Bowling Parser in C#

BowlingServiceParserTest.cs

[TestClass]
    public class BowlingServiceParserTest
    {
        [TestMethod]
        public void number_from_one_to_nine_translate_to_the_number()
        {
            int[] result = BowlingServiceParser.Parse("123456789");

            CollectionAssert.AreEqual(new int[] {1,2,3,4,5,6,7,8,9}, result);
        }

        [TestMethod]
        public void gutter_symbols_translate_to_zero()
        {
            int[] result = BowlingServiceParser.Parse("--");

            CollectionAssert.AreEqual(new int[] { 0, 0 }, result);
        }

        [TestMethod]
        public void char_x_translate_to_the_number_ten()
        {
            int[] result = BowlingServiceParser.Parse("X");

            CollectionAssert.AreEqual(new int[] {10}, result);
        }

        [TestMethod]
        public void char_slash_translate_to_ten_minus_previous_number()
        {
            int[] result = BowlingServiceParser.Parse("1/");

            CollectionAssert.AreEqual(new int[] {1, 9}, result);
        }
    }
    
    public class BowlingServiceParser
    {
        public static int[] Parse(string symbols)
        {
            var numbers = new List<int>();

            foreach(var symbol in symbols)
            {
                if (symbol == '-')
                {
                    numbers.Add(0);
                }
                else if (symbol == 'X')
                {
                    numbers.Add(10);
                }
                else if (symbol == '/')
                {
                    numbers.Add(10 - numbers.Last());
                }
                else {
                    numbers.Add(Convert.ToInt32(Char.GetNumericValue(symbol)));
                } 
            }

            return numbers.ToArray();
        }
    }