public void TestTheBug() { // arrange var stack = new StackService(); stack.PushToStack(1); stack.PushToStack(2); stack.PushToStack(3); stack.PushToStack(4); stack.PushToStack(5); int[] result = stack.PopAllItemsAndReturnResult(); // assert Assert.AreEqual(5, result[0]); Assert.AreEqual(4, result[1]); Assert.AreEqual(3, result[2]); Assert.AreEqual(2, result[3]); Assert.AreEqual(1, result[4]); }