dotnet-clean-architecture

# .NET Clean Architecture Project Scaffolder

## Overview

This skill generates a complete .NET solution following Clean Architecture (also known as Onion Architecture or Hexagonal Architecture). The architecture enforces separation of concerns through distinct layers with unidirectional dependencies pointing inward.

## Architecture Layers

```
┌─────────────────────────────────────────────────────────────┐
│                        API Layer                            │
│  Controllers, Middleware, Request/Response DTOs             │
├─────────────────────────────────────────────────────────────┤
│                   Infrastructure Layer                       │
│  EF Core, Repositories, External Services, Authentication   │
├─────────────────────────────────────────────────────────────┤
│                    Application Layer                         │
│  Commands, Queries, Handlers, Validators, DTOs              │
├─────────────────────────────────────────────────────────────┤
│                      Domain Layer                            │
│  Entities, Value Objects, Domain Events, Interfaces         │
└─────────────────────────────────────────────────────────────┘
```

**Dependency Rule**: Dependencies point inward. Domain has no dependencies. Application depends only on Domain. Infrastructure implements interfaces from Domain/Application.

## Quick Reference

| Task | Command/Action |
|------|----------------|
| Create solution | `dotnet new sln -n {SolutionName}` |
| Create Domain project | `dotnet new classlib -n {name}.domain` |
| Create Application project | `dotnet new classlib -n {name}.application` |
| Create Infrastructure project | `dotnet new classlib -n {name}.infrastructure` |
| Create API project | `dotnet new webapi -n {name}.api` |
| Add project to solution | `dotnet sln add src/{project}/{project}.csproj` |
| Add project reference | `dotnet add reference ../other/other.csproj` |

---

## Project Structure

```
{SolutionName}/
├── src/
│   ├── {name}.domain/
│   │   ├── Abstractions/
│   │   │   ├── Entity.cs
│   │   │   ├── IDomainEvent.cs
│   │   │   ├── IUnitOfWork.cs
│   │   │   └── Result.cs
│   │   ├── {Aggregate}/
│   │   │   ├── {Entity}.cs
│   │   │   ├── {Entity}Errors.cs
│   │   │   ├── I{Entity}Repository.cs
│   │   │   ├── ValueObjects/
│   │   │   └── Events/
│   │   └── {name}.domain.csproj
│   │
│   ├── {name}.application/
│   │   ├── Abstractions/
│   │   │   ├── Behaviors/
│   │   │   │   ├── LoggingBehavior.cs
│   │   │   │   └── ValidationBehavior.cs
│   │   │   ├── Messaging/
│   │   │   │   ├── ICommand.cs
│   │   │   │   ├── ICommandHandler.cs
│   │   │   │   ├── IQuery.cs
│   │   │   │   └── IQueryHandler.cs
│   │   │   ├── Authentication/
│   │   │   ├── Clock/
│   │   │   └── Data/
│   │   ├── {Feature}/
│   │   │   ├── Create{Entity}/
│   │   │   ├── Update{Entity}/
│   │   │   ├── Delete{Entity}/
│   │   │   └── Get{Entity}/
│   │   ├── DependencyInjection.cs
│   │   └── {name}.application.csproj
│   │
│   ├── {name}.infrastructure/
│   │   ├── Authentication/
│   │   ├── Authorization/
│   │   ├── Clock/
│   │   ├── Configurations/
│   │   ├── Repositories/
│   │   ├── Outbox/
│   │   ├── ApplicationDbContext.cs
│   │   ├── DependencyInjection.cs
│   │   └── {name}.infrastructure.csproj
│   │
│   └── {name}.api/
│       ├── Controllers/
│       ├── Middleware/
│       ├── Extensions/
│       ├── Program.cs
│       ├── appsettings.json
│       └── {name}.api.csproj
│
├── tests/
│   ├── {name}.domain.tests/
│   ├── {name}.application.tests/
│   └── {name}.api.tests/
│
└── {SolutionName}.sln
```

---

## Step 1: Create Solution and Projects

```bash
# Create solution
dotnet new sln -n {SolutionName}

# Create projects
dotnet new classlib -n {name}.domain -o src/{name}.domain
dotnet new classlib -n {name}.application -o src/{name}.application
dotnet new classlib -n {name}.infrastructure -o src/{name}.infrastructure
dotnet new webapi -n {name}.api -o src/{name}.api

# Add projects to solution
dotnet sln add src/{name}.domain/{name}.domain.csproj
dotnet sln add src/{name}.application/{name}.application.csproj
dotnet sln add src/{name}.infrastructure/{name}.infrastructure.csproj
dotnet sln add src/{name}.api/{name}.api.csproj

# Add project references
cd src/{name}.application
dotnet add reference ../{name}.domain/{name}.domain.csproj

cd ../{name}.infrastructure
dotnet add reference ../{name}.domain/{name}.domain.csproj
dotnet add reference ../{name}.application/{name}.application.csproj

cd ../{name}.api
dotnet add reference ../{name}.application/{name}.application.csproj
dotnet add reference ../{name}.infrastructure/{name}.infrastructure.csproj
```

---

## Step 2: Domain Layer Setup

### Entity Base Class

```csharp
// src/{name}.domain/Abstractions/Entity.cs
namespace {name}.domain.abstractions;

public abstract class Entity
{
    private readonly List<IDomainEvent> _domainEvents = new();

    protected Entity(Guid id)
    {
        Id = id;
    }

    protected Entity() { } // EF Core

    public Guid Id { get; init; }

    public IReadOnlyList<IDomainEvent> GetDomainEvents() => _domainEvents.ToList();

    public void ClearDomainEvents() => _domainEvents.Clear();

    protected void RaiseDomainEvent(IDomainEvent domainEvent) => _domainEvents.Add(domainEvent);
}
```

### Domain Event Interface

```csharp
// src/{name}.domain/Abstractions/IDomainEvent.cs
using MediatR;

namespace {name}.domain.abstractions;

public interface IDomainEvent : INotification
{
}
```

### Unit of Work Interface

```csharp
// src/{name}.domain/Abstractions/IUnitOfWork.cs
namespace {name}.domain.abstractions;

public interface IUnitOfWork
{
    Task<int> SaveChangesAsync(CancellationToken cancellationToken = default);
}
```

### Result Pattern (see result-pattern skill for full implementation)

```csharp
// src/{name}.domain/Abstractions/Result.cs
namespace {name}.domain.abstractions;

public class Result
{
    protected Result(bool isSuccess, Error error)
    {