dotnet-modern-csharp

Apply modern C# features within .NET LangVersion and TargetFramework constraints.

2|Updated Mar 17, 2026

Search Tags:#csharp #refactoring #migration #dotnet #code-quality #language-features

Ready to run

npx skills add https://github.com/sayedihashimi/copilot-skill-eval --skill dotnet-modern-csharp-sayedihashimi

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: dotnet-modern-csharp
Source: https://github.com/sayedihashimi/copilot-skill-eval/tree/main/examples/aspnet-razor-pages/skills/managedcode-dotnet-skills/dotnet-modern-csharp
Command: npx skills add https://github.com/sayedihashimi/copilot-skill-eval --skill dotnet-modern-csharp-sayedihashimi

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Write modern, version-aware C# code for .NET repositories, ensuring compatibility with LangVersion and TargetFramework constraints while guiding safe feature adoption.

Core Features & Use Cases

Detect the real language ceiling from TargetFramework and LangVersion settings.
Prefer stable, repo-supported features and provide actionable deltas.
Validate changes with build and analyzer steps, coordinating with project tooling.

Quick Start

Use this skill to assess and apply modern C# features in your repo with safety checks.

Frequently Asked Questions about dotnet-modern-csharp

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I safely migrate C# code to use modern language features in existing .NET repos?▼

Modern C# migration is done by detecting the language ceiling from TargetFramework and LangVersion settings, then applying stable feature deltas while validating changes with build and analyzer steps. This ensures feature adoption does not break existing framework constraints.

What is the best way to determine which C# version features are supported in my .NET project?▼

To determine supported C# features, analyze the project's explicit LangVersion and TargetFramework settings to calculate the real language ceiling. This identifies the stable, repo-supported features available for code quality and performance improvements.

Can I apply C# refactoring for code quality without changing the target framework?▼

Yes, you can apply C# refactoring without changing the target framework by respecting the existing LangVersion constraints. The process selects stable features compatible with the current framework and validates them through end-to-end build and test analysis.

Why does my C# language feature migration fail the build in .NET?▼

C# feature migrations often fail the build when selected features exceed the constraints of the TargetFramework or LangVersion settings. Safe migration requires plan-driven changes that prefer repo-supported features and validate with coordinated build and analyzer steps.

Does this approach work with .NET projects planning API reshaping and performance improvements?▼

Yes, this approach works for .NET projects planning API reshaping and performance improvements by applying version-aware C# features safely. It coordinates with project tooling to validate changes across build, test, and analysis steps.

What are the limitations of adopting modern C# features in an older .NET codebase?▼

The primary limitation is the TargetFramework constraint, which caps the available language features regardless of the LangVersion setting. Safe feature selection must respect this ceiling to avoid introducing incompatible code that fails build validation.