Atbash Cipher Test Cases Might Be Wrong

Exercism Bugs & Feature Requests
1

I’ve been looking at Atbash Cipher test cases, and it seems to be they are not really testing for what Atbash Cipher really is.

The exercise description states:

(Atbash) Ciphertext is written out in groups of fixed length, the traditional group size being 5 letters, leaving numbers unchanged, and punctuation is excluded.

But the actual Atbash cipher, as generally understood, leaves punctuation as-is and doesn’t group letters in 5 letter-groups.

Any relevant definition or tool I found online confirms this (e.g. Atbash)

I think we should either write the exercise to actually work like Atbash, or we should rename the exercise, so as not to cause confusion.

2

Exercism relies heavily on test driven development. Students are expected to run the tests to understand the details of what is actually required. The tests make the requirements quite clear. Students should not assume implementing details from any source other than the tests. This is true of all the practice exercises.