Add specific test case reproducing exact GitHub issue #61341 scenario

Co-authored-by: javiercn <[email protected]>

Author: Copilot

src/Components/Endpoints/test/HttpContextFormValueMapperTest.cs

@@ -100,6 +100,57 @@ public void Map_DoesNotDeserializeWhenCanMapReturnsFalse()
         // Before the fix, this might have been a MyModel instance due to deserializer running
         Assert.Null(context.Result);
     }
+
+    [Fact]
+    public void SupplyParameterFromForm_WithRecursiveModel_ExactGitHubIssueScenario()
+    {
+        // Arrange - Reproduce the EXACT scenario from GitHub issue #61341
+        var formData = new Dictionary<string, StringValues>()
+        {
+            ["Name"] = "Test Name"
+            // Note: No data for Parent property, but it should still bind the Name
+        };
+
+        var httpContext = new DefaultHttpContext();
+        httpContext.Request.Method = "POST";
+        httpContext.Request.ContentType = "application/x-www-form-urlencoded";
+        
+        // Set up form data provider to simulate the exact scenario
+        var formDataProvider = new HttpContextFormDataProvider();
+        formDataProvider.SetFormData("RequestForm", formData, new FormFileCollection());
+        
+        // Create the mapper (this will use our fix)
+        var options = Options.Create(new RazorComponentsServiceOptions());
+        var mapper = new HttpContextFormValueMapper(formDataProvider, options);
+
+        // Act - Try to map the recursive model type (the exact case that was failing)
+        var context = new FormValueMappingContext("", "RequestForm", typeof(MyModel), "Model");
+        mapper.Map(context);
+
+        // Assert - The model should be created successfully, not null
+        // Before the fix, this would be null due to the missing return statement
+        Assert.NotNull(context.Result);
+        var result = Assert.IsType<MyModel>(context.Result);
+        Assert.Equal("Test Name", result.Name);
+        Assert.Null(result.Parent); // Parent should be null since no data was provided
+    }
+
+    [Fact]
+    public void CanMap_WithRecursiveModel_ShouldReturnTrue()
+    {
+        // Arrange - Test the CanMap method specifically for recursive types
+        var formDataProvider = new HttpContextFormDataProvider();
+        formDataProvider.SetFormData("RequestForm", new Dictionary<string, StringValues>(), new FormFileCollection());
+        
+        var options = Options.Create(new RazorComponentsServiceOptions());
+        var mapper = new HttpContextFormValueMapper(formDataProvider, options);
+
+        // Act
+        var canMap = mapper.CanMap(typeof(MyModel), "", "RequestForm");
+
+        // Assert - Should be able to map recursive model types
+        Assert.True(canMap, "Should be able to map recursive model types");
+    }
 }
 
 internal class MyModel