No idea what you're doing but, you passed the kata and with your current code I can't reproduce that error. The control function returns "Winner!" for that input too. You can see that for yourself.
The tests only pass strings containing letters. Otherwise, it is expectable the description would state it, and provide some more examples to see the different cases.
from your test where does 'b' come from?
Your code do a correct answer, don't mind whats wrong with it
done
Because the author doesn't mention it and everyone is lazy pretty much
Probably that's because that solution mutates the input, affecting the expected value.
Post your code that fails: https://docs.codewars.com/training/troubleshooting#post-discourse so it can be checked.
No idea what you're doing but, you passed the kata and with your current code I can't reproduce that error. The control function returns
"Winner!"for that input too. You can see that for yourself.The tests only pass strings containing letters. Otherwise, it is expectable the description would state it, and provide some more examples to see the different cases.
The input has a C. Not a kata issue.