[Serializer] Improve test coverage of the MaxDepth annotation

Author: dunglas

Tests/Annotation/MaxDepthTest.php

@@ -18,6 +18,22 @@
  */
 class MaxDepthTest extends \PHPUnit_Framework_TestCase
 {
+    /**
+     * @expectedException \Symfony\Component\Serializer\Exception\InvalidArgumentException
+     */
+    public function testNotSetMaxDepthParameter()
+    {
+        new MaxDepth(array());
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Serializer\Exception\InvalidArgumentException
+     */
+    public function testEmptyMaxDepthParameter()
+    {
+        new MaxDepth(array('value' => ''));
+    }
+
     /**
      * @expectedException \Symfony\Component\Serializer\Exception\InvalidArgumentException
      */
@@ -28,9 +44,7 @@ public function testNotAnIntMaxDepthParameter()
 
     public function testMaxDepthParameters()
     {
-        $validData = 3;
-
-        $groups = new MaxDepth(array('value' => 3));
-        $this->assertEquals($validData, $groups->getMaxDepth());
+        $maxDepth = new MaxDepth(array('value' => 3));
+        $this->assertEquals(3, $maxDepth->getMaxDepth());
     }
 }