csharp-extension-methods

name	csharp-extension-methods
description	A skill for generating C# extension methods. Use this whenever you are going to generate an extension method in C#

Avoid this keyword for extension methods. Prefer extension blocks from C# 14 instead.

You can also use the Microsoft Learn MCP server to learn more about extension blocks in C# >= 14.

Bad

public static class StringExtensions
{
    public static bool IsNullOrEmpty(this string str)
    {
      return string.IsNullOrEmpty(str);
    }
}

Good

public static class StringExtensions
{
  extension(string str)
  {
    public bool IsNullOrEmpty()
    {
      return string.IsNullOrEmpty(str);
    }
  }
}