Clearly there are always multiple solutions, but prioritising the possible answers as follows seems to succeed:
(1) Solutions that don't involve fractions.
(2) Solutions that refer to the "first seen" variables in the list of examples.

OP solved it, closing

I would love to know too. Two people already tried to explain it to me and failed ;D There must be a reason why this kata is tagged as puzzle.

good

That is just an artifact of how the test results are printed, it's not an error in your solution.

It should be other way around, and for that there are many issue raised below.

Not if the kata hasn't Node 12.x enabled.

Javascript tests are ok.

Those are the expected values, your function always returns 0, 1 or 2 (and it's wrong).

You're returning different data type and mark your post as having spoiler content next time, please. The same when you comment a solution.

The string has a length greater or equal to one and contains only letters from a to z.

Any letter not in a to m is an error. Read the description again.

Please don't post solutions in Discourse.