CqsLite 1.1.0

CqsLite

CqsLite is a lightweight library for implementing the Command–Query Separation (CQS) pattern in .NET applications. It provides a simple, extensible way to decouple your business logic using command and query handlers, without relying on complex frameworks.

✨ Features

• ✅ Lightweight and minimal
• 🧱 Built around ICommand, IQuery<TQuery, TResult>, and their respective handlers
• ⚙️ Simple dispatcher pattern (ICommandDispatcher, IQueryDispatcher)
• 🔍 Automatic registration via reflection (AddCqsLite(...))
• 🔌 Fully compatible with ASP.NET Core and .NET dependency injection

📦 Installation

You can install CqsLite directly from NuGet:

dotnet add package CqsLite

Or via the Package Manager Console:

Install-Package CqsLite

🚀 Getting Started

1. Define a Command or Query

public record CreateUserCommand(string Name, string Email) : ICommand;
public record GetUserByIdQuery(Guid Id) : IQuery<UserDto>;

2. Create a Handler

public class CreateUserCommandHandler : ICommandHandler<CreateUserCommand>
{
    public Task HandleAsync(CreateUserCommand command, CancellationToken cancellationToken)
    {
        // Your logic here...
        return Task.CompletedTask;
    }
}

public class GetUserByIdQueryHandler : IQueryHandler<GetUserByIdQuery, UserDto>
{
    public Task<UserDto> HandleAsync(GetUserByIdQuery query, CancellationToken cancellationToken)
    {
        // Your logic here...
        return Task.FromResult(new UserDto { Id = query.Id, Name = "John" });
    }
}

3. Register CqsLite

builder.Services.AddCqsLite(typeof(Program).Assembly); // Automatically scans your handlers

4. Dispatch

var result = await _queryDispatcher.DispatchAsync<GetUserByIdQuery, UserDto>(new GetUserByIdQuery(id));
await _commandDispatcher.DispatchAsync<CreateUserCommand>(new CreateUserCommand("Alice", "alice@example.com"));

🧪 Testing

Includes unit and integration tests for:

• Dispatcher behavior
• Handler resolution via DI
• Reflection-based service registration

Run tests with:

dotnet test

📂 Project Structure

CqsLite/
├── Abstractions/        # ICommand, IQuery<TResult>, and handler interfaces
├── Dispatching/         # CommandDispatcher and QueryDispatcher
├── Extensions/          # IServiceCollection.AddCqsLite()
└── CqsLite.csproj

📄 License

MIT © Miguel