separate formatDate tests into individual tests per responsebility

tests/Solarium/Query/HelperTest.php

@@ -185,29 +185,35 @@ class Solarium_Query_HelperTest extends PHPUnit_Framework_TestCase
         );
     }
 
-    public function testFormatDate()
+    public function testFormatTimestampInput()
     {
-        //accepts a time
         $this->assertNotEquals(
             false,
             $this->_helper->formatDate(strtotime('2011-10-01')),
             'Expects timestamp input to be accpted'
         );
+    }
 
-        //accepts a date
+    public function testFormatDateStringInput()
+    {
         $this->assertNotEquals(
             false,
             $this->_helper->formatDate(date('Y-m-d', strtotime('2011-10-01'))),
             'Expects date string inputs to be accepted'
         );
+    }
 
-        //accepts a DateTime object
+    public function testFormatDateTimeInput()
+    {
         $this->assertNotEquals(
             false,
             $this->_helper->formatDate(new DateTime(strtotime('2011-10-01'))),
             'Expects DateTime object to be accepted'
         );
+    }
 
+    public function testFormatDate()
+   {
         //check if timezone is stripped
         $expected = strtoupper('Z');
         $actual = substr($this->_helper->formatDate(time()), 19, 20);