dotnet-best-practices

name	dotnet-best-practices
description	Ensure .NET/C# code meets best practices for the solution/project.
last_updated	"2026-06-04T00:00:00.000Z"
framework_revision	dotnet-10

.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

• Create comprehensive XML documentation comments for all public classes, interfaces, methods, and properties
• Include parameter descriptions and return value descriptions in XML comments
• Follow the Biotrackr namespace pattern: Biotrackr.{Domain}.{Type} (e.g., Biotrackr.Activity.Api, Biotrackr.Sleep.Svc)

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 from async methods
• Use ConfigureAwait(false) where appropriate
• Handle async exceptions properly

Testing Standards

• Use xUnit as the test runner
• Use FluentAssertions for assertions
• Use Moq for mocking dependencies
• Use AutoFixture for test data generation
• Follow AAA pattern (Arrange, Act, Assert) with explicit // Arrange / // Act / // Assert comments
• 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

AI Integration (Microsoft Agent Framework + Copilot SDK)

• Use Microsoft Agent Framework (MAF) for conversational agents and tool orchestration
• Use the Microsoft Copilot SDK for sidecar-style code generation and reviewer workflows
• Register agent services with appropriate lifetimes; prefer managed identity for inter-service authentication
• Handle AI model settings (chat completion, embedding, structured output) via MAF configuration
• 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# 14 features and .NET 10 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