fix: Use NullDispatchTestRenderer for detached rendering

CHANGELOG.md

@@ -13,6 +13,7 @@ All notable changes to **bUnit** will be documented in this file. The project ad
 ### Changed
 
 - Change all bUnit services registration from singleton to scoped. By [@egil](https://github.com/egil). Closes https://github.com/bUnit-dev/bUnit/issues/1138.
+- `MarkupMatches` is using own detached renderer. By [@linkdotnet](https://github.com/linkdotnet). Closes https://github.com/bUnit-dev/bUnit/issues/1143.
 
 ## [1.21.9] - 2023-07-02
 

src/bunit.web/Asserting/MarkupMatchesAssertExtensions.cs

@@ -3,7 +3,6 @@
 using Bunit.Diffing;
 using Bunit.Extensions;
 using Bunit.Rendering;
-
 namespace Bunit;
 
 /// <summary>
@@ -299,8 +298,8 @@ public static void MarkupMatches(this IRenderedFragment actual, RenderFragment e
  if (expected is null)
  throw new ArgumentNullException(nameof(expected));
 
- var testContext = actual.Services.GetRequiredService<TestContextBase>();
- var renderedFragment = (IRenderedFragment)testContext.RenderInsideRenderTree(expected);
+ var detachedRenderer = actual.Services.GetRequiredService<NullDispatcherTestRenderer>();
+ var renderedFragment = (IRenderedFragment)detachedRenderer.RenderFragment(expected);
  MarkupMatches(actual, renderedFragment, userMessage);
  }
 

src/bunit.web/Extensions/TestServiceProviderExtensions.cs

@@ -48,6 +48,7 @@ public static IServiceCollection AddDefaultTestContextServices(this IServiceColl
  // bUnit specific services
  services.AddScoped<TestContextBase>(_ => testContext);
  services.AddScoped<WebTestRenderer>();
+ services.AddTransient<NullDispatcherTestRenderer>();
  services.AddScoped<TestRenderer>(s => s.GetRequiredService<WebTestRenderer>());
  services.AddScoped<Renderer>(s => s.GetRequiredService<WebTestRenderer>());
  services.AddScoped<ITestRenderer>(s => s.GetRequiredService<WebTestRenderer>());

src/bunit.web/Rendering/Internal/NullDispatcher.cs

@@ -0,0 +1,50 @@
+namespace Bunit.Rendering;
+
+/// <summary>
+/// A dispatcher that directly invokes the work item on the current thread.
+/// </summary>
+internal sealed class NullDispatcher : Dispatcher
+{
+ public override bool CheckAccess() => true;
+
+ public override Task InvokeAsync(Action workItem)
+ {
+ if (workItem is null)
+ {
+ throw new ArgumentNullException(nameof(workItem));
+ }
+
+ workItem();
+ return Task.CompletedTask;
+ }
+
+ public override Task InvokeAsync(Func<Task> workItem)
+ {
+ if (workItem is null)
+ {
+ throw new ArgumentNullException(nameof(workItem));
+ }
+
+ return workItem();
+ }
+
+ public override Task<TResult> InvokeAsync<TResult>(Func<TResult> workItem)
+ {
+ if (workItem is null)
+ {
+ throw new ArgumentNullException(nameof(workItem));
+ }
+
+ return Task.FromResult(workItem());
+ }
+
+ public override Task<TResult> InvokeAsync<TResult>(Func<Task<TResult>> workItem)
+ {
+ if (workItem is null)
+ {
+ throw new ArgumentNullException(nameof(workItem));
+ }
+
+ return workItem();
+ }
+}

src/bunit.web/Rendering/Internal/NullDispatcherTestRenderer.cs

@@ -0,0 +1,23 @@
+using Microsoft.Extensions.Logging;
+
+namespace Bunit.Rendering;
+
+/// <summary>
+/// A renderer that uses a <see cref="NullDispatcher"/> to invoke work items.
+/// </summary>
+internal sealed class NullDispatcherTestRenderer : TestRenderer
+{
+ public override Dispatcher Dispatcher { get; } = new NullDispatcher();
+
+ public NullDispatcherTestRenderer(IRenderedComponentActivator renderedComponentActivator, TestServiceProvider services, ILoggerFactory loggerFactory)
+ : base(renderedComponentActivator, services, loggerFactory)
+ {
+ }
+
+#if NET5_0_OR_GREATER
+ public NullDispatcherTestRenderer(IRenderedComponentActivator renderedComponentActivator, TestServiceProvider services, ILoggerFactory loggerFactory, IComponentActivator componentActivator)
+ : base(renderedComponentActivator, services, loggerFactory, componentActivator)
+ {
+ }
+#endif
+}

src/bunit.web/Rendering/WebTestRenderer.cs

@@ -7,34 +7,33 @@
 using Microsoft.JSInterop;
 #endif
 
-namespace Bunit.Rendering
+namespace Bunit.Rendering;
+
+/// <summary>
+/// Represents a <see cref="ITestRenderer"/> that is used when rendering
+/// Blazor components for the web.
+/// </summary>
+public class WebTestRenderer : TestRenderer
 {
  /// <summary>
- /// Represents a <see cref="ITestRenderer"/> that is used when rendering
- /// Blazor components for the web.
+ /// Initializes a new instance of the <see cref="WebTestRenderer"/> class.
  /// </summary>
- public class WebTestRenderer : TestRenderer
+ public WebTestRenderer(IRenderedComponentActivator renderedComponentActivator, TestServiceProvider services, ILoggerFactory loggerFactory)
+ : base(renderedComponentActivator, services, loggerFactory)
  {
- /// <summary>
- /// Initializes a new instance of the <see cref="WebTestRenderer"/> class.
- /// </summary>
- public WebTestRenderer(IRenderedComponentActivator renderedComponentActivator, TestServiceProvider services, ILoggerFactory loggerFactory)
- : base(renderedComponentActivator, services, loggerFactory)
- {
 #if NET5_0_OR_GREATER
-  ElementReferenceContext = new WebElementReferenceContext(services.GetRequiredService<IJSRuntime>());
+ ElementReferenceContext = new WebElementReferenceContext(services.GetRequiredService<IJSRuntime>());
 #endif
-  }
+ }
 
 #if NET5_0_OR_GREATER
- /// <summary>
- /// Initializes a new instance of the <see cref="WebTestRenderer"/> class.
- /// </summary>
- public WebTestRenderer(IRenderedComponentActivator renderedComponentActivator, TestServiceProvider services, ILoggerFactory loggerFactory, IComponentActivator componentActivator)
- : base(renderedComponentActivator, services, loggerFactory, componentActivator)
- {
- ElementReferenceContext = new WebElementReferenceContext(services.GetRequiredService<IJSRuntime>());
- }
-#endif
+ /// <summary>
+ /// Initializes a new instance of the <see cref="WebTestRenderer"/> class.
+ /// </summary>
+ public WebTestRenderer(IRenderedComponentActivator renderedComponentActivator, TestServiceProvider services, ILoggerFactory loggerFactory, IComponentActivator componentActivator)
+ : base(renderedComponentActivator, services, loggerFactory, componentActivator)
+ {
+ ElementReferenceContext = new WebElementReferenceContext(services.GetRequiredService<IJSRuntime>());
  }
-}
+#endif
+}

tests/bunit.testassets/SampleComponents/InvokeAsyncInsideContinueWith.razor

@@ -0,0 +1,35 @@
+@if (Task != null)
+{
+ @if (Task.IsCompleted)
+ {
+ <span>done</span>
+ }
+ else
+ {
+ <span>waiting</span>
+ }
+}
+@code {
+ [Parameter] public Task? Task { get; set; }
+
+ private Task? registeredTask;
+
+ protected override void OnParametersSet()
+ {
+ var task = Task;
+ if (task != registeredTask)
+ {
+ registeredTask = task;
+
+ _ = task?.ContinueWith((t, o) =>
+ {
+ if (t == Task)
+ {
+ _ = InvokeAsync(StateHasChanged);
+ }
+ }, null);
+ }
+
+ base.OnParametersSet();
+ }
+}

tests/bunit.web.tests/Asserting/MarkupMatchesTests.razor

@@ -0,0 +1,20 @@
+@using Bunit.TestAssets.SampleComponents
+@inherits TestContext
+
+@code {
+#if NET5_0_OR_GREATER
+ [Fact]
+ public void MarkupMatchesShouldNotBeBlockedByRenderer()
+ {
+ var tcs = new TaskCompletionSource();
+
+ var cut = Render(@<InvokeAsyncInsideContinueWith Task="@tcs.Task"/>);
+
+ cut.MarkupMatches(@<span>waiting</span>);
+
+ tcs.SetCanceled();
+
+ cut.WaitForAssertion(() => cut.MarkupMatches(@<span>done</span>));
+ }
+#endif
+}