Trinity of test - XUnit

TrinityTestXUnit.cs

[Theory]
[InlineData(2)]
[InlineData(0)]
[InlineData(-1)]
public void Should_Correctly_Detect_Negative(int value)
{
    var service = new NegativeService();
    if(value < 0)
        Assert.True(service.IsNegative(value));
    else
        Assert.False(service.IsNegative(value));
}