Cursor rule

1---
2paths:
3  - "**/*.cs"
4  - "**/*.csx"
5---
6# C# Patterns
7 
8> This file extends [common/patterns.md](../common/patterns.md) with C#-specific content.
9 
10## API Response Pattern
11 
12```csharp
13public sealed record ApiResponse<T>(
14    bool Success,
15    T? Data = default,
16    string? Error = null,
17    object? Meta = null);
18```
19 
20## Repository Pattern
21 
22```csharp
23public interface IRepository<T>
24{
25    Task<IReadOnlyList<T>> FindAllAsync(CancellationToken cancellationToken);
26    Task<T?> FindByIdAsync(Guid id, CancellationToken cancellationToken);
27    Task<T> CreateAsync(T entity, CancellationToken cancellationToken);
28    Task<T> UpdateAsync(T entity, CancellationToken cancellationToken);
29    Task DeleteAsync(Guid id, CancellationToken cancellationToken);
30}
31```
32 
33## Options Pattern
34 
35Use strongly typed options for config instead of reading raw strings throughout the codebase.
36 
37```csharp
38public sealed class PaymentsOptions
39{
40    public const string SectionName = "Payments";
41    public required string BaseUrl { get; init; }
42    public required string ApiKeySecretName { get; init; }
43}
44```
45 
46## Dependency Injection
47 
48- Depend on interfaces at service boundaries
49- Keep constructors focused; if a service needs too many dependencies, split responsibilities
50- Register lifetimes intentionally: singleton for stateless/shared services, scoped for request data, transient for lightweight pure workers
51