Ah OK, my mistake! Thank you for clarifying. :)

No, it shouldn't. The input array has number 111 in it, and you somehow managed to change it / remove it.

Fixed test case is: expected [ 1, 1, 5, 11, 2, 1, 11, 0 ] to deeply equal [ 1, 1, 5, 11, 2, 11, 111, 0 ]

[ 1, 1, 5, 11, 2, 1, 11, 0 ] is not the input array, it's your returned answer. You can see which input caused it by printing it to console.