lodash/lodash.mixin/index.js

/**
 * lodash 4.1.1 (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 keys = require('lodash.keys');

/** `Object#toString` result references. */
var funcTag = '[object Function]',
    genTag = '[object GeneratorFunction]';

/**
 * A specialized version of `_.forEach` for arrays without support for
 * iteratee shorthands.
 *
 * @private
 * @param {Array} array The array to iterate over.
 * @param {Function} iteratee The function invoked per iteration.
 * @returns {Array} Returns `array`.
 */
function arrayEach(array, iteratee) {
  var index = -1,
      length = array.length;

  while (++index < length) {
    if (iteratee(array[index], index, array) === false) {
      break;
    }
  }
  return array;
}

/**
 * A specialized version of `_.filter` for arrays without support for
 * iteratee shorthands.
 *
 * @private
 * @param {Array} array The array to iterate over.
 * @param {Function} predicate The function invoked per iteration.
 * @returns {Array} Returns the new filtered array.
 */
function arrayFilter(array, predicate) {
  var index = -1,
      length = array.length,
      resIndex = 0,
      result = [];

  while (++index < length) {
    var value = array[index];
    if (predicate(value, index, array)) {
      result[resIndex++] = value;
    }
  }
  return result;
}

/**
 * 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;
}

/** Used for built-in method references. */
var objectProto = Object.prototype;

/**
 * Used to resolve the
 * [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
 * of values.
 */
var objectToString = objectProto.toString;

/**
 * The base implementation of `_.functions` which creates an array of
 * `object` function property names filtered from `props`.
 *
 * @private
 * @param {Object} object The object to inspect.
 * @param {Array} props The property names to filter.
 * @returns {Array} Returns the new array of filtered property names.
 */
function baseFunctions(object, props) {
  return arrayFilter(props, function(key) {
    return isFunction(object[key]);
  });
}

/**
 * Copies the values of `source` to `array`.
 *
 * @private
 * @param {Array} source The array to copy values from.
 * @param {Array} [array=[]] The array to copy values to.
 * @returns {Array} Returns `array`.
 */
function copyArray(source, array) {
  var index = -1,
      length = source.length;

  array || (array = Array(length));
  while (++index < length) {
    array[index] = source[index];
  }
  return array;
}

/**
 * Checks if `value` is classified as a `Function` object.
 *
 * @static
 * @memberOf _
 * @since 0.1.0
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is correctly classified,
 *  else `false`.
 * @example
 *
 * _.isFunction(_);
 * // => true
 *
 * _.isFunction(/abc/);
 * // => false
 */
function isFunction(value) {
  // The use of `Object#toString` avoids issues with the `typeof` operator
  // in Safari 8 which returns 'object' for typed array and weak map constructors,
  // and PhantomJS 1.9 which returns 'function' for `NodeList` instances.
  var tag = isObject(value) ? objectToString.call(value) : '';
  return tag == funcTag || tag == genTag;
}

/**
 * Checks if `value` is the
 * [language type](http://www.ecma-international.org/ecma-262/6.0/#sec-ecmascript-language-types)
 * of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
 *
 * @static
 * @memberOf _
 * @since 0.1.0
 * @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(_.noop);
 * // => true
 *
 * _.isObject(null);
 * // => false
 */
function isObject(value) {
  var type = typeof value;
  return !!value && (type == 'object' || type == 'function');
}

/**
 * Adds all own enumerable string keyed function properties of a source
 * object to the destination object. If `object` is a function, then methods
 * are added to its prototype as well.
 *
 * **Note:** Use `_.runInContext` to create a pristine `lodash` function to
 * avoid conflicts caused by modifying the original.
 *
 * @static
 * @since 0.1.0
 * @memberOf _
 * @category Util
 * @param {Function|Object} [object=lodash] The destination object.
 * @param {Object} source The object of functions to add.
 * @param {Object} [options={}] The options object.
 * @param {boolean} [options.chain=true] Specify whether mixins are chainable.
 * @returns {Function|Object} Returns `object`.
 * @example
 *
 * function vowels(string) {
 *   return _.filter(string, function(v) {
 *     return /[aeiou]/i.test(v);
 *   });
 * }
 *
 * _.mixin({ 'vowels': vowels });
 * _.vowels('fred');
 * // => ['e']
 *
 * _('fred').vowels().value();
 * // => ['e']
 *
 * _.mixin({ 'vowels': vowels }, { 'chain': false });
 * _('fred').vowels();
 * // => ['e']
 */
function mixin(object, source, options) {
  var props = keys(source),
      methodNames = baseFunctions(source, props);

  var chain = (isObject(options) && 'chain' in options) ? options.chain : true,
      isFunc = isFunction(object);

  arrayEach(methodNames, function(methodName) {
    var func = source[methodName];
    object[methodName] = func;
    if (isFunc) {
      object.prototype[methodName] = function() {
        var chainAll = this.__chain__;
        if (chain || chainAll) {
          var result = object(this.__wrapped__),
              actions = result.__actions__ = copyArray(this.__actions__);

          actions.push({ 'func': func, 'args': arguments, 'thisArg': object });
          result.__chain__ = chainAll;
          return result;
        }
        return func.apply(object, arrayPush([this.value()], arguments));
      };
    }
  });

  return object;
}

module.exports = mixin;