there are now sample tests in Ruby and the assertions use RSpec. the only thing missing is random tests

It would be helpful if the description of kata mentioned functions and operators instead of "SQL magic"

0's don't make sense, how should those be treated ..

wowww. Nice. now I feel stupid xD

I haven't taken on this kata yet, but I already want to say that yes, this is a greate classic task, thanks!

fixed in ruby too

fixed for JS. if applicable to Ruby, please reraise.

All languages now have random tests, closing.

Fixed for JS

🤦 that was embarassing. thanks for your help :)

Your current unshift() function will actually move the existing values by the length of the original list list.length, not the amount of added by unshift elements elements.length; since the filter fixed tests are using the list after unshift tests and other, it'd be broken.

can you check the Ensuring the original list is not changed test ? I am fairly certain that my filter implementation is pure, but i get list[3] has been modified: expected 10 to equal 2. it seems as though this test is actually checking the original list against the filtered one

Reworked the tests so that the error messages should be more concise now.

Really good kata, I learned a lot while struggling to reduce chars.