diff --git a/tests/src/Kernel/CoolPreviewFormatterTest.php b/tests/src/Kernel/CoolPreviewFormatterTest.php
index b7b29dd5..5be1617c 100644
--- a/tests/src/Kernel/CoolPreviewFormatterTest.php
+++ b/tests/src/Kernel/CoolPreviewFormatterTest.php
@@ -16,7 +16,6 @@
 
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\Display\EntityDisplayInterface;
-use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\entity_test\Entity\EntityTest;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
@@ -53,11 +52,9 @@ protected function setUp(): void {
     $this->installEntitySchema('entity_test');
     $this->createMediaType('file', ['id' => 'document']);
 
-    // Create test files.
+    // Create test file.
     file_put_contents('public://file-1.txt', $this->randomString());
     File::create(['uri' => 'public://test-1.txt'])->save();
-    file_put_contents('public://file-2.txt', $this->randomString());
-    File::create(['uri' => 'public://test-2.txt'])->save();
   }
 
   /**
@@ -72,7 +69,7 @@ public function testViewElements(): void {
 
     $media = Media::create([
       'bundle' => 'document',
-      $field_name => ['1', '2'],
+      $field_name => '1',
     ]);
     $media->save();
 
@@ -82,21 +79,6 @@ public function testViewElements(): void {
     ]));
 
     // Field is rendered correctly.
-    $this->assertCoolPreviewField(
-      [
-        $media->getName(),
-        $media->getName(),
-      ],
-      [
-        'contexts' => ['user.permissions'],
-        'tags' => ['media:1'],
-        'max-age' => Cache::PERMANENT,
-      ],
-      $media_display->build($media)[$field_name]
-    );
-
-    // After deleting one of the files, only one iframe is displayed.
-    File::load('1')->delete();
     $this->assertCoolPreviewField(
       [
         $media->getName(),
@@ -112,7 +94,7 @@ public function testViewElements(): void {
     // Iframe is not displayed for other entities than media.
     $test_display = $this->createCoolPreviewField($field_name, 'entity_test', 'entity_test');
     $entity = EntityTest::create([
-      $field_name => ['1', '2'],
+      $field_name => '1',
     ]);
     $entity->save();
     $this->assertCoolPreviewField(
@@ -142,7 +124,7 @@ public function testViewElements(): void {
       'access content',
       'preview document in collabora',
     ]));
-    File::load('2')->delete();
+    File::load('1')->delete();
     $this->assertCoolPreviewField(
       [],
       [
@@ -172,7 +154,6 @@ protected function createCoolPreviewField(string $field_name, string $entity_typ
       'field_name' => $field_name,
       'entity_type' => $entity_type,
       'type' => 'file',
-      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
     ]);
     $field_storage->save();
 
@@ -208,8 +189,13 @@ protected function assertCoolPreviewField(array $expected_medias, array $expecte
     $this->assertEqualsCanonicalizing($expected_cache, $build['#cache']);
 
     $crawler = new Crawler((string) \Drupal::service('renderer')->renderRoot($build));
+
+    // Library is present in case we have medias to render.
+    $expected_libraries = $expected_medias ? ['library' => ['collabora_online/cool.previewer']] : [];
+    $this->assertEquals($expected_libraries, $build['#attached']);
+
     $elements = $crawler->filter('div.cool-preview__wrapper');
-    $this->assertCount(count($expected_medias), $elements);
+    $this->assertSameSize($expected_medias, $elements);
 
     // Check each of the files from the media.
     foreach ($expected_medias as $i => $media) {
@@ -224,8 +210,6 @@ protected function assertCoolPreviewField(array $expected_medias, array $expecte
       $dialog = $elements->eq($i)->filter('dialog#cool-editor__dialog.cool-editor__dialog');
       $this->assertCount(1, $dialog);
       $this->assertCount(1, $dialog->filter('iframe.cool-frame__preview'));
-      // Library for each file.
-      $this->assertEquals(['collabora_online/cool.previewer'], $build[$i]['#attached']['library']);
     }
   }