findLastIndex

/**
 * Find the index of the last element in an array that satisfies a predicate function.
 *
 * @param {Array} array
 * @param {Function} predicate
 * @param {number} [fromIndex=array.length - 1]
 * @returns {number}
 */

function findLastIndex(array, predicate, fromIndex = array.length - 1) {
  const length = array.length;
  // Handle negative fromIndex
  let start =
    fromIndex < 0
      ? Math.max(length + fromIndex, 0)
      : Math.min(fromIndex, length - 1);
  for (let i = start; i >= 0; i--) {
    if (predicate(array[i], i, array)) {
      return i;
    }
  }

  return -1;
}