General

## General

* Make only high confidence suggestions when reviewing code changes.
* Always use the latest version C#, currently C# 13 features.

## Formatting

* Prefer file-scoped namespace declarations and single-line using directives.
* Insert a newline before the opening curly brace of any code block (e.g., after `if`, `for`, `while`, `foreach`, `using`, `try`, etc.).
* Ensure that the final return statement of a method is on its own line.
* Use pattern matching and switch expressions wherever possible.
* Use `nameof` instead of string literals when referring to member names.
* Ensure that XML doc comments are created for any public APIs. When applicable, include `<example>` and `<code>` documentation in the comments.

### Nullable Reference Types

* Declare variables non-nullable, and check for `null` at entry points.
* Always use `is null` or `is not null` instead of `== null` or `!= null`.
* Trust the C# null annotations and don't add null checks when the type system says a value cannot be null.

### Testing

* We use xUnit SDK v3 for tests.
* Do not emit "Act", "Arrange" or "Assert" comments.
* Use Moq for mocking in tests.
* Copy existing style in nearby files for test method names and capitalization.