What I've done today is Nesting Structure Comparison in JavaScript.

CodeWars

Problem

Nesting Structure Comparison

Complete the function/method (depending on the language) to return true/True when its argument is an array that has the same nesting structure as the first array.

For example:

 // should return true
[ 1, 1, 1 ].sameStructureAs( [ 2, 2, 2 ] );          
[ 1, [ 1, 1 ] ].sameStructureAs( [ 2, [ 2, 2 ] ] );  

 // should return false 
[ 1, [ 1, 1 ] ].sameStructureAs( [ [ 2, 2 ], 2 ] );  
[ 1, [ 1, 1 ] ].sameStructureAs( [ [ 2 ], 2 ] );  

// should return true
[ [ [ ], [ ] ] ].sameStructureAs( [ [ [ ], [ ] ] ] ); 

// should return false
[ [ [ ], [ ] ] ].sameStructureAs( [ [ 1, 1 ] ] );     

Solution

Array.prototype.sameStructureAs = function (other) {
  if (this.length !== other.length) return false;
  for (let i = 0; i < this.length; ++i) {
    if (Array.isArray(this[i]) && !this[i].sameStructureAs(other[i])) return false;
    if (!Array.isArray(this[i]) && Array.isArray(other[i])) return false;
  }
  return true;
};

////

Array.prototype.sameStructureAs = function (other) {
  return (this.length === other.length) ? this.every(
    (e, i) => Array.isArray(e) ? e.sameStructureAs(other[i]) : true
  ) : false;
};