePublisher<IMessage> publisher = new MessagePublisher<IMessage>("tcp://localhost:5556",
+            IMessagePublisher<IMessage> publisher = new MessagePublisher<IMessage>("tcp://localhost:5561",
                 new ProtoBufMessageSerializer(), topic);
 
             await publisher.PublishAsync(new TestMessage1 { Id = 1 });
@@ -95,7 +98,11 @@ public async Task TestSendingAndReceivingBytesOverLocalHost()
             await publisher.PublishAsync(new TestMessage2 { Id = 2 });
             await publisher.PublishAsync(new TestMessage1 { Id = 3 });
             await publisher.PublishAsync(new TestMessage2 { Id = 3 });
-            await Task.Delay(TimeSpan.FromSeconds(2));
+            await Task.Delay(TimeSpan.FromSeconds(2), TestContext.Current.CancellationToken);
+
+            sub.Dispose();
+            source.Dispose();
+            publisher.Dispose();
 
             Assert.True(messages.OfType<TestMessage1>().Any(msg => msg.Id == 1), "TestMessage1 1 not received");
             Assert.True(messages.OfType<TestMessage1>().Any(msg => msg.Id == 2), "TestMessage1 2 not received");
@@ -104,9 +111,6 @@ public async Task TestSendingAndReceivingBytesOverLocalHost()
             Assert.True(messages.OfType<TestMessage2>().Any(msg => msg.Id == 1), "TestMessage2 1 not received");
             Assert.True(messages.OfType<TestMessage2>().Any(msg => msg.Id == 2), "TestMessage2 2 not received");
             Assert.True(messages.OfType<TestMessage2>().Any(msg => msg.Id == 3), "TestMessage2 3 not received");
-
-            sub.Dispose();
-            source.Dispose();
         }
 
 		[Fact, Trait("Category", "Explicit")]
@@ -117,8 +121,10 @@ public async Task TestMessagesLongerThan32Characters()
 
 			const string topic = "TestTopicxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
 			IDisposable sub;
+			MessageSource<IMessage> source;
+			MessagePublisher<IMessage> publisher;
 			{
-			    var source = new MessageSource<IMessage>("tcp://localhost:5557",
+			    source = new MessageSource<IMessage>("tcp://localhost:5562",
 				    new IMessageDeserializer<IMessage>[]
 				    {
 						new ProtoBufMessageDeserializer<TestMessageWhereTypeIsVeryMuchDefinitionLongerThen32Characters>(), 
@@ -134,7 +140,7 @@ public async Task TestMessagesLongerThan32Characters()
 		    }
 
 		    {
-			    var publisher = new MessagePublisher<IMessage>("tcp://localhost:5557",
+			    publisher = new MessagePublisher<IMessage>("tcp://localhost:5562",
 				    new ProtoBufMessageSerializer(), 
 				    topic);
 
@@ -147,9 +153,11 @@ await publisher.PublishAsync(new TestMessageWhereTypeIsVeryMuchDefinitionLongerT
 			    }
 		    }
 
-            await Task.Delay(TimeSpan.FromSeconds(2));
+            await Task.Delay(TimeSpan.FromSeconds(2), TestContext.Current.CancellationToken);
 
             sub.Dispose();
+            source.Dispose();
+            publisher.Dispose();
 	    }
 
         [ProtoContract]

diff --git a/Obvs.NetMQ.Tests/TestServiceBusWithNetMq.cs b/Obvs.NetMQ.Tests/TestServiceBusWithNetMq.cs
@@ -139,7 +139,12 @@ public async Task TestServiceEndpointsOverLocalHostSockets()
             serviceBusClient2.GetResponses(new TestRequest1 { Id = 6 }).Subscribe(fakeClient1);
 
             // wait some time until we think all messages have been sent and received
-            await Task.Delay(TimeSpan.FromSeconds(3));
+            await Task.Delay(TimeSpan.FromSeconds(3), TestContext.Current.CancellationToken);
+
+            // dispose before asserting, so a failed assertion doesn't leave sockets bound for other tests
+            ((IDisposable)serviceBus).Dispose();
+            ((IDisposable)serviceBusClient1).Dispose();
+            ((IDisposable)serviceBusClient2).Dispose();
 
             // test we got everything we expected
             Assert.True(messages.OfType<TestCommand1>().Count() == 2, "TestCommand1");

diff --git a/Obvs.RabbitMQ.Tests/Obvs.RabbitMQ.Tests.csproj b/Obvs.RabbitMQ.Tests/Obvs.RabbitMQ.Tests.csproj
@@ -1,5 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
@@ -11,7 +12,7 @@
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

diff --git a/Obvs.RabbitMQ.Tests/TestSendingAndReceiving.cs b/Obvs.RabbitMQ.Tests/TestSendingAndReceiving.cs
@@ -62,7 +62,7 @@ public async Task TestSendReceiveAs(string format)
                 await messagePublisher.PublishAsync(message);
             }
 
-            await Task.Delay(TimeSpan.FromSeconds(2));
+            await Task.Delay(TimeSpan.FromSeconds(2), TestContext.Current.CancellationToken);
 
             Assert.True(receivedMessages1.Count == 7, "Incorrect number of messages received for first subscription");
             Assert.True(receivedMessages2.Count == 7, "Incorrect number of messages received for second subscription");
@@ -80,7 +80,7 @@ public async Task TestSendReceiveAs(string format)
             sub2.Dispose();
             messagePublisher.Dispose();
             messageSource.Dispose();
-            await connection.Value.CloseAsync();
+            await connection.Value.CloseAsync(cancellationToken: TestContext.Current.CancellationToken);
         }
 
         private static IMessagePublisher<IMessage> CreateMessagePublisher(string format, Lazy<IConnection> connection,

diff --git a/Obvs.RabbitMQ.Tests/TestServiceBus.cs b/Obvs.RabbitMQ.Tests/TestServiceBus.cs
@@ -48,7 +48,7 @@ public async Task ShouldSendAndReceiveMessagesOverServiceBus()
             var sub6 = serviceBus.GetResponses(new TestRequest { Id = 456 }).Subscribe(observer);
 
             // wait some time until we think all messages have been sent and received from RabbitMQ
-            await Task.Delay(TimeSpan.FromSeconds(1));
+            await Task.Delay(TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
 
             // test we got everything we expected
             Assert.True(messages.OfType<TestCommand>().Count() == 1, "TestCommand not received");

diff --git a/Obvs.Serialization.Tests/Obvs.Serialization.Tests.csproj b/Obvs.Serialization.Tests/Obvs.Serialization.Tests.csproj
@@ -1,5 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
     <Company>Christopher Read</Company>
     <Copyright>Copyright © Christopher Read 2014</Copyright>
@@ -10,7 +11,7 @@
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>

diff --git a/Obvs.Tests/Obvs.Tests.csproj b/Obvs.Tests/Obvs.Tests.csproj
@@ -1,5 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>    
+    <OutputType>Exe</OutputType>
     <TargetFramework>net10.0</TargetFramework>
     <Company>Christopher Read</Company>
     <Copyright>Copyright © Christopher Read 2014</Copyright>
@@ -10,7 +11,7 @@
     <PackageReference Include="FakeItEasy" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.Reactive.Testing" />
-    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>

diff --git a/Obvs.Tests/TestServiceBus.cs b/Obvs.Tests/TestServiceBus.cs
@@ -12,7 +12,6 @@
 using Obvs.Monitoring;
 using Obvs.Types;
 using Xunit;
-using Xunit.Abstractions;
 
 namespace Obvs.Tests
 {