@formname attribute always causes an error: System.InvalidOperationException : Invalid element frame type 'NamedEvent'

[suzu2469]

Describe the bug
I get an error when trying to test a component that contains a form with the @formname attribute
If I remove the @formname attribute, the error no longer occurs.
Here is a simple, reproducible repository
https://github.com/suzu2469/bunit-sample-tests

Example:
Testing this component: TestProduct.razor

<h1>Sample</h1>

<form method="post" @formname="sample-form">
	<button type="submit">Submit</button>
</form>

With this test:

@inherits TestContext

@code {
	[Fact]
	public void TestProductSampleTest() {
		var cut = RenderComponent<TestProduct>();

		Assert.NotNull(cut.Instance);
	}
}

Results in this output:

[xUnit.net 00:00:00.25]     SampleApp.TestProductTests.TestProductSampleTest [FAIL]
  失敗 SampleApp.TestProductTests.TestProductSampleTest [168 ms]
  エラー メッセージ:
   System.InvalidOperationException : Invalid element frame type 'NamedEvent'.
  スタック トレース:
     at Bunit.Htmlizer.RenderCore(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 123
   at Bunit.Htmlizer.RenderFrames(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position, Int32 maxElements) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 82
   at Bunit.Htmlizer.RenderChildren(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position, Int32 maxElements) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 236
   at Bunit.Htmlizer.RenderElement(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 190
   at Bunit.Htmlizer.RenderCore(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 104
   at Bunit.Htmlizer.RenderFrames(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position, Int32 maxElements) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 82
   at Bunit.Htmlizer.RenderChildComponent(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 137
   at Bunit.Htmlizer.RenderCore(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 116
   at Bunit.Htmlizer.RenderFrames(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position, Int32 maxElements) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 82
   at Bunit.Htmlizer.RenderChildComponent(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 137
   at Bunit.Htmlizer.RenderCore(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 116
   at Bunit.Htmlizer.RenderFrames(HtmlRenderingContext context, ReadOnlySpan`1 frames, Int32 position, Int32 maxElements) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 82
   at Bunit.Htmlizer.GetHtml(Int32 componentId, RenderTreeFrameDictionary framesCollection) in /_/src/bunit.web/Rendering/Internal/Htmlizer.cs:line 62
   at Bunit.Rendering.RenderedFragment.UpdateMarkup(RenderTreeFrameDictionary framesCollection) in /_/src/bunit.web/Rendering/RenderedFragment.cs:line 164
   at Bunit.Rendering.RenderedFragment.Bunit.IRenderedFragmentBase.OnRender(RenderEvent renderEvent) in /_/src/bunit.web/Rendering/RenderedFragment.cs:line 142
   at Bunit.Rendering.TestRenderer.ApplyRenderEvent(RenderEvent renderEvent) in /_/src/bunit.core/Rendering/TestRenderer.cs:line 401
   at Bunit.Rendering.TestRenderer.UpdateDisplayAsync(RenderBatch& renderBatch) in /_/src/bunit.core/Rendering/TestRenderer.cs:line 309
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()
--- End of stack trace from previous location ---
   at Bunit.Rendering.TestRenderer.AssertNoUnhandledExceptions() in /_/src/bunit.core/Rendering/TestRenderer.cs:line 629
   at Bunit.Rendering.TestRenderer.Render[TResult](RenderFragment renderFragment, Func`2 activator) in /_/src/bunit.core/Rendering/TestRenderer.cs:line 480
   at Bunit.Rendering.TestRenderer.RenderFragment(RenderFragment renderFragment) in /_/src/bunit.core/Rendering/TestRenderer.cs:line 101
   at Bunit.Extensions.TestContextBaseRenderExtensions.RenderInsideRenderTree(TestContextBase testContext, RenderFragment renderFragment) in /_/src/bunit.core/Extensions/TestContextBaseRenderExtensions.cs:line 43
   at Bunit.Extensions.TestContextBaseRenderExtensions.RenderInsideRenderTree[TComponent](TestContextBase testContext, RenderFragment renderFragment) in /_/src/bunit.core/Extensions/TestContextBaseRenderExtensions.cs:line 23
   at Bunit.TestContext.Render[TComponent](RenderFragment renderFragment) in /_/src/bunit.web/TestContext.cs:line 68
   at Bunit.TestContext.RenderComponent[TComponent](Action`1 parameterBuilder) in /_/src/bunit.web/TestContext.cs:line 54
   at SampleApp.TestProductTests.TestProductSampleTest() in /Users/souma_suzuki/Desktop/SampleApp/TestProductTests.razor:line 6
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)

失敗!   -失敗:     1、合格:     0、スキップ:     0、合計:     1、期間: < 1 ms - SampleApp.dll (net8.0)

Expected behavior:

The test succeeds without error.

Version info:

• bUnit version: 1.27.17
• .NET Runtime and Blazor version: 8.0.203
• OS type and version: MacOS 13.2.1（22D68）

Additional context:

I did a dotnet test immediately after starting a new Codespaces with the above repositories and the results were the same

[kato1628]

I had the same issue in my environment.

[egil]

Hey, thanks for reporting this. We will take a look ASAP.