_.findIndex

function findIndex(array, predicate, fromIndex) {
    var length = array == null ? 0 : array.length;
    if (!length) {
      return -1;
    }
    var index = fromIndex == null ? 0 : toInteger(fromIndex);
    if (index < 0) {
        // nativeMax = Math.max
      index = nativeMax(length + index, 0);
    }
    return baseFindIndex(array, getIteratee(predicate, 3), index);
  }


  /* @static
     * @memberOf _
     * @since 4.0.0
     * @category Lang
     * @param {*} value The value to convert.
     * @returns {number} Returns the converted integer.
     * @example
     *
     * _.toInteger(3.2);
     * // => 3
     *
     * _.toInteger(Number.MIN_VALUE);
     * // => 0
     *
     * _.toInteger(Infinity);
     * // => 1.7976931348623157e+308
     *
     * _.toInteger('3.2');
     * // => 3
     */
    function toInteger(value) {
      var result = toFinite(value),
          remainder = result % 1;

      return result === result ? (remainder ? result - remainder : result) : 0;
    }


     /**
     * Converts `value` to a finite number.
     *
     * @static
     * @memberOf _
     * @since 4.12.0
     * @category Lang
     * @param {*} value The value to convert.
     * @returns {number} Returns the converted number.
     * @example
     *
     * _.toFinite(3.2);
     * // => 3.2
     *
     * _.toFinite(Number.MIN_VALUE);
     * // => 5e-324
     *
     * _.toFinite(Infinity);
     * // => 1.7976931348623157e+308
     *
     * _.toFinite('3.2');
     * // => 3.2
     */
      function toFinite(value) {
        if (!value) {
          return value === 0 ? value : 0;
        }
        value = toNumber(value);
        if (value === INFINITY || value === -INFINITY) {
          var sign = (value < 0 ? -1 : 1);
          return sign * MAX_INTEGER;
        }
        return value === value ? value : 0;
      }


       /**
   * The base implementation of `_.findIndex` and `_.findLastIndex` without
   * support for iteratee shorthands.
   *
   * @private
   * @param {Array} array The array to inspect.
   * @param {Function} predicate The function invoked per iteration.
   * @param {number} fromIndex The index to search from.
   * @param {boolean} [fromRight] Specify iterating from right to left.
   * @returns {number} Returns the index of the matched value, else `-1`.
   */
  function baseFindIndex(array, predicate, fromIndex, fromRight) {
    var length = array.length,
        index = fromIndex + (fromRight ? 1 : -1);

    while ((fromRight ? index-- : ++index < length)) {
      if (predicate(array[index], index, array)) {
        return index;
      }
    }
    return -1;
  }