Litterally uses test.assert_equals as test.expect.

1. I have no idea what to do... so the description is a problem.
2. Your tests are written poorly (see my solution for hack)
3. What is the point of the <0.22ms thing?

Yet another transform-the-string kata, nothing novel.

Hi,

well, there are a lot of problems/things lacking in your kata. Not unusual for a first try, ofc. ;)

First, I'd recommend you to read those docs, so that you get some ideas about what's expected from a kata/kata author:

• https://github.com/codewars/codewars.com/wiki/Tutorial%3A-Create-Your-First-Kata
• https://github.com/codewars/codewars.com/wiki/Kata-Creator

And about your kata:

• no sample tests
• no random tests
• the description is especially unclear (we're supposed to apply those changes on "words" and not on the full input, for example / wording is sometime hard to understand (because of your english, as you stated it below. Like: "Change the first letter in the string to the last one(after converting to ASCII)" -> "Exchange... with the last one... ")

cheers