fix: Add test for FindComponents with base and derived components

Author: linkdotnet

CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to **bUnit** will be documented in this file. The project ad
 
 - Do not set the `Uri` or `BaseUri` property on the `FakeNavigationManager` if navigation is prevented by a handler on `net7.0` or greater. Reported and fixed by [@ayyron-dev](https://github.com/ayyron-dev) in [#1647](https://github.com/bUnit-dev/bUnit/issues/1647)
 - Use default renderer properties for AngleSharp. Reported by [@jtleaming](https://github.com/jtleaming) in [#1692].
+- `FindComponents` throws an exception, when a base and derived class was searched for. Reported by [@BlueDragon709](https://github.com/BlueDragon709) in [#1691].
 
 ## [1.38.5] - 2025-01-12
 

src/bunit.core/Rendering/TestRenderer.cs

@@ -610,7 +610,13 @@ private IRenderedComponentBase<TComponent> GetOrCreateRenderedComponent<TCompone
 	{
 		if (renderedComponents.TryGetValue(componentId, out var renderedComponent))
 		{
-			return (IRenderedComponentBase<TComponent>)renderedComponent;
+			if (renderedComponent is IRenderedComponentBase<TComponent> typedComponent)
+			{
+				return typedComponent;
+			}
+
+			renderedComponent.Dispose();
+			renderedComponents.Remove(componentId);
 		}
 
 		LoadRenderTreeFrames(componentId, framesCollection);

tests/bunit.web.tests/Rendering/RenderedComponentTest.cs

@@ -69,6 +69,36 @@ public void Test021()
 
 		cut.Instance.JSRuntime.ShouldNotBeNull();
 	}
+	
+	[Fact(DisplayName = "Searching first for derived component and then base component finds correct (#1691)")]
+	public void Test023()
+	{
+		var cut = RenderComponent<Wrapper>(
+			ps => ps.AddChildContent<BaseComponent>()
+				.AddChildContent<DerivedComponent>());
+
+		Should.NotThrow(() =>
+		{
+			cut.FindComponents<BaseComponent>();
+			cut.FindComponents<DerivedComponent>();
+		});
+	}
+
+	private class BaseComponent : ComponentBase
+	{
+		protected override void BuildRenderTree(RenderTreeBuilder builder)
+		{
+			builder.AddContent(0, "base");
+		}
+	}
+
+	private sealed class DerivedComponent : BaseComponent
+	{
+		protected override void BuildRenderTree(RenderTreeBuilder builder)
+		{
+			builder.AddContent(0, "derived");
+		}
+	}
 	#endif
 
 	[Fact(DisplayName = "Using relative units in style attribute can be retrieved")]