Fixed bug where multiple calls to FindComponents with the same parent… (#205)

* Fixed bug where multiple calls to FindComponents with the same parent and input would fail

* Automated dotnet-format update

Co-authored-by: Github Actions <[email protected]>

Author: egil

src/bunit.core/Rendering/TestRenderer.cs

@@ -186,10 +186,6 @@ private IReadOnlyList<IRenderedComponentBase<TComponent>> FindComponents<TCompon
 			lock (_renderTreeAccessLock)
 			{
 				FindComponentsInternal(parentComponent.ComponentId);
-				foreach (var rc in result)
-				{
-					_renderedComponents.Add(rc.ComponentId, rc);
-				}
 			}
 
 			return result;
@@ -205,10 +201,7 @@ void FindComponentsInternal(int componentId)
 					{
 						if (frame.Component is TComponent component)
 						{
-							var id = frame.ComponentId;
-							LoadRenderTreeFrames(id, framesCollection);
-							var rc = _activator.CreateRenderedComponent(id, component, framesCollection);
-							result.Add(rc);
+							GetOrCreateRenderedComponent(frame.ComponentId, component);
 
 							if (result.Count == resultLimit)
 								return;
@@ -221,6 +214,24 @@ void FindComponentsInternal(int componentId)
 					}
 				}
 			}
+
+			void GetOrCreateRenderedComponent(int componentId, TComponent component)
+			{
+				IRenderedComponentBase<TComponent> rc;
+
+				if (_renderedComponents.TryGetValue(componentId, out var rf))
+				{
+					rc = (IRenderedComponentBase<TComponent>)rf;
+				}
+				else
+				{
+					LoadRenderTreeFrames(componentId, framesCollection);
+					rc = _activator.CreateRenderedComponent(componentId, component, framesCollection);
+					_renderedComponents.Add(rc.ComponentId, rc);
+				}
+
+				result.Add(rc);
+			}
 		}
 
 		/// <summary>

tests/bunit.core.tests/Rendering/TestRendererTest.cs

@@ -234,6 +234,21 @@ public void Test022()
 			Should.Throw<ComponentNotFoundException>(() => sut.FindComponent<HasParams>(cut));
 		}
 
+		[Fact(DisplayName = "FindComponent returns same rendered component when called multiple times")]
+		public void Test023()
+		{
+			var sut = Services.GetRequiredService<ITestRenderer>();
+
+			var cut = sut.RenderComponent<HasParams>(
+				ChildContent<HasParams>()
+			);
+
+			var child1 = sut.FindComponent<HasParams>(cut);
+			var child2 = sut.FindComponent<HasParams>(cut);
+
+			child1.ShouldBe(child2);
+		}
+
 		[Fact(DisplayName = "FindComponents returns all components nested inside another rendered component")]
 		public void Test030()
 		{
@@ -275,6 +290,25 @@ public void Test031()
 			Should.Throw<ArgumentNullException>(() => sut.FindComponents<HasParams>(null!));
 		}
 
+		[Fact(DisplayName = "FindComponents returns same rendered components when called multiple times")]
+		public void Test032()
+		{
+			// arrange
+			var sut = Services.GetRequiredService<ITestRenderer>();
+			var cut = sut.RenderComponent<HasParams>(
+				ChildContent<HasParams>(
+					ChildContent<HasParams>()
+				)
+			);
+
+			// act
+			var childCuts1 = sut.FindComponents<HasParams>(cut);
+			var childCuts2 = sut.FindComponents<HasParams>(cut);
+
+			// assert
+			childCuts1.ShouldBe(childCuts2);
+		}
+
 		[Fact(DisplayName = "Retrieved rendered child component with FindComponent gets updated on re-render")]
 		public async Task Test040()
 		{