The expected value was already the first parameter of Assert.AreEqual in C#.

Although, it might be a good idea to move the empty string test out of the random tests, into its individual test case, to avoid confusion?

Yes, this is true. I will try to address this issue.

I apologize. It seems the problem was coming from the empty-string test showing a fail while I was still working on my solution and I got confused, thinking the previous test giving incorrect output.

Although, it might be a good idea to move the empty string test out of the random tests, into its individual test case, to avoid confusion? Also add it to the KATA's description that the expectation for an empty input is "true".

Can you show a screenshot of such incorrect test? I cannot reproduce the issue, both of your solutions consistently pass for me.

Sometimes the random tests are straight up incorrect in C#.
E.g. expecting "(" to return true. I had to ran the Kata with my solution a few times until it finally passed.

The assertions in the C# Random tests are also written incorrectly, mixing up the Expected and Actual. Please put the expected value as the first parameter of Assert.AreEqual. We regularly saw "Actual" not being what we Console logged as "our answer :".

why inside the loop cnt = -1 but outside the loop cnt = 0????

Please don't post solutions in Discourse like that. Discuss a solution in Solutions. You might find this useful too: Pythontutor