public void Throw_ArgumentException_If_Passed_Values_Is_Null(string x, string y)
{
var comparer = new PrefixStringComparer();
Action compareAction = () => comparer.Compare(x, y);
compareAction.Should().Throw <ArgumentException>().And.Message.Should().Be("Passed string could not be null");
}
public void TestCompares(string x, string y, int expectedResult)
{
var comparer = new PrefixStringComparer();
var result = comparer.Compare(x, y);
result.Should().Be(expectedResult);
}