/dotnet-design-pattern-review

name: dotnet-design-pattern-review
description: 'Review the C#/.NET code for design pattern implementation and suggest improvements.'

.NET/C# Design Pattern Review

Review the C#/.NET code in ${selection} for design pattern implementation and suggest improvements for the solution/project. Do not make any changes to the code, just provide a review.

Required Design Patterns

• **Command Pattern**: Generic base classes (`CommandHandler<TOptions>`), `ICommandHandler<TOptions>` interface, `CommandHandlerOptions` inheritance, static `SetupCommand(IHost host)` methods
• **Factory Pattern**: Complex object creation service provider integration
• **Dependency Injection**: Primary constructor syntax, `ArgumentNullException` null checks, interface abstractions, proper service lifetimes
• **Repository Pattern**: Async data access interfaces provider abstractions for connections
• **Provider Pattern**: External service abstractions (database, AI), clear contracts, configuration handling
• **Resource Pattern**: ResourceManager for localized messages, separate .resx files (LogMessages, ErrorMessages)

Review Checklist

• **Design Patterns**: Identify patterns used. Are Command Handler, Factory, Provider, and Repository patterns correctly implemented? Missing beneficial patterns?
• **Architecture**: Follow namespace conventions (`{Core|Console|App|Service}.{Feature}`)? Proper separation between Core/Console projects? Modular and readable?
• **.NET Best Practices**: Primary constructors, async/await with Task returns, ResourceManager usage, structured logging, strongly-typed configuration?
• **GoF Patterns**: Command, Factory, Template Method, Strategy patterns correctly implemented?
• **SOLID Principles**: Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion violations?
• **Performance**: Proper async/await, resource disposal, ConfigureAwait(false), parallel processing opportunities?
• **Maintainability**: Clear separation of concerns, consistent error handling, proper configuration usage?
• **Testability**: Dependencies abstracted via interfaces, mockable components, async testability, AAA pattern compatibility?
• **Security**: Input validation, secure credential handling, parameterized queries, safe exception handling?
• **Documentation**: XML docs for public APIs, parameter/return descriptions, resource file organization?
• **Code Clarity**: Meaningful names reflecting domain concepts, clear intent through patterns, self-explanatory structure?
• **Clean Code**: Consistent style, appropriate method/class size, minimal complexity, eliminated duplication?

Improvement Focus Areas

• **Command Handlers**: Validation in base class, consistent error handling, proper resource management
• **Factories**: Dependency configuration, service provider integration, disposal patterns
• **Providers**: Connection management, async patterns, exception handling and logging
• **Configuration**: Data annotations, validation attributes, secure sensitive value handling
• **AI/ML Integration**: Semantic Kernel patterns, structured output handling, model configuration

Provide specific, actionable recommendations for improvements aligned with the project's architecture and .NET best practices.