the code seems to work on SWI-Prolog but not online. Did I make a mistake concerning the return type?

Read the posts below: https://www.codewars.com/kata/577bd026df78c19bca0002c0/discuss#633918a2198a4c00166ab324

Cant make it with 3ple replaceAll in js..why?

Add a two words sample test for every language, see the "not issues" below about "IF-RUDYARD KIPLING"

Your code is wrong, not a kata issue, print the input and check why it fails. Read this: https://docs.codewars.com/training/troubleshooting

It'll also fail with this input: "HELL0 W0RLD"

I too have encountered the problem that n this test case (IF-RUDYARDOKIPLING should be IF-RUDYARD KIPLING). But i cant see specification about this situation ? What i do wrong ?

Your code is wrong, not a kata issue. The tests are fine.

There is a something wrong or a problem in this test case (IF-RUDYARDOKIPLING should be IF-RUDYARD KIPLING) so why ?

That's because it requires a Node's version that's not available yet in CodeWars.

'IF-RUDYARD KIPLING' what is this stupidness :(

decent

Very poor description, this is the task:

1. Split into lines
2. While the considered line has tabs, find position of FIRST '\t' and add spaces accordingly to its position and UPDATE the line (and consequently the position of the other '\t' in the line.)