polyfill of some array method in javascript

somePolyfill.js

Array.prototype.mySome = function() {
    
    var arr = this;
    var len = arr.length;
    var fn = arguments[0];
    var thisArg = arguments[1];
   
 
    for (var i = 0; i < len; i++) {
        if(fn.call(thisArg, arr[i], i, arr)) {
          return true;
        }
    }
    return false;

}

var arr = [1, 2, 3, 4, 5, 6, 7, 8];

var some = arr.some((item)=>item > 2);
var mySome = arr.mySome((item)=>item > 2);

console.log(some); // true
console.log(mySome); // true