Instruction file imported from oskarc/AssetHub (.github/instructions/csharp.instructions.md). Copyright stays with the author.

C# — AssetHub Overrides

These rules override generic C# guidance for the AssetHub project.

Project-Specific Rules

• C# 13 (.NET 9) —
• DataAnnotations only for validation — do not use FluentValidation. DTOs use [Required], [StringLength], [Range].
• sealed on all service and repository implementations.
• Primary constructors preferred for DI injection in services and repositories.
• Nullable reference types enabled globally — use is null / is not null, never == null.
• PostgreSQL + EF Core 9 — not SQL Server or SQLite.
• Keycloak OIDC for auth — not Microsoft Entra ID or ASP.NET Identity.
• ServiceResult<T> for business error handling — never throw for expected errors. No RFC 9457 Problem Details pattern.
• No Swagger/OpenAPI — endpoints are consumed by the Blazor UI, not external API clients.
• Apply .editorconfig formatting rules from the repository root.
• xUnit + Moq + Testcontainers for testing — not NUnit or MSTest.

General C# Patterns Still Apply

The generic C# instruction guidance for the following topics remains valid:

• PascalCase for types/methods/public members, camelCase for locals/fields.
• I prefix for interfaces.
• File-scoped namespaces, pattern matching, nameof.
• Async/await for I/O-bound operations.
• Structured logging with named arguments.
• Test naming: MethodName_Condition_ExpectedResult.
• No == null — use is null / is not null.