csharp-conventions

- .NET 8+ C# 12, file-scoped namespaces, primary constructors, `<Nullable>enable</Nullable>`. - Formatting: `dotnet format` + Roslyn analyzers, `<TreatWarningsAsErrors>true</TreatWarningsAsErrors>`. - Style enforcement: `.editorconfig` for consistent rules across team. Use an analyzer set (e.g., StyleCop.Analyzers or Roslynator). - Testing: xUnit with `[Theory]`/`[InlineData]`, an assertion library (e.g., FluentAssertions), a coverage tool (e.g., coverlet) at 80%+. - Benchmarking: a benchmark harness (e.g., BenchmarkDotNet) for performance testing — never `Stopwatch` loops. - `record` types for immutable data, `required` properties, pattern matching in switch expressions. - Async: `async`/`await` throughout — never `.Result` or `.Wait()`, `ValueTask` for hot paths, avoid deadlocks. - Security: `dotnet list package --vulnerable` for CVE scanning. Zero tolerance for critical/high. - Dependencies: NuGet `PackageReference`, commit `packages.lock.json`, `Directory.Build.props` for shared config. - Collection expressions (`[1, 2, 3]`), `required` modifier, raw string literals for multi-line. - Anti-patterns: `dynamic`, `object` params, unguarded `catch (Exception)`, `#pragma warning disable`.