C# Rules

Version: C# 12 / .NET 8 LTS

Tooling

• Build: dotnet CLI or Visual Studio 2026
• Testing: xUnit with coverage >= 85%
• Linting: dotnet format, Roslyn analyzers

Best Practices (2026)

• Use Primary Constructors for cleaner class definitions
• Use Collection Expressions: int[] nums = [1, 2, 3];
• Enable nullable reference types project-wide
• Use records for immutable DTOs
• Dynamic PGO is enabled by default (~15% performance boost)

C# 12 Features

// Primary constructor
public class UserService(IUserRepository repo, ILogger<UserService> logger)
{
    public User GetUser(int id) => repo.FindById(id);
}

// Collection expressions
List<int> numbers = [1, 2, 3, 4, 5];
int[] combined = [..numbers, 6, 7, 8];

// Required members
public class Config
{
    public required string ConnectionString { get; init; }
}

ASP.NET Core Patterns

• Use Minimal APIs for simple endpoints
• Use HybridCache for combined memory + distributed caching
• Implement rate limiting middleware for API protection
• Use Native AOT for serverless/container deployments

Migration Guidance

• Incremental upgrades recommended: 6 → 7 → 8 → 9 → 10
• Review breaking changes docs before each upgrade
• Use static analyzers to detect deprecated patterns

MoAI Integration

• Use Skill("moai-lang-csharp") for detailed patterns
• Follow TRUST 5 quality gates