Added sample and random test for JS.

i did it in the same way, but i passed all the test

Yes, so you can see with what values your code fails and fix your code.

Print the input.

• Please always mention which language you're using when posting a question, issue, or suggestion on a multi-language kata.
• Include enough information so that others can understand and reproduce your problem. In this case: "Expected 0 to equal 6" is far too little information.
• If the tests don't print enough information (which unfortunately many tests on Codementor do), add some print statements to your code.

I'll mark this as resolved. If you still need help, post a new question with more information.

Print newArray and newNum, so you'll realize where your code went wrong. You could also use something like Pythontutor to visualize it.

Please read this: https://docs.codewars.com/training/troubleshooting/ and mark your post as having spoiler content next time. To debug your code, print the middle values. Right now, your code only works with single digit numbers.