csharp-lang

Workflow

1. Use compliance date 2026-03-30.
2. Assume C# 14 on .NET 10 (net10.0) unless the repository already targets another version or the user asks otherwise.
   • Follow the repo's existing target frameworks and compatibility constraints before up-leveling code.
3. Before touching any .cs, .csproj, .props, or .targets file, load ${CLAUDE_SKILL_DIR}/resources/01_universal_guidelines.md.
   • This base guideline applies to all C# work.
4. Add only the guideline files that match the task.
   • 02_modern_syntax.md — records, primary constructors, extension members, field-backed properties, pattern matching, collection expressions
   • 03_async_patterns.md — async/await, ValueTask, cancellation, async enumerable, deadlock avoidance
   • 04_collections_linq.md — LINQ idioms, IEnumerable vs IQueryable, materialization, collection choices
   • 05_error_handling.md — exception patterns, Result types, nullable reference types, validation
   • 06_testing.md — xUnit/NUnit/MSTest tradeoffs, mocking, test naming, arrange-act-assert
   • 07_performance.md — Span, Memory, stackalloc, pooling, ref struct, benchmarks
   • 08_library_design.md — API shape, dependency injection boundaries, configuration, logging integration
   • 09_aot_source_generators.md — AoT compatibility, Native AOT, JSON source generators, trimmer safety
   • 10_documentation.md — XML docs, README patterns, example code
   • 11_project_baseline.md — net10.0 defaults, multi-targeting, LangVersion, analyzers, CI expectations
5. Read the needed guidance from ${CLAUDE_SKILL_DIR}/resources/.
   • For larger files, run rg '^## ' <file> first and read only the relevant sections.
   • These resources complement tooling by covering design judgment, API ergonomics, and modern C# idioms.
6. Apply the loaded guidance before generating, modifying, or reviewing any C# code.
   • Treat this skill as mandatory for all C# work, including small edits and review tasks.
   • Prefer modern C# syntax when it improves clarity, correctness, or API design; do not use newer constructs purely to shorten code.
   • Use records for value semantics and primary constructors when constructor parameters genuinely represent the type's ongoing state or dependencies.
   • Write comments and documentation in American English unless the user asks otherwise.
7. Do not add compliance marker comments to source files.
   • Record compliance in review output, tests, analyzers, or automation instead of code comments.