lodash/lodash.pickby/index.js

/**
 * lodash (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o ./`
 * Copyright jQuery Foundation and other contributors <https://jquery.org/>
 * Released under MIT license <https://lodash.com/license>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 */
var baseIteratee = require('lodash._baseiteratee'),
    keysIn = require('lodash.keysin');

/**
 * Appends the elements of `values` to `array`.
 *
 * @private
 * @param {Array} array The array to modify.
 * @param {Array} values The values to append.
 * @returns {Array} Returns `array`.
 */
function arrayPush(array, values) {
  var index = -1,
      length = values.length,
      offset = array.length;

  while (++index < length) {
    array[offset + index] = values[index];
  }
  return array;
}

/** Built-in value references. */
var getOwnPropertySymbols = Object.getOwnPropertySymbols;

/* Built-in method references for those with the same name as other `lodash` methods. */
var nativeGetPrototype = Object.getPrototypeOf;

/**
 * The base implementation of `getAllKeys` and `getAllKeysIn` which uses
 * `keysFunc` and `symbolsFunc` to get the enumerable property names and
 * symbols of `object`.
 *
 * @private
 * @param {Object} object The object to query.
 * @param {Function} keysFunc The function to get the keys of `object`.
 * @param {Function} symbolsFunc The function to get the symbols of `object`.
 * @returns {Array} Returns the array of property names and symbols.
 */
function baseGetAllKeys(object, keysFunc, symbolsFunc) {
  var result = keysFunc(object);
  return isArray(object) ? result : arrayPush(result, symbolsFunc(object));
}

/**
 * The base implementation of  `_.pickBy` without support for iteratee shorthands.
 *
 * @private
 * @param {Object} object The source object.
 * @param {Function} predicate The function invoked per property.
 * @returns {Object} Returns the new object.
 */
function basePickBy(object, predicate) {
  var index = -1,
      props = getAllKeysIn(object),
      length = props.length,
      result = {};

  while (++index < length) {
    var key = props[index],
        value = object[key];

    if (predicate(value, key)) {
      result[key] = value;
    }
  }
  return result;
}

/**
 * Creates an array of own and inherited enumerable property names and
 * symbols of `object`.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {Array} Returns the array of property names and symbols.
 */
function getAllKeysIn(object) {
  return baseGetAllKeys(object, keysIn, getSymbolsIn);
}

/**
 * Gets the `[[Prototype]]` of `value`.
 *
 * @private
 * @param {*} value The value to query.
 * @returns {null|Object} Returns the `[[Prototype]]`.
 */
function getPrototype(value) {
  return nativeGetPrototype(Object(value));
}

/**
 * Creates an array of the own enumerable symbol properties of `object`.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {Array} Returns the array of symbols.
 */
function getSymbols(object) {
  // Coerce `object` to an object to avoid non-object errors in V8.
  // See https://bugs.chromium.org/p/v8/issues/detail?id=3443 for more details.
  return getOwnPropertySymbols(Object(object));
}

// Fallback for IE < 11.
if (!getOwnPropertySymbols) {
  getSymbols = function() {
    return [];
  };
}

/**
 * Creates an array of the own and inherited enumerable symbol properties
 * of `object`.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {Array} Returns the array of symbols.
 */
var getSymbolsIn = !getOwnPropertySymbols ? getSymbols : function(object) {
  var result = [];
  while (object) {
    arrayPush(result, getSymbols(object));
    object = getPrototype(object);
  }
  return result;
};

/**
 * Checks if `value` is classified as an `Array` object.
 *
 * @static
 * @memberOf _
 * @since 0.1.0
 * @type {Function}
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is correctly classified,
 *  else `false`.
 * @example
 *
 * _.isArray([1, 2, 3]);
 * // => true
 *
 * _.isArray(document.body.children);
 * // => false
 *
 * _.isArray('abc');
 * // => false
 *
 * _.isArray(_.noop);
 * // => false
 */
var isArray = Array.isArray;

/**
 * Creates an object composed of the `object` properties `predicate` returns
 * truthy for. The predicate is invoked with two arguments: (value, key).
 *
 * @static
 * @memberOf _
 * @since 4.0.0
 * @category Object
 * @param {Object} object The source object.
 * @param {Array|Function|Object|string} [predicate=_.identity]
 *  The function invoked per property.
 * @returns {Object} Returns the new object.
 * @example
 *
 * var object = { 'a': 1, 'b': '2', 'c': 3 };
 *
 * _.pickBy(object, _.isNumber);
 * // => { 'a': 1, 'c': 3 }
 */
function pickBy(object, predicate) {
  return object == null ? {} : basePickBy(object, baseIteratee(predicate));
}

module.exports = pickBy;