My code in VS CODE works perfectly with basic tests, but in codewars, with random tests, that have a long expected result, I have a problem.
Is there any way to see test arguments?

It is not clear to me why the test with integers cannot pass. The function([1,2,3]) gives the expected result ['1','2','3'] but the test still does not pass

Pay attention, my friend, on last element of test2 array. There is diffrence. In instructions is "5", but in Tests is "3", becouse length of arrays is diffrent. In instructions parameter "n" presents maximum INDEX of fib. Array, and on Tests "n" presents maximum length of array.

I've tested my code in console, and it works as expected, but when it's pasted in codewars, error pops up. That's how error is spoted.

In JS version, in Test_2, expected result is 44 but it should be 10.

Problem is difference between instructions and tests
Instruction → INDEX in the Fibonacci sequence → Exemple 1, n=5, [0,1,1,2,3,5]
Tests → Arrray.length → Test 1, n=5, [0,1,1,2,3]

JavaScript, wrong samples 99 and 983212

I have problem with random receive. Every time random text include one unprintable character witch is not in range of ASCI code 32 - 127. As expected result I get some wierd characters. "to equal" result, same character is unprintable, even in VS code, when I copy/paste, it is presented as empty space.

Maybe you could enter this string as test:
' !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[]^_`abcdefghijklmnopqrstuvwxyz{|}~'

I keep getting this message: Cannot read property 'length' of null (javascript)

What do you expect to get for 'null' object?