From 27a43f76b0ede9020f357e2d713205480ca8ccef Mon Sep 17 00:00:00 2001
From: Steven Giesel <stgiesel35@gmail.com>
Date: Fri, 19 Apr 2024 16:26:51 +0200
Subject: [PATCH] fix: Htmlizer can handle NamedEvents

Fixes #1438
---
 CHANGELOG.md                                       |  2 ++
 src/bunit.web/Rendering/Internal/Htmlizer.cs       |  4 ++++
 .../SampleComponents/FormNameComponent.razor       |  3 +++
 .../Rendering/Internal/HtmlizerTests.cs            | 14 ++++++++++++++
 4 files changed, 23 insertions(+)
 create mode 100644 tests/bunit.testassets/SampleComponents/FormNameComponent.razor

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 77148ffe6..6776b28a6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,8 @@ All notable changes to **bUnit** will be documented in this file. The project ad
 ### Fixed
 
 - bUnit's built-in HTML parser did not correctly parse full HTML documents that included a &lt;!DOCTYPE html&gt; as the first element. Fixed by [@egil](https://github.com/egil).
+- `@formname` directive led to an `InvalidOperationException` when used on a form element. Reported by [@suzu2469](https://github.com/suzu2469) in [#1438](https://github.com/bUnit-dev/bUnit/issues/1438).
+  Fixed by [@egil](https://github.com/egil)/[@linkdotnet](https://github.com/linkdotnet).
 
 ### Changed
 - `NavigationManager` is again registered as a singleton instead of scoped.
diff --git a/src/bunit.web/Rendering/Internal/Htmlizer.cs b/src/bunit.web/Rendering/Internal/Htmlizer.cs
index 9db5e9892..24c42b7c7 100644
--- a/src/bunit.web/Rendering/Internal/Htmlizer.cs
+++ b/src/bunit.web/Rendering/Internal/Htmlizer.cs
@@ -119,6 +119,10 @@ int position
 			case RenderTreeFrameType.ElementReferenceCapture:
 			case RenderTreeFrameType.ComponentReferenceCapture:
 				return position + 1;
+#if NET8_0_OR_GREATER
+			 case RenderTreeFrameType.NamedEvent:
+				return position + 1;
+#endif
 			default:
 				throw new InvalidOperationException(
 					$"Invalid element frame type '{frame.FrameType}'."
diff --git a/tests/bunit.testassets/SampleComponents/FormNameComponent.razor b/tests/bunit.testassets/SampleComponents/FormNameComponent.razor
new file mode 100644
index 000000000..cd3ad3c4a
--- /dev/null
+++ b/tests/bunit.testassets/SampleComponents/FormNameComponent.razor
@@ -0,0 +1,3 @@
+<form method="post" @formname="sample-form">
+	<button type="submit">Submit</button>
+</form>
\ No newline at end of file
diff --git a/tests/bunit.web.tests/Rendering/Internal/HtmlizerTests.cs b/tests/bunit.web.tests/Rendering/Internal/HtmlizerTests.cs
index d626b86a7..ee2519a85 100644
--- a/tests/bunit.web.tests/Rendering/Internal/HtmlizerTests.cs
+++ b/tests/bunit.web.tests/Rendering/Internal/HtmlizerTests.cs
@@ -39,7 +39,21 @@ public void Test003()
 
 		cut.Find("button").HasAttribute("blazor:elementreference").ShouldBeTrue();
 	}
+	
+#if NET8_0_OR_GREATER
+	[Fact(DisplayName = "Htmlizer ignores NamedEvents")]
+	public void Test004()
+	{
+		var cut = RenderComponent<FormNameComponent>();
 
+		cut.MarkupMatches("""
+		                  <form method="post">
+		                    <button type="submit">Submit</button>
+		                  </form>
+		                  """);
+	}
+#endif
+	
 	private sealed class Htmlizer01Component : ComponentBase
 	{
 		public ElementReference ButtomElmRef { get; set; }