xUnit

Unit testing framework.

What is xUnit

xUnit is the de-facto test framework for .NET — tests are methods marked [Fact] or [Theory].

cli

bash

dotnet add package xunit

csharp

public class MathTests {
    [Theory]
    [InlineData(2, 3, 5)]
    public void Adds(int a, int b, int sum) => Assert.Equal(sum, a + b);
}

Official documentation: xUnit.