OP solved the kata

Thank you, this helped

The goal is to find the specialists who are doing mistakes in employee names.

So you have to return the specialist id, not the employee id. As written in the kata description:

Resultant columns:

1. specialist_id (int): The unique ID of the specialist (certifications.entered_by).

I hope that helps.

You are using operations which lose precision because numbers will be converted to floating point which is not sufficient for numbers with more than 53 bits.

But there was a similar bug also in the Ruby reference solution which I have fixed now.

It is unclear why in the described example "Annabelle Lee" is not included in the result, it has 1 record where the function returns the distance from 1 to 3

It's Over 9000!

Thanks! Updated the description.

Error in table description

stars | string

but integer is assumed

Thank you very much! It helps a lot when studying classes

The example in the description is not entirely successful, it would be better to add one non-day off and one day off that does not relate to the 23rd year

Can you please explain how you got this answer?

ORDER BY start of interval ASC

No, you're failing the second test in the "error handling" group:

it("error handling", () => {
  Test.assertEquals( encode( "abc", "x" ), null );
  Test.assertEquals( decode( "abc", [4] ), null );
  Test.assertEquals( decode( "abc", [-1,-2] ), null );
});

Not a kata issue.

JS - Fixed test error handling is broken when returning null

"abc" "x"

expected '' to equal null

duplicate

https://www.codewars.com/kata/54cf4fc26b85dc27bf000a6b