Is this kata a shameless advertisment?

Thanks, that was fun!

Duplicate Issue. Closing.

Duplicate issue anyway. Closing.

Added.

@bozh, I agree 👍 str.each_char seems like a better option.

str.chars is a shorthand for str.each_char.to_a (ref: http://ruby-doc.org/core-2.5.0/String.html#method-i-chars)

So, use str.chars before .map is inefficient.

Me too... Spoilers.... :)

language?

Needs random tests

Done.

On it.

JavaScript by convention uses camelCase, not snake_case. The JavaScript translation does not.

Please follow convention.

Added a Javascript translation!