v2 v3   Error

xUnit1049

"Do not use 'async void' for test methods as it is no longer supported"

Cause

A violation of this rule occurs when an async test method returns void.

Reason for rule

Support for async void test methods has been removed in xUnit.net v3. This rule will only trigger for v3 projects.

How to fix violations

To fix a violation of this rule, change the test method return type to Task or ValueTask.

Examples

Violates

using Xunit;

public class TestClass
{
    [Fact]
    public async void TestMethod()
    {
        // ...
    }
}

Does not violate

using System.Threading.Tasks;
using Xunit;

public class TestClass
{
    [Fact]
    public async Task TestMethod()
    {
        // ...
    }
}

using System.Threading.Tasks;
using Xunit;

public class TestClass
{
    [Fact]
    public async ValueTask TestMethod()
    {
        // ...
    }
}