lodash/lodash.update/index.js

/**
 * lodash 4.6.0 (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o ./`
 * Copyright 2012-2016 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2016 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <https://lodash.com/license>
 */
var baseSet = require('lodash._baseset'),
    toString = require('lodash.tostring');

/** Used to match property names within property paths. */
var reIsDeepProp = /\.|\[(?:[^[\]]*|(["'])(?:(?!\1)[^\\]|\\.)*?\1)\]/,
    reIsPlainProp = /^\w*$/,
    rePropName = /[^.[\]]+|\[(?:(-?\d+(?:\.\d+)?)|(["'])((?:(?!\2)[^\\]|\\.)*?)\2)\]/g;

/** Used to match backslashes in property paths. */
var reEscapeChar = /\\(\\)?/g;

/**
 * Casts `value` to `identity` if it's not a function.
 *
 * @private
 * @param {*} value The value to inspect.
 * @returns {Array} Returns the array-like object.
 */
function baseCastFunction(value) {
  return typeof value == 'function' ? value : identity;
}

/**
 * Casts `value` to a path array if it's not one.
 *
 * @private
 * @param {*} value The value to inspect.
 * @returns {Array} Returns the cast property path array.
 */
function baseCastPath(value) {
  return isArray(value) ? value : stringToPath(value);
}

/**
 * The base implementation of `_.get` without support for default values.
 *
 * @private
 * @param {Object} object The object to query.
 * @param {Array|string} path The path of the property to get.
 * @returns {*} Returns the resolved value.
 */
function baseGet(object, path) {
  path = isKey(path, object) ? [path + ''] : baseCastPath(path);

  var index = 0,
      length = path.length;

  while (object != null && index < length) {
    object = object[path[index++]];
  }
  return (index && index == length) ? object : undefined;
}

/**
 * The base implementation of `_.update`.
 *
 * @private
 * @param {Object} object The object to query.
 * @param {Array|string} path The path of the property to update.
 * @param {Function} updater The function to produce the updated value.
 * @param {Function} [customizer] The function to customize path creation.
 * @returns {Object} Returns `object`.
 */
function baseUpdate(object, path, updater, customizer) {
  return baseSet(object, path, updater(baseGet(object, path)), customizer);
}

/**
 * Checks if `value` is a property name and not a property path.
 *
 * @private
 * @param {*} value The value to check.
 * @param {Object} [object] The object to query keys on.
 * @returns {boolean} Returns `true` if `value` is a property name, else `false`.
 */
function isKey(value, object) {
  if (typeof value == 'number') {
    return true;
  }
  return !isArray(value) &&
    (reIsPlainProp.test(value) || !reIsDeepProp.test(value) ||
      (object != null && value in Object(object)));
}

/**
 * Converts `string` to a property path array.
 *
 * @private
 * @param {string} string The string to convert.
 * @returns {Array} Returns the property path array.
 */
function stringToPath(string) {
  var result = [];
  toString(string).replace(rePropName, function(match, number, quote, string) {
    result.push(quote ? string.replace(reEscapeChar, '$1') : (number || match));
  });
  return result;
}

/**
 * Checks if `value` is classified as an `Array` object.
 *
 * @static
 * @memberOf _
 * @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;

/**
 * This method is like `_.set` except that accepts `updater` to produce the
 * value to set. Use `_.updateWith` to customize `path` creation. The `updater`
 * is invoked with one argument: (value).
 *
 * **Note:** This method mutates `object`.
 *
 * @static
 * @memberOf _
 * @category Object
 * @param {Object} object The object to modify.
 * @param {Array|string} path The path of the property to set.
 * @param {Function} updater The function to produce the updated value.
 * @returns {Object} Returns `object`.
 * @example
 *
 * var object = { 'a': [{ 'b': { 'c': 3 } }] };
 *
 * _.update(object, 'a[0].b.c', function(n) { return n * n; });
 * console.log(object.a[0].b.c);
 * // => 9
 *
 * _.update(object, 'x[0].y.z', function(n) { return n ? n + 1 : 0; });
 * console.log(object.x[0].y.z);
 * // => 0
 */
function update(object, path, updater) {
  return object == null ? object : baseUpdate(object, path, baseCastFunction(updater));
}

/**
 * This method returns the first argument given to it.
 *
 * @static
 * @memberOf _
 * @category Util
 * @param {*} value Any value.
 * @returns {*} Returns `value`.
 * @example
 *
 * var object = { 'user': 'fred' };
 *
 * _.identity(object) === object;
 * // => true
 */
function identity(value) {
  return value;
}

module.exports = update;