Ensure only event handler names are included in error message as options for other events that can be triggered

Author: egil

src/bunit.web/EventDispatchExtensions/MissingEventHandlerException.cs

@@ -19,9 +19,8 @@ public MissingEventHandlerException(IElement element, string missingEventName) :
 		private static string CreateErrorMessage(IElement element, string missingEventName)
 		{
 			var result = $"The element does not have an event handler for the event '{missingEventName}'";
-			// TODO: This should also filter out the other non-eventHandler attributes like stoProporgation
 			var eventHandlers = element.Attributes?
-				.Where(x => x.Name.StartsWith(Htmlizer.BLAZOR_ATTR_PREFIX, StringComparison.Ordinal) && !x.Name.StartsWith(Htmlizer.ELEMENT_REFERENCE_ATTR_NAME, StringComparison.Ordinal))
+				.Where(x => x.Name.StartsWith(Htmlizer.BLAZOR_ATTR_PREFIX + "on", StringComparison.Ordinal))
 				.Select(x => $"'{x.Name.Remove(0, Htmlizer.BLAZOR_ATTR_PREFIX.Length)}'")
 				.ToArray() ?? Array.Empty<string>();