Cover expire_date with unit tests

Signed-off-by: Vitor Mattos <vitor@php.rio>

tests/lib/Comments/ManagerTest.php

@@ -516,15 +516,41 @@ class ManagerTest extends TestCase {
 			->setActor('users', 'alice')
 			->setObject('files', 'file64')
 			->setMessage('very beautiful, I am impressed!')
-			->setVerb('comment');
+			->setVerb('comment')
+			->setExpireDate(new \DateTime('+2 hours'));
 
 		$manager->save($comment);
 
-		$comment->setMessage('very beautiful, I am really so much impressed!');
+		$loadedComment = $manager->get($comment->getId());
+		// Compare current object with database values
+		$this->assertSame($comment->getMessage(), $loadedComment->getMessage());
+		$this->assertSame(
+			$comment->getExpireDate()->format('Y-m-d H:i:s'),
+			$loadedComment->getExpireDate()->format('Y-m-d H:i:s')
+		);
+
+		// Preserve the original comment to compare after update
+		$original = clone $comment;
+
+		// Update values
+		$comment->setMessage('very beautiful, I am really so much impressed!')
+			->setExpireDate(new \DateTime('+1 hours'));
 		$manager->save($comment);
 
 		$loadedComment = $manager->get($comment->getId());
+		// Compare current object with database values
 		$this->assertSame($comment->getMessage(), $loadedComment->getMessage());
+		$this->assertSame(
+			$comment->getExpireDate()->format('Y-m-d H:i:s'),
+			$loadedComment->getExpireDate()->format('Y-m-d H:i:s')
+		);
+
+		// Compare original object with database values
+		$this->assertNotSame($original->getMessage(), $loadedComment->getMessage());
+		$this->assertNotSame(
+			$original->getExpireDate()->format('Y-m-d H:i:s'),
+			$loadedComment->getExpireDate()->format('Y-m-d H:i:s')
+		);
 	}