every.js 2.21 KB
var arrayEvery = require('../internal/arrayEvery'),
    baseCallback = require('../internal/baseCallback'),
    baseEvery = require('../internal/baseEvery'),
    isArray = require('../lang/isArray'),
    isIterateeCall = require('../internal/isIterateeCall');

/**
 * Checks if `predicate` returns truthy for **all** elements of `collection`.
 * The predicate is bound to `thisArg` and invoked with three arguments:
 * (value, index|key, collection).
 *
 * If a property name is provided for `predicate` the created `_.property`
 * style callback returns the property value of the given element.
 *
 * If a value is also provided for `thisArg` the created `_.matchesProperty`
 * style callback returns `true` for elements that have a matching property
 * value, else `false`.
 *
 * If an object is provided for `predicate` the created `_.matches` style
 * callback returns `true` for elements that have the properties of the given
 * object, else `false`.
 *
 * @static
 * @memberOf _
 * @alias all
 * @category Collection
 * @param {Array|Object|string} collection The collection to iterate over.
 * @param {Function|Object|string} [predicate=_.identity] The function invoked
 *  per iteration.
 * @param {*} [thisArg] The `this` binding of `predicate`.
 * @returns {boolean} Returns `true` if all elements pass the predicate check,
 *  else `false`.
 * @example
 *
 * _.every([true, 1, null, 'yes'], Boolean);
 * // => false
 *
 * var users = [
 *   { 'user': 'barney', 'active': false },
 *   { 'user': 'fred',   'active': false }
 * ];
 *
 * // using the `_.matches` callback shorthand
 * _.every(users, { 'user': 'barney', 'active': false });
 * // => false
 *
 * // using the `_.matchesProperty` callback shorthand
 * _.every(users, 'active', false);
 * // => true
 *
 * // using the `_.property` callback shorthand
 * _.every(users, 'active');
 * // => false
 */
function every(collection, predicate, thisArg) {
  var func = isArray(collection) ? arrayEvery : baseEvery;
  if (thisArg && isIterateeCall(collection, predicate, thisArg)) {
    predicate = undefined;
  }
  if (typeof predicate != 'function' || thisArg !== undefined) {
    predicate = baseCallback(predicate, thisArg, 3);
  }
  return func(collection, predicate);
}

module.exports = every;