dotnet-best-practices

# .NET/C# Best Practices Your task is to ensure .NET/C# code in ${selection} meets the best practices specific to this solution/project. This includes: ## Documentation & Structure - **全ての public 型（class / interface / record / enum）および public メンバー（プロパティ・メソッド・フィールド）に `/// <summary>` を付与すること** - **XML ドキュメントコメントは日本語で記述する**（`<summary>`, `<param>`, `<returns>`, `<remarks>` 等すべて） - インターフェースを実装するメンバーには `/// <inheritdoc />` を使用し、定義元のドキュメントを継承する - Follow the established namespace structure: {Core|Console|App|Service}.{Feature} ### XML ドキュメントコメントの記述例 ```csharp // 型レベル: 1行目に役割、2行目以降に補足 /// <summary> /// 現在のリクエストユーザーを表すインターフェース。 /// Web では ClaimsPrincipal から、Azure Functions では認証トークンから生成する。 /// </summary> public interface ICurrentUser { /// <summary>ユーザーの一意識別子。</summary> string UserId { get; } } // インターフェース実装: inheritdoc で継承 public class CurrentUser : ICurrentUser { /// <inheritdoc /> public string UserId => _userId; } // static メソッド /// <summary>成功結果を生成する。</summary> public static Result Success() => new() { IsSuccess = true }; ``` ## Design Patterns & Architecture - Use primary constructor syntax for dependency injection (e.g., `public class MyClass(IDependency dependency)`) - Implement the Command Handler pattern with generic base classes (e.g., `CommandHandler<TOptions>`) - Use interface segregation with clear naming conventions (prefix interfaces with 'I') - Follow the Factory pattern for complex object creation. ## Dependency Injection & Services - Use constructor dependency injection with null checks via ArgumentNullException - Register services with appropriate lifetimes (Singleton, Scoped, Transient) - Use Microsoft.Extensions.DependencyInjection patterns - Implement service interfaces for testability ## Resource Management & Localization - Use ResourceManager for localized messages and error strings - Separate LogMessages and ErrorMessages resource files - Access resources via `_resourceManager.GetString("MessageKey")` ## Async/Await Patterns - Use async/await for all I/O operations and long-running tasks - Return Task or Task<T> from async methods - Use ConfigureAwait(false) where appropriate - Handle async exceptions properly ## Testing Standards - Use MSTest framework with FluentAssertions for assertions - Follow AAA pattern (Arrange, Act, Assert) - Use Moq for mocking dependencies - Test both success and failure scenarios - Include null parameter validation tests ## Configuration & Settings - Use strongly-typed configuration classes with data annotations - Implement validation attributes (Required, NotEmptyOrWhitespace) - Use IConfiguration binding for settings - Support appsettings.json configuration files ## Semantic Kernel & AI Integration - Use Microsoft.SemanticKernel for AI operations - Implement proper kernel configuration and service registration - Handle AI model settings (ChatCompletion, Embedding, etc.) - Use structured output patterns for reliable AI responses ## Error Handling & Logging - Use structured logging with Microsoft.Extensions.Logging - Include scoped logging with meaningful context - Throw specific exceptions with descriptive messages - Use try-catch blocks for expected failure scenarios ## Performance & Security - Use C# 12+ features and .NET 8 optimizations where applicable - Implement proper input validation and sanitization - Use parameterized queries for database operations - Follow secure coding practices for AI/ML operations ## Code Quality - Ensure SOLID principles compliance - Avoid code duplication through base classes and utilities - Use meaningful names that reflect domain concepts - Keep methods focused and cohesive - Implement proper disposal patterns for resources