tests: migrate integration tests to TUnit.AspNetCore WebApplicationTest

Directory.Packages.props

@@ -23,6 +23,7 @@
     <PackageVersion Include="Azure.Identity" Version="1.21.0" />
     <PackageVersion Include="Azure.Monitor.OpenTelemetry.AspNetCore" Version="1.5.0" />
     <PackageVersion Include="TUnit" Version="1.40.5" />
+    <PackageVersion Include="TUnit.AspNetCore" Version="1.40.5" />
     <PackageVersion Include="EssentialCSharp.Shared.Models" Version="$(ToolingPackagesVersion)" />
     <PackageVersion Include="HtmlAgilityPack" Version="1.12.4" />
     <PackageVersion Include="IntelliTect.Multitool" Version="2.1.0" />

EssentialCSharp.Web.Tests/ContentRateLimitingTests.cs

@@ -1,24 +1,18 @@
 using System.Net;
-using Microsoft.AspNetCore.Mvc.Testing;
 
 namespace EssentialCSharp.Web.Tests;
 
 /// <summary>
 /// HTTP integration tests for the "content" rate limit policy.
-/// Uses its own factory (PerClass) to get a fresh in-memory rate limiter for each run.
+/// Each test gets its own factory (fresh IHost) so the rate limiter starts from a clean state.
 /// Anonymous users are limited to 10 requests per minute on chapter content pages.
 /// </summary>
-[ClassDataSource<WebApplicationFactory>(Shared = SharedType.PerClass)]
-public class ContentRateLimitingTests(WebApplicationFactory factory)
+public class ContentRateLimitingTests : IntegrationTestBase
 {
     [Test]
     public async Task ContentEndpoint_ExceedingPerMinuteLimit_Returns429()
     {
-        // AllowAutoRedirect = false prevents redirect-following from consuming extra permits.
-        HttpClient client = factory.CreateClient(new WebApplicationFactoryClientOptions
-        {
-            AllowAutoRedirect = false
-        });
+        using HttpClient client = CreateClientWithoutAutoRedirect();
 
         // Anonymous limit is 10/min. First 10 requests should not be rate-limited.
         for (int i = 0; i < 10; i++)

EssentialCSharp.Web.Tests/EssentialCSharp.Web.Tests.csproj

@@ -13,6 +13,7 @@
     <PackageReference Include="Moq" />
     <PackageReference Include="Moq.AutoMock" />
     <PackageReference Include="TUnit" />
+    <PackageReference Include="TUnit.AspNetCore" />
     <PackageReference Include="Newtonsoft.Json" />
   </ItemGroup>
 

EssentialCSharp.Web.Tests/FunctionalTests.cs

@@ -2,9 +2,7 @@
 
 namespace EssentialCSharp.Web.Tests;
 
-[NotInParallel("FunctionalTests")]
-[ClassDataSource<WebApplicationFactory>(Shared = SharedType.PerClass)]
-public class FunctionalTests(WebApplicationFactory factory)
+public class FunctionalTests : IntegrationTestBase
 {
     [Test]
     [Arguments("/")]
@@ -15,8 +13,8 @@ public class FunctionalTests(WebApplicationFactory factory)
     [Arguments("/alive")]
     public async Task WhenTheApplicationStarts_ItCanLoadLoadPages(string relativeUrl)
     {
-        HttpClient client = factory.CreateClient();
-        using HttpResponseMessage response = await client.GetAsync(relativeUrl);
+        using HttpClient client = CreateClientWithoutAutoRedirect();
+        using HttpResponseMessage response = await GetFollowingGetRedirectsAsync(client, relativeUrl);
 
         await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.OK);
     }
@@ -31,8 +29,8 @@ public async Task WhenTheApplicationStarts_ItCanLoadLoadPages(string relativeUrl
     [Arguments("/about?someOtherParam=value")]
     public async Task WhenPagesAreAccessed_TheyReturnHtml(string relativeUrl)
     {
-        HttpClient client = factory.CreateClient();
-        using HttpResponseMessage response = await client.GetAsync(relativeUrl);
+        using HttpClient client = CreateClientWithoutAutoRedirect();
+        using HttpResponseMessage response = await GetFollowingGetRedirectsAsync(client, relativeUrl);
 
         await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.OK);
 
@@ -47,9 +45,9 @@ public async Task WhenPagesAreAccessed_TheyReturnHtml(string relativeUrl)
     [Test]
     public async Task WhenTheApplicationStarts_NonExistingPage_GivesCorrectStatusCode()
     {
-        HttpClient client = factory.CreateClient();
-        using HttpResponseMessage response = await client.GetAsync("/non-existing-page1234");
+        using HttpClient client = CreateClientWithoutAutoRedirect();
+        using HttpResponseMessage response = await GetFollowingGetRedirectsAsync(client, "/non-existing-page1234");
 
         await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.NotFound);
     }
-}
+}

EssentialCSharp.Web.Tests/IntegrationTestBase.cs

@@ -0,0 +1,84 @@
+using System.Net;
+using Microsoft.AspNetCore.Mvc.Testing;
+using Microsoft.Extensions.DependencyInjection;
+using TUnit.AspNetCore;
+
+namespace EssentialCSharp.Web.Tests;
+
+public abstract class IntegrationTestBase : WebApplicationTest<WebApplicationFactory, Program>
+{
+    /// <summary>
+    /// Creates an <see cref="HttpClient"/> with <c>AllowAutoRedirect = false</c> so callers can
+    /// assert exact redirect status codes and <c>Location</c> headers without the client
+    /// silently following them.
+    /// </summary>
+    protected HttpClient CreateClientWithoutAutoRedirect() =>
+        Factory.Inner.CreateClient(new WebApplicationFactoryClientOptions { AllowAutoRedirect = false });
+
+    /// <summary>
+    /// Executes an initial GET and follows redirect responses with subsequent GET requests.
+    /// This helper is intentionally GET-only.
+    /// </summary>
+    protected static async Task<HttpResponseMessage> GetFollowingGetRedirectsAsync(
+        HttpClient client,
+        string relativeUrl,
+        int maxRedirects = 10)
+    {
+        HttpResponseMessage response = await client.GetAsync(relativeUrl);
+
+        for (int redirectCount = 0;
+             redirectCount < maxRedirects && IsRedirectStatusCode(response.StatusCode);
+             redirectCount++)
+        {
+            Uri? location = response.Headers.Location;
+            if (location is null)
+            {
+                return response;
+            }
+
+            response.Dispose();
+
+            response = await client.GetAsync(location);
+        }
+
+        if (IsRedirectStatusCode(response.StatusCode))
+        {
+            response.Dispose();
+            throw new InvalidOperationException(
+                $"Exceeded redirect limit ({maxRedirects}) for '{relativeUrl}'. Last status: {(int)response.StatusCode} {response.StatusCode}.");
+        }
+
+        return response;
+    }
+
+    private static bool IsRedirectStatusCode(HttpStatusCode statusCode) =>
+        statusCode == HttpStatusCode.Moved ||
+        statusCode == HttpStatusCode.Found ||
+        statusCode == HttpStatusCode.RedirectMethod ||
+        statusCode == HttpStatusCode.TemporaryRedirect ||
+        statusCode == HttpStatusCode.PermanentRedirect;
+
+    protected T InServiceScope<T>(Func<IServiceProvider, T> action)
+    {
+        using IServiceScope scope = Factory.Services.GetRequiredService<IServiceScopeFactory>().CreateScope();
+        return action(scope.ServiceProvider);
+    }
+
+    protected void InServiceScope(Action<IServiceProvider> action)
+    {
+        using IServiceScope scope = Factory.Services.GetRequiredService<IServiceScopeFactory>().CreateScope();
+        action(scope.ServiceProvider);
+    }
+
+    protected async Task<T> InServiceScopeAsync<T>(Func<IServiceProvider, Task<T>> action)
+    {
+        using IServiceScope scope = Factory.Services.GetRequiredService<IServiceScopeFactory>().CreateScope();
+        return await action(scope.ServiceProvider);
+    }
+
+    protected async Task InServiceScopeAsync(Func<IServiceProvider, Task> action)
+    {
+        using IServiceScope scope = Factory.Services.GetRequiredService<IServiceScopeFactory>().CreateScope();
+        await action(scope.ServiceProvider);
+    }
+}

EssentialCSharp.Web.Tests/ListingSourceCodeControllerTests.cs

@@ -4,14 +4,13 @@
 
 namespace EssentialCSharp.Web.Tests;
 
-[ClassDataSource<WebApplicationFactory>(Shared = SharedType.PerClass)]
-public class ListingSourceCodeControllerTests(WebApplicationFactory factory)
+public class ListingSourceCodeControllerTests : IntegrationTestBase
 {
     [Test]
     public async Task GetListing_WithValidChapterAndListing_Returns200WithContent()
     {
         // Arrange
-        HttpClient client = factory.CreateClient();
+        HttpClient client = Factory.CreateClient();
 
         // Act
         using HttpResponseMessage response = await client.GetAsync("/api/ListingSourceCode/chapter/1/listing/1");
@@ -35,7 +34,7 @@ public async Task GetListing_WithValidChapterAndListing_Returns200WithContent()
     public async Task GetListing_WithInvalidChapter_Returns404()
     {
         // Arrange
-        HttpClient client = factory.CreateClient();
+        HttpClient client = Factory.CreateClient();
 
         // Act
         using HttpResponseMessage response = await client.GetAsync("/api/ListingSourceCode/chapter/999/listing/1");
@@ -48,7 +47,7 @@ public async Task GetListing_WithInvalidChapter_Returns404()
     public async Task GetListing_WithInvalidListing_Returns404()
     {
         // Arrange
-        HttpClient client = factory.CreateClient();
+        HttpClient client = Factory.CreateClient();
 
         // Act
         using HttpResponseMessage response = await client.GetAsync("/api/ListingSourceCode/chapter/1/listing/999");
@@ -61,7 +60,7 @@ public async Task GetListing_WithInvalidListing_Returns404()
     public async Task GetListingsByChapter_WithValidChapter_ReturnsMultipleListings()
     {
         // Arrange
-        HttpClient client = factory.CreateClient();
+        HttpClient client = Factory.CreateClient();
 
         // Act
         using HttpResponseMessage response = await client.GetAsync("/api/ListingSourceCode/chapter/1");
@@ -92,7 +91,7 @@ public async Task GetListingsByChapter_WithValidChapter_ReturnsMultipleListings(
     public async Task GetListingsByChapter_WithInvalidChapter_ReturnsEmptyList()
     {
         // Arrange
-        HttpClient client = factory.CreateClient();
+        HttpClient client = Factory.CreateClient();
 
         // Act
         using HttpResponseMessage response = await client.GetAsync("/api/ListingSourceCode/chapter/999");

EssentialCSharp.Web.Tests/McpApiTokenServiceTests.cs

@@ -1,13 +1,10 @@
 using EssentialCSharp.Web.Models;
 using EssentialCSharp.Web.Services;
-using Microsoft.AspNetCore.Mvc.Testing;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace EssentialCSharp.Web.Tests;
 
-[NotInParallel("McpTests")]
-[ClassDataSource<WebApplicationFactory>(Shared = SharedType.PerClass)]
-public class McpApiTokenServiceTests(WebApplicationFactory factory)
+public class McpApiTokenServiceTests : IntegrationTestBase
 {
     private readonly List<IServiceScope> _scopes = [];
 
@@ -21,16 +18,16 @@ public void DisposeScopes()
 
     private async Task<(string UserId, McpApiTokenService TokenService)> ArrangeAsync(string prefix)
     {
-        string userId = await McpTestHelper.CreateUserAsync(factory, prefix);
-        var scope = factory.Services.CreateScope();
+        string userId = await McpTestHelper.CreateUserAsync(Factory, prefix);
+        var scope = Factory.Services.CreateScope();
         _scopes.Add(scope);
         var tokenService = scope.ServiceProvider.GetRequiredService<McpApiTokenService>();
         return (userId, tokenService);
     }
 
     private async Task<McpApiTokenService> FillToLimitAsync(string userId)
     {
-        var scope = factory.Services.CreateScope();
+        var scope = Factory.Services.CreateScope();
         _scopes.Add(scope);
         var tokenService = scope.ServiceProvider.GetRequiredService<McpApiTokenService>();
         for (int i = 0; i < McpApiTokenService.MaxTokensPerUser; i++)