Code inspection: NUnit. Async test method must return Task or Task<T>

Category	NUnit
ID	`NUnit.AsyncMethodMustBeTask`
EditorConfig	`resharper_n_unit_async_method_must_be_task_highlighting`
Default severity	Warning
Language	C#
Requires SWA	No

Async test methods in NUnit 3.x must return either Task if no value is returned, or Task<T> if a value of type T is returned. Below are two situations where async tests will not be working correctly.

[Test]  // Warning: Async test method is void
public async void Test1()
{
    // do something
    await Task.CompletedTask;
}

[Test] // Warning: NUnit 3.10 does not support ValueTask
public async ValueTask<int> Test2()
{
    // do something
    return await Task.FromResult(100);
}

    

In both situations you need to rewrite test methods so that they return either Task or Task<T>.

Last modified: 11 February 2024