I think you have to add a condition to the array after this array is matched.

I figured out how to get test arrays, just output the arguments to the console)
console.log(iterable)
The problem was with [ 'a', 'b', 'b' ]

It's not working with empty array (without matches). This solution failed some tests!
TypeError: Cannot read property 'map' of null

Oh, this solution is 8-10 times faster, then solution with new Set. Looks great!

I don't understand which exactly char arrays are needed. All other tests are passed. What does it mean?

expected [ NaN, NaN ] to deeply equal [ 'a', 'b' ]```
P.S.: JavaScript