Add HttpClient result helpers with Polly integration

ManagedCode.Communication.Extensions/Http/ResultHttpClientExtensions.cs

@@ -0,0 +1,145 @@
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using ManagedCode.Communication;
+using ManagedCode.Communication.Extensions;
+using Polly;
+
+namespace ManagedCode.Communication.Extensions.Http;
+
+/// <summary>
+///     Helpers that execute <see cref="HttpClient"/> requests and transform the responses into
+///     <see cref="ManagedCode.Communication.Result"/> instances.
+/// </summary>
+public static class ResultHttpClientExtensions
+{
+    /// <summary>
+    ///     Sends a request built by <paramref name="requestFactory"/> and converts the HTTP response into a
+    ///     <see cref="Result{T}"/>. When a <paramref name="pipeline"/> is provided the request is executed through it,
+    ///     enabling Polly resilience strategies such as retries or circuit breakers.
+    /// </summary>
+    /// <typeparam name="T">The JSON payload type that the endpoint returns in case of success.</typeparam>
+    /// <param name="client">The <see cref="HttpClient"/> used to send the request.</param>
+    /// <param name="requestFactory">Factory that creates a fresh <see cref="HttpRequestMessage"/> for each attempt.</param>
+    /// <param name="pipeline">Optional Polly resilience pipeline that wraps the HTTP invocation.</param>
+    /// <param name="cancellationToken">Token that cancels the request execution.</param>
+    public static Task<Result<T>> SendForResultAsync<T>(
+        this HttpClient client,
+        Func<HttpRequestMessage> requestFactory,
+        ResiliencePipeline<HttpResponseMessage>? pipeline = null,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(client);
+        ArgumentNullException.ThrowIfNull(requestFactory);
+
+        return SendCoreAsync(
+            client,
+            requestFactory,
+            static response => response.FromJsonToResult<T>(),
+            pipeline,
+            cancellationToken);
+    }
+
+    /// <summary>
+    ///     Sends a request built by <paramref name="requestFactory"/> and converts the HTTP response into a
+    ///     <see cref="Result"/> without a payload. When a <paramref name="pipeline"/> is provided the request is executed
+    ///     through it, enabling Polly resilience strategies such as retries or circuit breakers.
+    /// </summary>
+    /// <param name="client">The <see cref="HttpClient"/> used to send the request.</param>
+    /// <param name="requestFactory">Factory that creates a fresh <see cref="HttpRequestMessage"/> for each attempt.</param>
+    /// <param name="pipeline">Optional Polly resilience pipeline that wraps the HTTP invocation.</param>
+    /// <param name="cancellationToken">Token that cancels the request execution.</param>
+    public static Task<Result> SendForResultAsync(
+        this HttpClient client,
+        Func<HttpRequestMessage> requestFactory,
+        ResiliencePipeline<HttpResponseMessage>? pipeline = null,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(client);
+        ArgumentNullException.ThrowIfNull(requestFactory);
+
+        return SendCoreAsync(
+            client,
+            requestFactory,
+            static response => response.FromRequestToResult(),
+            pipeline,
+            cancellationToken);
+    }
+
+    /// <summary>
+    ///     Performs a GET request for <paramref name="requestUri"/> and converts the response into a
+    ///     <see cref="Result{T}"/>. The optional <paramref name="pipeline"/> allows attaching Polly retry or circuit
+    ///     breaker strategies.
+    /// </summary>
+    /// <typeparam name="T">The JSON payload type that the endpoint returns in case of success.</typeparam>
+    /// <param name="client">The <see cref="HttpClient"/> used to send the request.</param>
+    /// <param name="requestUri">The request URI.</param>
+    /// <param name="pipeline">Optional Polly resilience pipeline that wraps the HTTP invocation.</param>
+    /// <param name="cancellationToken">Token that cancels the request execution.</param>
+    public static Task<Result<T>> GetAsResultAsync<T>(
+        this HttpClient client,
+        string requestUri,
+        ResiliencePipeline<HttpResponseMessage>? pipeline = null,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(client);
+        ArgumentException.ThrowIfNullOrEmpty(requestUri);
+
+        return client.SendForResultAsync<T>(
+            () => new HttpRequestMessage(HttpMethod.Get, requestUri),
+            pipeline,
+            cancellationToken);
+    }
+
+    /// <summary>
+    ///     Performs a GET request for <paramref name="requestUri"/> and converts the response into a non generic
+    ///     <see cref="Result"/>.
+    /// </summary>
+    /// <param name="client">The <see cref="HttpClient"/> used to send the request.</param>
+    /// <param name="requestUri">The request URI.</param>
+    /// <param name="pipeline">Optional Polly resilience pipeline that wraps the HTTP invocation.</param>
+    /// <param name="cancellationToken">Token that cancels the request execution.</param>
+    public static Task<Result> GetAsResultAsync(
+        this HttpClient client,
+        string requestUri,
+        ResiliencePipeline<HttpResponseMessage>? pipeline = null,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(client);
+        ArgumentException.ThrowIfNullOrEmpty(requestUri);
+
+        return client.SendForResultAsync(
+            () => new HttpRequestMessage(HttpMethod.Get, requestUri),
+            pipeline,
+            cancellationToken);
+    }
+
+    private static async Task<TResponse> SendCoreAsync<TResponse>(
+        HttpClient client,
+        Func<HttpRequestMessage> requestFactory,
+        Func<HttpResponseMessage, Task<TResponse>> convert,
+        ResiliencePipeline<HttpResponseMessage>? pipeline,
+        CancellationToken cancellationToken)
+    {
+        if (pipeline is null)
+        {
+            using var request = requestFactory();
+            using var directResponse = await client.SendAsync(request, cancellationToken).ConfigureAwait(false);
+            return await convert(directResponse).ConfigureAwait(false);
+        }
+
+        var httpResponse = await pipeline.ExecuteAsync(
+            async cancellationToken =>
+            {
+                using var request = requestFactory();
+                return await client.SendAsync(request, cancellationToken).ConfigureAwait(false);
+            },
+            cancellationToken).ConfigureAwait(false);
+
+        using (httpResponse)
+        {
+            return await convert(httpResponse).ConfigureAwait(false);
+        }
+    }
+}

ManagedCode.Communication.Extensions/ManagedCode.Communication.Extensions.csproj

@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <IsPackable>true</IsPackable>
+        <DebugType>embedded</DebugType>
+    </PropertyGroup>
+
+    <!--NuGet-->
+    <PropertyGroup>
+        <Title>ManagedCode.Communication.Extensions</Title>
+        <PackageId>ManagedCode.Communication.Extensions</PackageId>
+        <Description>Optional integrations for ManagedCode.Communication including Minimal API endpoint filters.</Description>
+        <PackageTags>managedcode;communication;result-pattern;minimal-api;endpoint-filter</PackageTags>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <FrameworkReference Include="Microsoft.AspNetCore.App" />
+        <ProjectReference Include="..\ManagedCode.Communication.AspNetCore\ManagedCode.Communication.AspNetCore.csproj" />
+        <PackageReference Include="Polly" Version="8.4.2" />
+    </ItemGroup>
+
+</Project>

ManagedCode.Communication.Extensions/MinimalApi/CommunicationEndpointExtensions.cs

@@ -0,0 +1,46 @@
+using System;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Routing;
+
+namespace ManagedCode.Communication.Extensions.MinimalApi;
+
+/// <summary>
+///     Extension helpers for wiring ManagedCode.Communication support into Minimal API route handlers.
+/// </summary>
+public static class CommunicationEndpointExtensions
+{
+    /// <summary>
+    ///     Adds <see cref="ResultEndpointFilter"/> to a specific <see cref="RouteHandlerBuilder"/> so that
+    ///     <c>Result</c>-returning handlers are converted into <see cref="Microsoft.AspNetCore.Http.IResult"/> automatically.
+    /// </summary>
+    /// <param name="builder">The endpoint builder.</param>
+    /// <returns>The same builder instance to enable fluent configuration.</returns>
+    public static RouteHandlerBuilder WithCommunicationResults(this RouteHandlerBuilder builder)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+
+        builder.AddEndpointFilterFactory(CreateFilter);
+        return builder;
+    }
+
+    /// <summary>
+    ///     Adds <see cref="ResultEndpointFilter"/> to an entire <see cref="RouteGroupBuilder"/> so that every child endpoint
+    ///     inherits automatic <c>Result</c> to <see cref="Microsoft.AspNetCore.Http.IResult"/> conversion.
+    /// </summary>
+    /// <param name="builder">The group builder.</param>
+    /// <returns>The same builder instance for chaining.</returns>
+    public static RouteGroupBuilder WithCommunicationResults(this RouteGroupBuilder builder)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+
+        builder.AddEndpointFilterFactory(CreateFilter);
+        return builder;
+    }
+
+    private static EndpointFilterDelegate CreateFilter(EndpointFilterFactoryContext context, EndpointFilterDelegate next)
+    {
+        var filter = new ResultEndpointFilter();
+        return invocationContext => filter.InvokeAsync(invocationContext, next);
+    }
+}

ManagedCode.Communication.Extensions/MinimalApi/ResultEndpointFilter.cs

@@ -0,0 +1,142 @@
+using System;
+using System.Collections.Concurrent;
+using System.Threading.Tasks;
+using ManagedCode.Communication;
+using ManagedCode.Communication.AspNetCore.Extensions;
+using ManagedCode.Communication.Constants;
+using Microsoft.AspNetCore.Http;
+using HttpResults = Microsoft.AspNetCore.Http.Results;
+using AspNetResult = Microsoft.AspNetCore.Http.IResult;
+using CommunicationResult = ManagedCode.Communication.IResult;
+using CommunicationResultOfObject = ManagedCode.Communication.IResult<object?>;
+using AspNetResultFactory = System.Func<object, Microsoft.AspNetCore.Http.IResult>;
+
+namespace ManagedCode.Communication.Extensions.MinimalApi;
+
+/// <summary>
+///     Endpoint filter that converts <see cref="ManagedCode.Communication.Result"/> responses into Minimal API results.
+/// </summary>
+public sealed class ResultEndpointFilter : IEndpointFilter
+{
+    private static readonly ConcurrentDictionary<Type, AspNetResultFactory> ValueResultConverters = new();
+
+    /// <inheritdoc />
+    public async ValueTask<object?> InvokeAsync(EndpointFilterInvocationContext context, EndpointFilterDelegate next)
+    {
+        ArgumentNullException.ThrowIfNull(context);
+        ArgumentNullException.ThrowIfNull(next);
+
+        var result = await next(context).ConfigureAwait(false);
+
+        if (result is null)
+        {
+            return null;
+        }
+
+        return ConvertResult(result);
+    }
+
+    private static object ConvertResult(object result)
+    {
+        if (result is AspNetResult aspNetResult)
+        {
+            return aspNetResult;
+        }
+
+        if (result is ManagedCode.Communication.Result nonGenericResult)
+        {
+            return nonGenericResult.ToHttpResult();
+        }
+
+        if (result is CommunicationResultOfObject valueResult)
+        {
+            return valueResult.IsSuccess
+                ? HttpResults.Ok(valueResult.Value)
+                : CreateProblem(valueResult.Problem);
+        }
+
+        if (TryConvertValueResult(result, out var converted))
+        {
+            return converted;
+        }
+
+        if (result is CommunicationResult communicationResult)
+        {
+            return communicationResult.IsSuccess
+                ? HttpResults.NoContent()
+                : CreateProblem(communicationResult.Problem);
+        }
+
+        return result;
+    }
+
+    private static AspNetResult CreateProblem(Problem? problem)
+    {
+        var normalized = NormalizeProblem(problem);
+
+        return HttpResults.Problem(
+            title: normalized.Title,
+            detail: normalized.Detail,
+            statusCode: normalized.StatusCode,
+            type: normalized.Type,
+            instance: normalized.Instance,
+            extensions: normalized.Extensions
+        );
+    }
+
+    private static Problem NormalizeProblem(Problem? problem)
+    {
+        if (problem is null || IsGeneric(problem))
+        {
+            return Problem.Create("Operation failed", "Unknown error occurred", 500);
+        }
+
+        return problem;
+    }
+
+    private static bool IsGeneric(Problem problem)
+    {
+        return string.Equals(problem.Title, ProblemConstants.Titles.Error, StringComparison.OrdinalIgnoreCase)
+               && string.Equals(problem.Detail, ProblemConstants.Messages.GenericError, StringComparison.OrdinalIgnoreCase);
+    }
+
+    private static bool TryConvertValueResult(object result, out AspNetResult converted)
+    {
+        converted = null!;
+
+        var type = result.GetType();
+        if (!typeof(CommunicationResult).IsAssignableFrom(type) || type == typeof(Result))
+        {
+            return false;
+        }
+
+        var converter = ValueResultConverters.GetOrAdd(type, CreateConverter);
+        converted = converter(result);
+        return true;
+    }
+
+    private static AspNetResultFactory CreateConverter(Type type)
+    {
+        var valueProperty = type.GetProperty("Value");
+
+        return valueProperty is null
+            ? result =>
+            {
+                var communicationResult = (CommunicationResult)result;
+                return communicationResult.IsSuccess
+                    ? HttpResults.NoContent()
+                    : CreateProblem(communicationResult.Problem);
+            }
+            : result =>
+            {
+                var communicationResult = (CommunicationResult)result;
+                if (communicationResult.IsSuccess)
+                {
+                    var value = valueProperty.GetValue(result);
+                    return HttpResults.Ok(value);
+                }
+
+                return CreateProblem(communicationResult.Problem);
+            };
+    }
+}