diff --git a/core/modules/system/src/Tests/Asset/LibraryCompletenessTest.php b/core/modules/system/src/Tests/Asset/LibraryCompletenessTest.php
index d791ee1..ab29e85 100644
--- a/core/modules/system/src/Tests/Asset/LibraryCompletenessTest.php
+++ b/core/modules/system/src/Tests/Asset/LibraryCompletenessTest.php
@@ -73,7 +73,7 @@ public function testCoreLibraryCompleteness() {
 
         // Check that all the assets exist.
         foreach (['css', 'js'] as $asset_type) {
-          foreach ($library[$asset_type] as $index => $asset) {
+          foreach ($library[$asset_type] as $asset) {
             $file = $asset['data'];
             $this->assertTrue(is_file($root . '/' . $file), "$file file referenced from the $extension/$library_name library exists.");
           }
@@ -95,9 +95,8 @@ protected function getAllLibraries() {
 
     $root = \Drupal::root();
     foreach ($modules as $module_name => $module) {
-      $path = $module->getPath();
-      $library_file = $path . '/' . $module_name . '.libraries.yml';
-      if (file_exists($root . '/' . $library_file)) {
+      $library_file = $module->getPath() . '/' . $module_name . '.libraries.yml';
+      if (is_file($root . '/' . $library_file)) {
         $libraries[$module_name] = $this->libraryDiscovery->getLibrariesByExtension($module_name);
       }
     }