Bump to v4.0.0.

flattenDeep.js

@@ -0,0 +1,22 @@
+define(['./internal/baseFlatten'], function(baseFlatten) {
+
+  /**
+   * This method is like `_.flatten` except that it recursively flattens `array`.
+   *
+   * @static
+   * @memberOf _
+   * @category Array
+   * @param {Array} array The array to recursively flatten.
+   * @returns {Array} Returns the new flattened array.
+   * @example
+   *
+   * _.flattenDeep([1, [2, 3, [4]]]);
+   * // => [1, 2, 3, 4]
+   */
+  function flattenDeep(array) {
+    var length = array ? array.length : 0;
+    return length ? baseFlatten(array, true) : [];
+  }
+
+  return flattenDeep;
+});