first it checks if n <= 2:

• negative numbers are not prime
• 0 is not prime
• 1 is not prime
• 2 is prime
  second check is to find out if number is even: n % 2 == 0:
• even numbers cannot be prime except for two
  So in the end if any of those checks is true it will execute: return n == 2
• return true is we check if 2 is prime - it is!
• return false for all other cases

flatMap is supported by Node 11 onwards.

Any idea why I can't use Array.flatMap() in js ?

I think it may have more to do with this:

Attempting to invoke an infinitely recursive pattern of any form (including non-recursive patterns which call on infinitely recursive patterns in their pattern body, etc.) in the global scope. Extreme cases (e.g. 500 levels of non-infinite recursion) will not be tested in the test cases so a sensible recursion limit will do.

well, I guess I miss something, then :/

What do you mean by speed required? There are no performance tests, if anything's slow then maybe you're missing some logic.

I'm doing this kata in js. Everything is fine and working, just trying to speed up things.
I see that people speak about 200 AST tests to pass. I do not have a clue about what it means.

So far, my code can run some ~2000 chars generated tests in ~4.3ms. (taken from the "attempt" tests via console.log)
Any way to measure if I'm still far from the speed required ?
Can I have an exemple of those "AST test" so I can measure my speed against 200's of them ?

:D

i was using =+ in stead of +=.

awesome.

Thanks, I'm actually print testing some different cases now. This is the first one I'm refusing to resort to google for and I'll give up on coding altogether before I skip it.

Given two integer arrays a, b, both of length >= 1

This means they'll always be filled. Maybe you didn't read the instructions carefully enough, or missing some edge cases. Try printing the inputs and look at what the errors are telling you.

How do you know how much randomized tests you passed ?
I can't seem to output anything once those starts. (JS)

I'm stuck on the solution for Python, I'm assuming it has something to do with "both of length >= 1" in the instructions, but what am I supposed to return if one of the arrays is len < 1? I'm getting Passed: 638 Failed: 39 Exit Code: 1

@FischerEnterprise
Thank you very much for your comment about counting details. It should be added to the kata description.

shouldWorkForRandomlyGeneratedMiniStringFuckPrograms

Last test, not working. Any hint?