Has anyone run into an issue where the first test always works but every test after returns "NaN"? Its like its storing a value from the previous test run somewhere in my function.

My code works in other environments but I get this error in codewars

expected { pos: [2,3], peaks: [3,2] } to deeply equal { pos: [2], peaks [3] }

I don't even know what test this is. Any ideas?

Can you explain how you brought an array into the function without 'let arr = []'?