Fixed. Thanks!

https://www.codewars.com/kata/reviews/525481903700c1a1ff0000e4/groups/5b12959dfe77c3f8fb000200

JSON.stringify is not welcomed here :-)

OK. Need more tests with arrays

I just check the case when a function has an arbitrary number of arguments.

sumArgs(1) should be cached as well as sumArgs(1,2) or even sumArgs()

Hi! I believe my kata has more strict requirements regarding function arguments and time complexity. Give me a chance :-)

Hi. The problem with this solution is that if an original object has the meh property we erase it.

I tried to identify this problem using Proxy. But since your property was added by Object.defineProperty my own test fails. Need to improve tests. Thanks for the case.

Wow

Seems like the idea to remove properties in it worked. I'll try to republish kata.

I'm glad I didn't have to wrap call and count calls because you kinda need call itself to wrap something.

Fixed

No idea how to resist this :-(
The problem is that I can't delete these properties from Function.prototype. The test framefork uses them.

Now updated tests invalidated your initial solution.
Thanks for the help!

setTimeout worked well. Thanks!

Good point!

I thought that a test passes only when done is called, otherwise the test runner has a timeout after which tests fail. And based on the dfhwze's solution I was wrong.