Using a directory is more simple ;-)

I think so.

PS: Have you seen my solution?

I'm not sure who marked you down, so I'll mark you back up, agree, and expand. 0 and 1 should probably be excluded from the domain of the function. factorize(0) == [0] and factorize(1) == [1] are mathematically untrue: both have infinite factors. The latter might make sense if the function was to return only a single instance of a factor (since the natural factors of 1 are an infinite sequence of 1s). Except, in that case, the descrition should have stuck with "smallest" and specified ℕ. Instead it mentions prime numbers, so 1 is out. For factorize(0), if it must be included, the output should be either ℕ or ℙ (where ℙ represents the set of prime numbers) depending on the description; or a successful run should just raise a memory error...

Should be retired?

No random tests (above all other issues mentioned below).

factorize(0) does not make any sense. Why're you even putting such a test case up in the first place?

Looks like a duplicate:
http://www.codewars.com/kata/prime-factors
http://www.codewars.com/kata/prime-factorization

Sorry, I managed to miss a mistake in my solution even after reviewing it several times.

You may be right, but the tests run fine with my code (and others).
Prehaps your algorithm is taking too long to run?
I am new to writing Katas - are my tests visible to you?
If so, can you point out the one that seems problematic?

Process was terminated. It took longer than 6000ms to complete
It looks like the problem is in the tests.

This... This works. How?

Nice Kata for fundamentals

Unfortunatly, I am all out of prizes:(
Title changed....

You might want to change the title, unless you plan to give out a prize! :)