fix tests and replace file_exists

tests/Models/CommentListMapperTest.php

@@ -24,6 +24,10 @@ use Modules\Comments\Models\CommentListMapper;
  */
 class CommentListMapperTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @covers Modules\Comments\Models\CommentListMapper
+     * @group module
+     */
     public function testCRUD() : void
     {
         $list = new CommentList();

tests/Models/CommentListTest.php

@@ -22,6 +22,10 @@ use Modules\Comments\Models\CommentList;
  */
 class CommentListTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @covers Modules\Comments\Models\CommentList
+     * @group module
+     */
     public function testDefault() : void
     {
         $list = new CommentList();
@@ -29,6 +33,10 @@ class CommentListTest extends \PHPUnit\Framework\TestCase
         self::assertEquals([], $list->getComments());
     }
 
+    /**
+     * @covers Modules\Comments\Models\CommentList
+     * @group module
+     */
     public function testGetSet() : void
     {
         $list    = new CommentList();

tests/Models/CommentMapperTest.php

@@ -24,6 +24,10 @@ use Modules\Comments\Models\CommentMapper;
  */
 class CommentMapperTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @covers Modules\Comments\Models\CommentMapper
+     * @group module
+     */
     public function testCRUD() : void
     {
         $comment = new Comment();

tests/Models/CommentTest.php

@@ -23,6 +23,10 @@ use Modules\Comments\Models\NullComment;
  */
 class CommentTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @covers Modules\Comments\Models\Comment
+     * @group module
+     */
     public function testDefault() : void
     {
         $comment = new Comment();
@@ -37,6 +41,10 @@ class CommentTest extends \PHPUnit\Framework\TestCase
         self::assertEquals('', $comment->getContent());
     }
 
+    /**
+     * @covers Modules\Comments\Models\Comment
+     * @group module
+     */
     public function testGetSet() : void
     {
         $comment = new Comment();