Add basic _#concat test.

lodash.src.js

@@ -6076,14 +6076,14 @@
      * @returns {Array} Returns the new concatenated array.
      * @example
      *
-     * var array = [1, 2];
-     * var wrapped = _(array).concat([3], 4);
+     * var array = [1];
+     * var wrapped = _(array).concat(2, [3], [[4]]);
      *
      * console.log(wrapped.value());
-     * // => [1, 2, 3, 4]
+     * // => [1, 2, 3, [4]]
      *
      * console.log(array);
-     * // => [1, 2]
+     * // => [1]
      */
     var wrapperConcat = restParam(function(values) {
       values = baseFlatten(values);

test/test.js

@@ -17173,6 +17173,19 @@
   QUnit.module('lodash(...).concat');
 
   (function() {
+    test('should concat arrays and values', 2, function() {
+      if (!isNpm) {
+        var array = [1],
+            wrapped = _(array).concat(2, [3], [[4]]);
+
+        deepEqual(wrapped.value(), [1, 2, 3, [4]]);
+        deepEqual(array, [1]);
+      }
+      else {
+        skipTest(2);
+      }
+    });
+
     test('should treat sparse arrays as dense', 3, function() {
       if (!isNpm) {
         var expected = [],