Bump to v3.0.0.

array/flatten.js

@@ -0,0 +1,32 @@
+import baseFlatten from '../internal/baseFlatten';
+import isIterateeCall from '../internal/isIterateeCall';
+
+/**
+ * Flattens a nested array. If `isDeep` is `true` the array is recursively
+ * flattened, otherwise it is only flattened a single level.
+ *
+ * @static
+ * @memberOf _
+ * @category Array
+ * @param {Array} array The array to flatten.
+ * @param {boolean} [isDeep] Specify a deep flatten.
+ * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
+ * @returns {Array} Returns the new flattened array.
+ * @example
+ *
+ * _.flatten([1, [2], [3, [[4]]]]);
+ * // => [1, 2, 3, [[4]]];
+ *
+ * // using `isDeep`
+ * _.flatten([1, [2], [3, [[4]]]], true);
+ * // => [1, 2, 3, 4];
+ */
+function flatten(array, isDeep, guard) {
+  var length = array ? array.length : 0;
+  if (guard && isIterateeCall(array, isDeep, guard)) {
+    isDeep = false;
+  }
+  return length ? baseFlatten(array, isDeep) : [];
+}
+
+export default flatten;