There are no random tests.

transcode_char_lambda is never needed or tested anywhere, the only method tested is render, so there are no reasons for the former to exist.

Arguably, the entire kata can be put in a function instead of a superficial class as well.

As mentioned below, :leave with valid strings aren't tested.

Also, true Unicode characters aren't tested. All test cases only test characters inside Extended ASCII.

You could also do (0...number) instead of (1...number)

added

thanks!

How does the .reduce({}) work?

Check the docs.

I get an error

You're not supplying a block which might be the source of the problem.

How does the .reduce({}) work?

If I try

str = "a=1, b=2, c=3, d=4"
str.split(', ').reduce({})

I get an error:

main.rb:5:in `reduce': {} is not a symbol nor a string (TypeError)

hehehe. noice.

Noting something is hard to understand isn't a resolvable issue as there is no way for anyone to know what you found hard to understand.

Language?

I haven't used the "Create kata" function of Codewars in ages. I have marked this a "resolved" since you yourself haven't been on here since January. However, I would love to hear what you mean is unclear and what you want better.

Fixed

Simple example:

{5: 10, 10: 5}

Both users have the nexus of 5, which is also the lowest nexus among all users.

It doesn't reinvent the wheel which is what makes it a good solution.

If the kata wanted us not to use Matrix#det, it should have locked that method.