Thank's @benjaminzwhite problem is solved by adding = to >

closing

Because you weren't returning the recursive call. Also, read this: https://docs.codewars.com/training/troubleshooting#expected-the-same

In my console code works perfect. Here doesnt work and i cannot understand why.
Error: expected undefined to equal 7. In my console result is equal to 7. Can explain someone this error?

Hi @Yassinmoh - it seems you are working in JavaScript; there are 65,000 solves in that language so tests seem to be working OK.

As your error message says - you are returning the value 10. The kata says: "...If that value has more than one digit, continue reducing in this way until a single-digit number is produced."

10 has more than one digit, so your solution is not correct, you need to keep performing the algorithm one more step (probably in your code you have something like when n <= 10: stop loop which should be < instead of <=)