For a question that is so closely related to pedantry (quirks and obscure details), it really should have a description that is correct:
'I can write numbers likes, 1, 2, 3.' does not include any numeric literals, that's a single string literal. Just say the source text cannot contain any digits and be done with it.

This did confuse me for a bit. These types of questions put me in the mindset of assuming a high degree of precision.

Good idea. I wish I'd thought of that when writing the kata. Alas, I think adding it now would be unfair to the people who've already submitted solutions, since I didn't specify in the description what the behavior should be when given an empty array.

Reading the docs often leads to a solution.

Very easy, solution in documentation you've provided

Perhaps there should be an empty array test case?