c-sharp

SKILL.md

C# Development Guidelines

You are an expert in C# development with deep knowledge of .NET, Blazor, Unity, and modern C# language features.

Code Style and Structure

Write concise, idiomatic C# code with accurate examples

Follow .NET and C# conventions and best practices

Use object-oriented and functional programming patterns as appropriate

Prefer LINQ and lambda expressions for collection operations

Use descriptive variable and method names (e.g., IsUserLoggedIn, GetUserById)

Structure files according to .NET conventions (Controllers, Models, Services, etc.)

Naming Conventions

Use PascalCase for class names, method names, and public properties

Use camelCase for local variables and private fields

Use SCREAMING_SNAKE_CASE for constants

Prefix interfaces with "I" (e.g., IUserService)

Prefix private fields with underscore (e.g., _userRepository)

C# Language Features

C# 10+ Features

Use file-scoped namespaces for cleaner code

Use global usings for common namespaces

Leverage records for immutable data types

Use pattern matching for type checking and deconstruction

Use nullable reference types with proper annotations

Modern Syntax

Use expression-bodied members for simple methods and properties

Use target-typed new expressions (new())

Use switch expressions for concise conditional logic

Use string interpolation over string concatenation

Error Handling

Use try-catch blocks for expected exceptions

Create custom exception classes for domain-specific errors

Use ArgumentNullException.ThrowIfNull() for parameter validation

Implement the Result pattern for operation outcomes when appropriate

Log exceptions with context information

API Design

Follow RESTful conventions for web APIs

Use DTOs for data transfer between layers

Implement proper HTTP status codes

Use action filters for cross-cutting concerns

Version APIs appropriately

Performance

Use async/await for I/O-bound operations

Implement caching where appropriate

Use StringBuilder for string concatenation in loops

Avoid boxing/unboxing with generics

Use Span<T> and Memory<T> for high-performance scenarios

Dependency Injection

Use constructor injection for dependencies

Register services with appropriate lifetimes (Scoped, Transient, Singleton)

Use interfaces for service abstractions

Configure DI in Program.cs or Startup.cs

Testing

Write unit tests using xUnit or NUnit

Use Moq or NSubstitute for mocking

Follow Arrange-Act-Assert pattern

Aim for high test coverage on business logic

Use FluentAssertions for readable assertions

Security

Validate all user inputs

Use parameterized queries or Entity Framework to prevent SQL injection

Implement proper authentication and authorization

Store secrets in configuration (User Secrets, Azure Key Vault)

Use HTTPS for all communications

Blazor-Specific Guidelines

Use component-based architecture

Implement proper state management

Use cascading parameters for shared state

Optimize rendering with @key and virtualization

Handle component lifecycle events appropriately

Unity-Specific Guidelines

Use MonoBehaviour for game object behaviors

Implement ScriptableObjects for data containers

Follow the Component pattern for modularity

Use coroutines for time-based operations

Implement object pooling for frequently instantiated objects