v7: Handlers, RequestAsync and MaxConcurrency

Directory.Packages.props

@@ -14,6 +14,7 @@
         <PackageVersion Include="Microsoft.Extensions.DependencyModel" Version="10.0.13"/>
         <PackageVersion Include="Microsoft.Extensions.Hosting" Version="10.0.13"/>
         <PackageVersion Include="Microsoft.Extensions.Hosting.Abstractions" Version="10.0.13"/>
+        <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.13"/>
         <PackageVersion Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="10.0.13"/>
         <PackageVersion Include="MsgPack.Cli" Version="1.0.1"/>
         <PackageVersion Include="NATS.Client.Core" Version="3.3.1"/>
@@ -25,6 +26,7 @@
         <PackageVersion Include="RabbitMQ.Client" Version="7.2.2"/>
         <PackageVersion Include="System.Reactive" Version="7.0.0"/>
         <PackageVersion Include="System.Reflection.Emit.Lightweight" Version="4.7.0"/>
+        <PackageVersion Include="System.Threading.Channels" Version="10.0.13"/>
         <PackageVersion Include="YamlDotNet" Version="18.1.0"/>
     </ItemGroup>
     <!-- Tests -->

Obvs.Tests/Hosting/Handlers/HandlerTestSupport.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections.Concurrent;
+using Microsoft.Extensions.Logging;
+using Obvs.Types;
+
+namespace Obvs.Tests.Hosting.Handlers
+{
+    public interface IOrderMessage : IMessage { }
+
+    public interface IShippingMessage : IMessage { }
+
+    public record PlaceOrder(string OrderId) : IOrderMessage, ICommand;
+
+    public record OrderPlaced(string OrderId) : IOrderMessage, IEvent;
+
+    public record GetQuote(string Sku) : IOrderMessage, IRequest
+    {
+        public string RequestId { get; set; }
+        public string RequesterId { get; set; }
+    }
+
+    public record Quote(string Sku, decimal Price) : IOrderMessage, IResponse
+    {
+        public string RequestId { get; set; }
+        public string RequesterId { get; set; }
+    }
+
+    public record ShipOrder(string OrderId) : IShippingMessage, ICommand;
+
+    public sealed record LogEntry(LogLevel Level, string Category, string Message, Exception Exception);
+
+    // Captures everything logged, so tests can check what handlers report
+    public sealed class ListLoggerProvider : ILoggerProvider
+    {
+        public ConcurrentQueue<LogEntry> Entries { get; } = new ConcurrentQueue<LogEntry>();
+
+        public ILogger CreateLogger(string categoryName) => new ListLogger(this, categoryName);
+
+        public void Dispose()
+        {
+        }
+
+        private sealed class ListLogger : ILogger
+        {
+            private readonly ListLoggerProvider _provider;
+            private readonly string _category;
+
+            public ListLogger(ListLoggerProvider provider, string category)
+            {
+                _provider = provider;
+                _category = category;
+            }
+
+            public IDisposable BeginScope<TState>(TState state) where TState : notnull => null;
+
+            public bool IsEnabled(LogLevel logLevel) => true;
+
+            public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
+            {
+                _provider.Entries.Enqueue(new LogEntry(logLevel, _category, formatter(state, exception), exception));
+            }
+        }
+    }
+}