add-feature

Prompt file imported from mhmtdev/CleanArcStack (.github/prompts/add-feature.prompt.md). Fill in {{featureName}} before use. Copyright stays with the author.

Add a complete vertical slice for a new feature: {{featureName}}

Follow this exact order. Implement all layers without asking for confirmation unless you hit an ambiguity that blocks progress.

1 — Domain layer (src/CleanArcStack.Domain/)

If a new entity is needed:

1. Strongly typed ID: src/Domain/Entities/{Entity}Id.cs

   public sealed record {Entity}Id(Guid Value);

2. Entity: src/Domain/Entities/{Entity}.cs

   • Inherit AggregateRoot (aggregates) or BaseEntity (child entities)
   • private/protected constructor + static Create(...) factory receiving TimeProvider
   • No public setters — state changes via domain methods
   • Private List<T> collections exposed as IReadOnlyList<T>
   • Call RaiseDomainEvent(...) inside factory/domain methods
   • Guid.CreateVersion7() — never Guid.NewGuid()
   • Throw DomainException for non-recoverable invariant violations
   • Return Result for recoverable failures

3. Domain event: src/Domain/Events/{Entity}{Action}DomainEvent.cs

   public sealed record {Entity}{Action}DomainEvent(Guid {Entity}Id) : IDomainEvent;

4. Repository interface: src/Domain/Repositories/I{Entity}Repository.cs

   • void Add/Update/Remove (not async — flushed by IUnitOfWork)
   • Task<{Entity}?> GetByIdAsync({Entity}Id id, CancellationToken ct = default)
   • IReadOnlyList<T> for collection returns

5. Error class: {Entity}Errors static class with Turkish messages:

   public static readonly Error NotFound = new("Entity.NotFound", "Türkçe mesaj.");

2 — Application layer (src/CleanArcStack.Application/Features/{FeatureName}/)

Structure:

Features/{FeatureName}/
├── Commands/   {Action}{Entity}Command.cs  (Command record + Validator in same file)
├── Queries/    Get{Entity}ByIdQuery.cs     (Query record + Validator in same file)
├── EventHandlers/  {Entity}{Action}DomainEventHandler.cs
├── DTOs/       {Entity}Response.cs         (+ static ToResponse() Mapster extension)
└── {Entity}Errors.cs

Rules:

• Handler return type: ValueTask<Result<T>> (Mediator, not MediatR — using Mediator;)
• Every Command/Query must have a paired AbstractValidator<T> in the same file
• Validation messages in Turkish
• No ConfigureAwait(false) in Application layer

3 — Infrastructure layer (src/CleanArcStack.Infrastructure/)

1. EF Core config: Persistence/Configurations/{Entity}Configuration.cs

   • HasConversion for strongly typed ID
   • HasIndex for common query patterns

2. Repository: Persistence/Repositories/{Entity}Repository.cs

   • AsNoTracking() on ALL read paths — no exceptions
   • ConfigureAwait(false) on every async call

3. Register in DependencyInjection.cs → AddPersistence:

   services.AddScoped<I{Entity}Repository, {Entity}Repository>();

4. Migration (after configs are done):

   dotnet ef migrations add $(date +%Y%m%d)_Add{Entity} \
     --project src/CleanArcStack.Infrastructure \
     --startup-project src/CleanArcStack.API

4 — API layer (src/CleanArcStack.API/Controllers/)

[ApiVersion("1.0")]
[Route("api/v{version:apiVersion}/[controller]")]
[Authorize]
public sealed class {Feature}Controller : ApiControllerBase
{
    [HttpPost]
    public async Task<IActionResult> Create([FromBody] Create{Entity}Request request, CancellationToken ct)
    {
        var result = await Sender.Send(new Create{Entity}Command(...), ct);
        return result.IsSuccess
            ? CreatedResponse("Get{Entity}ById", new { id = result.Value }, result.Value)
            : ErrorResponse(result.Error);
    }

    [HttpGet("{id:guid}", Name = "Get{Entity}ById")]
    public async Task<IActionResult> GetById(Guid id, CancellationToken ct) =>
        FromResult(await Sender.Send(new Get{Entity}ByIdQuery(id), ct));
}

5 — Unit Tests (tests/CleanArcStack.Unit.Tests/{FeatureName}/)

• {Entity}Tests.cs — domain entity behaviour (factory, invariants, domain events)
• Create{Entity}CommandHandlerTests.cs — handler with NSubstitute mocks + FakeTimeProvider
• Naming: {Method}_{Scenario}_{ExpectedResult}
• Guid.CreateVersion7() in test data

Checklist before finishing

Run dotnet build CleanArcStack.sln and fix all errors. Then verify:

• Strongly typed ID has HasConversion in EF config
• Every Command/Query has a validator
• Migration created and named YYYYMMDD_{Description}
• Repository registered in AddPersistence
• Error messages in Turkish, codes in English
• ConfigureAwait(false) on Infrastructure async calls
• AsNoTracking() on all read paths
• [AllowAnonymous] on any public endpoints