Bump to v3.0.0.

array/findIndex.js

@@ -0,0 +1,56 @@
+define(['../internal/baseCallback'], function(baseCallback) {
+
+  /**
+   * This method is like `_.find` except that it returns the index of the first
+   * element `predicate` returns truthy for, instead of the element itself.
+   *
+   * If a property name is provided for `predicate` the created "_.property"
+   * style callback returns the property value of the given element.
+   *
+   * 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 _
+   * @category Array
+   * @param {Array} array The array to search.
+   * @param {Function|Object|string} [predicate=_.identity] The function invoked
+   *  per iteration. If a property name or object is provided it is used to
+   *  create a "_.property" or "_.matches" style callback respectively.
+   * @param {*} [thisArg] The `this` binding of `predicate`.
+   * @returns {number} Returns the index of the found element, else `-1`.
+   * @example
+   *
+   * var users = [
+   *   { 'user': 'barney',  'age': 36, 'active': false },
+   *   { 'user': 'fred',    'age': 40, 'active': true },
+   *   { 'user': 'pebbles', 'age': 1,  'active': false }
+   * ];
+   *
+   * _.findIndex(users, function(chr) { return chr.age < 40; });
+   * // => 0
+   *
+   * // using the "_.matches" callback shorthand
+   * _.findIndex(users, { 'age': 1 });
+   * // => 2
+   *
+   * // using the "_.property" callback shorthand
+   * _.findIndex(users, 'active');
+   * // => 1
+   */
+  function findIndex(array, predicate, thisArg) {
+    var index = -1,
+        length = array ? array.length : 0;
+
+    predicate = baseCallback(predicate, thisArg, 3);
+    while (++index < length) {
+      if (predicate(array[index], index, array)) {
+        return index;
+      }
+    }
+    return -1;
+  }
+
+  return findIndex;
+});