I updated to JUnit5, added Random tests and used the example from the description for sample tests.

As someone who is also learning, I had the same issue trying to find the right part in any online resource to explain that I had to access 'this'. Now I can actually work on solving the challenge.

I find it difficult trying to access the string without it being passed as a parameter.
I read the documentation about prototype but I'm not sure how to access the string still.

yeah exactly

Hello jhoffner,
just as a friendly reminder: Can you please review and approve this change? I added the sample tests :)
I also solved the issue in the kotlin translation https://www.codewars.com/kumite/61f3c1737c4cb1000fb8d896?sel=62680f8514c014000fe0e884

Have you tried with this before asking? If you haven't, you should. Have you read the documentation about prototypes? If you haven't, you should.

when using String.prototype.isUpperCase = function(){...}
... how do I work with the related string in the function? like how do I reference it? With "this" or...?
Thanks!

Tests was missing because the origin kata had non. I added some sample tests :)

I agree some more Test cases then this can be approved.
Author seems to be inactive though, needs to be forked.

Thanks. There you have: https://www.codewars.com/kumite/6210b4c6abf04700583a2e1d?sel=621540f21db30300297bed13

Language-neutral descriptions were even made into a kata authoring guideline: https://docs.codewars.com/authoring/guidelines/description/#general , mostly to mitigate problems related to merge conflicts when translations were piling up and getting each in the way of another, making them difficult to approve and error-prone due to mistakes made while resolving merge conflicts.

Do you think it's a bad idea in general, or you just don't like to have it this way on your kata?

I didn't delete examples, I changed the description to make it language agnostic, just focusing on inputs and autputs. Language specific codeblocks are a pain for maintenance and cause indefinitely merge conflicts. In this case they are absolutely useless. Currently there is a block for C, while there's no C translation available, but there is no block for powershell.

It's become quite normal nowadays to have a single generic example instead of a multitude of almost identical language-specific code blocks. IMO, you should consider moving to the new format here as well, especially considering how little value these 20 code blocks provide.

I agree

Got you