lodash/internal/isIterateeCall.js

import isArrayLike from './isArrayLike';
import isIndex from './isIndex';
import isObject from '../lang/isObject';

/**
 * Checks if the provided arguments are from an iteratee call.
 *
 * @private
 * @param {*} value The potential iteratee value argument.
 * @param {*} index The potential iteratee index or key argument.
 * @param {*} object The potential iteratee object argument.
 * @returns {boolean} Returns `true` if the arguments are from an iteratee call, else `false`.
 */
function isIterateeCall(value, index, object) {
  if (!isObject(object)) {
    return false;
  }
  var type = typeof index;
  if (type == 'number'
      ? (isArrayLike(object) && isIndex(index, object.length))
      : (type == 'string' && index in object)) {
    var other = object[index];
    return value === value ? (value === other) : (other !== other);
  }
  return false;
}

export default isIterateeCall;