Array.forEach.stopIteration.js

const
  arrPrototype = Object.getPrototypeOf([]);

const {
  from: arrayFrom,
  isArray,

} = Array;

function isFunction(type) {
  return (
       (typeof type === 'function')
    && (typeof type.call === 'function')
    && (typeof type.apply === 'function')
  );
}
function getSanitizedTarget(type) {
  return (type ?? null);
}

function forEachWithStopIteration(callback, target) {
  const arr = ((isArray(this) && this) || arrayFrom(this ?? []));

  // fail silently.
  if (arr && isFunction(callback)) {

    let proceed = true;
    const stopIteration = () => proceed = false;

    target = getSanitizedTarget(target);

    let idx = -1;
    const len = arr.length;

    while (proceed && (++idx < len)) {

      // acknowledge sparse array slots.
      if (idx in arr) {

        callback.call(target, arr[idx], idx, arr, stopIteration);
      }
    }
  }
}

Object.defineProperty(arrPrototype, 'forEachSI', {
  configurable: true,
  writable: true,
  value: forEachWithStopIteration
});
Object.defineProperty(arrPrototype.forEachSI, 'toString', {
  value: () => 'function forEachSI() { [custom code] }'
});

// export default Array;

/*
(new Array(100))
  .fill(null)
  .forEachSI(function (elm, idx, arr, stopIteration) {
  
    console.log([this, idx]);

    if (idx > 4) {
      stopIteration();
    }
  }, "foo");
*/