I got same error message

My test result was

Test Failed: Expected: {"b":2,"y":1,"o":1}, instead got: {"b":2,"y":1,"o":1}

I find this funny...

Cool learned something new about .reduce()

This is composition, not concatenation. There are two contexts where you can talk about concatenating functions but neither really make sense in javascript (reader monoid and endomorphism monoid).

I was confounded by this too. If you are going to specify something for this case, specify throwing an exception.

Indeed, the description of the problem and the test case for it don't match up. Mysteriously, I saw:

Test Failed: Expected: a = 1,b = 2, instead got: a = 1,b = 2,

Actually, I understood that only ASCII-characters should be counted, and I was later stunned by the fact that almost no other solution bothered about this.

Yes, I think so. Either change the description or the description and the tests. The choice is up to you, it's your kata after all :)

Well I might change the kata description so that the solution also accepts all the UTF-8 characters, I think this would be better ?

Instructions not clear... I'm not sure whether to return an object or a stringified object. :-/

EDIT: OK, the function needs to return an object. :p

I just tried it again, and now I can't reproduce it. Might have been wrong.

Maybe I missed it, but you state that you want the ASCII values, and I see no test for that. Reading the question I assumed that you meant only values like [A-Z] or [a-z] only.

Good point, added also the functionality to really compare the object content, previously I was using Test inspect function which makes objects to string and compares. This problem should be now solved.

Thank you, for your feedback added this in kata.

The description didn't make it obvious that the cache should copy arguments, could it be made explicit that the cache should be aware of mutations?