C# Analyzer and Code Fix Developer

This skill provides comprehensive guidance for developing Roslyn analyzers and code fix providers in the OpenRewrite C# project.

Project Structure and Placement

Analyzers: [Category][Action]Analyzer.cs (e.g., NamingConventionAnalyzer.cs, ActionContextAccessorObsoleteAnalyzer.cs)
Code Fix Providers: [Category][Action]CodeFixProvider.cs (e.g., NamingConventionCodeFixProvider.cs)
Test Files: [AnalyzerName]Tests.cs and [CodeFixProviderName]Tests.cs
If analyzer targets an interface (such as IActionContextAccessor), the analyzer name should drop the I from the prefix as that clashes with naming convention identying interfaces - an analyzer is not an interface. Instead, it should name it like ActionContextAccessorObsoleteAnalyzer.
Analyzers shall define DiagnosticId starting with characters OR (meaning OpenRewrite developed recipes). The next set of characters shall identify the target framework or package that the diagnostic is targeting. For example for recipes that help identify / fix issues when migration .NET framework versions, it would include NETX. The X is the roman numeral of the version 10 of .NET implying that the recipes targets migration to version 10. Roman numerals are used here as to not clash with the last digits of diagnostic id which are sequentially imported. The last number are 4 digits incrementing number for that specific issue for the target version. Full example for analyzer targeting issues in .NET 10: ORNETX0001.