adjust unit tests

apps/dav/tests/unit/comments/commentnode.php

@@ -71,12 +71,7 @@ class CommentsNode extends \Test\TestCase {
 	}
 
 	public function testGetLastModified() {
-		$dateTime = new \DateTime('2016-01-10 18:48:00');
-		$this->comment->expects($this->once())
-			->method('getCreationDateTime')
-			->will($this->returnValue($dateTime));
-
-		$this->assertSame($this->node->getLastModified(), $dateTime->getTimestamp());
+		$this->assertSame($this->node->getLastModified(), null);
 	}
 
 	public function testUpdateComment() {

apps/dav/tests/unit/comments/commentsplugin.php

@@ -23,6 +23,7 @@ namespace OCA\DAV\Tests\Unit\Comments;
 
 use OC\Comments\Comment;
 use OCA\DAV\Comments\CommentsPlugin as CommentsPluginImplementation;
+use Sabre\DAV\Exception\NotFound;
 
 class CommentsPlugin extends \Test\TestCase {
 	/** @var \Sabre\DAV\Server */
@@ -146,6 +147,9 @@ class CommentsPlugin extends \Test\TestCase {
 		$this->plugin->httpPost($request, $response);
 	}
 
+	/**
+	 * @expectedException \Sabre\DAV\Exception\NotFound
+	 */
 	public function testCreateCommentInvalidObject() {
 		$commentData = [
 			'actorType' => 'users',

apps/dav/tests/unit/comments/entitytypecollection.php

@@ -74,7 +74,7 @@ class EntityTypeCollection extends \Test\TestCase {
 	}
 
 	/**
-	 * @expectedException \Sabre\DAV\Exception\Forbidden
+	 * @expectedException \Sabre\DAV\Exception\NotFound
 	 */
 	public function testGetChildException() {
 		$this->folder->expects($this->once())