Fix hot reload routing issue by validating route templates in EndpointHtmlRenderer

src/Components/Endpoints/src/Rendering/EndpointHtmlRenderer.cs

@@ -135,7 +135,13 @@ internal async Task InitializeStandardComponentServicesAsync(
             routingStateProvider.RouteData = new RouteData(componentType, httpContext.GetRouteData().Values);
             if (httpContext.GetEndpoint() is RouteEndpoint routeEndpoint)
             {
-                routingStateProvider.RouteData.Template = routeEndpoint.RoutePattern.RawText;
+                // Verify that the endpoint route pattern matches the current component's route attributes
+                // to prevent stale route data during hot reload scenarios
+                if (IsValidRouteTemplateForComponent(componentType, routeEndpoint.RoutePattern.RawText))
+                {
+                    routingStateProvider.RouteData.Template = routeEndpoint.RoutePattern.RawText;
+                }
+                // If template doesn't match, leave Template as null to force normal routing
             }
         }
     }
@@ -253,6 +259,29 @@ private static string GetContextBaseUri(HttpRequest request)
         return result.EndsWith('/') ? result : result += "/";
     }
 
+    private static bool IsValidRouteTemplateForComponent(Type componentType, string? routeTemplate)
+    {
+        // If route template is null or empty, it's not valid
+        if (string.IsNullOrEmpty(routeTemplate))
+        {
+            return false;
+        }
+
+        // Get the current route attributes from the component type
+        var routeAttributes = componentType.GetCustomAttributes(typeof(RouteAttribute), inherit: false);
+
+        // Check if the endpoint's route template matches any of the component's current route attributes
+        foreach (RouteAttribute attribute in routeAttributes)
+        {
+            if (string.Equals(attribute.Template, routeTemplate, StringComparison.OrdinalIgnoreCase))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     private sealed class FormCollectionReadOnlyDictionary : IReadOnlyDictionary<string, StringValues>
     {
         private readonly IFormCollection _form;