Why is the unit test not working?

Question

C++ / C#

I wrote a simple test that checks for null, but for some reason it does not work.
There is a class:
class StringHelper
public static string Cut(string text, int tLength)
{
if(text.Length>twittLength)
{
text = text.Remove(twittLength);
}
return text;
}
I am writing a test for the Cut method:
[TestMethod]
public void TestNullText()
{
var text = StringHelper.Cut(null, default(int));
Assert.IsNull(text);
}
it is not executed, I can not understand what the error is, please tell me.

Answer 1

Cohenically, the test will fail with an exception, because there is no check for null in the desired function