feat: add ConfigureAppHost hook to AspireFixture

TUnit.Aspire/AspireFixture.cs

@@ -5,6 +5,7 @@
 using Aspire.Hosting.ApplicationModel;
 using Aspire.Hosting.Testing;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using TUnit.Core;
 using TUnit.Core.Interfaces;
 
@@ -123,6 +124,16 @@ protected virtual void LogProgress(string message)
     /// </remarks>
     protected virtual string[] Args => [];
 
+    /// <summary>
+    /// Override to configure the <see cref="DistributedApplicationOptions"/> and
+    /// <see cref="Microsoft.Extensions.Hosting.HostApplicationBuilderSettings"/> passed to
+    /// <see cref="DistributedApplicationTestingBuilder.CreateAsync{TEntryPoint}(string[], Action{DistributedApplicationOptions, Microsoft.Extensions.Hosting.HostApplicationBuilderSettings}, CancellationToken)"/>.
+    /// This callback is invoked during builder creation, before <see cref="ConfigureBuilder"/>.
+    /// </summary>
+    /// <param name="options">The distributed application options.</param>
+    /// <param name="settings">The host application builder settings.</param>
+    protected virtual void ConfigureAppHost(DistributedApplicationOptions options, HostApplicationBuilderSettings settings) { }
+
     /// <summary>
     /// Override to customize the builder before building the application.
     /// </summary>
@@ -201,7 +212,7 @@ public virtual async Task InitializeAsync()
         var sw = Stopwatch.StartNew();
 
         LogProgress($"Creating distributed application builder for {typeof(TAppHost).Name}...");
-        var builder = await DistributedApplicationTestingBuilder.CreateAsync<TAppHost>(Args);
+        var builder = await DistributedApplicationTestingBuilder.CreateAsync<TAppHost>(Args, ConfigureAppHost);
         ConfigureBuilder(builder);
         LogProgress($"Builder created in {sw.Elapsed.TotalSeconds:0.0}s");
 

docs/docs/examples/aspire.md

@@ -92,6 +92,7 @@ public class ApiTests(AppFixture fixture)
 │                  FIXTURE LIFECYCLE                                │
 ├──────────────────────────────────────────────────────────────────┤
 │  1. CreateAsync<TAppHost>()    Build the Aspire test builder     │
+│     ↳ ConfigureAppHost()       Configure options & host settings │
 │  2. ConfigureBuilder()         Your customization hook           │
 │  3. BuildAsync()               Build the distributed app         │
 │  4. StartAsync()               Start containers & projects       │
@@ -197,6 +198,7 @@ When a timeout occurs, the error includes:
 | `InitializeAsync()` | Full lifecycle | Override to add post-start logic (migrations, seeding) |
 | `DisposeAsync()` | Stop and dispose app | Override to add custom cleanup |
 | `Args` | Empty | Command-line arguments passed to the AppHost entry point |
+| `ConfigureAppHost(options, settings)` | No-op | Configure `DistributedApplicationOptions` and `HostApplicationBuilderSettings` during builder creation |
 | `ConfigureBuilder(builder)` | No-op | Customize the builder before building |
 | `ResourceTimeout` | 60 seconds | How long to wait for startup and resources |
 | `WaitBehavior` | `AllHealthy` | Which resources to wait for |
@@ -246,8 +248,9 @@ public class AppFixture : AspireFixture<Projects.MyAppHost>
 }
 ```
 
-:::tip When to use `Args` vs `ConfigureBuilder`
+:::tip When to use `Args` vs `ConfigureAppHost` vs `ConfigureBuilder`
 - Use **`Args`** for configuration values that the AppHost reads during `CreateBuilder(args)` — these must be set *before* the builder is created.
+- Use **`ConfigureAppHost`** to configure `DistributedApplicationOptions` (e.g., `DisableDashboard`) and `HostApplicationBuilderSettings` — these are passed to `CreateAsync` during builder creation.
 - Use **`ConfigureBuilder`** for service registrations, HTTP client defaults, and other configuration that can be applied *after* the builder is created.
 :::