Cost of destructuring polyfill

Benchmark created on February 18, 2026

Description

Setup

function signal() {
  var a = Math.random(),
    b = Math.random();
  return [
    function () {
      return a;
    },
    function () {
      return b;
    },
  ];
}
function wrap(a) {
  return function () {
    console.log("start");
    var b = a();
    console.log("end");
    return b;
  };
}

function destructureAndNewArray() {
  const [get, set] = signal();
  return [wrap(get), wrap(set)];
}

function c(a) {
  var b = 0;
  return function () {
    return b < a.length ? { done: !1, value: a[b++] } : { done: !0 };
  };
}
function polyfilledDestructureAndNewArray() {
  var a = signal();
  var b = typeof Symbol != "undefined" && Symbol.iterator && a[Symbol.iterator];
  if (b) a = b.call(a);
  else if (typeof a.length == "number") a = { next: c(a) };
  else throw Error(String(a) + " is not an iterable or ArrayLike");
  b = a;
  a = b.next().value;
  b = b.next().value;
  return [wrap(a), wrap(b)];
}
function newArray() {
  var a = signal();
  return [wrap(a[0]), wrap(a[1])];
}
function mutateArray() {
  var a = signal();
  a[0] = wrap(a[0]);
  a[1] = wrap(a[1]);
  return a;
}

Test runner

destructureAndNewArray();

polyfilledDestructureAndNewArray();

newArray();

mutateArray();

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.

• Revision 1: published on February 18, 2026