do not use the issue tag to ask for help. your code does not work for a single, non-iterable argument, you return the arguments object in that case.

7 years later this is still missing from the description.

Nice Kata.

What the...

Nice Kata!

Nice Kata!

Nice Kata!

OP solved it, closing

I am throwing error for negative cases, but still getting this - expected [Function] to throw an error. any idea?

Nice kata! Learned a new topic today.

That plateau after the peak is not a plateau-peak, it's just a plateau.

At index 20 there is a plateau-peak.

for arr [1,2,5,4,3,2,3,6,4,1,2,3,3,4,5,3,2,1,2,3,5,5,4,3],
expected { pos: [ 2, 7, 14 ], peaks: [ 5, 6, 5 ] } to deeply equal { pos: [ 2, 7, 14, 20 ], peaks: [ 5, 6, 5, 5 ] }. How ?

Nice Kata!

By solving 4,5,6kyu.😏