The description doesn't say you can ignore casing. Most of the answers assume "Zero", "FOUR", or "tWo" don't exist.

It'd be nice if the problem said you only recieve lowercase letters. Maybe it can be an extra level of difficulty too. :)

The task at its code is "replace a list of substrings with their corresponing substrings", so the idea is not novel at all.

The specs does not mention what is the set of things that should be replaced: what about eleven? hundred?

Hi,

lots of problems here... :/

• your internal algo is bad: you send strings with trailing whitespaces, but expect them to be removed in the output while it's not specified (don't use split...)
• no fixed tests...
• ... but not enough tests too
• range of the numbers to handle is unspecified (edit: I guess that "digits" could be enough there, yes...)
• duplicate of other "words -> numbers" kata we already have.

Imo, you should just unpulbish this one. ;)