Is this meant to be a golfing kata? The description is extremely unclear as to what is expected here.

My friends will help me to solve those problems, but they cannot fork while in draft status, so I need to publish it.

Unpublishing until the issues reported below get fixed.

.

.

.

True 👍

unfortunately

Tests are vulnerable to input mutation.

I'll admit this is a weird one.

Just don't reuse inputs; declare a new input for every test, and this won't happen.

Frankly, it was not very effective as I wrote kata for the first time and I looked at the test logic from many places, but we can say that it was unsuccessful and yes, I will try to solve the test logic.

You'd think this is impossible. But it really happens, because of the way chai executes code out of order. It turns out arr.length = 0 is executed before the assertion in the it.

Testing with an example solution that depends on the input being non-empty could have prevented this.

So you published without random tests again, making other, different, rookie mistakes as well. Read more documentation, read more tests of kata you solved, and get more reviews on Discord before publishing. Support is available if only you'll take it.

One of these days you might publish a kata without it getting unpublished immediately.

Submit tests do not include fixed tests, which makes it possible to fail the example tests but pass the submit tests. That should never happen. Always copy the example tests into the submit tests as fixed tests.

Random tests generate empty input, which are out of spec.