It depends on the language used to solve the kata. In Python, if using the new style classes, you can define read-only attributes. For example,

@property
def progress(self):
    return self._progress

will define a read-only attribute with the name progress. A client may invoke user.progress rather than user.progress(). Java does not have read-only fields, so the test suite should have used getters instead of referencing fields. Something got lost in translation. For the Python version, tests should be added to make sure that setting the rank or the progress fails.

In my opinion, this is an 'advanced' language feauture of Python, and if the kata had provided the tests suggested above, I would have given it 3 kyu. I am solving katas in Python while learning Python, and this kata definitely taught me something I didn't already know.

I had already downgraded this to 4kyu from 3kyu (which was definitely too high). This could maybe be a 5 kyu. Its tricky because this kata requires understanding business rules and following them, which a lot of people struggle with way more than others would think. I personally find some 7/6 kyu kata really hard just because I suck at math - but others can solve those problems in 10 seconds and find them trivial.

A big concern I have lately is that on average no one seems to think anything is harder than a 5 kyu anymore, because the community is now so large and we all think certain things are easier than others. Approving a 4 - 1kyu kata these days very rarely happens.

As for the Java translation. It seems to be offending a number of people due to the reasons @bkaes mentioned. If someone wants to fork their java solution and rewrite it the way that uses best OOP practices, I can update the kata manually with it.

Publicly accessible fields, …

That's actually a problem of the current translation process. The translator took the JS description as a hard requirement and didn't account for OOP practices.

By the way, I think Jake said that this kata wouldn't be 4kyu today. That being said, the difficulty is choosen by users during beta.

Agree, this was my first 4kyo kata and it felt simpler than other 5kyo that I solved earlier.

These were the exact same thoughts that ran through my mind as I was fleshing out the solution of this kata. Publicly accessible fields, ridiculously easy business logic, absence of advanced algorithms of any kind, a single class solution, no custom exceptions, enums or anything fancy to justify a 3kyu difficulty. The devout Java programmer in me was wincing the whole time; at least it was a short one :|

1. It's said:

you have to produce a sorted array P of the form
[ [p, sum of all ij of I for which p is a prime factor (p positive) of ij] ...]
P will be sorted by increasing order of the prime numbers.

So no need to tell the same thing about ordering once more, maybe you didn't read very well the description.:-)
2) Yes, we could use long or even ulong (C#) or even BigIntegers in C# or Java (Ruby, Python, Clojure do it without any pain), everything is possible... But it's too late for that now.
3) Yes I could have used more test cases... Maybe another day when I have time!

Anayway, lots of thanks for your feedback!

I added some large array tests and noted this in the description. I didn't want to be more verbose than necessary- did you have a suggestion for something I should add to the description?

Thank you, and you're definitely welcome to refactor your solution if you see some room for improvement, but I must say that due to a bug in the CodeWars platform the authorship of this solution is attributed to me, the author of the original Python kata, while in fact the credit goes to pablo.varela who made a Java translation, and we all say thankya, Pablo! :)