describe("Solution", function() {
  it("should test for something", function() {
    // Test.assertEquals(1 + 1, 2);
    // assert.strictEqual(1 + 1, 2);
  });
});

Is it String split or both?

I found something Helpful suggestion from early comments and just want to repost what he commented
It is pretty helpful to understand that's why..
Crd --- Tigerdevon
Example:

longest_consec(["it","wkppv","ixoyx", "3452", "zzz4zzzz9zzz"], 3)
The three options:

1) [0]"it"    [1]"wkppv" [2]"ixoyx"        ; "itwkppvixoyx"
2) [1]"wkppv" [2]"ixoyx" [3]"3452"         ; "wkppvixoyx3452"
3) [2]"ixoyx" [3]"3452"  [4]"zzz4zzzz9zzz" ; "ixoyx3452zzz4zzzz9zzz" 

k(int) is the reason why there are 3 strings per answer

The answer is:

3) "ixoyx3452zzz4zzzz9zzz"

I really can't use console.log() bro
I need to use return if not it keeps showing errors.

wish someone might help with my problems :(
not like i don't want to try another solution...
just want to know about my code.....

I know but it keep saying error in expected even tho i got the right one :((

I used return becoz i can't use console.log if i use it it won't work and
if u don't mind can u show me how to ?
I appreciate ur reply.