AsyncFixer 1.3.0

Here are async/await misuses (i.e., anti-patterns) that AsyncFixer can currently detect:

AsyncFixer01: Unnecessary async/await usage

There are some async methods where there is no need to use async/await keywords. It is important to detect this kind of misuse because adding the async modifier comes at a price. AsyncFixer automatically removes async/await keywords from those methods.

AsyncFixer02: Long-running or blocking operations inside an async method

Developers use some potentially long-running or blocking operations inside async methods even though there are corresponding asynchronous versions of these methods in .NET or third-party libraries. Some examples for such operations: Task.Wait(), Task.Result, StreamReader.ReadToEnd(), Thread.Sleep(), etc.

AsyncFixer automatically replaces those operations with their corresponding asynchronous operations and inserts an await expression. For instance, it converts Thread.Sleep(...) to await Task.Delay(...).

AsyncFixer03: Fire & forget async void methods

Some async methods are 'fire & forget', which return void. Unless a method is only called as an event handler, it must be awaitable. Otherwise, it is a code smell because it complicates control flow and makes error detection & correction difficult.

AsyncFixer automatically converts void to Task.

AsyncFixer04: Fire & forget async call inside a using block

Inside a using block, developers insert a fire & forget async call which uses a disposable object as a parameter or target object. It can cause potential exceptions or wrong results. For instance, developers create a Stream in the using statement, pass it to the asynchronous method, and then Stream will be implicitly disposed via a using block. When the asynchronous method comes around to writing to Stream, it is (very likely) already disposed and you will have an exception.

AsyncFixer05: Downcasting from a nested task to an outer task.

Downcasting from a nested task (Task<Task>) to a Task or awaiting a nested task is dangerous. There is no way to wait for and get the result of the child task.

Visual Studio Extension

If you want AsyncFixer to work just in the IDE and to work as an analyzer on every project you open in Visual Studio, please download the VSIX extension instead of this NuGet package from here: AsyncFixer - Visual Studio plugin