Duplicate the current BeNullOrEmpty() & NotBeNullOrEmpty() but test for NullOrWhiteSpace.
Example.
string actual = "ABCDEFGHI";
actual.Should().NotBeNullOrWhiteSpace() // does not throw exception.
string actual = " ";
actual.Should().NotBeNullOrWhiteSpace() // does throw exception.
Example.
string actual = "ABCDEFGHI";
actual.Should().NotBeNullOrWhiteSpace() // does not throw exception.
string actual = " ";
actual.Should().NotBeNullOrWhiteSpace() // does throw exception.