LeetCode_Algorithms_2_Add_Two_Numbers_TestCase2

LeetCode_Algorithms_2_Add_Two_Numbers_TestCase2.cs

[TestMethod]
public void OneDigit_AddOneDigit_ReturnValueGreaterThan10_3_Plus_9_Equal12()
{
    No2_AddTwoNumbers.ListNode firstNumber = new No2_AddTwoNumbers.ListNode(3);
    No2_AddTwoNumbers.ListNode secondNumber = new No2_AddTwoNumbers.ListNode(9);

    No2_AddTwoNumbers.ListNode result = solution.AddTwoNumbers(firstNumber, secondNumber);

    // result should be 12, first digit in linked list is 2, the second digit is 1
    Assert.AreEqual(2, result.val);
    Assert.AreEqual(1, result.next.val);
}