Fix up mongo db handler and add tests

tests/Monolog/Handler/MongoDBHandlerTest.php

@@ -0,0 +1,54 @@
+<?php
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (c) Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Monolog\Handler;
+
+use Monolog\TestCase;
+use Monolog\Logger;
+
+class MongoDBHandlerTest extends TestCase
+{
+    public function testHandle()
+    {
+        $mongo = $this->getMock('Mongo', array('selectCollection'));
+        $collection = $this->getMock('stdClass', array('save'));
+
+        $mongo->expects($this->once())
+            ->method('selectCollection')
+            ->with('DB', 'Collection')
+            ->will($this->returnValue($collection));
+
+        $record = $this->getRecord(Logger::WARNING, 'test', array('data' => new \stdClass, 'foo' => 34));
+
+        $expected = array(
+            'message' => 'test',
+            'context' => array('data' => '[object] (stdClass: {})', 'foo' => 34),
+            'level' => Logger::WARNING,
+            'level_name' => 'WARNING',
+            'channel' => 'test',
+            'datetime' => $record['datetime']->format('Y-m-d H:i:s'),
+            'extra' => array(),
+        );
+
+        $collection->expects($this->once())
+            ->method('save')
+            ->with($expected);
+
+        $handler = new MongoDBHandler($mongo, 'DB', 'Collection');
+        $handler->handle($record);
+    }
+}
+
+if (!class_exists('Mongo')) {
+    class Mongo {
+        public function selectCollection() {}
+    }
+}