Nice Kata overall. Nice to use OOP for once whereas you can get away with static methods for most other Katas (Java).

Surprised there was no tests and it would have clarified things about the task however, was still good as I actually wrote a whole suite of tests on a Kata for once.

I feel like an example could be used for 0 itemIndex as I wasn't reading properly and unsure whether item was indexed or not. helper.pageIndex(0); //should == 0 (itemIndex = 0, pageIndex = 0)

Are we supposed to use recursion? I thought the Kata suggests so but after finishing I saw loads of solutions that don't.

Accidentally cheated the Kata. Really needs a fix. I thought is something missing?. Well ... can see my thought process in my solution.

But looking at the solutions, no idea how people came to the conclusion for bomb #IsSomethingMissing?

I don't understand the task. The inputs are string of code that does xyz, I understand. Byte array from the String also given as input which you use only when , code is reached?? Everything else, I don't. Am I supposed to initalise a byte list/array and use this with the data pointer? Or is that from the String input??

(Javascript) Test cases doesn't include negative numbers. My solution passed this Kyu but custom tests fails with negative numbers.

Gosh I feel dumb.

What's the big O notation for this?

Are the random tests wrong?
input: [37, 1, 10, 87, 47, 47, 21, 64, 92, 94, 28, 7]

returned: [1, 20, 261, 188, 235, 126, 448, 736, 846, 280, 77] but should equal [20, 522, 564, 940, 630, 2688, 5152, 6768, 2520, 770]

The expected answer is the derivative of the derivative but I'm only expecting it to be done once.

Didn't realise suggestions meant suggested changes for the question. Thought it simply was there to help people solve it. My bad

For JS this.valueOf() returns you the actual string to manipulate.

use this.valueOf() which provides the actual string which to use. I've spend hours looking for in documentation only to stumble onto it accidentally in my IDE.