Revert NotifyAsync

Author: kzu

src/Merq.Abstractions/IMessageBus.cs

@@ -103,7 +103,7 @@ public interface IMessageBus
     /// <param name="callerName">Optional calling member name, provided by default by the compiler.</param>
     /// <param name="callerFile">Optional calling file name, provided by default by the compiler.</param>
     /// <param name="callerLine">Optional calling line number, provided by default by the compiler.</param>
-    Task NotifyAsync<TEvent>(TEvent e, [CallerMemberName] string? callerName = default, [CallerFilePath] string? callerFile = default, [CallerLineNumber] int? callerLine = default);
+    ValueTask NotifyAsync<TEvent>(TEvent e, [CallerMemberName] string? callerName = default, [CallerFilePath] string? callerFile = default, [CallerLineNumber] int? callerLine = default);
 
     /// <summary>
     /// Observes the events of a given type <typeparamref name="TEvent"/>.

src/Merq.Abstractions/IMessageBusExtensions.cs

@@ -1,6 +1,7 @@
 using System;
 using System.ComponentModel;
 using System.Runtime.CompilerServices;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Merq;
@@ -17,7 +18,11 @@ public static class IMessageBusExtensions
     [EditorBrowsable(EditorBrowsableState.Never)]
     [Obsolete("Use await NotifyAsync instead.")]
     public static void Notify<TEvent>(this IMessageBus bus, TEvent e, [CallerMemberName] string? callerName = default, [CallerFilePath] string? callerFile = default, [CallerLineNumber] int? callerLine = default)
-        => bus.NotifyAsync(e, callerName, callerFile, callerLine).Forget();
+    {
+        var result = bus.NotifyAsync(e, callerName, callerFile, callerLine);
+        while (!result.IsCompleted)
+            Thread.SpinWait(1);
+    }
 
     /// <summary>
     /// Notifies the bus of a new event instance of <typeparamref name="TEvent"/>.
@@ -30,7 +35,7 @@ public static void Notify<TEvent>(this IMessageBus bus, TEvent e, [CallerMemberN
     /// <summary>
     /// Notifies the bus of a new event instance of <typeparamref name="TEvent"/>.
     /// </summary>
-    public static Task NotifyAsync<TEvent>(this IMessageBus bus, [CallerMemberName] string? callerName = default, [CallerFilePath] string? callerFile = default, [CallerLineNumber] int? callerLine = default) where TEvent : new()
+    public static ValueTask NotifyAsync<TEvent>(this IMessageBus bus, [CallerMemberName] string? callerName = default, [CallerFilePath] string? callerFile = default, [CallerLineNumber] int? callerLine = default) where TEvent : new()
         => bus.NotifyAsync(new TEvent(), callerName, callerFile, callerLine);
 
     /// <summary>

src/Merq.Abstractions/TaskExtensions.cs

@@ -21,22 +21,14 @@ public partial record OtherMessageEvent(string Message)
 
 public class DynamicDuckTyping : DuckTyping
 {
-    protected override IMessageBus CreateMessageBus(IServiceCollection? services = null)
-    {
-        services ??= new ServiceCollection();
-        services.AddSingleton<IMessageBus>(sp => new DynamicallyMessageBus(sp));
-        return services.BuildServiceProvider().GetRequiredService<IMessageBus>();
-    }
+    protected override IMessageBus CreateMessageBus(IServiceProvider? services = null) =>
+        new DynamicallyMessageBus(services ?? new MockServiceProvider());
 }
 
 public class AutoMapperDuckTyping : DuckTyping
 {
-    protected override IMessageBus CreateMessageBus(IServiceCollection? services = null)
-    {
-        services ??= new ServiceCollection();
-        services.AddSingleton<IMessageBus>(sp => new AutoMapperMessageBus(sp));
-        return services.BuildServiceProvider().GetRequiredService<IMessageBus>();
-    }
+    protected override IMessageBus CreateMessageBus(IServiceProvider? services = null) =>
+        new AutoMapperMessageBus(services ?? new MockServiceProvider());
 
     [Fact]
     public void ExecuteWithExtraCtorArg()
@@ -45,7 +37,7 @@ public void ExecuteWithExtraCtorArg()
         var services = new ServiceCollection();
         services.AddSingleton(handler.Object);
         services.AddSingleton(typeof(IServiceCollection), _ => services);
-        var bus = CreateMessageBus(services);
+        var bus = CreateMessageBus(services.BuildServiceProvider());
 
         var cmd = new Library2::Library.Echo2("Foo");
 
@@ -57,7 +49,7 @@ public void ExecuteWithExtraCtorArg()
 
 public abstract class DuckTyping
 {
-    protected abstract IMessageBus CreateMessageBus(IServiceCollection? services = null);
+    protected abstract IMessageBus CreateMessageBus(IServiceProvider? services = null);
 
 #if NET6_0_OR_GREATER
     [Fact]
@@ -118,7 +110,7 @@ public void CanHandleDuck()
         var services = new ServiceCollection();
         services.AddSingleton<ICommandHandler<Library1::Library.Echo, string>, Library1::Library.EchoHandler>();
         services.AddSingleton(typeof(IServiceCollection), _ => services);
-        var bus = CreateMessageBus(services);
+        var bus = CreateMessageBus(services.BuildServiceProvider());
 
         Assert.True(bus.CanHandle<Library2::Library.Echo>());
         Assert.True(bus.CanHandle(new Library2::Library.Echo("Foo")));
@@ -130,7 +122,7 @@ public void CanExecuteDuck()
         var services = new ServiceCollection();
         services.AddSingleton<ICommandHandler<Library1::Library.Echo, string>, Library1::Library.EchoHandler>();
         services.AddSingleton(typeof(IServiceCollection), _ => services);
-        var bus = CreateMessageBus(services);
+        var bus = CreateMessageBus(services.BuildServiceProvider());
 
         var cmd = new Library2::Library.Echo("Foo");
 
@@ -143,7 +135,7 @@ public void ExecuteCommand()
         var services = new ServiceCollection();
         services.AddSingleton<ICommandHandler<Library1::Library.Echo, string>, Library1::Library.EchoHandler>();
         services.AddSingleton(typeof(IServiceCollection), _ => services);
-        var bus = CreateMessageBus(services);
+        var bus = CreateMessageBus(services.BuildServiceProvider());
 
         var cmd = new Library2::Library.Echo("Foo");
 
@@ -158,7 +150,7 @@ public void ExecuteNoOpCommand()
         var services = new ServiceCollection();
         services.AddSingleton<ICommandHandler<Library1::Library.NoOp>, Library1::Library.NoOpHandler>();
         services.AddSingleton(typeof(IServiceCollection), _ => services);
-        var bus = CreateMessageBus(services);
+        var bus = CreateMessageBus(services.BuildServiceProvider());
 
         var cmd = new Library2::Library.NoOp();
 
@@ -171,7 +163,7 @@ public async Task ExecuteAsyncCommandAsync()
         var services = new ServiceCollection();
         services.AddSingleton<IAsyncCommandHandler<Library1::Library.EchoAsync, string>, Library1::Library.EchoAsyncHandler>();
         services.AddSingleton(typeof(IServiceCollection), _ => services);
-        var bus = CreateMessageBus(services);
+        var bus = CreateMessageBus(services.BuildServiceProvider());
 
         var cmd = new Library2::Library.EchoAsync("Foo");
 
@@ -186,7 +178,7 @@ public async Task ExecuteNoOpAsyncCommandAsync()
         var services = new ServiceCollection();
         services.AddSingleton<IAsyncCommandHandler<Library1::Library.NoOpAsync>, Library1::Library.NoOpAsyncHandler>();
         services.AddSingleton(typeof(IServiceCollection), _ => services);
-        var bus = CreateMessageBus(services);
+        var bus = CreateMessageBus(services.BuildServiceProvider());
 
         var cmd = new Library2::Library.NoOpAsync();
 

src/Merq.Tests/DuckTyping.cs

@@ -324,7 +324,7 @@ public System.Collections.Generic.IAsyncEnumerable<TResult> ExecuteStream<TResul
 #endif
 
     /// <inheritdoc/>
-    public Task NotifyAsync<TEvent>(TEvent e, [CallerMemberName] string? callerName = default, [CallerFilePath] string? callerFile = default, [CallerLineNumber] int? callerLine = default)
+    public ValueTask NotifyAsync<TEvent>(TEvent e, [CallerMemberName] string? callerName = default, [CallerFilePath] string? callerFile = default, [CallerLineNumber] int? callerLine = default)
     {
         var type = (e ?? throw new ArgumentNullException(nameof(e))).GetType();
         using var activity = StartEventActivity(type, e, callerName, callerFile, callerLine);
@@ -372,7 +372,7 @@ public Task NotifyAsync<TEvent>(TEvent e, [CallerMemberName] string? callerName
             Publishing.Record(watch.ElapsedMilliseconds, new Tag("Event", type.FullName));
         }
 
-        return Task.CompletedTask;
+        return new ValueTask();
     }
 
     /// <summary>

src/Merq/MessageBus.cs

@@ -24,29 +24,42 @@ public void Execute(NoOp command) { }
 }
 
 [Service]
-public class EchoHandler(IMessageBus bus) : ICommandHandler<Echo, string>
+public class EchoHandler : ICommandHandler<Echo, string>
 {
+    readonly IMessageBus? bus;
+
+    public EchoHandler() { }
+
+    public EchoHandler(IMessageBus bus) => this.bus = bus;
+
     public bool CanExecute(Echo command) => !string.IsNullOrEmpty(command.Message);
 
     public string Execute(Echo command)
     {
         if (string.IsNullOrEmpty(command.Message))
             throw new NotSupportedException("Cannot echo an empty or null message");
 
-        bus.NotifyAsync(new OnDidSay(command.Message)).Forget();
+        bus?.Notify(new OnDidSay(command.Message));
         return command.Message;
     }
 }
 
 [Service]
-public class EchoAsyncHandler(IMessageBus bus) : IAsyncCommandHandler<EchoAsync, string>
+public class EchoAsyncHandler : IAsyncCommandHandler<EchoAsync, string>
 {
+    readonly IMessageBus? bus;
+
+    public EchoAsyncHandler() { }
+
+    public EchoAsyncHandler(IMessageBus bus) => this.bus = bus;
+
+
     public bool CanExecute(EchoAsync command) => true;
 
-    public async Task<string> ExecuteAsync(EchoAsync command, CancellationToken cancellation = default)
+    public Task<string> ExecuteAsync(EchoAsync command, CancellationToken cancellation = default)
     {
-        await bus.NotifyAsync(new OnDidSay(command.Message));
-        return command.Message;
+        bus?.Notify(new OnDidSay(command.Message));
+        return Task.FromResult(command.Message);
     }
 }