same solution)

there are no real random tests in Ruby

It's regular expressions, they are not supposed to be readable. It's a great tool that you shouldn't avoid just because it doesn't look pretty.

Very nice and original kata.

Ruby 3.0 should be enabled (Refer this & this for more detail)

Need more some specific, random, as well as, corner test case.

Well thought regex. Simply loved it!

Removing the last $ would leak matches such as 255.255.255.255.123456789.
However, removing the second last $ would still work.

Could you help me understand the rule?

Test.assertSimilar(calculate("@~~~~@+@~@@"), "@~~~@~@@@") // 1001+12 => 1013

I'm coufunsed why the result is "@~~~@@@@" rather than "@~~@@@@". Thanks.

Agreed... definitely not best practices haha. As Voile said though it's a RegEx issue, not a JS issue.

Awesome! I think you can save one char; redundant $ at the very end. Unless someone can find a case where it's needed?

To be fair, it has nothing to do with JS but has to do with regexes. There's another kata of the same task (but in C#) and it's still the same kind of mess.

I think it's not a bug rather than lack of proper documentation. (updated)
But thanks for asking! :)

I just worried about I've asked a stupid question, rather than having found a bug on the kata 

The original rules of calculating quipu is what I mentioned above. (I will update the description instead of the tests)
Do you mind to change it according to that?