Steamroller
Flatten a nested array
You must account for varying levels of nesting
Tests
steamrollArray([[["a"]], [["b"]]]) should return ["a", "b"]
steamrollArray([1, [2], [3, [[4]]]]) should return [1, 2, 3, 4]
steamrollArray([1, [], [3, [[4]]]]) should return [1, 3, 4]
steamrollArray([1, {}, [3, [[4]]]]) should return [1, {}, 3, 4]
Your solution should not use the Array.prototype.flat() or Array.prototype.flatMap() methods
Global variables should not be used