Refactor dispatcher to support JSON and MessagePack clients

Author: pwelter34

Directory.Packages.props

@@ -13,7 +13,7 @@
     <PackageVersion Include="Azure.Communication.Email" Version="1.1.0" />
     <PackageVersion Include="Azure.Communication.Sms" Version="1.0.2" />
     <PackageVersion Include="BenchmarkDotNet" Version="0.15.8" />
-    <PackageVersion Include="Blazilla" Version="2.2.0" />
+    <PackageVersion Include="Blazilla" Version="2.2.1" />
     <PackageVersion Include="Bogus" Version="35.6.5" />
     <PackageVersion Include="CsvHelper" Version="33.1.0" />
     <PackageVersion Include="dbup-sqlserver" Version="6.0.16" />
@@ -58,7 +58,7 @@
     <PackageVersion Include="OpenTelemetry.Instrumentation.SqlClient" Version="1.11.0-beta.2" />
     <PackageVersion Include="Riok.Mapperly" Version="4.3.1" />
     <PackageVersion Include="Rocks" Version="10.0.0" />
-    <PackageVersion Include="Scalar.AspNetCore" Version="2.12.8" />
+    <PackageVersion Include="Scalar.AspNetCore" Version="2.12.10" />
     <PackageVersion Include="SendGrid.Extensions.DependencyInjection" Version="1.0.1" />
     <PackageVersion Include="Serilog.AspNetCore" Version="10.0.0" />
     <PackageVersion Include="starkbank-ecdsa" Version="1.3.3" />
@@ -69,9 +69,9 @@
     <PackageVersion Include="TestHost.Abstracts" Version="2.0.0" />
     <PackageVersion Include="Testcontainers.MongoDb" Version="4.10.0" />
     <PackageVersion Include="Testcontainers.MsSql" Version="4.10.0" />
-    <PackageVersion Include="TUnit" Version="1.11.45" />
+    <PackageVersion Include="TUnit" Version="1.11.56" />
     <PackageVersion Include="Twilio" Version="7.14.1" />
     <PackageVersion Include="Verify.TUnit" Version="31.9.4" />
     <PackageVersion Include="YamlDotNet" Version="16.3.0" />
   </ItemGroup>
-</Project>
+</Project>

samples/EntityFramework/src/Tracker.Client/Services/ServiceRegistration.cs

@@ -34,7 +34,7 @@ public static void Register(IServiceCollection services, ISet<string> tags)
         if (tags.Contains("WebAssembly"))
         {
             services
-                .AddRemoteDispatcher((sp, client) =>
+                .AddMessagePackDispatcher((sp, client) =>
                 {
                     var hostEnvironment = sp.GetRequiredService<IOptions<EnvironmentOptions>>();
                     client.BaseAddress = new Uri(hostEnvironment.Value.BaseAddress);

src/Arbiter.CommandQuery/CommandQueryExtensions.cs

@@ -81,6 +81,26 @@ public static IServiceCollection AddEntityHybridCache(this IServiceCollection se
         return services;
     }
 
+    /// <summary>
+    /// Adds MessagePack options to the service collection.
+    /// </summary>
+    /// <param name="services">The <see cref="IServiceCollection"/> to add services to.</param>
+    /// <param name="configure">An optional action to configure the MessagePack serializer options.</param>
+    /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
+    /// <seealso cref="MessagePackDefaults"/>
+    public static IServiceCollection AddMessagePackOptions(this IServiceCollection services, Action<MessagePack.MessagePackSerializerOptions>? configure = null)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+
+        // Configure MessagePack options
+        var options = MessagePackDefaults.DefaultSerializerOptions;
+        configure?.Invoke(options);
+
+        // MessagePack Serializer Options Registration
+        services.TryAddSingleton(options);
+
+        return services;
+    }
 
     /// <summary>
     /// Adds the entity query behaviors to the service collection.

src/Arbiter.CommandQuery/MessagePackDefaults.cs

@@ -0,0 +1,39 @@
+using MessagePack;
+using MessagePack.Resolvers;
+
+namespace Arbiter.CommandQuery;
+
+/// <summary>
+/// Provides default values and settings for MessagePack serialization.
+/// </summary>
+public static class MessagePackDefaults
+{
+    /// <summary>
+    /// The content type for MessagePack serialized data.
+    /// </summary>
+    public const string MessagePackContentType = "application/x-msgpack";
+
+    /// <summary>
+    /// The default serializer options for MessagePack.
+    /// </summary>
+    public static readonly MessagePackSerializerOptions DefaultSerializerOptions =
+        MessagePackSerializerOptions.Standard
+            .WithResolver(
+                CompositeResolver.Create(
+                [
+                    // 0) Uses the Roslyn source generator output produced automatically.
+                    SourceGeneratedFormatterResolver.Instance,
+
+                    // 1) Attribute-based + built-ins (enums, primitives, etc.)
+                    StandardResolver.Instance,
+
+                    // 2) Typeless (for object-typed or unknown static types)
+                    TypelessObjectResolver.Instance,
+
+                    // 3) Contractless fallback for POCOs without attributes
+                    ContractlessStandardResolver.Instance,
+                ])
+            )
+            .WithCompression(MessagePackCompression.Lz4Block);
+
+}

src/Arbiter.Dispatcher.Client/Client/JsonDispatcher.cs

@@ -0,0 +1,75 @@
+using System.Buffers;
+using System.Net.Http.Headers;
+using System.Net.Mime;
+using System.Text.Json;
+
+using Arbiter.CommandQuery.Definitions;
+using Arbiter.CommandQuery.Models;
+using Arbiter.Mediation;
+
+using Microsoft.Extensions.Caching.Hybrid;
+
+namespace Arbiter.Dispatcher.Client;
+
+/// <summary>
+/// Implements a remote dispatcher that sends requests to a remote HTTP endpoint using JSON serialization.
+/// Supports optional hybrid caching for cacheable requests.
+/// </summary>
+public class JsonDispatcher : RemoteDispatcherBase
+{
+    private static readonly MediaTypeHeaderValue _mediaTypeHeader = new(MediaTypeNames.Application.Json);
+    private readonly JsonSerializerOptions _options;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="JsonDispatcher"/> class.
+    /// </summary>
+    /// <param name="httpClient">The HTTP client used to send requests to the remote endpoint.</param>
+    /// <param name="options">The JSON serialization options.</param>
+    /// <param name="hybridCache">Optional hybrid cache for caching responses. When provided, requests implementing <see cref="ICacheResult"/> will be cached.</param>
+    /// <exception cref="ArgumentNullException">Thrown when <paramref name="httpClient"/> or <paramref name="options"/> is null.</exception>
+    public JsonDispatcher(HttpClient httpClient, JsonSerializerOptions options, HybridCache? hybridCache = null)
+        : base(httpClient, hybridCache)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+
+        _options = options;
+    }
+
+    /// <inheritdoc/>
+    protected override MediaTypeHeaderValue ContentType { get; } = _mediaTypeHeader;
+
+    /// <inheritdoc/>
+    protected override void Serialize<TResponse>(
+        IBufferWriter<byte> bufferWriter,
+        IRequest<TResponse> request,
+        Type requestType,
+        CancellationToken cancellationToken)
+    {
+        using var writer = new Utf8JsonWriter(bufferWriter);
+        JsonSerializer.Serialize(writer, request, requestType, _options);
+    }
+
+    /// <inheritdoc/>
+    protected override TResponse? Deserialize<TResponse>(
+        ReadOnlyMemory<byte> buffer,
+        CancellationToken cancellationToken)
+        where TResponse : default
+    {
+        return JsonSerializer.Deserialize<TResponse>(buffer.Span, _options);
+    }
+
+    /// <inheritdoc/>
+    protected override async ValueTask<ProblemDetails?> TryProblemDetails(
+        HttpResponseMessage responseMessage,
+        CancellationToken cancellationToken = default)
+    {
+        // check content type is JSON
+        var mediaType = responseMessage.Content.Headers.ContentType?.MediaType;
+        if (!string.Equals(mediaType, MediaTypeNames.Application.ProblemJson, StringComparison.OrdinalIgnoreCase))
+            return null;
+
+        // deserialize problem details from buffer
+        var responseBytes = await responseMessage.Content.ReadAsByteArrayAsync(cancellationToken).ConfigureAwait(false);
+        return JsonSerializer.Deserialize<ProblemDetails>(responseBytes, _options);
+    }
+}

src/Arbiter.Dispatcher.Client/Client/MessagePackDispatcher.cs

@@ -0,0 +1,80 @@
+using System.Buffers;
+using System.Diagnostics.CodeAnalysis;
+using System.Net;
+using System.Net.Http.Headers;
+using System.Net.Http.Json;
+using System.Net.Mime;
+using System.Text.Json;
+
+using Arbiter.CommandQuery;
+using Arbiter.CommandQuery.Definitions;
+using Arbiter.CommandQuery.Extensions;
+using Arbiter.CommandQuery.Models;
+using Arbiter.Mediation;
+
+using MessagePack;
+
+using Microsoft.Extensions.Caching.Hybrid;
+
+namespace Arbiter.Dispatcher.Client;
+
+/// <summary>
+/// Implements a remote dispatcher that sends requests to a remote HTTP endpoint using MessagePack serialization.
+/// Supports optional hybrid caching for cacheable requests.
+/// </summary>
+public class MessagePackDispatcher : RemoteDispatcherBase
+{
+    private readonly MessagePackSerializerOptions _options;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="MessagePackDispatcher"/> class.
+    /// </summary>
+    /// <param name="httpClient">The HTTP client used to send requests to the remote endpoint.</param>
+    /// <param name="options">The MessagePack serialization options.</param>
+    /// <param name="hybridCache">Optional hybrid cache for caching responses. When provided, requests implementing <see cref="ICacheResult"/> will be cached.</param>
+    /// <exception cref="ArgumentNullException">Thrown when <paramref name="httpClient"/> or <paramref name="options"/> is null.</exception>
+    public MessagePackDispatcher(
+        HttpClient httpClient,
+        MessagePackSerializerOptions options,
+        HybridCache? hybridCache = null) : base(httpClient, hybridCache)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+
+        _options = options;
+    }
+
+    /// <inheritdoc/>
+    protected override MediaTypeHeaderValue ContentType { get; } = DispatcherConstants.MessagePackMediaTypeHeader;
+
+    /// <inheritdoc/>
+    protected override void Serialize<TResponse>(IBufferWriter<byte> bufferWriter, IRequest<TResponse> request, Type requestType, CancellationToken cancellationToken)
+    {
+        MessagePackSerializer.Serialize(requestType, bufferWriter, request, _options);
+    }
+
+    /// <inheritdoc/>
+    protected override TResponse? Deserialize<TResponse>(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken)
+        where TResponse : default
+    {
+        return MessagePackSerializer.Deserialize<TResponse>(buffer, _options, cancellationToken);
+    }
+
+    /// <inheritdoc/>
+    protected override async ValueTask<ProblemDetails?> TryProblemDetails(HttpResponseMessage responseMessage, CancellationToken cancellationToken = default)
+    {
+        // check content type is MessagePack
+        var mediaType = responseMessage.Content.Headers.ContentType?.MediaType;
+        if (!string.Equals(mediaType, MessagePackDefaults.MessagePackContentType, StringComparison.OrdinalIgnoreCase))
+            return null;
+
+        // make sure it's a problem details response
+        responseMessage.Headers.TryGetValues(DispatcherConstants.ResponseTypeHeader, out var responseTypeValues);
+        var responseType = responseTypeValues?.FirstOrDefault();
+        if (string.IsNullOrEmpty(responseType) || !string.Equals(responseType, typeof(ProblemDetails).GetPortableName(), StringComparison.OrdinalIgnoreCase))
+            return null;
+
+        // deserialize problem details from buffer
+        var responseBytes = await responseMessage.Content.ReadAsByteArrayAsync(cancellationToken).ConfigureAwait(false);
+        return MessagePackSerializer.Deserialize<ProblemDetails>(responseBytes, _options, cancellationToken);
+    }
+}