Add WireMock.Net.AspNetCore.Middleware (#1175)

* Add WireMock.Net.AspNetCore.Middleware

* .

* WireMock.Net.Middleware.Tests

* .

* X-WireMock-Response-Delay

src/WireMock.Net.AspNetCore.Middleware/AppConstants.cs

@@ -0,0 +1,9 @@
+// Copyright © WireMock.Net
+
+namespace WireMock.Net.AspNetCore.Middleware;
+
+internal static class AppConstants
+{
+    internal const string HEADER_REDIRECT = "X-WireMock-Redirect";
+    internal const string HEADER_RESPONSE_DELAY = "X-WireMock-Response-Delay";
+}

src/WireMock.Net.AspNetCore.Middleware/HttpDelegatingHandler/WireMockDelegationHandler.cs

@@ -0,0 +1,72 @@
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Logging;
+using Stef.Validation;
+using WireMock.Server;
+
+namespace WireMock.Net.AspNetCore.Middleware.HttpDelegatingHandler;
+
+/// <summary>
+/// DelegatingHandler that takes requests made via the <see cref="HttpClient"/>
+/// and routes them to the <see cref="WireMockServer"/>.
+/// </summary>
+internal class WireMockDelegationHandler : DelegatingHandler
+{
+    private readonly ILogger<WireMockDelegationHandler> _logger;
+    private readonly WireMockServerInstance _server;
+    private readonly IHttpContextAccessor _httpContextAccessor;
+    private readonly WireMockDelegationHandlerSettings _settings;
+
+    /// <summary>
+    /// Creates a new instance of <see cref="WireMockDelegationHandler"/>
+    /// </summary>
+    public WireMockDelegationHandler(
+        ILogger<WireMockDelegationHandler> logger,
+        WireMockServerInstance server,
+        IHttpContextAccessor httpContextAccessor,
+        WireMockDelegationHandlerSettings settings
+    )
+    {
+        _server = Guard.NotNull(server);
+        _httpContextAccessor = Guard.NotNull(httpContextAccessor);
+        _logger = Guard.NotNull(logger);
+        _settings = Guard.NotNull(settings);
+    }
+
+    /// <inheritdoc />
+    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+    {
+        Guard.NotNull(request);
+        Guard.NotNull(_httpContextAccessor.HttpContext);
+
+        if (_settings.AlwaysRedirect || IsWireMockRedirectHeaderSetToTrue())
+        {
+            _logger.LogDebug("Redirecting request to WireMock server");
+            if (_server.Instance?.Url != null)
+            {
+                request.RequestUri = new Uri(_server.Instance.Url + request.RequestUri!.PathAndQuery);
+            }
+        }
+
+        if (TryGetDelayHeaderValue(out var delayInMs))
+        {
+            await Task.Delay(delayInMs, cancellationToken);
+        }
+
+        return await base.SendAsync(request, cancellationToken);
+    }
+
+    private bool IsWireMockRedirectHeaderSetToTrue()
+    {
+        return
+            _httpContextAccessor.HttpContext!.Request.Headers.TryGetValue(AppConstants.HEADER_REDIRECT, out var values) &&
+            bool.TryParse(values.ToString(), out var shouldRedirectToWireMock) && shouldRedirectToWireMock;
+    }
+
+    private bool TryGetDelayHeaderValue(out int delayInMs)
+    {
+        delayInMs = 0;
+        return
+            _httpContextAccessor.HttpContext!.Request.Headers.TryGetValue(AppConstants.HEADER_RESPONSE_DELAY, out var values) &&
+            int.TryParse(values.ToString(), out delayInMs);
+    }
+}

src/WireMock.Net.AspNetCore.Middleware/HttpDelegatingHandler/WireMockDelegationHandlerSettings.cs

@@ -0,0 +1,8 @@
+// Copyright © WireMock.Net
+
+namespace WireMock.Net.AspNetCore.Middleware.HttpDelegatingHandler;
+
+internal class WireMockDelegationHandlerSettings
+{
+    public bool AlwaysRedirect { get; set; }
+}

src/WireMock.Net.AspNetCore.Middleware/ServiceCollectionExtensions.cs

@@ -0,0 +1,52 @@
+// Copyright © WireMock.Net
+
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Http;
+using Stef.Validation;
+using WireMock.Net.AspNetCore.Middleware.HttpDelegatingHandler;
+using WireMock.Server;
+using WireMock.Settings;
+
+namespace WireMock.Net.AspNetCore.Middleware;
+
+/// <summary>
+/// Extension methods for <see cref="IServiceCollection"/>.
+/// </summary>
+public static class ServiceCollectionExtensions
+{
+    /// <summary>
+    /// Adds all the components necessary to run WireMock.Net as a background service.
+    /// </summary>
+    public static IServiceCollection AddWireMockService(
+        this IServiceCollection services,
+        Action<WireMockServer> configure,
+        bool alwaysRedirectToWireMock = true,
+        WireMockServerSettings? settings = null
+    )
+    {
+        Guard.NotNull(services);
+        Guard.NotNull(configure);
+
+        services.AddTransient<WireMockDelegationHandler>();
+
+        services.AddSingleton(new WireMockServerInstance(configure, settings));
+
+        services.AddSingleton(new WireMockDelegationHandlerSettings
+        {
+            AlwaysRedirect = alwaysRedirectToWireMock
+        });
+
+        services.AddHostedService<WireMockBackgroundService>();
+        services.AddHttpClient();
+        services.AddHttpContextAccessor();
+        services.ConfigureAll<HttpClientFactoryOptions>(options =>
+        {
+            options.HttpMessageHandlerBuilderActions.Add(builder =>
+            {
+                builder.AdditionalHandlers.Add(builder.Services.GetRequiredService<WireMockDelegationHandler>());
+            });
+        });
+
+        return services;
+    }
+}

src/WireMock.Net.AspNetCore.Middleware/WireMock.Net.AspNetCore.Middleware.csproj

@@ -0,0 +1,49 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Description>Middleware which can be used to host WireMock.Net as a AspNetCore Middleware in a WebApplication</Description>
+        <AssemblyTitle>WireMock.Net.AspNetCore.Middleware</AssemblyTitle>
+        <Authors>Matt Yost;Stef Heyenrath</Authors>
+        <TargetFramework>net8.0</TargetFramework>
+        <GenerateDocumentationFile>true</GenerateDocumentationFile>
+        <AssemblyName>WireMock.Net.AspNetCore.Middleware</AssemblyName>
+        <PackageId>WireMock.Net.AspNetCore.Middleware</PackageId>
+        <PackageTags>dotnet;middleware;wiremock;service;webapplication</PackageTags>
+        <ProjectGuid>{B6269AAC-170A-4346-8B9A-579DED3D9A13}</ProjectGuid>
+        <PublishRepositoryUrl>true</PublishRepositoryUrl>
+        <AllowedOutputExtensionsInPackageBuildOutputFolder>$(AllowedOutputExtensionsInPackageBuildOutputFolder);.pdb</AllowedOutputExtensionsInPackageBuildOutputFolder>
+        <EmbedUntrackedSources>true</EmbedUntrackedSources>
+        <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+        <GenerateBindingRedirectsOutputType>true</GenerateBindingRedirectsOutputType>
+        <CodeAnalysisRuleSet>../WireMock.Net/WireMock.Net.ruleset</CodeAnalysisRuleSet>
+        <SignAssembly>true</SignAssembly>
+        <AssemblyOriginatorKeyFile>../WireMock.Net/WireMock.Net.snk</AssemblyOriginatorKeyFile>
+        <PublicSign Condition=" '$(OS)' != 'Windows_NT' ">true</PublicSign>
+        <PackageLicenseExpression>MIT</PackageLicenseExpression>
+        <PackageIcon>WireMock.Net-LogoAspire.png</PackageIcon>
+        <ApplicationIcon>../../resources/WireMock.Net-LogoAspire.ico</ApplicationIcon>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Remove="IWireMockContext.cs" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <None Remove="../../resources/WireMock.Net-Logo.png" />
+        <None Include="../../resources/WireMock.Net-LogoAspire.png" Pack="true" PackagePath="" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.1" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\WireMock.Net\WireMock.Net.csproj" />
+    </ItemGroup>
+
+    <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+        <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    </PropertyGroup>
+
+</Project>

src/WireMock.Net.AspNetCore.Middleware/WireMockBackgroundService.cs

@@ -0,0 +1,39 @@
+// Copyright © WireMock.Net
+
+using Microsoft.Extensions.Hosting;
+using Stef.Validation;
+using WireMock.Server;
+
+namespace WireMock.Net.AspNetCore.Middleware;
+
+/// <summary>
+/// A <see cref="BackgroundService"/> used to start/stop the <see cref="WireMockServer"/>
+/// </summary>
+internal class WireMockBackgroundService : BackgroundService
+{
+    private readonly WireMockServerInstance _serverInstance;
+
+    /// <summary>
+    /// Creates a new <see cref="BackgroundService"/> using an instance
+    /// of <see cref="WireMockServerInstance"/>
+    /// </summary>
+    /// <param name="serverInstance"></param>
+    public WireMockBackgroundService(WireMockServerInstance serverInstance)
+    {
+        _serverInstance = Guard.NotNull(serverInstance);
+    }
+
+    /// <inheritdoc />
+    protected override Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        _serverInstance.Start();
+        return Task.CompletedTask;
+    }
+
+    /// <inheritdoc />
+    public override Task StopAsync(CancellationToken cancellationToken)
+    {
+        _serverInstance.Stop();
+        return base.StopAsync(cancellationToken);
+    }
+}

src/WireMock.Net.AspNetCore.Middleware/WireMockServerInstance.cs

@@ -0,0 +1,49 @@
+// Copyright © WireMock.Net
+
+using Stef.Validation;
+using WireMock.Server;
+using WireMock.Settings;
+
+namespace WireMock.Net.AspNetCore.Middleware;
+
+/// <summary>
+/// WireMockServer Instance object
+/// </summary>
+internal class WireMockServerInstance
+{
+    private readonly Action<WireMockServer> _configureAction;
+    private readonly WireMockServerSettings? _settings;
+
+    /// <summary>
+    /// Creates a new instance and provides ability to add configuration
+    /// for the start method of <see cref="WireMockServer"/>
+    /// </summary>
+    public WireMockServerInstance(Action<WireMockServer> configure, WireMockServerSettings? settings = null)
+    {
+        _configureAction = Guard.NotNull(configure);
+        _settings = settings;
+    }
+
+    /// <summary>
+    /// Instance accessor for the <see cref="WireMockServer" />
+    /// </summary>
+    public WireMockServer? Instance { get; private set; }
+
+    /// <summary>
+    /// Configures and starts <see cref="WireMockServer"/> instance for use.
+    /// </summary>
+    public void Start()
+    {
+        Instance = _settings != null ? WireMockServer.Start(_settings) : WireMockServer.Start();
+
+        _configureAction.Invoke(Instance);
+    }
+
+    /// <summary>
+    /// Stops the <see cref="WireMockServer"/>
+    /// </summary>
+    public void Stop()
+    {
+        Instance?.Stop();
+    }
+}