If the execution in your if statement is a return, you don't need an else block after it, because the function will not continue to execute once it's returned.

And with the spread operator, you can now simplify the use of Math.min and Math.max to Math.min(...array) and Math.max(...array), respectively.

That's your code's problem. Don't use global vars, they keep their value between tests. Read this: https://docs.codewars.com/training/troubleshooting/#works-but-no