csharp-conventions

name	csharp-conventions
description	C# coding conventions for CSharpEssentials. Use when writing, reviewing, or refactoring C# code in this project.

C# Conventions

• Nullable reference types are enabled globally. Every public API must have explicit nullability (string? vs string).
• Private fields: _camelCase. Properties and methods: PascalCase. Locals and parameters: camelCase.
• One public type per file; filename must match the type name exactly.
• Prefer sealed on concrete classes that are not designed for inheritance.
• Use readonly on fields that are set only in constructors.
• Extension methods live in a static class named <Subject>Extensions in the appropriate package.
• No dynamic. No object as a catch-all return type when generics work.
• Functional types (Result, Maybe, Any) use implicit operators for ergonomic construction — maintain this pattern in new types.
• Record types are preferred over classes for immutable value objects.
• TreatWarningsAsErrors=true is global — never suppress a warning without understanding why it fires.