Add tests for the new DbFormatter

Each Formatter should be covered by unit tests.

tests/ZendTest/Log/Formatter/DbTest.php

@@ -0,0 +1,73 @@
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @link      http://github.com/zendframework/zf2 for the canonical source repository
+ * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   http://framework.zend.com/license/new-bsd New BSD License
+ * @package   Zend_Log
+ */
+
+namespace ZendTest\Log\Formatter;
+
+use DateTime;
+use ZendTest\Log\TestAsset\StringObject;
+use Zend\Log\Formatter\Db as DbFormatter;
+
+/**
+ * @category   Zend
+ * @package    Zend_Log
+ * @subpackage UnitTests
+ * @group      Zend_Log
+ */
+class DbTest extends \PHPUnit_Framework_TestCase
+{
+    public function testDefaultDateTimeFormat()
+    {
+        $formatter = new DbFormatter();
+        $this->assertEquals(DbFormatter::DEFAULT_DATETIME_FORMAT, $formatter->getDateTimeFormat());
+    }
+
+    /**
+     * @dataProvider provideDateTimeFormats
+     */
+    public function testSetDateTimeFormat($dateTimeFormat)
+    {
+        $formatter = new DbFormatter();
+        $formatter->setDateTimeFormat($dateTimeFormat);
+
+        $this->assertEquals($dateTimeFormat, $formatter->getDateTimeFormat());
+    }
+
+    /**
+     * @return array
+     */
+    public function provideDateTimeFormats()
+    {
+        return array(
+            array('r'),
+            array('U'),
+            array(DateTime::RSS),
+        );
+    }
+
+    /**
+     * @dataProvider provideDateTimeFormats
+     */
+    public function testAllowsSpecifyingDateTimeFormatAsConstructorArgument($dateTimeFormat)
+    {
+        $formatter = new DbFormatter($dateTimeFormat);
+
+        $this->assertEquals($dateTimeFormat, $formatter->getDateTimeFormat());
+    }
+
+    public function testFormatDateTimeInEvent()
+    {
+        $datetime = new DateTime();
+        $event = array('timestamp' => $datetime);
+        $formatter = new DbFormatter();
+
+        $format = DbFormatter::DEFAULT_DATETIME_FORMAT;
+        $this->assertContains($datetime->format($format), $formatter->format($event));
+    }
+}