I have manged to solve my issue!
Posting the solution incase anyone else encounters this problem:
Using list.includes(object) in JS I can get it to search for whether my list contains the object.
Python code: FriendsList.append(Who) --> JS code: FriendsList.push(Who)
Python code: if FriendsList.count(‘Rabbit’) > 0: --> JS code: if FriendsList.includes(‘Rabbit’) == true
I know this isnt doing exactly the same thing, but it works just fine for what I need.