Code scaffolding patterns for .NET 10 features, entities, and tests. Generates complete feature slices, entities with EF Core configuration, and integration tests following the project's chosen architecture. Load when: "scaffold", "create feature", "add feature", "new endpoint", "generate", "add entity", "new entity", "scaffold test", "add module".
Code scaffolding patterns for .NET 10 features, entities, and tests. Generates complete feature slices, entities with EF Core configuration, and integration tests following the project's chosen architecture. Load when: "scaffold", "create feature", "add feature", "new endpoint", "generate", "add entity", "new entity", "scaffold test", "add module".
Scaffolding
Core Principles
Architecture-aware generation — Never scaffold without knowing the project's architecture (VSA, CA, DDD, Modular Monolith). If unknown, ask first or run the architecture-advisor questionnaire.
Complete vertical slices — Never generate half a feature. A scaffold includes endpoint, handler, validation, DTOs, EF configuration, and tests as a single unit.
Tests included by default — Every scaffolded feature includes at least one integration test using WebApplicationFactory + Testcontainers. Skip only if explicitly told to.
Modern C# 14 patterns — Primary constructors, collection expressions, file-scoped types, records for DTOs, sealed on all handler classes.
Convention-matching — Before generating, check existing code for naming patterns (*Handler, *Service, *Endpoint), folder structure, and access modifiers. Match what exists.
Scaffold Checklist (MANDATORY)
Every scaffolded feature MUST include ALL of the following. Do not skip any item:
Result pattern — Handlers return Result<T>, not raw responses. Endpoints map Result to HTTP (success → TypedResults, failure → ToProblemDetails())
on every async method and passed to every async call
CancellationToken
FluentValidation validator class with meaningful rules (ranges, required fields, max lengths)
ValidationFilter wiring — .AddEndpointFilter<ValidationFilter<T>>() on mutating endpoints
Domain logic lives in the aggregate; handler orchestrates persistence:
// Domain/Orders/Order.cs — Aggregate root with invariant enforcementpublicsealedclassOrder : AggregateRoot
{
privatereadonly List<OrderItem> _items = [];
public IReadOnlyList<OrderItem> Items => _items.AsReadOnly();
publicdecimal Total { get; privateset; }
public OrderStatus Status { get; privateset; }
publicstatic Order Place(string customerId, List<(Guid ProductId, int Qty, decimal Price)> items, DateTimeOffset now)
{
if (items.Count == 0) thrownew DomainException("Order must have at least one item.");
var order = new Order { Id = Guid.NewGuid(), Status = OrderStatus.Placed };
foreach (var (productId, qty, price) in items)
order._items.Add(OrderItem.Create(productId, qty, price));
order.Total = order._items.Sum(i => i.LineTotal);
order.AddDomainEvent(new OrderPlacedEvent(order.Id, customerId, order.Total, now));
return order;
}
}
Feature Scaffold — Modular Monolith
Feature within a module boundary with its own DbContext. Handler passes CancellationToken, publishes integration events:
// BAD — Generating code without knowing if project uses VSA, CA, or DDDpublicclassCreateOrderHandler { /* random structure */ }
// GOOD — Ask first: "I see feature folders, so I'll scaffold using VSA patterns."publicstaticclassCreateOrder { /* VSA single-file feature */ }
Feature Without Tests
Always scaffold feature + test as a single unit. CreateOrder.cs + CreateOrderTests.cs are never generated separately.
Entity Without EF Configuration
// BAD — data annotations scattered in entitypublicclassProduct { [Key] public Guid Id { get; set; } [MaxLength(200)] publicstring Name { get; set; } = ""; }
// GOOD — clean entity + separate IEntityTypeConfiguration<T>publicsealedclassProduct { /* No attributes */ }
internalsealedclassProductConfiguration : IEntityTypeConfiguration<Product> { /* All EF config */ }
Anemic DTOs That Mirror Entities 1:1
// BAD — DTO mirrors entity with no purposepublicrecordProductDto(Guid Id, string Name, string Sku, decimal Price, bool IsActive, DateTime CreatedAt, DateTime? UpdatedAt);
// GOOD — response shaped for the consumerpublicrecordProductSummary(Guid Id, string Name, decimal Price);
