Setting the solution variable to the solution is non-standard. I think it would be better to call Safe.open(solution) at the end or properly explain that setting solution is all that is required.

I think this would make the instructions more clear:

"You need to return a new array with only those elements of array that range from start to end (inclusive)."

Trivial for javascript, description probably needs improvement for other languages to clearly specify return values.

The sample tests for this kata do not exist.

Issues with the random test have been resolved. ty!

@GiacomoSorbi the issue was due to the issues with the test, not my stated preference for the data structure.

The description for the third sample test is incorrect:

it('should return 0 to 9 when called with 10',_=>Test.assertSimilar(arr(4), [0,1,2,3]));

I believe the random test suite is completely broken.

I think the input data is modeled pooly. I think it would be better like this:
{
name: 'Jim'
ate: {
hamburgers: 1,
hotdogs: 2,
chickenwings: 3
}
}

Great, ty!

It would be good to have at least 2 sample test cases, one for each sex.

function template is for twoOldestAges and there are no sample tests.

Thank you, that works.

My javascript output is visually identical to the expected output and the test will pass if I change to assertSimilar. Any hints?

Can you explain the rules behind the corner cases?