no-inplace-sort

A tiny Javascript module that changes Array.prototype.sort to return the sorted array without changing the input array. Effectivly making the Array#sort method pure while retaining most of its performance.

NPM: npm i no-inplace-sort

require('no-inplace-sort');

const a = [2, 3, 1, 4];
const b = a.sort();

console.log(a); // [2, 3, 1, 4]
console.log(b); // [1, 2, 3, 4]

The entire implementation is 5 lines long:

Array.prototype.sort = (nativeInplaceSort => function(...args) {
  const arr = [...this]; // Shallow copy
  arr.sort = nativeInplaceSort; // Use native sort 
  return [...arr.sort(...args)]; // Remove native sort
})(Array.prototype.sort);

Fiddle demo: https://jsfiddle.net/szynrjcv/40/