affaan-m/ecc

dotnet-patterns

Idiomatic C and .NET patterns, conventions, dependency injection, async/await, and best practices for building robust, maintainable .NET applications.

查看源码

使用方法

  1. 复制安装命令,在自己的智能体环境安装前先检查源码包。
  2. 从原始文档核对所需工具、凭据和支持的宿主。
  3. 说明输入材料与期望交付物,并对照来源检查输出。
npx skills add https://github.com/affaan-m/ecc --skill dotnet-patterns

开始前需了解

  • 安装不包含模型订阅、API 额度或访问文件的权限。
  • 仓库星数和安装量反映活跃情况,不等于独立质量或安全测试。
仓库原始内容

按源仓库内容呈现,保留标题、案例、代码、表格、链接以及原文引用的演示图片。

.NET Development Patterns

Idiomatic C# and .NET patterns for building robust, performant, and maintainable applications.

When to Activate

  • Writing new C# code
  • Reviewing C# code
  • Refactoring existing .NET applications
  • Designing service architectures with ASP.NET Core

Core Principles

1. Prefer Immutability

Use records and init-only properties for data models. Mutability should be an explicit, justified choice.

csharp
// Good: Immutable value object
public sealed record Money(decimal Amount, string Currency);

// Good: Immutable DTO with init setters
public sealed class CreateOrderRequest
{
    public required string CustomerId { get; init; }
    public required IReadOnlyList<OrderItem> Items { get; init; }
}

// Bad: Mutable model with public setters
public class Order
{
    public string CustomerId { get; set; }
    public List<OrderItem> Items { get; set; }
}

2. Explicit Over Implicit

Be clear about nullability, access modifiers, and intent.

csharp
// Good: Explicit access modifiers and nullability
public sealed class UserService
{
    private readonly IUserRepository _repository;
    private readonly ILogger<UserService> _logger;

    public UserService(IUserRepository repository, ILogger<UserService> logger)
    {
        _repository = repository ?? throw new ArgumentNullException(nameof(repository));
        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
    }

    public async Task<User?> FindByIdAsync(Guid id, CancellationToken cancellationToken)
    {
        return await _repository.FindByIdAsync(id, cancellationToken);
    }
}

3. Depend on Abstractions

Use interfaces for service boundaries. Register via DI container.

csharp
// Good: Interface-based dependency
public interface IOrderRepository
{
    Task<Order?> FindByIdAsync(Guid id, CancellationToken cancellationToken);
    Task<IReadOnlyList<Order>> FindByCustomerAsync(string customerId, CancellationToken cancellationToken);
    Task AddAsync(Order order, CancellationToken cancellationToken);
}

// Registration
builder.Services.AddScoped<IOrderRepository, SqlOrderRepository>();

Async/Await Patterns

Proper Async Usage

csharp
// Good: Async all the way, with CancellationToken
public async Task<OrderSummary> GetOrderSummaryAsync(
    Guid orderId,
    CancellationToken cancellationToken)
{
    var order = await _repository.FindByIdAsync(orderId, cancellationToken)
        ?? throw new NotFoundException($"Order {orderId} not found");

    var customer = await _customerService.GetAsync(order.CustomerId, cancellationToken);

    return new OrderSummary(order, customer);
}

// Bad: Blocking on async
public OrderSummary GetOrderSummary(Guid orderId)
{
    var order = _repository.FindByIdAsync(orderId, CancellationToken.None).Result; // Deadlock risk
    return new OrderSummary(order);
}

Parallel Async Operations

csharp
// Good: Concurrent independent operations
public async Task<DashboardData> LoadDashboardAsync(CancellationToken cancellationToken)
{
    var ordersTask = _orderService.GetRecentAsync(cancellationToken);
    var metricsTask = _metricsService.GetCurrentAsync(cancellationToken);
    var alertsTask = _alertService.GetActiveAsync(cancellationToken);

    await Task.WhenAll(ordersTask, metricsTask, alertsTask);

    return new DashboardData(
        Orders: await ordersTask,
        Metrics: await metricsTask,
        Alerts: await alertsTask);
}

Options Pattern

Bind configuration sections to strongly-typed objects.

csharp
public sealed class SmtpOptions
{
    public const string SectionName = "Smtp";

    public required string Host { get; init; }
    public required int Port { get; init; }
    public required string Username { get; init; }
    public bool UseSsl { get; init; } = true;
}

// Registration
builder.Services.Configure<SmtpOptions>(
    builder.Configuration.GetSection(SmtpOptions.SectionName));

// Usage via injection
public class EmailService(IOptions<SmtpOptions> options)
{
    private readonly SmtpOptions _smtp = options.Value;
}

Result Pattern

Return explicit success/failure instead of throwing for expected failures.

csharp
public sealed record Result<T>
{
    public bool IsSuccess { get; }
    public T? Value { get; }
    public string? Error { get; }

    private Result(T value) { IsSuccess = true; Value = value; }
    private Result(string error) { IsSuccess = false; Error = error; }

    public static Result<T> Success(T value) => new(value);
    public static Result<T> Failure(string error) => new(error);
}

// Usage
public async Task<Result<Order>> PlaceOrderAsync(CreateOrderRequest request)
{
    if (request.Items.Count == 0)
        return Result<Order>.Failure("Order must contain at least one item");

    var order = Order.Create(request);
    await _repository.AddAsync(order, CancellationToken.None);
    return Result<Order>.Success(order);
}

Repository Pattern with EF Core

csharp
public sealed class SqlOrderRepository : IOrderRepository
{
    private readonly AppDbContext _db;

    public SqlOrderRepository(AppDbContext db) => _db = db;

    public async Task<Order?> FindByIdAsync(Guid id, CancellationToken cancellationToken)
    {
        return await _db.Orders
            .Include(o => o.Items)
            .AsNoTracking()
            .FirstOrDefaultAsync(o => o.Id == id, cancellationToken);
    }

    public async Task<IReadOnlyList<Order>> FindByCustomerAsync(
        string customerId,
        CancellationToken cancellationToken)
    {
        return await _db.Orders
            .Where(o => o.CustomerId == customerId)
            .OrderByDescending(o => o.CreatedAt)
            .AsNoTracking()
            .ToListAsync(cancellationToken);
    }

    public async Task AddAsync(Order order, CancellationToken cancellationToken)
    {
        _db.Orders.Add(order);
        await _db.SaveChangesAsync(cancellationToken);
    }
}

Middleware and Pipeline

csharp
// Custom middleware
public sealed class RequestTimingMiddleware
{
    private readonly RequestDelegate _next;
    private readonly ILogger<RequestTimingMiddleware> _logger;

    public RequestTimingMiddleware(RequestDelegate next, ILogger<RequestTimingMiddleware> logger)
    {
        _next = next;
        _logger = logger;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        var stopwatch = Stopwatch.StartNew();
        try
        {
            await _next(context);
        }
        finally
        {
            stopwatch.Stop();
            _logger.LogInformation(
                "Request {Method} {Path} completed in {ElapsedMs}ms with status {StatusCode}",
                context.Request.Method,
                context.Request.Path,
                stopwatch.ElapsedMilliseconds,
                context.Response.StatusCode);
        }
    }
}

Minimal API Patterns

csharp
// Organized with route groups
var orders = app.MapGroup("/api/orders")
    .RequireAuthorization()
    .WithTags("Orders");

orders.MapGet("/{id:guid}", async (
    Guid id,
    IOrderRepository repository,
    CancellationToken cancellationToken) =>
{
    var order = await repository.FindByIdAsync(id, cancellationToken);
    return order is not null
        ? TypedResults.Ok(order)
        : TypedResults.NotFound();
});

orders.MapPost("/", async (
    CreateOrderRequest request,
    IOrderService service,
    CancellationToken cancellationToken) =>
{
    var result = await service.PlaceOrderAsync(request, cancellationToken);
    return result.IsSuccess
        ? TypedResults.Created($"/api/orders/{result.Value!.Id}", result.Value)
        : TypedResults.BadRequest(result.Error);
});

Guard Clauses

csharp
// Good: Early returns with clear validation
public async Task<ProcessResult> ProcessPaymentAsync(
    PaymentRequest request,
    CancellationToken cancellationToken)
{
    ArgumentNullException.ThrowIfNull(request);

    if (request.Amount <= 0)
        throw new ArgumentOutOfRangeException(nameof(request.Amount), "Amount must be positive");

    if (string.IsNullOrWhiteSpace(request.Currency))
        throw new ArgumentException("Currency is required", nameof(request.Currency));

    // Happy path continues here without nesting
    var gateway = _gatewayFactory.Create(request.Currency);
    return await gateway.ChargeAsync(request, cancellationToken);
}

Anti-Patterns to Avoid

Anti-PatternFix
async void methodsReturn Task (except event handlers)
.Result or .Wait()Use await
catch (Exception) { }Handle or rethrow with context
new Service() in constructorsUse constructor injection
public fieldsUse properties with appropriate accessors
dynamic in business logicUse generics or explicit types
Mutable static stateUse DI scoping or ConcurrentDictionary
string.Format in loopsUse StringBuilder or interpolated string handlers

按任务相关推荐

来自同一仓库

更多 Skills

全部 Skills
affaan-m
社区

scientific-thinking-literature-review

Systematic literature-review workflow for academic, biomedical, technical, and scientific topics, including search planning, source screening, synthesis, citation checks, and evidence logging. Use when the task is to find, screen, synthesize, and cite a body of academic or technical literature.

安装量
3
GitHub Stars
28.9万
最近更新
10月25日
affaan-m
社区

docker-patterns

Docker and Docker Compose patterns for local development, hardened CLI installer harnesses, container security, networking, volumes, and multi-service orchestration. Use when creating or reviewing Dockerfiles and Compose services, testing installers across Linux distributions, or planning accurate native macOS and Windows validation.

安装量
4
GitHub Stars
28.8万
最近更新
10月20日
affaan-m
社区

agentic-engineering

Operate as an agentic engineer using eval-first execution, decomposition, and cost-aware model routing. Use when planning or executing engineering work that agents will carry out end to end.

安装量
3
GitHub Stars
28.8万
最近更新
10月20日
affaan-m
社区

backend-patterns

Backend architecture patterns, API design, database optimization, and server-side best practices for Node.js, Express, and Next.js API routes. Use when building or reviewing Node.js, Express, or Next.js API routes and their data access.

安装量
3
GitHub Stars
28.8万
最近更新
10月20日