General .NET Detectors

These detectors flag common .NET anti-patterns. They work on any .NET codebase.

AP001 — AsyncVoidDetector

Severity: Error

Detects async void methods. These cannot be awaited, swallow exceptions, and cause unpredictable behavior. Use async Task instead.

// Bad
public async void DoWork() { await Task.Delay(1); }

// Good
public async Task DoWork() { await Task.Delay(1); }

Exception: Event handlers (void OnClick(object sender, EventArgs e)) are excluded.

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AP002 — SyncOverAsyncDetector

Severity: Warning

Detects synchronous blocking on async code: .Result, .Wait(), .GetAwaiter().GetResult(). These cause deadlocks in ASP.NET Core.

// Bad
var result = GetDataAsync().Result;
GetDataAsync().Wait();
var result = GetDataAsync().GetAwaiter().GetResult();

// Good
var result = await GetDataAsync();

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AP003 — HttpClientInstantiationDetector

Severity: Warning

Detects new HttpClient(). This causes socket exhaustion under load. Use IHttpClientFactory instead.

// Bad
var client = new HttpClient();

// Good — inject via DI
public MyService(IHttpClientFactory factory)
{
    var client = factory.CreateClient();
}

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AP004 — DateTimeDirectUseDetector

Severity: Warning

Detects DateTime.Now and DateTime.UtcNow. These are untestable. Inject TimeProvider (or IClock) instead.

// Bad
var now = DateTime.UtcNow;

// Good
public MyService(TimeProvider timeProvider)
{
    var now = timeProvider.GetUtcNow();
}

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AP005 — BroadCatchDetector

Severity: Warning

Detects catch (Exception) without a re-throw. Broad catches hide bugs and swallow critical exceptions like OutOfMemoryException.

// Bad
catch (Exception ex) { logger.LogError(ex, "Failed"); }

// Good
catch (Exception ex) { logger.LogError(ex, "Failed"); throw; }

// Better — catch specific exceptions
catch (HttpRequestException ex) { ... }

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AP006 — LoggingInterpolationDetector

Severity: Warning

Detects string interpolation in log calls. Interpolated strings are always allocated, even when the log level is disabled. Use structured logging templates.

// Bad
logger.LogInformation($"User {userId} logged in");

// Good
logger.LogInformation("User {UserId} logged in", userId);

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AP007 — PragmaWithoutRestoreDetector

Severity: Info

Detects #pragma warning disable without a matching #pragma warning restore. Forgotten restores suppress warnings for the rest of the file.

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AP008 — MissingCancellationTokenDetector

Severity: Info

Detects async methods that don't accept a CancellationToken parameter. Without cancellation support, long-running operations cannot be stopped gracefully.

Note: Requires semantic model (full compilation). Skipped in syntax-only mode.

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AP009 — EfCoreNoTrackingDetector

Severity: Info

Detects EF Core queries that don't use .AsNoTracking(). Read-only queries should use AsNoTracking() to avoid change tracker overhead.

Note: Requires semantic model (full compilation). Skipped in syntax-only mode.