async-hygiene

name	async-hygiene
description	Find and fix async/await anti-patterns in C# code — blocking calls, async void, missing cancellation, fire-and-forget. Use when reviewing async code, diagnosing deadlocks or thread-pool starvation, or when the user asks about async correctness.

Async/Await Hygiene Sweep

Scan the target scope (default: whole solution) for each anti-pattern, in this order, and fix with the standard remedy:

Anti-pattern	Find	Fix
Sync-over-async	.Result, .Wait(), .GetAwaiter().GetResult()	Make the caller async and await
async void	any non-event-handler	Return Task
Missing CancellationToken	async public methods without a token parameter	Add CancellationToken cancellationToken = default and thread it through
Fire-and-forget	unawaited Task-returning calls	Await, or route through a background service with error handling
Task.Run in ASP.NET request path	Task.Run( in Api project	Remove — the request is already on a thread-pool thread
Async lambda passed to sync delegate	async lambda to Action<>	Change delegate type or restructure
Unnecessary async/await wrapper	method whose only await is the final return	Return the Task directly (unless in a using/try)
Blocking I/O in async method	File.ReadAllText, Thread.Sleep inside async	Use async equivalents (ReadAllTextAsync, Task.Delay)

Process: grep for each pattern → read the surrounding code (some hits are legitimate, e.g. Main, console tools) → fix true positives → dotnet build → report a table of what changed and any hits deliberately left alone with reasoning.