I'm trying to use the arr.includes(item). The function should return True if the item is an element of the array. But it doesn't seem to be able to do so with a multidimensional array. Take a look at this screenshot (running node in the console):
I got a similar result on my Google Chrome.
Is it because it's an EC6 function, and not yet completely functional?
No information on such a problem on the Mozille page.