public void FindNextBiggerNumber_NegativeTests(int number)
        {
            var expected = -1;

            Assert.AreEqual(expected, IntNumberOperations.FindNextBiggerNumber(number));
        }
 public void FindNextBiggerNumber_ThrowsArgumentException(int number)
 {
     Assert.Throws <ArgumentException>(() => IntNumberOperations.FindNextBiggerNumber(number));
 }
 public void FindNextBiggerNumber_PositiveTests(int number, int expected)
 {
     Assert.AreEqual(expected, IntNumberOperations.FindNextBiggerNumber(number));
 }