lodash/lodash.set/index.js

/**
 * lodash 3.7.4 (Custom Build) <https://lodash.com/>
 * Build: `lodash modern modularize exports="npm" -o ./`
 * Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <https://lodash.com/license>
 */
var toPath = require('lodash._topath'),
    isArray = require('lodash.isarray');

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

/** Used to detect unsigned integer values. */
var reIsUint = /^\d+$/;

/**
 * Used as the [maximum length](http://ecma-international.org/ecma-262/6.0/#sec-number.max_safe_integer)
 * of an array-like value.
 */
var MAX_SAFE_INTEGER = 9007199254740991;

/**
 * Checks if `value` is a valid array-like index.
 *
 * @private
 * @param {*} value The value to check.
 * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
 * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
 */
function isIndex(value, length) {
  value = (typeof value == 'number' || reIsUint.test(value)) ? +value : -1;
  length = length == null ? MAX_SAFE_INTEGER : length;
  return value > -1 && value % 1 == 0 && value < length;
}

/**
 * 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) {
  var type = typeof value;
  if ((type == 'string' && reIsPlainProp.test(value)) || type == 'number') {
    return true;
  }
  if (isArray(value)) {
    return false;
  }
  var result = !reIsDeepProp.test(value);
  return result || (object != null && value in toObject(object));
}

/**
 * Converts `value` to an object if it's not one.
 *
 * @private
 * @param {*} value The value to process.
 * @returns {Object} Returns the object.
 */
function toObject(value) {
  return isObject(value) ? value : Object(value);
}

/**
 * Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`.
 * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an object, else `false`.
 * @example
 *
 * _.isObject({});
 * // => true
 *
 * _.isObject([1, 2, 3]);
 * // => true
 *
 * _.isObject(1);
 * // => false
 */
function isObject(value) {
  // Avoid a V8 JIT bug in Chrome 19-20.
  // See https://code.google.com/p/v8/issues/detail?id=2291 for more details.
  var type = typeof value;
  return !!value && (type == 'object' || type == 'function');
}

/**
 * Sets the property value of `path` on `object`. If a portion of `path`
 * does not exist it's created.
 *
 * @static
 * @memberOf _
 * @category Object
 * @param {Object} object The object to augment.
 * @param {Array|string} path The path of the property to set.
 * @param {*} value The value to set.
 * @returns {Object} Returns `object`.
 * @example
 *
 * var object = { 'a': [{ 'b': { 'c': 3 } }] };
 *
 * _.set(object, 'a[0].b.c', 4);
 * console.log(object.a[0].b.c);
 * // => 4
 *
 * _.set(object, 'x[0].y.z', 5);
 * console.log(object.x[0].y.z);
 * // => 5
 */
function set(object, path, value) {
  if (object == null) {
    return object;
  }
  var pathKey = (path + '');
  path = (object[pathKey] != null || isKey(path, object)) ? [pathKey] : toPath(path);

  var index = -1,
      length = path.length,
      lastIndex = length - 1,
      nested = object;

  while (nested != null && ++index < length) {
    var key = path[index];
    if (isObject(nested)) {
      if (index == lastIndex) {
        nested[key] = value;
      } else if (nested[key] == null) {
        nested[key] = isIndex(path[index + 1]) ? [] : {};
      }
    }
    nested = nested[key];
  }
  return object;
}

module.exports = set;