feat: Easier handling of triggering stub events

CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to **bUnit** will be documented in this file. The project ad
 
 - `net8.0` support
 - Increased timeout of `WaitForAssertion` to infinite when a debugger is attached. By [@linkdotnet](https://github.com/linkdotnet).
+- Easier overloads for Stub's to invoke `EventCallback`s
 
 ### Fixed
 

src/bunit.web/Extensions/RenderedComponentStubExtensions.cs

@@ -0,0 +1,36 @@
+#if NET5_0_OR_GREATER
+using System.Linq.Expressions;
+using Bunit.TestDoubles;
+
+namespace Bunit;
+
+/// <summary>
+/// Extension methods for using component doubles.
+/// </summary>
+public static class RenderedComponentStubExtensions
+{
+ /// <summary>
+ /// Invokes the event callback from the stub.
+ /// </summary>
+ public static Task InvokeEventCallback<TComponent>(this IRenderedComponent<Stub<TComponent>> component,
+ Expression<Func<TComponent, EventCallback>> selector) where TComponent : IComponent
+ {
+ if (component is null)
+ throw new ArgumentNullException(nameof(component));
+
+ return component.Instance.InvokeEventCallback(selector);
+ }
+
+ /// <summary>
+ /// Invokes the event callback from the stub.
+ /// </summary>
+ public static Task InvokeEventCallback<TComponent, TU>(this IRenderedComponent<Stub<TComponent>> component,
+ Expression<Func<TComponent, EventCallback<TU>>> selector, TU value) where TComponent : IComponent
+ {
+ if (component is null)
+ throw new ArgumentNullException(nameof(component));
+
+ return component.Instance.InvokeEventCallback(selector, value);
+ }
+}
+#endif

src/bunit.web/Extensions/RenderedFragmentExtensions.cs

@@ -1,5 +1,7 @@
+using System.Linq.Expressions;
 using AngleSharp.Dom;
 using Bunit.Rendering;
+using Bunit.TestDoubles;
 
 namespace Bunit;
 

src/bunit.web/TestDoubles/Components/ComponentDoubleBase{TComponent}.cs

@@ -15,6 +15,11 @@ public abstract class ComponentDoubleBase<TComponent> : IComponent
  /// </summary>
  protected static readonly Type DoubledType = typeof(TComponent);
 
+ /// <summary>
+ /// Invokes the given <see cref="Func{TResult}"/> in the context of the associated <see cref="Renderer"/>.
+ /// </summary>
+ protected Task InvokeAsync(Func<Task> workItem) => renderHandle.Dispatcher.InvokeAsync(workItem);
+
  /// <summary>
  /// Gets the parameters that was passed to the <typeparamref name="TComponent"/>
  /// that this stub replaced in the component tree.

src/bunit.web/TestDoubles/Components/Stub{TComponent}.cs

@@ -1,5 +1,6 @@
 #if NET5_0_OR_GREATER
 using System.Diagnostics;
+using System.Linq.Expressions;
 
 namespace Bunit.TestDoubles;
 
@@ -33,6 +34,26 @@ public Stub(object? replacement)
  throw new ArgumentException($"The type of replacement is not supported. Replacement type = {replacement.GetType()}", nameof(replacement));
  }
 
+ /// <summary>
+ /// Triggers an event callback from the stub.
+ /// </summary>
+ /// <param name="selector">Event to trigger.</param>
+ public Task InvokeEventCallback(Expression<Func<TComponent, EventCallback>> selector)
+ {
+ var callback = Parameters.Get(selector);
+ return InvokeAsync(callback.InvokeAsync);
+ }
+
+ /// <summary>
+ /// Triggers an event callback from the stub.
+ /// </summary>
+ /// <param name="selector">Event to trigger.</param>
+ public Task InvokeEventCallback<TU>(Expression<Func<TComponent, EventCallback<TU>>> selector, TU? value)
+ {
+ var callback = Parameters.Get(selector);
+ return InvokeAsync(() => callback.InvokeAsync(value));
+ }
+
  /// <inheritdoc/>
  public override string ToString() => $"Stub<{DoubledType.Name}>";
 

tests/bunit.testassets/SampleComponents/DisposeComponents/DisplayInput.razor

@@ -0,0 +1,5 @@
+<p>User wrote: @value</p>
+<InputText @bind-Value="value" />
+@code {
+ private string value;
+}

tests/bunit.web.tests/TestDoubles/Components/StubTest.cs

@@ -1,3 +1,6 @@
+using Bunit.TestAssets.SampleComponents.DisposeComponents;
+using Microsoft.AspNetCore.Components.Forms;
+
 #if NET5_0_OR_GREATER
 namespace Bunit.TestDoubles.Components;
 
@@ -26,5 +29,17 @@ public void Test002(string header, string attrValue)
  ps => ps.ShouldContain(x => x.Key == nameof(Simple1.AttrValue) && attrValue.Equals(x.Value)),
  ps => ps.Count.ShouldBe(2));
  }
+
+ [Fact(DisplayName = "Stub<TComponent> can invoke event callbacks")]
+ public async Task Test003()
+ {
+ ComponentFactories.AddStub<InputText>();
+ var cut = RenderComponent<DisplayInput>();
+ var stubbedInput = cut.FindComponent<Stub<InputText>>();
+
+ await stubbedInput.InvokeEventCallback(t => t.ValueChanged, "Hello World");
+
+ cut.Find("p").MarkupMatches("<p>User wrote: Hello World</p>");
+ }
 }
 #endif