Function mapFirstN: maps the first N elements found, given a predicate and transformation function

mapFirst.js

console.clear();

function measure(msg, fn) {
  const start = Date.now();
  fn();
  console.log(msg, Date.now() - start, 'ms');
}

/**
 * @description Will look for the first N elements that matches the predicate.
 * If found, the elements will be mapped using the provided transformation function
 * and the iteration through the collection will be aborted. If not found, a shallow
 * copy of the array will be returned with no item changed.
 * @name mapFirstN
 * @param {Number} n Maximum number of items to be mapped, if found
 * @param {Function} predicate Function used to find an item
 * @param {Function} transform Function used to transform the found item
 * @param {any[]} arr Collection to map over
 * @return {any[]} Mapped collection
 */
function mapFirstN(toTake, predicate, transform, arr) {
  var result, m, i, item, found;
  result = [];
  m = arr.length;
  found = 0;
  i = 0;
  for (i; i < m; i++) {
    item = arr[i];
    if (predicate(item, i) && found < toTake) {
      found++;
      result.push(transform(item, i));
    } else if (found >= toTake) {
      return result.concat(arr.slice(i));
    } else {
      result.push(item);
    }
  }
  return result;
}

/**
 * @description Will look for the first element that matches the predicate.
 * If found, the element will be mapped using the provided transformation function
 * and the iteration through the collection will be aborted. If not found, a shallow
 * copy of the array will be returned with no item changed.
 * @name mapFirst
 * @param {Function} predicate Function used to find an item
 * @param {Function} transform Function used to transform the found item
 * @param {any[]} arr Collection to map over
 * @return {any[]} Mapped collection
 */
function mapFirst(predicate, transform, arr) {
  var result, m, i, item;
  result = [];
  m = arr.length;
  i = 0;
  for (i; i < m; i++) {
    item = arr[i];
    if (predicate(item, i)) {
      return result.concat(transform(item, i), arr.slice(1 + i));
    } else {
      result.push(item);
    }
  }
  return result;
}

// node 10.0.0, macbook pro 2,7 GHz Intel Core i5, list length: 200000

const bigList = Array.from({ length: 200000 }, (_, idx) => ({ id: idx + 1, value: idx }));

measure('mapFirst, no element found: ', function () {
  // time: ~11 ms
  mapFirst(el => el.id === 0, el => ({ ...el, value: el.value + 10 }), bigList);
});

measure('Native, no element found: ', function () {
  // time: ~38 ms
  bigList.map(el => el.id === 0 ? { ...el, value: el.value + 10 } : el);
});

measure('mapFirst, id: 2: ', function () {
  // time: ~7 ms
  mapFirst(el => el.id === 2, el => ({ ...el, value: el.value + 10 }), bigList);
});

measure('Native, id: 2: ', function () {
  // time: ~38 ms
  bigList.map(el => el.id === 2 ? { ...el, value: el.value + 10 } : el);
});