Docs: last bits of passing parameters

Author: egil

docs/samples/components/Wrapper.razor

@@ -0,0 +1,7 @@
+@ChildContent
+
+@code
+{
+  [Parameter]
+  public RenderFragment ChildContent { get; set; }
+}

docs/samples/tests/razor/NestedComponentTest.razor

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+@inherits TestComponentBase
+
+<Fixture Test="HelloWorldTest">
+  <ComponentUnderTest>
+    <Wrapper>
+      <HelloWorld />
+    </Wrapper>
+  </ComponentUnderTest>
+
+  @code
+  {
+    void HelloWorldTest(Fixture fixture)
+    {
+      var cut = fixture.GetComponentUnderTest<HelloWorld>();
+    }
+  }
+</Fixture>

docs/samples/tests/xunit/NestedComponentTest.cs

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+using Xunit;
+using Bunit;
+using System.Collections.Generic;
+using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components.Web;
+
+using static Bunit.ComponentParameterFactory;
+
+namespace Bunit.Docs.Samples
+{
+  public class NestedComponentTest
+  {
+    [Fact]
+    public void NestedComponent()
+    {
+      using var ctx = new TestContext();
+
+      // Using C# factory methods
+      var wrapper1 = ctx.RenderComponent<Wrapper>(
+        ChildContent<HelloWorld>()
+      );
+      var cut1 = wrapper1.FindComponent<HelloWorld>();
+
+      // Using parameter builder
+      var wrapper2 = ctx.RenderComponent<Wrapper>(parameters => parameters
+        .AddChildContent<HelloWorld>()
+      );
+      var cut2 = wrapper2.FindComponent<HelloWorld>();
+    }
+  }
+}