C# Skill

Generates C# code following VanDaemon's clean architecture with nullable reference types, async patterns, and structured logging. All services are singletons with constructor injection. Entities live in Core, services in Application, controllers in Api.

Quick Start

Creating a Service

// Application/Interfaces/IFuelService.cs
public interface IFuelService
{
    Task<IReadOnlyList<FuelReading>> GetAllReadingsAsync(CancellationToken cancellationToken = default);
    Task<FuelReading?> GetByIdAsync(Guid id, CancellationToken cancellationToken = default);
}

// Application/Services/FuelService.cs
public class FuelService : IFuelService
{
    private readonly ILogger<FuelService> _logger;
    private readonly JsonFileStore _fileStore;

    public FuelService(ILogger<FuelService> logger, JsonFileStore fileStore)
    {
        _logger = logger;
        _fileStore = fileStore;
    }

    public async Task<IReadOnlyList<FuelReading>> GetAllReadingsAsync(CancellationToken cancellationToken = default)
    {
        var readings = await _fileStore.LoadAsync<List<FuelReading>>("fuel.json", cancellationToken);
        return readings?.AsReadOnly() ?? new List<FuelReading>().AsReadOnly();
    }
}

Creating an Entity

// Core/Entities/FuelReading.cs
public class FuelReading
{
    public Guid Id { get; set; }
    public double Level { get; set; }
    public DateTime Timestamp { get; set; }
    public bool IsActive { get; set; } = true;  // Soft delete pattern
}

Key Concepts

Concept	Usage	Example
Nullable types	All reference types nullable-aware	`Tank?`, `string?`
CancellationToken	Required on all async methods	`Task<T> MethodAsync(CancellationToken ct = default)`
Soft deletes	Never remove, set `IsActive = false`	`entity.IsActive = false;`
Structured logging	Named placeholders	`_logger.LogInformation("Tank {TankId} at {Level}%", id, level)`
Private fields	Underscore prefix	`private readonly ILogger _logger;`

Common Patterns

Plugin Implementation

When: Adding hardware integration

public class MyPlugin : ISensorPlugin, IDisposable
{
    private readonly ILogger<MyPlugin> _logger;
    private readonly Dictionary<string, double> _values = new();
    private bool _disposed;

    public string Name => "My Plugin";
    public string Version => "1.0.0";

    public async Task InitializeAsync(Dictionary<string, object> config, CancellationToken ct = default)
    {
        _logger.LogInformation("Initializing {PluginName}", Name);
        // Setup from config dictionary
    }

    public Task<double> ReadValueAsync(string sensorId, CancellationToken ct = default)
        => Task.FromResult(_values.GetValueOrDefault(sensorId, 0.0));

    public void Dispose()
    {
        if (_disposed) return;
        _disposed = true;
        // Cleanup
    }
}

SignalR Broadcast

When: Pushing real-time updates to clients

await _hubContext.Clients.Group("tanks").SendAsync(
    "TankLevelUpdated", tankId, currentLevel, tankName, cancellationToken);

Related Skills

See the dotnet skill for build commands and project structure
See the aspnet-core skill for controllers and middleware
See the xunit skill for testing patterns
See the serilog skill for logging configuration

csharp