Unexpected GreaterThan(NaN) behavior about nunit

[manfred-brands]

@shimat I can confirm this issue, but what is correct is not that straight forward:

NUnit will use Double.CompareTo

This contains the following table:

[Test]
public void CompareWithNaN()
{
    const double actual = 0.1;

    Assert.Multiple(() =>
    {
        Assert.That(actual.CompareTo(double.NaN), Is.Positive);
        Assert.That(double.NaN.CompareTo(actual), Is.Negative);
        Assert.That(double.NaN.CompareTo(double.NaN), Is.Zero);

        Assert.That(actual, Is.GreaterThan(double.NaN));
        Assert.That(double.NaN, Is.LessThan(actual));
        Assert.That(double.NaN, Is.EqualTo(double.NaN));

        Assert.That(actual > double.NaN, Is.True);
        Assert.That(double.NaN < actual, Is.True);
        Assert.That(double.NaN == double.NaN, Is.True);
    });
}

Which matches the current NUnit behaviour, but not the C# expression as only the last 3 tests fail.

[shimat]

Thank you, I understand.
I still think GreaterThan when NaN is in the argument is misleading behavior, but I understand the reason and this issue can be closed.